Definition
- Keratoconus is a progressive eye disease in which the normally round cornea thins & begins to bulge into a cone – like shape.
- This cone deflects light as it enters the eye on its way to the light – sensitive retina, causing distorted vision, double vision, near – sightedness, astigmatism & light sensitivity.
Causes
- While the cause is unknown, it is believed to occur due to a combination of genetic, environmental & hormonal factors.
- About 7 % of those affected have a family history of keratoconus.
- Keratoconus is most common in children with chronic eye allergies who have the habit of rubbing their eyes vigorously. It normally starts between 10 and 15 years of age and presents with frequent change of glass power with predominantly increasing cylindrical power.
- Early detection is important. If left unaddressed, it progresses very fast and causes maximum damage by 20 years of age.
Management
Visual Rehabilitation
- With keratoconus, try to avoid rubbing your eyes. This can damage the already thin corneal tissue & make your symptoms worse.
- If you have itchy eyes that cause you to rub, speak to your ophthalmologist about medicines to control your allergies.
- In early stages, glasses or soft contact lenses can suffice to correct for the mild astigmatism.
- As the condition progresses, the condition is managed with rigid contact lenses, known as rigid, gas – permeable (RGP) lenses. RGP lenses provide a good level of visual correction, but do not arrest progression of the disease.
Retarding the Progression of the Disease
- Corneal Collage Cross-Linking (CX3R) is a novel, FDA – approved treatment which aims to strengthens the cornea.
- In this technique, a special “UV light” & “Riboflavin” eye drops are used to strengthen the cornea.
- Doing this helps to flatten or stiffen the cornea, keeping it from bulging further.
Restoring the Normal Shape of Cornea
- A possible surgical alternative to corneal transplant is the insertion of intrastromal corneal ring segments (INTACS).
- “Intacs” are FDA – approved clear, arc – shaped corneal inserts that are surgically positioned within the peripheral cornea to reshape the front surface of the eye for clearer vision.
- This procedure offers the benefit of being reversible & even potentially exchangeable as it involves no removal of eye tissue.
Replacing the Scarred Cornea
- If the cornea is scarred or extremely thinned out, a corneal transplantation (full – thickness or partial – thickness) may be required.
- Corneal transplantation for keratoconus generally is very successful.
Investigative, Diagnostic & Surgical Tools Available at MPEH
- iTrace Aberrometer (TRACEY)
- Orbscan (BAUSCH & LOMB)
- Anterior Segment OCT (TOPCON)
- FS – 200 (Femto Laser System) (Wavelight – ALCON).
- Collagen Cross – Linking (CX3R) Rapid (APPASAMY)
- INTACS