09 August 2010
By Jayashree Nandi
Rise In Cases Of New Disorder Of The Cornea, Keratoconus
Keratoconus, a degenerative disorder of the eye, in which structural changes within the cornea cause it to thin and change its shape, is one of the most common eye diseases today.
Vice–president, Narayana Nethralaya, Dr Rohit Shetty, is currently carrying out research on keratoconus. Strangely, this disease is increasing only in parts of Asia, such as India and Pakistan, Turkey, parts of Saudi Arabia, Africa and Latin America. Many doctors link the trend to heat and pollution that is common to all these countries. The incidence used to be one in 3,000 in India, but the latest research shows it is in the range of one in 1,500 today!
A cornea surgeon from Mexico, Dr Juan Carlos, who is currently working with Shetty on keratoconus, says its incidence has increased drastically in Mexico too. "It is very common in Central America, Africa, Turkey, it’s strange. Could it be because all these countries are closer to the equator? The pollution and heat levels are higher in these parts," he said.
"We are very close to finding a gene responsible for this disorder. It has always been thought of as a non–genetic disease but certain strange attributes like the fact it is location–specific and that certain people are prone to these allergies, tell us it could be genetic," Dr Shetty said.
Naveen SP, 19, from a remote village near Chikkaballapur in Karnataka, used to walk 11 km daily to attend a government school. He used to top the class until he noticed blurred vision and irritation in the eye. He managed to pass his PUC examination with 93%. While the village panchayat members were happy about his excellent performance, they brought him to Narayana Nethralaya.
He was diagnosed with an advanced stage of keratoconus. Many children like Naveen, from urban areas too, are reaching hospitals only to find that they have to get a cornea replacement. It is extremely difficult to get a young cornea because most of those who donate are elderly persons. "How can we use a 60–year–old’s cornea for an 11–year–old?" asks Dr Shetty.
However, a cornea replacement in case of keratoconus is required only for 50% of the cases. Now there are some other therapies like collagen cross–linking and INTACS, a form of corneal implant.
Pregnant women are extremely vulnerable to it and the disease gradually disappears as you cross 40 years. "It occurs at the most productive age. I have had patients who were in sectors where they had to face comp u t e r screens for very long hours. But that only intensifies the symptoms of keratoconus as it makes your eyes very dry. They had to quit their jobs and take up another one. One of them was a techie," says Dr Shetty.
"Even while it is increasing in all these countries, hardly anyone knows about keratoconus. It’s important to detect these early. Almost all patients speak about intensive rubbing of eyes. People should watch out whether they are getting such allergies frequently. Almost all patients who have this disease have very high short–sight or eye power. They can be called legally blind," adds Dr Shetty.
Progressive increase in glass/ contact lens power
Poor vision Not able to tolerate contact lens
Poor vision at night
Increase in cylinder power/ astigmatism
Narayana Nethralaya’s Findings:
- 3,500 patients in 10 years; mean age group of 24 yrs
- Urban predominance increased in past 5–6 yrs
- Male/female equal
- 45% progressive in nature
- 80% need contact lens for good vision
- 65% had history of eye rubbing in teens and beyond
- 2% showed increase in symptoms during pregnancy
- 50% needed surgical intervention
- 15% needed cornea transplant
- 5% had family history – genetic role
Lubricate your eyes
regularly. See a specialist as soon as you see symptoms like frequent rubbing of eyes, blurred vision, frequent changing of glasses