Health & Fitness

When the cornea thins and bulges out

Keratoconus is triggered by overexposure to ultraviolet rays from the sun, excessive eye rubbing, and a history of poorly fitted contact lenses. PHOTO | FILE
Keratoconus is triggered by overexposure to ultraviolet rays from the sun, excessive eye rubbing, and a history of poorly fitted contact lenses. PHOTO | FILE 

A medically proven problem facing users of contact lenses affects the cornea, the curved clear or transparent layer forming the front of an eye.

In the case of one Peter Wambasi, 29, who suffers from keratoconus (thinning of the cornea to the point of blurring vision), his condition cannot be corrected by spectacles but by soft custom contact lenses.

Keratoconus is a progressive eye disease in which the normally round cornea thins and begins to bulge into a cone-like shape. Instead of perceiving light naturally, affected eyes have their cornea deflecting light as it enters the eye on its way to the light-sensitive retina, causing distorted vision.

“The doctors at Lions SightFirst Eye Hospital told me that my condition can only be corrected by corneal crosslinking, a surgery meant to strengthen my corneal tissue to stop it from bulging,” said Peter in an interview.

“After surgery I can only wear special contact lenses — spectacles would not be of much help to me.”

His condition started almost a decade ago but was simply ignored, after all he could still see.

“Keratoconus worsens with time,” said an phthalmologist at the Columbia Africa Hospital, Zelalen Wudineh.

“The condition is triggered by overexposure to ultraviolet rays from the sun, excessive eye rubbing, and a history of poorly fitted contact lenses or chronic eye irritation. It can also affect more than one member of the same family due to its genetic predisposition,” he said.

Dr Wudineh was speaking during an interview at his office in Park Place, Nairobi. He said that due to its nature, treatment for progressive keratoconus is surgery and contact lenses (post- surgery).

Contact lenses are made from flexible soft plastic material to allow free oxygen flow through the eye cornea.

There are of two types, soft and rigid contact lenses, with the latter being more firm with high optics. The rigid contact lenses are approved for overnight wear though you are not supposed to sleep while still wearing them, said Dr Wudineh.
According to a doctor’s prescription, there are disposable contact lenses in the market that can cost you up to Sh70,000 annually if you change them every two weeks. A single buy can cost about Sh2,000.

The worst thing that can happen to a contact lens wearer is an eye infection, he said.

“Eye infections might lead to loss of vision and even brain damage, simply due to poor cleaning of the lenses,” he said.
“You can simply do anything with them but remember to clean them regularly.”

Contact lenses are more superior to glasses and that is why it is highly recommended for sports men and women who have eye discrepancies, said the eye expert.

They are usually prescribed for eye patients with the power of one of their eyes being more than four diopter. A diopter is the unit measurement of refractive power of how far the eye lenses can see.

“In such cases, the brain would not fuse the two eye powers together thus forcing someone to see double images and for correction, contact lenses are the only solution,” said Dr Wudineh.

However, when going swimming, you are advised to always wear protective swimming goggles to prevent them from possible movement inside your eye. They might also trap bacteria hence causing an infection, which should be the last thing you would wish to have.

If you are a wearer, avoid longer exposure to dust.

Dust is the worst nightmare for a contact lenses wearer, Cynthia Musyimi, 25, who works with a logistics firm in Nairobi.

Cynthia had travelled upcountry to Machakos for a family get-together when dust entered her eyes. She was wearing her medical contact lenses.

Acting on impulse, she rubbed her eyes and that is when she realised she had them on.

“Rubbing my eyes while having contact lenses on was my worst experience. I opted for them because I thought they were fun and I did not have to walk around with ‘bulky’ spectacles,” said Cynthia.

“I could not use my tomato-red eyes for a whole 24 hours later until I got prescription for some antibiotic eye drops at the eye clinic my mum took me to.”

As a precaution you are not supposed to sleep with the contact lenses on. Dr Wudineh said they should be removed every night and cleaned in antibiotic solution.

Children can wear them but it is advisable for 18 year-olds and over.

This is because a mature person is aware of the risks and will always remember to disinfect their hands and clean the lenses before and after using them. “They may not be a comfortable bet for young children but if they are mature enough to understand that they should not rub their eyes while playing or cleaning procedure, no harm,” he said.

The status of the eye should first be determined by a specialist before contact lenses are prescribed – avoid over the counter acquisition.

Conditions like chronic dry-eye syndrome, inflammation, cornea defects should hinder you from acquiring contact lenses.

“If you have any form of eye infection, do not use contact lenses not unless clearly advised by an ophthalmologist,” said Dr Wudineh.