Of 15 million blind people, 75 % have preventable blindness

A resent research reveals that India has an average of 15 million blind people of which 75 per cent have preventable blindness. After cataract, refractive errors and glaucoma, corneal blindness is a leading cause of avoidable blindness. Currently India has 1,20,000 unilateral corneal blind populations and according to the

National Programme for Control of Blindness

it is estimated to reach 10.6 million by 2020.

“Cornea is the outermost transparent dome like structure of our eye which lies in front of the pupil through which all light enters our eye and helps us to see. It is composed of six layers each one contributing in its own special way to keep the cornea clear.What causes corneal blindness are several factors such as vitamin A deficiency, scarring which is caused as an aftereffect of bacterial, fungal or viral infections, congenital diseases,

corneal dystrophies

, keratoconus, trauma to the eye causing scarring, chemical injuries and post-surgical complications leading to decompensation,” says Dr Preethi Naveen, Consultant Opthalmologist,

Dr Agarwal Eye Hospital

, Chennai.

To know the condition first and foremost, a detailed evaluation by an ophthalmologist is very vital. The grade of scar will totally determine the treatment options. Depending on that glasses or contact lenses will be given if the person’s vision is reasonably good. For people who have a very poor quality of vision, surgery is the better option.

“The only part of the eye which we transplant is the cornea. We retrieve this from donor within six hours of their demise. With advances in medical science, we now have surgeries where only the particular layer which has been damaged can be replaced instead of the complete cornea,” says Dr Preethi.

Talking about the treatment she adds, “In traditional Penetrating Keratoplasty all six layers of the cornea are transplanted. The chances of rejection are higher in this type of surgery because of the immune system. There are lamellar surgeries called Deep Anterior Lamellar Keratoplasty (DALK) where only the front layers of the cornea which are scarred are transplanted. The recovery period is much faster compared to full thickness and also chances of rejection are low. In certain cases, the innermost layer of cornea alone is damaged due to conditions like Fuchs dystrophy or post cataract surgery and as a result the endothelial cells which play an important role in maintaining corneal transparency are damaged leading to fluid accumulation and swelling of cornea. This in turn affects the patient’s vision,” adds Dr Preethi.

Corneal surgeries have a very high success rate among transplants. Post-surgery the patient will have to be under close follow-ups with their ophthalmologist.