Glossary of Terms
Used in Laser Eye Surgery
Removal of tissue using a laser - the corneal tissue is evaporated by the energy of the laser. An average of 0.25 microns of corneal can be ablated per laser pulse. One micron is one thousands of a milimeter = 0.001mm (the average treatment depth is 60 microns about half the thickness of a human hair).
Irregularities in the optical system of the eye, which are measured by wavefront scanning.
A circular area of tissue removed by the laser. It is a minute disc shaped like a lens and is effectively a 'contact lens' lasered on to the eye surface. Usually, a 6.5mm ablation zone, which can be expanded up to 9mm is given. Doctors take into account maximum pupil dilation when programming the laser to minimize night time problems the pupil should not be larger than the treatment zone.
Oral drug prescribed to reduce intra-ocular pressure. Possible side effects include loss of appetite, drowsiness and depression. Rashes and blood disorders occur rarely.
The ability to change the focusing of the eye to see well close to the eye. Adjustment of the lens within the eye allows near objects to be brought into focus but making the lens thicker in the middle, increasing the power of the lens. This ability is lost when the lens becomes more rigid with age, around the age of 45 and reading glasses are needed.
ACTIVITIES FOLLOWING EYE SURGERY
Once the patient has attended the clinic for aftercare and been given the all clear from the optometrist or doctor, all normal activities can be resumed depending on the vision. (Check with the medical staff if there is anything in particular that they wish to confirm would okay to resume after treatment). Swimming should be avoided for two weeks as the chlorine in the water will sting the eye and risk of infection is increased.
Also see DRIVING
The measurement of visual sharpness. Best corrected visual acuity (VA) is the measurement of the best vision achieved with glasses or contact lenses. Uncorrected VA is the sharpness of vision without lenses.
Non-steroidal anti-inflammatory drop which can help reduce pain and aid healing.
Complications which arise quickly and need immediate attention. They are very rare and appear during the first days after treatment. These will be picked up and monitored at the first weekly check up.
Used on prescriptions and refers to the power added to the lens for reading glasses, usually seen on prescriptions for people aged over 45. When laser treatment puts the power of the eye to zero, a patient with "add 2" will need reading glasses of +2 after treatment.
An unexpected and unfavourable reaction to drops or drugs. If a patient feels they are having an adverse reaction, they should contact Optimax immediately.
Course of post-operative treatment involving the monitoring progress of the treated eye through regular check ups performed at Optimax clinics, or by local optometrists. Drugs or other treatment may need to be prescribed. We have a network of optometrists around the country who are trained in aftercare for laser surgery, and it is possible for some of the checks to be arranged there.
The legal minimum age for laser eye treatment is 18 years. All patients must provide past prescriptions to prove the stability of the refraction. The usual age for reaching stability is 21 years of age and this is the generally accepted minimum age for treatment. If the prescription has changed within the last year it may not yet be stable enough. Patients can be refused treatment if there is any doubt as to the stability of the prescription. There is no upper age limit. Middle-aged people with low myopia should be advised that they may be switching their distance glasses for reading glasses. All patients should be warned of the need for reading glasses from about 45 years old (with or without treatment).
See also PRESBYOPIA
AGE RELATED MACULAR DEGENERATION
Loss of the detection of and reaction to light resulting in decreased vision and sometimes blindness. However, the decision on whether or not to treat lies a person with this condition with the treating doctor. Most doctors would prefer to carry out the PRK process on such patients as opposed to LASIK.
Abbreviation for Astigmatic Keratotomy. This is the use of a diamond shaped knife to make a small incision in the outer part of the eye to reduce astigmatism.
Abbreviation for Automated Lamellar Keratoplasty, a surgical procedure to replace the front of a damaged cornea. This technique is not performed at Optimax.
Clinical name for a lazy eye, blind or low-functioning eye. Certain forms of mild amblyopia can be helped with laser treatment. We do not treat an only good eye in case there is a problem, which could end up leaving the patient with poor vision in both eyes or vision below driving standard.
Anaesthetic eye drops administered immediately before treatment. Numbs the eye completely, making treatment totally pain free.
Also see PROXYMETACAIN
Anaesthetic eye drops which numb the eye for about an hour, with no injections required.
A difference in imaging size between the two eyes.
A difference in refractive power of the two eyes in which the variance is at least one dioptre.
A condition which causes regular infections in the eye. The eye needs to be clear of infection at the time of treatment and severe cases are advised not to have treatment.
Deviation from the normal.
The fluid filled area at the front of the eye, between the cornea and the iris.
Inflamation at the front of the eye.
Drugs taken in the form of drops or ointments which reduce the inflammation and aid in pain relief.
Given in the form of ointments or drops to be administered regularly for the first few days after treatment. Chloramphenicol or Exocin are commonly used at Optimax.
Patients who suffer from anxiety or depression should mention this at the time of booking, particularly if on any medication. The clinic will check with the treating doctor about medication in case it is a contra-indication.
The fluid in the eye, which is kept under pressure to maintain the roundness of the eye.
Rheumatoid Arthritis is a contra indication to treatment.
People suffering from arthritis can be treated but the treating doctor will need to know what prescription medication is being taken.
Lens implant used for Implantable Contact Lens. These lenses are custom made according to the patient's prescription.
Common medication, not a contra-indication to treatment, But because it thins the blood, some doctors recommend LASEK
Usually preliminary tests are carried out to see if a patient may be suitable for consultation.
Also see OPEN DAYS
Condition in which the surface of the eye is not truly round (asymmetrical) and causes the eye to focus unevenly. Vision is blurred and distorted at all distances. For example, when an astigmatic person looks at the spokes of a wheel, some spokes appear clearer than others. The optician can prescribe a lens to rectify this distortion so that when looking at the wheel, each spoke would be equally as clear.
Also see CYLINDER
An automatic eye test machine to assess the patient's prescription is used as a double check to assist the doctor in consultation.
The angle of the astigmatism across the cornea, measured in degrees from 0 degrees - 180 degrees. It is noted in the third box of your prescription. 90 degrees is vertical (against the rule) and 180 degrees is horizontal (with the rule) - in minus cyl form.
A prescription for one eye with a symbol BAL (or B/S-balance sphere). A lens of the same power is given to balance the weight and look of the glasses. This means that this eye is non-functioning and the patient is not suitable for treatment.
Also see AMBLYOPIA
BANDAGE CONTACT LENS
This is a contact lens which the doctor places on the eye directly after treatment, in order to protect the eye and reduce pain. Patients should not remove them. An appointment is necessary for two or three days later to be removed professionally.
A measurement used in prescribing a contact lens: the radius of the central posterior surface. Base curve is not relevant to laser eye surgery.
See Balance Prescription.
BEAM SIZE (ZONE SIZE)
The beam size of the laser determines the zone size of the ablation. Patients with larger pupils will need to be treated with a wider beam size or there is a higher risk of halos. Optimax lasers use a standard beam size of 6.5mm but this can be expanded to 9mm.
Also see HALOS
Used as a local anaesthetic in the form of eye drops.
BEST CORRECTED VISUAL ACUITY
The measurement of the best vision sharpness achieved with the aid of glasses or contact lenses.
Best Corrected Visual Acuity. See above.
Anti-inflammatory ointment used following treatment.
Drops used to reduce the intra-ocular pressure - a possible side effect is dry eyes.
Glasses or contact lenses with a different power for distance vision at the top and a prescription for reading at the bottom of the lenses (sometimes you can see the dividing line on the glasses if you look closely). Patients with bifocal lenses will need reading glasses if fully corrected by laser, unless mono vision or Prelex implantable lenses are chosen.
Treatment to both eyes, usually in the same sitting.
Latin bini-two + oculus-eye. Both eyes used in conjunction give better quality of vision and depth perception.
Use of both eyes working together.
Patients with large pupils are given extra treatment at the outer edge of the cornea to improve on night vision problems. Where the pupil expands beyond the treatment zone.
See TRANSITION ZONE
Inflammation of the eyelids, a common problem but not a contra-indication. Eyes should be clear of this condition prior to treatment.
Following LASEK treatment, your vision will be blurry for the first few days after treatment. This is because your epithelium (the surface cells of your eye) is healing and also partly due to the ointment/drops you are using post-treatment.
The top layer of tissue between the epithelium and the stroma (5-10 microns thick -- .005 to .01 millimetres), which is removed with the LASEK procedure but not with LASIK.
Mother should wait until three months after weaning before having laser eye treatment.
BROAD BEAM LASER
A medical instrument that produces a powerful beam of light that is focused at close range to remove corneal tissue. A broad beam laser uses a relatively large beam diameter, from 6.0 to 8.0 millimetres, which can be manipulated to reprofile the cornea.
A flap complication, in which the flap has a central hole in it. Treatment is abandoned and the flap is replaced to heal. It is usual to re-treat three months later but there is a small risk of scarring and decreased vision so close follow up is essential.
People with pacemakers should be suitable for treatment.
Procedure carried out to test the laser before treatment sessions. This is to ensure that the laser is functioning properly and emitting the correct energy level.
A clouding of the lens, usually in older people. Optimax offers cataract removal in its London clinics. It is possible to correct a patient's short or long sight at the same time. A lens with the corrective power to eliminate glasses is inserted when the clouded lens is removed.
High speed trackers and iris recognition is used to ensure the laser is properly centred on the visual axis of the eye.
German manufacturer of the Excimer laser 'Technolas 217 & 217A lasers'.
Antibiotic ointment to be administered after treatment by some doctors.
The brownish membrane of the eyeball between the sclera (outer) and the retina (inner).
CK - CONDUCTIVE KERATOPLASTY
A non-surgical procedure for the correction of presbyopia (the need for reading glasses). CK uses a probe to apply high frequency radio waves into the corneal tissue, causing shrinkage. This controlled shrinkage reshapes the cornea to change refractive error; learn more here
The part of the eye that connects the choroid with the iris.
Diseases of the fibrous protein of connective tissue and bones. A contra-indication to laser treatment as healing is abnormal and unpredictable. A typical symptom is raised large scarring of wounds on the body.
Also see CONTRA-INDICATIONS
During the healing process patients may experience pain on waking up, tenderness, grittiness, glare around lights at night (halos), droopy eye lids, slight double vision or loss of best visual sharpness. These effects reduce gradually and rarely persist in the long term.
A lens with a hollow shape like the inside surface of a ball. Concave lenses are - (minus) power lenses and are used to correct myopia or near-sightedness.
Nystagmus is the involuntary movement of the eye, which reduces vision. This is common in Albinos. Congenital Nystagmus is thought to be present at birth. A contra-indication to laser treatment.
Delicate inner surface of the eyelid expanding to the white part of the eyeball.
The inflammation or infection of the conjunctiva. A person who has conjunctivitis has to wait until it has cleared before having laser treatment.
The legal contract document outlining the risks involved in and alternatives to laser vision correction surgery. Each patient booking for treatment receives a consent form prior to coming to Optimax and should read this carefully beforehand.
An appointment with the specialist Optimax staff (which includes an eye test) and thorough examination to discuss suitability and expectations of the patient and their specific case.
CONSULTANT OPHTHALMIC SURGEON/OPHTHALMOLOGIST
In order to become a consultant in the UK a doctor must be on the Specialist Register of the General Medical Council (GMC). Entry to the Specialist Register is with the CCST (Certificate of Completion of Specialist Training) or through equivalent qualifications under the European Union Law.
Small lens which can be placed directly onto the eye to correct imperfect vision. After LASEK treatment the doctor will place a bandage contact lens on the treated eye. This is to help protect the cornea and must only be removed by the Optometrist or Doctor (NOT by the patient) in the following few days.
CONTACT LENS REMOVAL
Contact lenses must be removed prior to the treatment appointment as they affect the shape of the eye and this will alter the result. For best results, patients should follow the guidelines in the Optimax information pack (one week for soft lenses, three weeks for GP and hard lenses).
A reason that makes a patient unsuitable for laser treatment. These are listed in the Optimax information pack. For example, Kerataconous, Amblyopia, Nystagmus, age under 20 (unstable prescription), collagen diseases, rheumatoid arthritis, viral infections, prisms, pregnancy and breastfeeding.
The ability to perceive differences between an object and its background. Reduced contrast sensitivity is a possible side effect of laser eye treatment and is particularly troublesome in poor illumination.
Home Office regulated and monitored prescription drugs.
The ability to turn both eyes inward to 'aim' at the object being viewed. Involuntary covergence is called a squint and is not correctable with a laser.
A lens with a bulging surface like the outer surface of a ball. Convex lenses are + (plus) power lenses and are used to correct hyperopia (long or far sight) and for reading glasses as needed in presbyopia.
Transparent layer covering the front of the eye. The cornea accounts for two thirds of the focusing power of the eye. Flattening of the cornea by the laser reduces its focusing power, thereby eliminating short sight.
The outward bulging of the cornea. This usually happens when the cornea is not thick enough to leave an adequate stromal bed (thickest layer of the cornea) following treatment. A rare but serious complication of LASIK surgery.
The inner layer of renewable cells on the inside surface of the cornea, which supply the cornea with nutrients and oxygen.
The outer surface layer of the cornea, like the epidermis or outer layer of the skin. These cells regenerate themselves every 24 hours or so and have to be displaced prior to lasering in LASEK laser treatment.
This is staining of the surface of the eye which can result from contact lens use or disease. It will depend on the consultation with our medical staff as to whether the patient is suitable for treatment or not.
Erosion of the cornea, due to surface dryness, trauma or other causes. Corneal erosion is very painful (similar to ARK eye) for a period of minutes to hours. This is a rare complication of LASEK.
An opacification or cloudiness of the normally clear cornea, which can occur as a side effect of LASEK. Any build up of inflammatory infiltrates (white blood cells), extra moisture, scar tissue, or foreign substances such as drugs, can cause a clouding of the cornea. Most types of haze will disappear with time or drug treatment but sometimes, permanent haze or scars can form.
Measured in microns by a Pachymeter. Essential in checking if there is enough tissue for LASIK treatment which involves cutting a flap in the cornea. Patients with a thin cornea may not be suitable for LASIK but may be suitable for LASEK or Implantable Contact Lenses.
Also see PACHYMETER
CORNEAL TOPOGRAPHICAL MAP
A corneal topography which shows the surface profile of the cornea. Height mapping is shown in colour of the front surface of the eye to show the surface shape of the cornea. Optimax has topography machines and Orbscan machines in all clinics. This is a very important part of our initial screening and aftercare monitoring.
Ulcer on the front of the eye - it can be motivation to have laser treatment for short or long sight. Suitability is dependent on the doctor's decision.
CROHN'S DISEASE - (Inflammatory bowel disease)
Does not preclude treatment unless patient is using immunosuppressants or oral steroids.
Amount of curve on the front of eye.
This refers to Wavefront guided treatment. When the laser has been programmed specifically for the patient's irregularities of cornea based on their topography or on Wavefront scans.
In ophthalmology, a line that is the symmetrical centre of a curved optical surface. Measure of astigmatism.
An examination of the eye to determine refractive error while the natural crystalline lens of the eye is paralyzed and unable to accommodate.
Drops used to dilate the pupil.
Diploma in Child Health.
Removal of tissue or foreign object from a wound.
In the perfect centration the centre of the Epiflap corneal ablation exactly coincides with the centre of the visual axis and/or pupil. This is like looking through the very centre of your spectacle lens. If you look through the periphery of your lens you might end up seeing partly through the lens and partly through edge of the lens this is decentration. Decentration can cause various symptoms including edge glare or even monocular double vision. Other factors such as the normal size of the pupil, whether it is dark out or the size of the Epiflap laser ablation zone will affect the severity or presence of symptoms. Optimax eye trackers and iris recognition avoid laser decentralisations.
When the eye heals slower than the normal rate. This can result in leaving the patient long-sighted, or suffering from haze.
Patients suffering from depression should be capable of accepting any associated risks/complications of surgery and in some cases we may advise against treatment if we decide this is in the patient’s best interest.
The layer of the cornea between the stroma and the endothelium. Five microns thick (.005 millimetres), this membrane provides an adhesion layer for the endothelium.
Level of correction the doctor aims at with the laser setting. Optimax aims to get all patients to within plus or minus one half of a dioptre. This is range that opticians usually ignore and would not prescribe glasses.
This is a serious condition affecting the back lining of the eye. If repaired successfully it may be possible to perform laser treatment on the eye. This would need to be discussed at the clinic upon consultation.
The balance of hydration in the eye.
Drops used to reduce post-operative inflammation following eye operations, also in ointment form such as Maxitrol.
People suffering abnormal levels of blood sugars and can result in raised internal eye pressure. Most well-controlled diabetic sufferers are suitable for treatment.
Also see IOP
A process by which the pupil is enlarged, in order to see the back of the eye.
Unit of measuring the refractive power of a lens. A lens with strength of 1 dioptre will converge distant light at a point of one meter from the lens.
Double vision or seeing double, usually with both eyes open as in binocular diplopia, but can be with only one eye as in monocular diplopia.
Soft, throw away contact lenses. These need to be left out for one week prior to laser surgery.
Sense of unbalance. This is a normal symptom after treatment and should subside after a few days. If it persists then mention it to the doctor at the check up. Rest can often help to reduce the symptom.
DLK (DIFFUSE LAMELLER KERATITIS)
Also known as Sands of Sahara Syndrome (SOSS). Inflammation between the corneal flap and the bed of the eye. No specific cause, but should be noted as one of the possible complications after LASIK. Not an infection. It is necessary to treat DLK without delay to avoid long term side effects and is effectively treated with steroids.
Diploma in Ophthalmology.
Optimax doctors are all fully qualified medical practitioners who have specialised in Ophthalmology. Each is registered with the General Medical Council (GMC). Doctors who are Fellows or Members of the Royal College of Ophthalmology, or Fellows of the Royal College of Surgeons perform all treatments. Also see abbreviations of qualifications for more information.
Usually the eye used to focus a camera or fire a gun. This eye is would usually be treated second if the patient is only having one eye treated at a time. Most of the time patients now have both eyes treated at the same sitting.
Seeing two or more images, often shown with a prism reading on the prescription. Not suitable for laser treatment. Laser treatment can only treat the distance vision problem. If you are happy with the vision from contact lenses, then you should be suitable for laser treatment.
After laser treatment, do not drive until you feel completely confident; this may take up to two weeks or longer depending on the individual's rate of healing. Don't forget, it is illegal to drive if you cannot read a car number plate at 67 feet.
DROOPY EYE LID
A rare side effect of laser treatment. The treated eyelid droops down to varying degrees. There are surgical procedures available to correct this. Medical term for this is Ptosis (pronounced Tosis). Usually if this occurs it is only very slight (about 1mm) and in most cases it rectifies itself with time.
Also see PTOSIS.
A condition where the eye fails to produce enough tears. If this is a severe condition then it is considered to be a contra-indication to treatment. Post treatment, doctors normally prescribe Hypromellose (artificial tears) which are available over the counter. This should relieve the discomfort the patient is experiencing. If discomfort continues or is severe, the patient should contact us for an appointment to check it. Dry eye is not usually a contra-indication for LASEK.
Abbreviation for dioptre sphere - the measurement of short/long sight.
A progressive corneal thinning and bulging.
See CORNEAL ECSTASIA
If the condition is acute then suitability will be determined at consultation, and may depend on any medication taken to manage the condition, and whether it affects the eye.
People who have no refractive error.
The ophthalmic term for normal sight without glasses: no near-sightedness, far-sightedness or astigmatism. This is what laser surgery aims to achieve.
An inflammation within the eye. Endophthamistis is usually used to indicate an infectious disease as occasionally occurs as a complication of ICL surgery. It should be treated with utmost urgency to avoid the loss of the eye.
The inner layer of cells on the inside surface of the cornea.
See CORNEAL ENDOTHELIUM
Extra laser treatment made to refine or improve the original visual result.
Controlled Epilepsy is not a contra-indication to laser eye treatment.
A complication of LASIK wherein epithelial cells grow underneath the corneal flap. This requires remedial treatment at Optimax.
Transparent layer of protective watery loose cells covering the eye constantly by renewing 'skin'. It is 'peeled' back from the treatment site immediately prior to LASEK. The LASEK method is believed to be beneficial in that it reduces the risk of haze and is much less painful for the patient during the healing. Occasionally it may be removed completely and grows back within a few days. This is the older method of PRK preparation and can be very uncomfortable in the first week.
Corneal erosion is where cells are not being replaced and the blinking action can cause the eye to be painful and sore, particularly on waking.
See CORNEAL EROSION
A small amount of this alcohol is used in the preparation of the eye for LASEK. It softens the epithelial tissue so that it can be manipulated and peeled back ready for treatment.
EXCited diMER a dimer molecule which consists of two unstable identical simpler molecules which emit light on combining and splitting on excitation by an external electrical force.
Argon/Fluoride laser emitting a beam of ultra violet light, capable of removing microscopic amounts of tissue from the cornea. Optimax uses the Nidek laser which is a second-generation 6.5mm beam laser. We also have a Technolas 217 laser in our Aberdeen, Leeds and London clinics.
This is a muscle imbalance, which makes your eyes turn outwards. If it is severe or you need a prism you would not be considered suitable for treatment.
Antibiotics sometimes favoured by doctors for use after treatment.
Drugs administered to the eye in drop form -
Tropicamide: Dilating drops to examine the back of the eye.
Amethocaine: Anaesthetic drops to numb eyes before treatment.
Proxymetacain: Anaesthetic drops to numb eyes before treatment.
Hypromellose: Administered for dry eyes.
Pilocarpine: Constricting drops for the pupil.
FML: Steroid drops administered to slow down the healing process. Mainly used for patients who are regressing.
Exocin: See above.
A gauze pad which is placed on your eye with micropore tape to keep your eyelids closed. This is to be removed on the treating doctor's instruction, usually within 24 hours.
A standard eye test that determines the fluid pressure inside the eye. The test is called a tonometry. Increased pressure within the eye is a possible sign of glaucoma and must be treated to avoid blindness. Well controlled glaucoma is not a contraindication to laser treatment.
An eye examination used to measure the power of glasses needed. The level of correction for best possible sight, also known as "refraction" (or R).
The American term for long sight (hyperopia).
Also see HYPEROPIA
Abbreviated as fs, a femtosecond is one quadrillionth of a second.
The femtosecond laser for ophthalmology is used to create a LASIK flap in a procedure commonly called IntraLASIK or 'all laser LASIK'.
It is a silent, bladeless, computer-guided laser used in Step One of LASIK to safely create corneal flaps of exact size, shape, and depth. The lasers uses femtosecond technology to pass through the cornea at 15,000 pulses per second.
Patients are advised to check the Fire Brigades policy on applicants who have undergone laser refractive surgery. Usually the minimum sight requirements are: 6/6 in each eye (uncorrected). The maximum degree of short sight allowed is 0.25 dioptres or 0.5 cylinder. Applicants who are able to achieve an acuity of 6/6 in each eye unassisted but who in retinoscopy are found to have greater than -0.25 dioptres sphere or 0.5 cylinder are disqualified by myopia. The maximum degree of long sight that is allowed is +1.50 dioptres.
The ability to direct and maintain steady visual attention on a target. Fixation is required during treatment, where you will be asked to stare at a small coloured light.
In LASIK a thin layer is cut into the cornea to create the 'flap'. The hinge should be sufficient to replace the flap properly after treatment. Complications can occur such as the 'free flap' where the flap becomes detached, or an incomplete flap or buttonhole flap etc.
The point at which the flap, cut by the microkeratome, remains connected to the cornea. This hinge may be nasal (toward the nose) or superior (toward the top).
If there has been a malfunction of the microkeratome, the flap creation process may have been aborted prematurely, resulting in an incomplete flap. In this instance the laser treatment is abandoned and the flap is replaced and left for three months to heal before laser treatment can be given again.
Congealment of the liquid inside the eye into lumps which float around in the eye causing blurring if they pass through the visual axis. Floaters are not necessarily a contra-indication to treatment but they cannot be cured by LASEK or LASIK.
Patient can expect their vision to fluctuate during the day for the first two to three weeks after laser eye treatment.
A way to test for dryness on the ocular surface. A tiny amount of sodium fluorescein dye is place in the tear film. The colour will make microscopic dots appear where the eye has become dry. Excessive staining is an indication of dryness which may need further treatment.
Steroid eye drops used for local treatment of inflammation.
Fluorometholone (with liquifilm) -mild steroid drops- 5ml bottles prescribed for short-term use only. Used in local treatment for inflammation. Reduced tendency to raise IOP. Only prescribed at the doctor's discretion and is obtained from the local chemist, chargeable to the patient. Steroids have a tendency to raise internal eye pressure and the eyes must be monitored closely to avoid glaucoma, which in prolonged cases can cause blindness.
A machine to measure the strength of glasses. Can be used to get a measurement of your prescription from a pair of glasses in place of a printed prescription.
Point at which light rays meet. When these rays focus correctly on the retina (at the back of the eye) the image is clear. In short sighted people the light rays meet just too short of the retina and images are blurred. In long-sighted people the light rays meet just behind the retina so near vision is not in focus.
FORME FRUSTE KERATOCONUS
This is keratoconus in the very early stages and is a contra-indication to laser treatment.
FORME FRUSTE INTACTS
Intacs can treat kerataconus by the insertion of small plastic implants within the edges of the cornea.
Fellow of the Royal College of Ophthalmologists.
Fellow of the Royal College of Surgeons.
Fellow of the Royal College of Surgeons - Edinburgh.
Fellow of the Royal College of Surgeons in Ireland.
FREE CAP (FLAP)
A complication occurring during the creation of the LASIK flap, where there is no hinge and the flap becomes free-standing. Usually, laser treatment can proceed and the flap is replaced normally.
FUCH'S CORNEAL DISTROPHY
Eye drops used for bacterial infections.
Examination of the back of the eye (fundus) to ensure that it is healthy and not showing any signs of detachment, retinal holes or tears. Sometimes it is necessary to put dilating drops (Tropicomide) into the eye to examine the retina more closely- particularly for people who are over -6.00 dioptres. In this case it is not possible for the patient to drive home as they should wait until the pupil has retracted to its normal size.
GAS PERMEABLE CONTACT LENSES
Type of contact lens allowing oxygen to penetrate through, enabling the cornea to breathe. Gas permeable lenses need to be removed about three weeks prior to the consultation and treatment.
Not necessary for LASEK or LASIK or ICL's so not available at Optimax.
Eye drops used for bacterial infections.
A fainter second image of the object you are viewing.
Flaring and star burst effect when looking at bright lights, particularly noticeable at night. Can be a symptom of halos and haze and is the most common side effect of laser treatment.
Increased pressure of the fluid in the eye, which and can cause irreversible loss of sight. Usually occurs in middle age and there is frequently a family history of glaucoma. Not an ideal candidate for laser treatment, if the pressure is not under control.
Correction resulting within 1 dioptre of the aim.
This condition can be caused by hyperthyroidism. It can cause severe dry eye and other ocular ocular problems so those with this condition are not suitable.
After the first 12-24 hours, following LASEK the eye may start to feel gritty or sting. This will gradually improve over the next two to four days. Patients must try not to rub the eye and should rest it as much as possible.
Drops normally used to lower the internal eye pressure for patients with glaucoma.
Doctor's ethical guidelines do not allow for 'guarantees'. LASEK and LASIK are medical procedures and like all medical procedures, cannot be guaranteed.
This side effect is associated with patients who have large pupils. Our lasers can treat 6.5mm pupils but this can be expanded to a treatment zone of 9mm. If the pupil dilates beyond the treated area then the patient may experience this halo effect at night. Glare around bright lights can be particularly distracting when driving.
The flap cutting device is the microkeratome. It is used for creating the corneal flap during to LASIK treatment.
Hard or rigid lenses can correct small amounts of astigmatism because the tear film fills the gap between the lens and the uneven spots on the cornea. Soft lenses cannot do this because they hug to the surface of the eye. Hard lenses need to be removed and not worn for three weeks prior to laser treatment.
Patients should check at the one-week check up when they are able to resume using hayfever drops. It is normally fine to do so after 7-10 days but check with medical staff to confirm this.
Also referred to as healing tissue or scar tissue. This can affect LASEK patients to varying degrees but it is usually mild and clears up within a few months. Patients sometimes complain of glare at night and vision that is similar to that when looking through frosted glass or dirty glasses. Limiting LASEK to -5d has reduced incidence of haze to minimal levels.
This is an occasional normal side effect after treatment. Some patients experience headaches within an hour but if television and reading is avoided for a few days the headaches should ease. Usually within three to four days the headaches have subsided.
A government body responsible for regulating Laser Eye Treatment establishments.
Conditions passed down from generation to generation. It is important to advise the treating doctor of any known medical conditions in the patient's parents e.g. glaucoma, as some eye conditions are hereditary. The doctor can then consider these specific symptoms.
HERPES SIMPLEX KERATITIS
A virus infection of the cornea which would endanger the cornea if treated by LASEK or LASIK. Contra-indication.
Patients affected by HIV should avoid treatment as there is an increased risk of infection.
HIGHER ORDER ABERRATIONS
Optical (corneal) irregularities not measurable with conventional eye exams and not correctable with spectacles or soft contact lenses. Higher order aberrations are detected by Wavefront diagnosis and treated accordingly.
Drops used to dilate pupils.
Raised internal eye pressure.
See GLAUCOMA and INTRA OCULAR EUE PRESSURE
Artificial tears. To be used if your eyes are not producing enough natural tears and causing you discomfort. They are available over the counter without prescription. If discomfort continues when using these drops, or it is severe, the patient should contact us for an aftercare appointment.
Can be treated with ICL (Lens implants) from age 30+, and with laser eye surgery from age 35+.
The medical term for long sightedness. In the hyperopic eye, images are focused beyond the retina. The hyperopic eye is often described as being too flat or too short. In young people hyperopia can be overcome by accommodation, the natural ability to increase the focusing power of the eye. A magnifying lens is required to correct the sight when the natural ability has been lost due in middle age.
Procedures performed within an organisation e.g. in-house check ups are performed within an Optimax clinic.
Laser eye treatment is usually used to eliminate astigmatism. However, in cases where the astigmatism has increased or caused it where it didn't exist prior to treatment it is referred to as induced astigmatism.
There risk of infection is present with any surgery. Patients are issued with anti-biotics to minimise this risk. If patients suspect infection they are advised to contact Optimax as soon as possible. Uncontrolled infection can lead to blindness.
Lower part of the eye.
The body's reaction to trauma, infection or a foreign substance often associated with pain, heat, redness, swelling, and/or loss of function.
Latin term meaning 'in place' or not removed.
Drug used in controlling diabetes.
Also see DIABETES.
Well controlled diabetics without eye damage are suitable for laser treatment.
Intrastromal Corneal Ring Segments used to treat kerataconus. An alternative refractive surgery using two ring shaped implants, surgically inserted into the cornea. This has a flattening effect on the cornea caused by kerataconus and is potentially reversible.
The implantation INTACS are the first approved non-laser procedure to correct mild myopia or nearsightedness. As in all surgical vision treatment, the objective of the intrastromal corneal ring segments procedure is to reshape the cornea in order to correct for imperfections. Unlike most other refractive eye surgery procedures, however, the ICRS procedure corrects the vision problems without removing any eye tissue.
The basis of the ICRS procedure is the surgical implantation of two ultra thin arcs in the peripheral area of the cornea. These arcs (or segments) are manufactured from a polymer that has been safely used in cataract surgery for more than 40 years. When the arcs are implanted, they flatten the cornea to the degree required to correct the myopic condition. The procedure does not cut or remove any tissue, making this quite different from other refractive surgery procedures that permanently alter the cornea. They are designed to remain permanently in place, although the segments can later be removed or replaced to correct for possible sight changes as the eye ages.
The best candidates for the corneal ring procedure are usually those patients with mild myopia (-1.00 to -3.00) who have no more than 1.00 dioptre of astigmatism. Patients should also be at least 21 years of age with vision that has been stable for at least one year and be free of eye disease.
Particles left in the flap interface when the flap is replaced after lasering. Interface debris is not usually visually significant depending on its nature, quantity and location.
INTOLERANCE - Contact Lenses
Some patients are 'contact lens intolerant' always, or after a certain period of time. This is a major reason why people have laser eye surgery.
INTRA-OCULAR PRESSURE (IOP)
Pressure in eye's fluid inside of the eye which keeps the globe of the eye inflated and round. Normal IOP pressure is in the range of 15 to 20mm of mercury raised pressure must be dealt with without delay if sustained for a long period of time it can lead to blindness. The use of steroids can increase IOP above safe limits and careful monitoring of pressure is essential.
LASIK procedure where the flap is created by an Intralase laser and not with a microkeratome as in standard LASIK. It eliminates the blade and associated flap complications.
INTRASTROMAL CORNEAL RING
INTRA-OCULAR LENS (IOL)
Intraocular lens surgery is used to treat severe cases of hyperopia, astigmatism and myopia wide range of hyperopia and myopia. This procedure involves inserting an implant called an intra-ocular lens into the eyes.
The coloured ring of tissue behind the cornea and immediately in front of the lens. The Iris expands and contracts to alter the amount of light entering the eye.
An inflammation of the iris. Not a definite contra-indication to treatment unless severe and repeated. This needs to be discussed with the doctor at the consultation.
A refractive error caused by an irregular shape of the cornea in which the curve on one side of the meridian or axis is not symmetrical with the curve on either side. Customised Wavefront is used to treat the condition.
A prefix indicating the cornea (or window) of the eye.
An inflammation or infection of the cornea and conjunctiva.
An eye condition where the front of the eye (cornea) is extremely is cone shaped. It is the cause of unusually marked astigmatism and usually develops in the late teens. It can occur in one or both eyes. Special contact lenses can usually restore good sight, but this condition is progressive. This is a contra-indication to laser treatment. Also called a conical cornea. Kerataconous can be relieved by an operation called intra corneal implants. (Intacts).
Surgical excision of part of the cornea with a diamond knife. Kera-cornea, Tectomy-cutting. Also see RK, AK, radial keratectomy.
The inflammation or infection of the cornea.
Measurement of the curvature of the cornea. Can be obtained by using instruments such as the Oculus Keratometer or the Orbscan.
Surgical procedure on the cornea using a corneal graft instead of laser treatment to correct short sight.
Surgery of the cornea including a complete corneal transplant from a donor eye used when a patient has a diseased or damaged cornea.
Surgical incision of the cornea.
The glands in the upper eyelid that produce the tear film.
The replacement of superficial layers of the cornea with the layers of donor eye. Necessary to restore sight for those with damaged surfaces to the eye.
LASEK - LASER ASSISTED SUB-EPITHELIUM KERATOMILEUSIS
This is a technique that involves preserving as much of the epithelium as possible by loosening the cells with an alcohol solution. This allows the surgeon to fold back the epithelium similar to the flap in LASIK, prior to lasering
An acronym for light amplification by stimulated emission of radiation. The laser used in refractive eye treatment is an Argon Fluoride laser cool beam of pulsating ultraviolet invisible light. Lasers are extremely precise and computer controlled and are given for the correction required for each eye.
LTK - LASER THERMAL KERATOPLASTY
A form of laser eye surgery using a holmium YAG laser where two rings of laser energy were applied to the midperiphery of the cornea, heating the collagen in the cornea to change its shape. In this procedure, no instrument comes into physical contact with the cornea. Optimax uses this laser for enhancments to reduce induced hyperopia.
LASIK - LASER ASSISTED IN-SITU KERATMOLEUSIS
The front of the cornea is cut to form a flap and exposed corneal bed is treated with the laser is treated with the laser. The flap is then replaced. This procedure is very popular with patients and doctors throughout the world. It is estimated that two million LASIK treatments are performed each year worldwide.
Non-functioning eye, usually a contra-indication to laser treatment. Also see AMBLYOPIA. Mild forms can sometimes be helped by laser treatment
Scars that are dense and white.
A transparent material used to bend light and form images correctly onto the back of the retina. Lenses placed in a frame and worn as glasses, or placed directly onto the surface of the eye as contact lenses, or surgically placed inside th eye. The natural lens inside the eye bends the light as it passses through can change shape (accommodate) in order to see objects at different distances. In older age this lens can become stiff which results in the need for reading glasses and is called presbyopia. In old age this lens can become cloudy and is called a cataract which then requires removal and replacement by a new lens.
The visual borderline between the clear window (cornea) and the white globe (sclera) of the eye. The conjunctival layer which covers the globe also joins at the limbus.
Anaesthetic eye drops are administered to the patient just before treatment and these completely numb the eye during surgery. It can begin to wear off after about an hour, when further medication is given is necessary.
This is the condition when long sight is clearer then close up sight. Known as far sight in the USA, it has the medical name Hyperopia. The lens of the eye is too weak, corrected by a magnifying type lens. These glasses will magnify small print.
Also see HYPEROPIA
LOSS OF BEST CORRECTED VISUAL ACUITY - BCVA
A reduction in the best acuity a patient can achieve wearing glasses, usually described in terms of the number of lines on the Snellen test eye chart a patient has lost. If a patient's BCVA prior to surgery was 20:20 and after surgery is 20:40 the patient has lost three lines of BCVA.
Master of Arts - university degree.
The small highly sensitive area of the central retina which provides vision for reading and fine detailed vision directly into the line of sight.
An eye condition that can be serious and affects the vision, which indicates a contra-indication to treatment. The macula is an area of the retina responsible for central vision. It is used to view objects straight ahead. Degeneration results in a reduction in vision and, sometimes, severe loss of visual acuity (sharpness). The cause is not unknown but contributory factors could include nutrition, genetic link, hypertension (glaucoma), smoking and excessive exposure to UV rays.
The collection of fluid in and under the macular portion of the retina causing swelling.
To focus light to a point, or use a lens to enlarge an image. Glasses for long sighted people magnify objects.
Make up must be removed before treatment. It is advised that patients do not wear eye make up until after the first after care visit.
If the patient is planning to travel abroad, it is safest to leave treatment until at least three weeks after the course of treatment for Malaria is complete as some tablets would make the patient unsuitable. Chloroquine Phosphates - leave deposits on the cornea, the patient will not be suitable for treatment until a few weeks after the course is finished. Taludrin pills which don't leave deposits; and suitability should not be affected.
Steroidal anti-inflammatory ointment sometimes issued to patients after treatment. If the patient suspects an allergic reaction to the ointment they are advised to stop using it and contact the clinic at their soonest opportunity. The doctor or nurse can then advise. Steroids may increase intra ocular pressures, and these should be monitored on a weekly basis or as advised by the doctor concerned.
Bachelor of Medicine.
Bachelor of Medicine and Surgery.
Bachelor of Medicine and Surgery.
Member of the British College of Optometrists (Ophthalmic Opticians).
Doctorate in Medicine.
Oily secretions from the eyelid glands that supply the outer portion of tear film prevent rapid tear evaporation and tear overflow.
A surgical device that is affixed to the eye by use of a vacuum ring. When secured, a blade is used to cut a flap on the cornea at a depth of about one quarter of the corneas thickness. The flap is then repositioned over the cornea after it has been lasered.
The term micrometer has replaced the term micron which was used prior to 1967.
One thousandth of a millimetre.
Fold or wrinkles in the LASIK flap and can cause loss of sharpness of vision.
Surgery carried out while a microscope to view the tissue being operated on. The term is often used in refractive surgery to describe RK (Radial Keratotomy), the surgical technique for correcting short sight where the surgeon makes deep cuts into the cornea resembling the spokes of a wheel. These cuts have same effect of flattening the cornea. It is considered less accurate than laser and long term safety issues has lead this type of treatment being abandoned in favour of laser treatment worldwide. Optimax can, in some cases, treat people who have undergone RK to improve their result.
MILD SHORT SIGHT
Short sight 0 to -3.00 dioptres of short sight. Treatment is most predictable and there are fewer complications experienced by patients who are in the mild range.
MODERATE SHORT SIGHT
Short sight -3.25 to -6.00 dioptres of short sight.
Vision with the use of only eye for reading and the other eye for clear distance vision. Some older patients who have one eye treated may find monovision a distinct advantage in that they do not neeed glasses at all. Monovision can take a very long time to get used to and perseverance is necessary. It can be simulated using contact lenses of the same strength as the intended laser correction.
Member of the Royal College of Ophthalmologists.
Master of Science in Ophthalmology.
These lenses are a type of ICL or Implantable Contact Lens. They are implanted inside the eye and give a correction for both distance and near vision, thus removing the need for reading glasses.
Medical term for short sight. Myopia is hereditary and affects about 20% of the population. If you are myopic, objects at a distance will appear blurred, while objects nearby can be seen clearly. The eye being too long for its focusing power causes the images to be out of focus on the back of the (retina). Myopia can be successfully treated with laser surgery by reducing the focusing power of the eye (cornea) and severe cases can be treated using implantable contact lenses.
This condition can make it difficult to treat the patient depending on how advanced it is. Suitability is up to the doctor and during the consultation this can be assessed and discussed with the patient. Any medication must be noted at the time of booking and referred to the treating doctor before the patient attends a consultation. Optimax has successfully treated patients with this condition.
A corneal flap where the uncut portion left attached to the cornea (the hinge) is towards the nose.
Feeling of sickness and an urge to vomit. This is not an unusual complaint in the first few days after treatment. It can be a reaction to the painkillers. The patient is advised to stop taking the tablets and substitute them with their usual painkillers, (eg Paracetemol, ibroprophen etc)
The American term for short sight.
Scars which are translucent.
NEGATIVE POWER LENS
The shape of the lens used in glasses or contact lenses for people suffering from short sight. The lens is thinner in the middle than the outside. A negative lense, diverges (bends outwards) light to compensate for the over-bending by the eye's natural lens, inside the eye. A minus sign in front of your prescription indicates a negative lense if you are short sighted.
NHS - NATIONAL HEALTH SERVICE
LASEK and LASIK are not available on the NHS at present, unless for medical conditions or research.
A surgeon's adjustment to the laser's computer calculation to further refine his or her own results.
NON DOMINANT EYE
The non dominant eye is the eye which is left short sighted when Monovision is chosen. The dominant eye is the one most used for distance, i.e the one used to aim a gun.
Abbreviation for non-steroidal anti-inflammatory drugs.
This is the involuntary constant jerking movement of the eye. People with nystagmus are not usually suitable for laser treatment.
Persons who become fixated on one idea to the point of obsession do not make good candidates for laser treatment as perfect results are not guarenteed.
Patients should consider their occupation carefully before deciding on having treatment. It is the patient's responsibility to ensure that their employer (or potential employer) will accept a candidate who has undergone Laser surgery. This often applies to the Police, Fire Brigade and the Armed Forces as they have very strict regulations governing visual performance. Some organisations will not employ people who have had laser treatment. If the patient depends on good sight for their occupation e.g. lorry drivers and pilots, they should carefully consider all the risks associated with laser surgery.
Relating to the eye. Oculus is Latin for eye.
OCULAR HYPERTENSION (GLAUCOMA)
See INTRA OCULAR PRESSURE
Right eye, abbreviated from the Latin: Oculus Dextra.
Abbreviation for Ophthalmic Medical Practitioner. A qualified doctor specialising in eye care.
Abbreviation for Ophthalmic Optician (American word equivalent to Optometrist).
OPD (Optimised Path Difference) SCAN
The Nidek system that combines Wavefront analysis with corneal topography to map the aberrations of the entire optical system. 8,000 points of light are measured as they pass through the eye. Any minute deviation of the light (path difference) is used to calculate a personalized laser beam profile used to correct these imperfections. The result is that better sharpness of vision can be achieved than with glasses. This is mainly used where glasses can not give perfect vision.
Optimax holds open days at all our clinics each month. Those interested in vision correction surgery visit the clinic and have a free assessment.
A specialist doctor studying the eye and its diseases. Most of our treating doctors are Ophthalmologists and are either Members or Fellows of the Royal College Of Ophthalmology.
The millions of optical nerve fibres connecting to the eye to the brain and in the brain where images are processed.
Relating to the eye or to the passage of light through lenses.
Centre of the eye (cornea) through which light passes to the retina.
A general name used to refer to a person selling glasses. When the person is qualified to perform eye tests he is called an Optomotrist.
Optimax has a network of experienced opticians and it is possible to arrange for check ups to be carried out more locally if the patient prefers not to travel back to Optimax. LASIK patients need to return to Optimax for their one day after care visit in our network. Opticians in our network are not employed by Optimax and will charge their normal fees direct to the patient.
A modern name for an Ophthalmic Optician.
An instrument used for corneal mapping (topography). It analyses the eye's surface including corneal thickness and keratometry-curvature readings. OS left eye, abbreviation from Latin: Oculus Sinestra.
Over the counter drugs available from a chemist without prescription.
A complication of refractive surgery where the achieved amount of correction is more than desired, usually reversible.
Significant reduction in vision, not correctable with spectacles or contact lenses, but at a level where the person is not yet registered blind. Lasers cannot help the partially sighted.
Instrument used to measure the corneal thickness (in microns). Patients need sufficient corneal thickness to allow safe removal of tissue. People with thin corneas are usually suitable for LASEK or Implantable Contact Lenses.
The treatment itself is pain free, although some patients find a small amount of discomfort from the eye clamp. After LASEK most patients feel some pain and grittiness for a day or so, but this is helped with painkillers given at the time of treatment. Occasional severe pain is experienced which passes after 12 to 24 hours. LASIK patients rarely experience pain after treatment, but there have been some reports of headaches for the first few days.
Optimax only refers to people as patients once they have undergone treatment. Px is a symbol used for patients.
The ability to see or be aware of objects and movement outside one's direct line of vision. Peripheral vision can be damaged by prolonged raised interenal eye pressure (glaucoma).
As measured over ten years, indications are that reversal of the effects of laser do not occur. However, treatment cannot prevent the natural changes that occur with the eye and for this reason we wait until the patient's eyesight appears to be stable.
The most advanced type of cataract surgery. Most cataract surgeries today are performed using phacoemulsification, a procedure in which the lens with the cataract is broken up by ultrasound, liquified, and suctioned out. The word 'phako' in Greek for lens. When the cataract lens is removed it is replaced with an artificial one which has correct strength to enable good vision.
Meaning that the natural crystalline lens of the eye left in place.
This is a tiny plastic lens that is placed inside the eye in front of the natural crystalline lens to provide additional refractive change. A lens is placed eiimmediately behind or in front of the iris.
An optical instrument containing many lenses that are used to determine the power of glasses or refractive error. This instrament greatly increase the speed of the eye test.
The cold process of tissue removal which occurs with laser radiation. Ultra violet light is so powerful that the molecular bonds of the target tissue are broken apart causing ablation. Microscopic pictures show incredibly precise cuts with no evidence of tissue burning in adjacent cells.
Unusual sensitivity to light. It can be a side effect of laser treatment, in the initial few months of treatment.
The Civil Aviation Authority (CAA) does not recommend eye surgery for certification purposes. Patients who are considering a career in this field must investigate the current regulations and recommendations before proceeding with laser surgery.
A yellowish spot seen on the white of the eye at the junction of the clear cornea and white sclera of the eye. These lesions are usually caused by over exposure to sunlight (UV radiation). The white surface of the eye cannot "tan" and therefore cannot protect itself from sunburn.
PITUITARY GLAND TUMOR
Can affect visual fields and therefore treatment may be inadvisable.
Plain glass lens (no prescription).
The current sight requirements to enter the police force depend on the constabulary. The minimum sight requirement is 20:20 (6:6 in metric) vision with binocular vision, but not all constabularies will accept applicants who have had laser treatment. Patients are advised that they are to take responsibility for finding out the regulations that apply to them if they are considering this type of career.
Corticosteroid eye drop used to reduce corneal haze and regulate healing response after LASEK. Regular pressure checks are required to ensure the patient does not have raised internal eye pressures.
Steroid drops. See above
Women should not be treated during pregnancy or while they are breast-feeding. They are advised to wait until three months afterwards. The pain relief given is not usually suitable during pregnancy and the eyes can also change during and after pregnancy meaning that the vision can alter slightly. Optimax cannot treat any patient unless their vision is stable.
The need for reading glasses which comes with age. Reading Glasses are needed by virtually everyone on reaching middle age. Age related changes occur within the lens, making the lens harder and less elastic. This means the muscles in the eye are no longer able to flex the lens as effectively resulting in the eye being unable to focus clearly on objects close up. If the patient has a reading addition in their glasses prescription and they are suitable for treatment, they must be aware that even with a good result the need for reading glasses will still apply immediately after treatment. Monovision can be a good compromise to avoid the need for reading glasses.
Drugs only available with a prescription from a qualified doctor.
A lens to correct a slight squint. An additional centring of the lens in glasses, usually for patients with double vision caused by a squint. A likely contra-indication to treatment. However if the patient is happy with their sight with contact lenses they are probably suitable for laser treatment.
PRK (PHOTOREFRACTIVE KERATECTOMY)
Treatment for short sight using the Excimer Laser. The laser is set to the correction required for each eye. PRK was used at Optimax from 1992 - 1999 when it is combined with epiflap is known as Epi-LAKEK.
Rules setting out our procedures. Guidelines or rules. Medical protocols are set down to maintain high standards and safe procedures throughout the company. A register of up to date protocols is maintained by Optimax Head Office.
A growth of scar tissue on the cornea. These lesions like pinguecula are caused by an ultraviolet burn to the surface layer or epithelium. You will not be suitable if in the area of the scar is the proposed treatment.
PTK (PHOTOTHERAPEUTIC KERATECTOMY)
The use of the Excimer laser to treat eye problems such as pronounced haze. Not surgery for short sight.
The medical name for droopy eyelid. It can be a temporary side effect after laser treatment. It is thought to be due to the 'eye clamp' pulling the eyelid muscles to hold the eye open. Is rarely a permanent but can be surgically corrected is necessary.
Tear drains located in the upper and lower eyelids in the corners of the eye lids towards the nose.
Small silicone or plastic plugs that are inserted into any or all of the punctum to prevent tears from draining. Punctal plugs are used in the treatment of dry eyes.
A hole in the centre of the iris that changes size in response to changes in lighting. It gets larger in dim lighting conditions and gets smaller in brighter lighting conditions.
Pupil irregularity is not usually a bar to laser eye treatment.
Instrument which measures the size of the pupil.
Large pupils can be greater then the laser eye laser treatment area and this can cause night time vision problems. The maximum width of the pupil (dilated) in subdued lighting is an important measurement, as it will determine the laser beam size needed for treatment. The Nidek laser beam can expand up to 9mm enabling us to treat most patients.
Needed by virtually everyone after they reach middle age. This is because the muscles in the eye slowly become stiffer and is no longer able to focus clearly on objects very close up. The need is medically known as PRESBYOPIA
Also known as prescription. The measurement of the power of a lens needed to bend light rays sufficiently to cause the image to be focussed onto the retina. The symbol for this is Rx, the prescription for glasses.
Bending light caused by lenses e.g. glasses, contact lenses etc makes images focus correctly on the retina.
This is the process of correcting refractive errors. There are many different forms of refractive correction, such as spectacles, contact lenses, surgical and non surgical laser procedures and also non laser treatments such as CK.
Short sight long sight and astigmatism are all refractive errors which mean that light is not focussed correctly onto the retina, causing images to blur.
The strength of a lens to bend light as it passes through it.
Any surgical procedure that attempts to decrease or remove the patient's need for glasses. Usually the surgeon alters the shape of the cornea in order to change the focussing power of the eye.
Nurse who is registered with the government to perform certain levels of care.
Optimax is registered with the Healthcare Commission as of April 2004. Prior to this we were registered with the Local Health Authorities. All laser eye treatment establishments and doctors have to be registered.
Patients can regress after treatment. Occasionally, they can revert back to the pre-treatment prescription. This is not predictable and depending on the level of regression, the patient can have a re-treatment once the sight is stable.
Natural replacement of tissue.
A refractive error caused by the shape of the cornea, being like a rugby ball insead of a football shape. It is called regular when shape is symmetrical across the centre of the eye. Regular astigmatism is treatable by laser. Astigmatism causes distortion of sight at all distances.
Light sensitive membrane at the back of the eye. Light is focused onto the retina and is then transmitted to the brain as impulses via the optic nerve. The brain interprets these impulses into images.
Damage to this thin membrane can occur as a result of an eye or head injury, but there can also be a genetic link to retinal disease. Very high short sight (myopia) can occassionaly 'stretch' the retina and lead to detachment. This is a separation of the retina from the outer layers of the eye. It can occasionally cause symptoms such as floaters (though these are not necessarily an indication of detachment) or bright flashes of light in the peripheral vision. This can usually be successfully treated if detected early.
RETINAL HOLES AND TEARS
If these are properly treated and heal normally, they will not prevent laser eye treatment.
In some cases it may be necessary to perform a re-treatment to improve a result. This should always be discussed with the treating doctor prior to booking. See the information pack for the current re-treatment charges.
Connective tissue disorder. This disease fights the body's own tissue and can cause the eyes to swell, much the same way as the joints. A bar (contra-indication) to laser laser treatment.
All surgical procedures carry risks and laser treatment is not risk free. Patients will be fully informed of all known risks and side effects before signing the Consent form. If there is any doubt as to their acceptance of such risks, the patient will be advised give the matter further consideration before treatment.
RK (RADIAL KERATOTOMY)
RK is the surgical technique for correcting short sight made famous by the Russian touring ship. The surgeon makes deep cuts using a diamond tipped knife, into the cornea, like the spokes of a wheel. This has the effect of flattening the cornea. However, it is considered to be less safe and less accurate as laser treatment. RK is also known as Microsurgery.
ROYAL COLLEGE OF OPHTHALMOLOGISTS (RCO)
Official body which authorises Ophthalmologists to practice. Optimax treating doctors are usually members or fellows of the RCO.
As a result of excellent research combined with low incidence of side effects, laser treatment has been adopted worldwide as a safe effective alternative to glasses and contact lenses. Treatment however is a surgical procedure and carry risks of complications and long term side effects as outlined in the consent forms.
SANDS OF SAHARA SYNDROME (SOSS)
Inflammation underneath the corneal flap after LASIK. Not an inflection known by it's latin name of DLK - Diffuse Lamela Keratitis - and can effectively treated with high doses of steroids.
The firm white fibrous membrane that forms the white part of the eye.
SCUBA - DIVING
Patients should not scuba-dive for at least two weeks after treatment. Patients must always check with the optometrist at the time of their check up as to suitability of sporting activities.
This is a staining of the surface of the eye which could result as a side effect from contact lens use. It will depend on the consultation with the doctor as to whether the patient is suitable for treatment.
Senior House Officer.
Dioptres of -6.00 or above. Generally, the higher the prescription, the higher risk of complications. Patients must be aware that they may still need to wear glasses after treatment, though the prescription may be much reduced. Most patients over -6.00 dioptres will be more suitable for LASIK as this is more successful than Lasek for higher prescriptions. Optimax offers ICL (Implantable Contact Lenses) for very severe short sight if above -5 to -23.
The distortion of sight because the eye is too long for its focusing power. The laser corrects this by reducing the curvature of the cornea which enables light to reach the retina at the back of the eye. The short-sighted eye bends light too much and focuses the image in front of the retina. To reduce this 'over bending' a negative lens distorts the light before it gets into the eye and so the light can be focused on to the retina.
Side effects are the unwanted effects of treatment. Some side effects usually resolve themselves when the treatment or the medication is stopped.
A microscope used to study the eye using a narrow beam of light. Used to rule out any significant corneal abnormalities such as scarring or the presence of a cataract.
A line of same-sized letters on an eye chart that is used to test a patient's vision.
SNELLEN VISUAL ACUITY CHART
Mr Snellen was the scientist who invented the eye test measurment and chart in 1862 . This eye chart that measures how well a person sees at various levels of correction with glasses.
SOFT CONTACT LENSES
These should be removed before the laser treatment and the consultation for at least seven days. Lenses can affect the surface of the eye. We require the most accurate refraction when the patient attends with a view to treatment. If the lenses are not left out of the eye for long enough, treatment can be postponed.
Pain relief tablets containing 500mg Paracetemol and 30mg Codeine, side effects include nausea, light-headedness, constipation, dry mouth and blurred vision. Often prescribed to patients after Epiflap (LASEK).
SpR - SPECIALIST REGISTRAR
The progression from SHO. This is higher specialist training and lasts four and a half years.
A small clamp which is used to keep the eyelid open during treatment. It is pain free, although some people feel it is a little uncomfortable to begin with but can cause the eyelids to swell and cause droopy eyelids for a short period after removal.
Measurement of distance vision correctable by a round (spherical) lens as opposed to a cylindrical lens. Measured in dioptres. A minus sign in the box means the patient is short sighted and a plus sign in the box indicates long sight.
A person who concentrates on a particular medical procedure. Our doctors are all specialists in Ophthalmology and refractive surgery in paticular.
Patients should expect to resume normal sporting activity after the first week check up, but the doctor should always confirm this. Patients who partake in contact sports and swimming should wait until the eye is completely healed.
It is more common in childhood and a childhood history does not make a patient unsuitable for treatment. However, squints in adults may indicate that the eyes are not working properly together and may be a contra-indication to surgery. This would need to be assessed during the consultation by the doctor. A person who can tolerate contact lenses can usually be treated.
Laser eye treatment is only given to those people whose eye sight has stopped changing. Otherwise the benefit of treatment will be slowly lost. If a patient's prescription has changed by 1 dioptre or more over two years, the sight is not considered stable. Most people have stable eyesight by the time they are reach their early 20's. Patients should be able to demonstrate that their prescription is stable by providing prescriptions dating over the last two years which show little (1/2d) or no change.
A known complication of refractive surgery that causes images from bright light sources to blur with spikes radiating out from the centre. Starbursts can can also occur naturally or with contact lenses.
STICKY EYE LIDS
If the eyelids are sticky you should gently wipe them with a piece of cotton wool soaked in cool boiled water, then dry the eye with a soft clean tissue. Do not use Optrex or any other cleansing agent in the first few weeks after treatment.
Patients who have had LASEK may notice that after the first 12-24 hours the eye may start to feel gritty or sore. This should gradually improve over the next two to four days but it can sometimes persist. The patient should try to avoid rubbing the eye as much as possible and rest in a darkened room. If concerned, speak to the doctor or optometrist.
STEROID EYE DROPS
Steroid drops are sometimes prescribed to slow down the healing process if patients are healing 'too much'. These drops are not often prescribed, but when they are, patients should have a check up every four weeks to monitor IOP. Also see FML
This can also be referred to as 'cross eyes' and is a condition where the two eyes are not properly aligned. One of the eyes may be turned in or out. Vision is significantly impaired by this misalignment and this condition can also lead to a lazy eye. It is usually a contra-indication to treatment patients who are happy with their sight with contact lenses can be considered for laser treatment.
The middle, thickest layer of tissue in the cornea. The stroma is lasered to change its refractive power (lens strength).
This is a small lump on the inner or outer surface of the eyelid caused by an inflammatory reaction to a blocked secreting gland in the eyelid. Patients are advised to wait until the inflammation has cleared before undergoing vision laser treatment.
SUNBEDS AND LASER TREATMENT
Patients are advised against use of sun beds for at least one month after treatment. It is thought that UV rays can affect the healing process and in some patients it could be a contributory factor to regression.
Patients are advised to wear UV protective sunglasses in bright daylight and hot climates for three months after treatment.
Patients are advised to avoid swimming for at least two weeks after treatment due to the risk of infection and irritation. LASIK patients are advised to avoid any contact sports for at least three months.
SWOLLEN EYE LIDS
The eyelids may be swollen or puffy after treatment and the eye may be sensitive. This is normal and may take a few weeks to improve. Patients should discuss with the doctor any side effects that they are concerned about during the aftercare appointments.
SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)
A chronic inflammatory autoimmune disorder. It may affect many organ systems including the skin. SLE is a bar (contra indication) to laser treatment.
This miscrosurgical procedure is performed in order to reduce astigmatism following laser refractive surgery. It is only suitable for a certain range of astigmatism that is combined with low amounts of hyperopia (long-sightedness). Also known as astigmatic keratectectomy.
A small green light on the laser which you stare at during treatment.
A very thin film of watery nutrients covering the epithelium that lubricates the front of the eye.
A make of excimer laser most commonly installed in Europe.
Sleeping pills given to some patients after treatment to help them sleep through the first day.
Stories from Optimax patients on their treatment journey and how Laser Eye Surgery has affected their lives can be found in the treatment section of this website.
Equipment used to test the internal fluid pressure inside the eye (IOP). A puff Ionument is an instrument can be used without touching the eye by blowing a small puff of air into the eye.
TOPICAL PROPARACAINE HYDROCHLORIDE
Anaesthetic eye drops.
A steroid drug applied topically locally as opposed to being swallowed.
Mapping a surface of the eye used to determine the corneal profile and it's suitability for laser treatment.
Special contact lenses for people who require astigmatism correction. Contact lenses affect the shape of the eye will need to be removed prior to consultation and treatment for laser treatment. One week for soft lenses, three weeks for hard lenses or GP lenses.
The area of laser ablation that changes for the full correction of the central ablation zone optical ablation zone to the original surface depth of the cornea.
Drops which dilate the pupil. Used in some cases during the eye examination to see the back of the eye. When Tropicomide drops are administered, the pupil takes some time recover. This can take up to 24 hours and the vision can be blurry during this time. Patients should not drive immediately after having these drops administered. They should ensure that their vision is back to normal before attempting to drive.
The name for normal sight. The measurement of what you can see at twenty feet compared to what normal sighted people see at twenty feet. The metric equivalent is six metres over six metres -6/6. Either of these fractions (ratios) can be converted into a number i.e. 20/20 =1.00. Optimax uses 1.00 to represent normal sight. Fighter pilots need better than normal sight and their vision can be as good as (20/10)=2. If they can see at twenty feet what normal sighted people can only see at ten feet. Twice as good sight as normal peoplewith 20:20 vision.
Uncorrected Visual Acuity. This is the best vision measurement taken without the use of glasses or contact lenses.
Ulcers need to be healed prior to laser surgery.
See CORNEAL ULCER
Unaided sight is the vision achieved without correction by glasses or contact lenses.
A complication of refractive surgery where the achieved amount of correction is less than desired.
Treatment to only one eye.
Part of the eye consisting of the iris, ciliary body and choroid below the surface of the cornea, the pupil etc.
Inflammation of the uvea.
Patients should not have vaccinations within a few days either side of their treatment as they could react with the medication given afterwards such as pain relief.
Glasses that incorporate an addition for reading as well as a distance prescription. People with varifocal lenses will require reading glasses after laser treatment unless they consider mono vision, or prelex implantable contact lenses.
Dizziness can be as a result of imbalance if one eye has been treated.
An infection caused by a virus. If the patient has a viral infection of the eye they will need to inform. Laser treatment should be postponed to when the eye is free of infection.
Clarity of vision-sharpness as measured in the snellen eye test chart. See our statistics chart to which show the effect of laser treatment on V.A.
The transparent colourless mass of gel that lies behind the lens and in front of the retina and fills the centre of the eyeball.
Eyes that water excessively.
New technology enabling customized treatment for smoother and more accurate results, for those with damaged or irregular patterns on the eyes surface.
A diagnostic instrument, The results programme used to measure the waves of light as they pass through the eye. Laser for a Wavefront customised laser treatment.
Up to a week after the treatment the pupil in the treated eye can be wider than normal due to drops administered at the end of treatment. This settles down and goes back to normal after a few days.
Zernike Polynomials are mathematical models of optical aberrations measured with Wavefront technology.
Pain relief tablets given after treatment to be taken as needed in accordance with the instructions on the packet. Each tablet contains 50mg of Tramadol. Side effects include nausea, light-headedness, skin irritation, constipation and dry mouth..