Brussels eye doctors - Keratoconus

Keratoconus is often diagnosed in an adolescent or young adult, between ten and twenty years old, who seeks medical help due to blurred vision and/or visual distortion. These problems may be accompanied by hypersensitivity to light (photophobia) and reflection problems.

It is a rare disease which generally appears in adolescence and would affect about 50 to 230 people out of 100,000. Female preponderance is not certain.

The disease is spread uniformly throughout the world. Apparently, there is not geographic, cultural or social disparity.

The true causes of keratoconus currently remain unknown. Researchers have, however, identified several factors which appear to favour it. The first of these is heredity.

The role of heredity has been suggested by observing numerous family cases. In particular, it has been able to be established that 7% of patients suffering from keratoconus had at least one other member of their family affected by keratoconus. Nevertheless, the risk of being affected due to descendent is assessed at less than 10% when one of the two parents is a keratoconus carrier.

Keratoconus may accompany other anomalies such as Down’s Syndrome, certain diseases affecting the conjunctive tissue (Ehlers-Danlos syndrome). They also occur in individuals with a predisposition to pathologies like asthma or eczema, or in people who have a tendency to rub their eyes.

Keratoconus is progressive: it takes years to fully develop and can stop at any stage. It has however been noted that overall, the disease progressed especially between the age of 10 and 20 years. Between 20 and 30 years old, progression becomes slower and very reduced after 30 years of age.

In a more advanced stage, keratoconus leads to a rapid decrease in visual acuity due to the deformation of the cornea. Sometimes the central cornea develops a scar that also contributes to a loss of eyesight.

Sometimes, a patient complains of “pulsatile” vision especially after physical exercise. This shows the existence of an already considerable thinning of the cornea.

The ultimate stage of acute keratoconus rarely appears. The cornea then thins to such a point that this may cause a rupture of the endothelium with appearance of an oedema.

Clinical examination will attempt to show up the disease’s characteristic alterations.

Deformation of the cornea and irregular corneal astigmatism can be diagnosed by various methods:

Examination with a slit lamp enables eccentric protrusion of the cornea to be located. In a more ad-vanced stage, the cornea becomes thinner and corneal opacities appear.

Keratometry enables the curvatures of the cornea to be measured and is therefore of major im-portance. In effect, in the initial stage, irregular astigmatism is the only element and it is naturally es-sential to be certain that it did not exist beforehand.

Corneal topography is an examination that enables the cornea to be mapped and therefore makes an image of irregular astigmatism as if the contours of a mountain were being studied. This examination gives graphic results which tell you a lot and which can be compared from one examination to the next Unfortunately, not all ophthalmologic practices have a topographer.

Keratoconus cannot be prevented, but its worsening can be prevented by avoiding rubbing one’s eyes. This practice must be avoided at all costs.

Introduction

There are several solutions for treating keratoconus starting with wearing corrective lenses. If glasses or lenses are not enough, then there is a need to resort to surgical techniques.

Treating keratoconus depends on the severity of the disease and vision requirements. Initially, glasses will be able to correct the astigmatism with some success. These are rarely tolerated continuously and patients are often disappointed due to the relative visual discomfort. It should definitely be stressed to patients to tolerate a correction for as long as possible in order to delay the anatomical aggression that contact lenses may cause. Whereas, when the peripheral part of the cornea not reached by the cone, has an astigmatic deformation, only specialised rigid contact lenses will be able to give optimal correction. Nowadays, there are more and more options for contact lenses for keratoconus.

Lastly, when good vision is no longer possible even with contact lenses or a person develops an intolerance to lenses, a cornea transplant will then be recommended. A corneal transplant is essential in only 10% of cases. Keratoplasty is then envisaged: the central part of the diseased cornea is removed then replaced by the cornea of a deceased person. Keratoconus currently represents 8 to 12% of indications for corneal transplants. The vision results that are generally obtained are good: post-operatively, fairly often an astigmatism appears which is not foreseeable and which can possibly be treated in a second stage (after the sutures are removed) due to techniques using the excimer laser (PRK guided by topography or LASIK).

For several years it has been possible to stabilise the irregular deformation of the cornea caused by keratoconus, by means of Ultra-violet Crosslinking (cross-linking corneal collagen fibres by ultra-violet rays). After impregnation of vitamin B12 (Riboflavin), the cornea is exposed to ultra-violet rays: this causes the riboflavin structure to change, which causes rigidification and solidification of the cornea. Once corneal stability is established, the irregular astigmatism can, in a second step, be dealt with, partially by excimer laser techniques; guided by topography (PRK).

First of all, it has to be determined whether it is a progressive or non progressive keratoconus. In this respect, Cross-Linking by UV rays constitutes a new treatment, which increases the tissues’ stability. This treatment is recommended for all patients less than 20 years old and patients suffering from progressive keratoconus.

After a Cross-linking type treatment by UV rays, patients need to have functional vision restored. There are several techniques available to do this:

glasses with suitable lenses may be a good solution, but there may still be visual distortion.

rigid contact lenses are another solution

if rigid contact lenses are not suitable, hybrid or scleral contact lenses may be adjusted

for patients who are unable to tolerate lenses, lastly there are three surgical techniques to obtain visual revalidation: surface treatment by laser (PKR) guided by topography, implanting phakic lenses, intracorneal ring segments (ICRS)

In the case of a highly pronounced keratoconus, the progressive deformation of the cornea may be such that light can no longer be evenly focused on the retina. In this case a total or partial corneal transplant is the last alternative:

transfixiant keratoplasty or corneal transplant consists of replacing the damaged cornea by the cornea from a donor.

DALK (Deep Anterior Lamellar Keratoplasty) treatment consists of replacing the front layer of the cornea.

Ultra-violet crosslinking

Introduction

Treatment’s purpose

Procedure

The operation’s stages

3 weeks before the pre-operative examination

If you wear hard or semi-hard contact lenses, they must be removed at least two weeks before the operation. This is particularly necessary if you have been wearing contact lenses for a long time.

1 week before the pre-operative examination

Remove soft contact lens.

The day before the operation

Look for prescribed medicines: Dafalgan Codeine (a sedative), Trafloxal (an anti-inflammatory), Vexolone, Indocollyre (a painkiller), Systane and Oxyal / Hyal-Drop / Hylogel (artificial tears solution) and linseed oil.

Do not put any mascara.

Contact the driver who will be taking you.

The day of the operation

1/2 hour before your appointment, take 1 tablet of Dafalgan Codeine. This medicine will relax you and may make you sleepy.

Do not put any mascara, make-up or perfume on.

Bring with you to the clinic: Indocollyre, Trafloxal, Vexolone, Systane and Oxyal / Hyal-Drop (do not open the bottles).

The examination and operation last approximately 2 hours. If there was to be a delay caused by previous treatments, you will need to take waiting time into account.

During the operation

Anaesthesia is carried out using 3 drops, just immediately before the operation.

The ophthalmologist will take care to explain everything to you: no surprises.

Your eye will be held open by an eyelid spreader, which will prevent you from blinking.

First of all the ophthalmologist will place a metal ring on your eye that he will then fill with an alcohol solution. After a few seconds, the alcohol solution will be absorbed and the epithelium is removed. The cornea is rinsed to eliminate impurities and dried. Next, riboflavin (Vitamin B12) will be applied for 15 minutes (1 drop every 20 seconds).

Before the treatment, the ophthalmologist will check, in his rooms, under a slit lamp, whether the cornea and anterior chamber are sufficiently impregnated with fluorescent solution. Now, you are ready for cross linking treatment by uv rays.

The ophthalmologist centres your eye in light of the UV light source. From then on, you are going to have to stare at this light for 10 minutes. Your eye will be abundantly irrigated and you will also have an anaesthetising drop instilled every 5 minutes. Due to the chemical reaction that occurs between the vitamin B12 and the ultra-violet rays, links are created between the collagen fibres. Thus, the cornea solidifies and stabilises and will not deform any more in the future.

After the operation, a contact lens will be placed on your eye.

After the operation

You will have to apply drops according to the plan given below:

The day of the operation

Trafloxal (an anti-inflammatory): 4 times a day during the week following the operation.

Indocollyre (a painkiller): as required, in case of a gritty or burning sensation.

From the next day, the following need to be added:

Systane (artificial tears solution): to be used up to 3 times a day, especially the first week after the operation, you may also use Oxyal / Hyal-Drop artificial tears solution, which are more viscous, as needed if your eyes remain dry.

Linseed oil: 2 capsules a day, 1 in the morning and 1 in the evening at meal time.

3 days after the operation

After re-epithelisation, apply Vexolone 3 times a day for 5 weeks.

The technique for instilling drops is very important: do not touch the eyeball. Pull the lower eyelid down, while looking upwards. Apply the drop and close the eye.

The contact lens will remain on your eye for 3 days. During this time, you will still not be functional: vision remains blurred, the eye may be painful and red. After 3 days, the lens will be removed during a post-operative check-up, and vision will slowly improve. The pain and redness will subside. Vision becomes clearer in about one week, but vision quality will still continue to improve for 1 to 2 months after the operation.

Post-operative check-ups are scheduled 3 days, 1 week, 1 month, 3 months, 6 months and one year after the operation. You will have to remove your contact lens for the operated eye for 3 weeks before the check-up.

If you suffer significant pain or you are worried, do not hesitate to contact your ophthalmologist.

Do not plan major or sporting activities over the days following the operation.

The first 2 weeks: do not use make-up.

The first 3 weeks: do not go swimming.

You will have to avoid UV rays for 6 months (wear sunglasses if you are exposed to full sunlight).

In case of unilateral treatment, be careful when driving a car as you depth vision is not good, while the second eye has not been operated on.

You must schedule check-up appointments with your ophthalmologist on the third day and the first week after the operation, until the time the wound has healed.

The final result will be assessed by topographies to check if the cornea is stable. In a second phase, in some patients, short-sightedness and astigmatism will be able to be treated using PRK guides by topographies or by implanting an Artisan intraocular torical lens.

Post-operative check-ups

Visual rehabilitation after UV-CXL (or crosslinking by UV rays and visual rehabilitation in patients suffering from keratoconus)

If, after a UV Crosslinking, it can be shown, via a topography, that the keratoconus is stabilised, a surgical operation may be envisaged in order to obtain visual rehabilitation: a topography-guided surface treatment (TG-PRK) or implanting an Artisan or Artiflex (PIOL) torical lens.

This type of operation is of interest especially for patients who no longer tolerate their contact lenses. The aim is to obtain visual rehabilitation but not to become emmetropic: the eye operated on will see enough so as not to have to systematically wear glasses or lenses.

It is important that the patient realises that vision quality before the operation with contact lenses will always be better than vision quality after the operation without correction.

For patients over 30 years old with a stabilised keratoconus, visual rehabilitation can be done at the earliest 3 months after Crosslinking by UV rays. The surface treatment guided by topography can also be done at the same time as Crosslinking by UV rays.

For younger patients with a keratoconus that is still developing, a treatment can be done at the earliest 2 years after Crosslinking by UV rays.

The choice of a PIOL or TG-PRK treatment depends on several parameters among which the equivalent sphere, the degree of astigmatism and the thickness of the cornea.

During TG-PRK treatments, 75 % of cylinder refractive errors are corrected and part of the sphere’s refractive errors depend on the thickness of the cornea. A maximum 50 µm are removed. The optic zone includes a minimum 5 mm.

In some patients, TG-PRK treatment is combined with Crosslinking by UV rays treatment: initially, the cornea is resculpted and the lower layers are then directly treated using Crosslinking by UV rays.

The result is not only stabilisation of the keratoconus but also a better visual acuity. This is much more comfortable for the patients given that there is only one treatment.

Doctor Vryghem, since December 2005, for 23 eyes has a post-operative follow-up (number of lines gained in visual acuity, maximum keratometry, spherical equivalent, astigmatism, …) for more than 6 months, available on patients who resorted to a treatment for visual rehabilitation. In these patients, using a satisfaction questionnaire, we have assessed their dependence on glasses / lenses, their overall satisfaction and their side effects (circles of light, light dispersion, problems with night time vision, double vision).

The results from this study are encouraging, but patients’ expectations must be realistic. Visual acuity with contact lenses before the operation will always be better than after the operation. More complaints (halos, circles of light, double vision) were recorded in the group of patients that underwent a TG-PRK operation (69 % satisfaction rate). The operated eye will also remain in competition with the good unoperated eye. It is always possible – provided that the thickness of the cornea is sufficient – to do a re-treatment.

Satisfaction in patients who had a PIOL implant (86 % satisfaction rate) is higher, given that their ametropia (short-sightedness and associated astigmatism) is corrected.

The combination of TG-PRK and a PIOL implant is possible, but there are still no long term results.

If, for some patients, there is no appropriate technique, a “DALK” (Deep Anterior Lamellar Keratoplasty) corneal transplant or a PKP (Penetrating Keratoplasy) is always possible.

Transfixiant keratoplasty or corneal transplant

What is a corneal transplant?

Indications for a corneal transplant

Success rate for corneal transplants

The procedure for a corneal transplant

A complete pre-operative examination prior to surgery is required. The procedure generally lasts approximately one hour and the majority of adults can be operated on under local anaesthetic. General anaesthetics are generally required for children and anxious patients or those who do not cooperate. After anaesthesia, the surgeon places a ring on the eye surface to hold the eye. The central part of the donor’s cornea is prepared using a corneal “punch” or “trephine” to create a corneal button. The diseased or damaged cornea is then removed using a corneal trephine, in order to create a bed for the cornea to be transplanted. In a certain type of corneal transplant (penetrating keratoplasty), the removed disk as well as the replacement disk represent the total thickness of the cornea. Whereas during lamellar keratoplasty, only the outer layer of the cornea is removed and replaced. Lastly, the donor’s cornea is lightly attached using ultra-thin sutures (approximately 1/3 of the thickness of a human hair, or less).

Corneal transplant can be combined with other procedures, more especially with cataract surgery with implanting an intraocular lens.

After the operation, eye drops will be prescribed and will have to be instilled for several weeks after the operation. These drops include antibiotics to prevent infections as well as corticosteroids to reduce inflammation and prevent transplant rejections. During the days following the corneal surgery, the patient is capable of resuming light activities with particular restrictions. Patients must expect a gradual recovery of vision. The healing process can vary enormously from one person to another. In reality, the best vision cannot be obtained before 6 to 12 months or more after the operation. Even if, in some cases, vision may be improved right from the first day after the operation. The surgeon is probably going to start removing a few sutures from the cornea during the weeks or months following the operation. However, all the sutures will have to be removed to relieve astigmatism once the cornea starts to show signs of secure healing. During the post-operative period, the surgeon checks the healing of the cornea using specific computerised maps which are called topographies. These enable the ophthalmologist to assess the shape of the new cornea.

Transplant rejections occur in 5-30 % of patients, this is a possible complication during any operation involving a tissue transplant from another person. As the cornea does not normally contain blood vessels, it has a very minimal percentage of rejections. Generally, the blood group and tissue type are not taken into consideration for corneal transplants, and compatibility between the donor and recipient is not required. Rejection symptoms include persistent discomfort, sensitivity to light, redness or a change in vision.

The corneal tissue for transplanting comes from an eye bank. The health of the donor graft is inspected before this is used for a corneal transplant.

The operation’s stages

A minimum of one week before the pre-operative examination

The patient’s general practitioner will be consulted to check whether there are any contraindications for operating under local anaesthetic. In most cases an electrocardiogram and a routine blood test are carried out, if this has not been done during the last six months.

Look for the prescribed drugs: Tobrex eye drops (see below), Predmycine Forte, Trafloxal, Isoptocarpine 4 % (in order to have a small pupil before the operation), Tobradex eye drops (an anti-inflammatory) and Homatropine collyre 1 % drops.

3 days before the operation

Instil 1 drop of Tobrex 3 times a days into the eye that will be treated.

Stop taking anticoagulant drugs or ask your general practitioner for advice to obtain a replacement drug.

The day before the operation

Call 02 / 741.69.99 to find out the time of your operation.

Contact the driver who will accompany you.

The day of the operation

Do not put any mascara or make-up on.

In the morning, you can use all the drugs as usual except the anticoagulant.

If the operation takes place in the morning, you must not have anything to eat or drink whereas if you are operated on in the afternoon, you will be able to have a light lunch.

1 hour before the operation

Every quarter of an hour, instil 1 drop of Isoptocarpine in the eye to be treated.

Bring with you to the Parc Léopold clinic: Tobradex drops (do not open the bottle) and the Homatropine 1 % drops.

The operation and preparation last +/- 2 hours. If there was to be a delay caused by previous treatments, you will need to take waiting time into account.

During the operation

Anaesthesia is carried out using an injection in the cheek and 2 drops in the eye before the operation.

The ophthalmologist takes his time to explain everything to you: no surprises.

Your eye will be held open by a spacer, which will prevent you from blinking.

You will feel no pain.

The operation lasts about 45 minutes to an hour.

After the operation

Your eye will be covered with a compress that you will have to keep on until the morning after the operation.

The transparent protective shell must be worn every night for one week after the operation.

Drops will have to be applied according to the plan given below from the day after the operation:

Trafloxal eye drops: 1 drop 4 times a day for 2 weeks.

Predmycine Forte eye drops: 1 drop 6 times a day for at least 2 months.

Then long term continue according to the declining plan determined by your ophthalmologist.

Homatropine collyre1 %: 1 drop twice a day for +/- 3 weeks.

Atropine + Tobradex to be taken with 5 minute intervals.

The technique for instilling drops is very important: do not touch the eyeball. Pull the lower eyelid down, while looking upwards. Apply the drop and close the eye.

Vision will still be very blurred for a start and will become clearer in the months following the operation. You will most probably need corrective lenses for distant vision. Any adaption of the lenses will be able to take place at the earliest after 3 months.

In case of significant pain or worry, contact the ophthalmologist at Brussels Eye Doctors (02 / 741.69.99), on his GSM 0475 / 71.08.71 or via the Parc Léopold Clinic’s emergency department (02 / 287.50.42).

Do not plan major or sporting activities over the days following the operation.

The first three weeks: do not rub the eye!!!

The first 3 weeks: do not go swimming.

The first 2 weeks: do not use make-up.

Avoid dusty environments!

After a corneal transplant, patients very often have to continue using cortisone based drops for life (once or twice a day).

You must schedule check-up appointments with your ophthalmologist on the 1st, 3rd and 10th day, 3rd, 6th week and 3 months after the operation, until the wound heals. The final result will be assessed after +/- 3 months.

Post-operative check-ups

DSAEK (Descemet Stripping Automated Endothelial Keratoplasty)

Introduction

Indications for DSAEK

DSAEK is indicated in patients suffering from corneal pathologies, located on the endothelial layer. This generally occurs in patients who suffer from persistent traumas on the endothelial layer after cataract surgery complications or in patients who have intrinsic diseases of the corneal endothelium called Fuch’s endothelial dystrophy.

During the last fifty years, penetrating keratoplasty, or replacing the total thickness of the cornea, has been the standard treatment for patients suffering from corneal endothelium disorders. Although the anatomical results are excellent, the vision results relating to speed, quality and predictability are poor. Typically, a patient who has undergone a corneal transplant may have poor vision for 2 years. It is very difficult to anticipate the final curvature of the cornea, this is why glasses or contact lenses will be necessary, in the majority of cases, after surgery. The sutures remain in place for a long time and a rupture wound always involves a serious risk. Patients who have bilateral disorders must often wait for a long time before the other eye is treated once the first has healed.

However, recently cornea specialists have started to replace only the diseased layer of the cornea, instead of replacing the complete thickness. Not only is this technique faster, healing time is shorter, pain fades away (or disappears), but the procedure also gives better vision for the patients.

The various benefits of DSAEK are that the procedure uses a small surgical incision instead of a complete opening of the front part of the eye and does not require sutures. This generally results in a faster re-establishment of vision for patients who have undergone DSAEK and a greater probability that the patients only have to wear a slight correction to be functional. In addition, the risk of dangerous complications for vision which may occur following the PKP procedure (such as an intra-operative expulsive haemorrhage or a post operative wound rupture) is reduced.

Description of the procedure

During the pre-operative examination, the necessary measurements and examinations will be carried out in order to determine whether the patient is a good candidate for DSAEK. A check will be made to see if the patient is suffering from other pathologies such as a cataract, macular degeneration etc… In most cases, the patient will first undergo a cataract operation before envisaging DSAEK.

This procedure is conducted in a day hospital. The patient takes a sedative and he is injected with an anaesthetising product behind the eye. The patient is awake but feels nothing.

During a first stage, the posterior lamella of the donor’s cornea is prepared with healthy epithelium. This tissue, the graft, comes from a cornea bank. Implementation of the lamella is done using a keratome (a modified version of the device used for LASIK operations).

After the local anaesthetic has started to take effect, the eye is surrounded by a sterile drape. DSAEK is a micro-surgical technique that is practised through a special operating microscope. During the first DSAEK stage, a very small incision is made in the corneal limbus and the damaged endothelial cells will be removed (Descemet stripping). During the second stage of the procedure, this diseased tissue is replaced by the corneal lamella containing healthy cells from the donor’s cornea (endothelial keratoplasty).

The donor’s folded tissue is inserted in the eye.

In order to attach the new tissue on the back part of the old cornea, an air bubble is used to completely fill the front part of the eye. The air bubble makes the lamella adhere. The procedure lasts 45 minutes. Patients are recommended to lie on their backs for the rest of the day and they will then be examined the following morning. The air bubble progressively disappears over the two following days.

Patients are able to resume their normal activities within two weeks, except swimming. Antibiotic eye drops are used for six weeks. Steroid based drops are used for a minimum of a year and often for the remainder of life to prevent graft rejection. Fortunately, graft rejections are very rare. Every 6 months you will have to come for a check-up.

The operations’ stages

Introduction

The inner layer of corneal cells enables the cornea’s clarity to be maintained. This layer of cells may be diseased or have been damaged by a previous operation, resulting in a corneal oedema. DSAEK or corneal transplant without sutures is a surgical technique that enables a diseased cornea to be replaced by a lamellar transplant from a donor. This will enable the corneal oedema to disappear and vision to be regained in the affected eye.

A minimum of one week before the pre-operative examination

The patient’s general practitioner will be consulted to check whether there are any contraindications for operating under local anaesthetic. In most cases an electrocardiogram and a routine blood test are carried out, if this has not been done during the last six months.

Look for the prescribed drugs: Tobrex eye drops (see below), Predmycine Forte, Trafloxal, Isoptocarpine 4 % (in order to have a small pupil before the operation), Tobradex eye drops (an anti-inflammatory) and Atropine collyre 1 % drops.

3 days before the operation

Instil 1 drop of Tobrex 3 times a days into the eye that will be treated.

Stop taking anticoagulant drugs or ask your general practitioner for advice to obtain a replacement drug.

The day before the operation

Telephone 02 / 741.69.99 to find out the time of your operation.

Contact the driver who will accompany you.

The day of the operation

Do not put any mascara or make-up on.

In the morning, you can use all the drugs as usual except the anticoagulant.

If the operation takes place in the morning, you must not have anything to eat or drink whereas if you are operated on in the afternoon, you will be able to have a light lunch.

Bring with you to the Parc Léopold clinic: all the prescribed drops.

The operation and preparation last +/- 1 hours. If there was to be a delay caused by previous treatments, you will need to take waiting time into account.

During the operation

Anaesthesia is carried out using 3 drops in the eye just before the operation.

The ophthalmologist takes his time to explain everything to you: no surprises.

Your eye will be held open by a spacer, which will prevent you from blinking.

You will feel no pain.

The operation lasts about 45 minutes.

After the operation

The transparent protective shell must be worn every night for one week after the operation.

Drops will have to be applied according to the plan given below from the day after the operation:

Trafloxal eye drops: 1 drop 4 times a day for 2 weeks.

Predmycine Forte eye drops: 1 drop 6 times a day for at least 2 months.

Then long term continue according to the declining plan determined by your ophthalmologist.

Homatropine collyre1 %: 1 drop twice a day for +/- 3 weeks.

Homatropine + Trafloxal + Predmycine Forte: to be taken with 5 minute intervals.

The technique for instilling drops is very important: do not touch the eyeball. Pull the lower eyelid down, while looking upwards. Apply the drop and close the eye.

Vision will still be very blurred for a start and will become clearer in the weeks following the operation. Any adaption of the lenses will be able to take place at the earliest after 2 months.

In case of significant pain or worry, contact Dr. J.C. Vryghem at Brussels Eye Doctors (02 / 741.69.99), on his GSM 0475 / 71.08.71 or via the Parc Léopold Clinic’s emergency department (02 / 287.50.42)

Do not plan major or sporting activities over the days following the operation.

The first three weeks: do not rub the eye!!!

The first 3 weeks: do not go swimming.

The first 2 weeks: do not use make-up.

Avoid dusty environments!

After a corneal transplant, patients very often have to continue using cortisone based drops for life (once or twice a day).

You must schedule check-up appointments with your ophthalmologist on the 1st, 3rd and 10th day, 3rd week, 2 and 6 months after the operation until the wound heals. The final result will be assessed after +/- 2 months and 6 months.

Post-operative check-ups

Deep anterior lamellar keratoplasty (DALK)

Introduction

Indications for DALK

There are various conditions that must be satisfied before deciding whether a corneal transplant can be envisaged. The most common indications are:

Defects in the first part of the cornea (epithelium, Bowman membrane, but in particular the stroma) with a normal endothelial layer: corneal dystrophies.

Highly pronounced keratoconus: progressive deformation of the cornea where light is no longer evenly projected on the retina.

Corneal scarring: after a trauma, post-infection (e.g.: herpetic keratitis, caused by bacteria, after burns).

During the last 50 years, keratoplasty (PKP), or replacing the total thickness by the cornea from a donor, was the standard treatment for patients suffering from corneal disorders. Although the anatomical results are excellent, the vision results relating to speed, quality and predictability are less satisfactory. A typical patient who has undergone a corneal transplant may continue have poor vision for 2 years. It is very difficult to anticipate the final curvature of the cornea, therefore after the operations, it is still necessary to wear glasses or lenses in most cases. The sutures are removed after a long delay and a tear after an accident remains a major risk. Patients who have bilateral disorders must often wait for a long time before the other eye is treated once the first has healed.

Over the last few years, cornea transplant specialists have developed techniques where only the diseased layer of the cornea is replaced, instead of replacing the cornea in entirety: these are lamellar keratoplasty techniques.

When the first part of the cornea is found to be the reason for poor vision, as is the case for keratoconus or corneal dystrophies, only the epithelium and stroma (the most important part of the eye) are replaced. This is Deep Anterior Lamellar Keratoplasty, DALK. The patient’s Descemet membrane and endothelium are saved and form the mat to receive the graft. Due to this technique, the healing process is shorter and the refractive result is more predictable: the patient has more chance of having better vision afterwards and the eye is also stronger.

DALK is going to be increasingly more widely used in future and will therefore increasingly often replace PKP.

Benefits of DALK

Description of the procedure

Post-operative care