What is Keratoconus?

Sahani Dias Bsc Optometry

Keratoconus is a disorder of the anterior (front) surface of the eye-that is, the cornea. In simple terms, the cornea becomes thinner, causing it to bulge from its normal round shape to form a cone shape. This bulging interferes with one's vision and can severely affect the way objects are seen, making simple tasks like reading, watching TV or driving very difficult. The distortion caused by Keratoconus has been compared to that of viewing a street sign through the windscreen of a car during a driving rainstorm.

The progression of Keratoconus is unpredictable but it generally occurs slowly and may even cease at some stage. While Keratoconus interferes with the clarity of a person's sight, it rarely causes blindness. In its early stages, it causes slight blurring, distortion of vision and increased sensitivity to glare and light.

In its early stages, the vision impairment caused by keratoconus can be treated by using spectacles to correct the resultant minor myopia (nearsightedness) and astigmatism. As the disorder develops, the degree of vision obtained though spectacles becomes steadily less acceptable. If the condition continues to worsen and vision is not improved with the aid of spectacles, specially made gas permeable (GP) contact lenses will be required.

Precise measurements of the eye are first made using special equipment in order to generate a computerized picture of the shape of the cone and the cornea. This information and other date on the corrections required for myopia and astigmatism are fed into special electronically-controlled lathes which then proceed to manufacture the precise lenses required. It is thus ensured that the lenses are custom-made to suit individual eyes. The perfect fir achieved leads not only to optimum visual acuity (sharpness of vision) but also to better comfort.

Needless to say, the testing, manufacturing and fitting of these lenses require highly skilled personnel and the most modern equipment. The majority of patients can successfully manage their keratoconus with the GP contact lenses. However, in small number of cases, where the cornea can no longer be successfully fitted with contact lenses, a corneal transplant may become unavoidable, as a last resort.