KERATOCONUS- AN OPTOMETRIC DISORDER

OVERVIEW

This is a disease where the central mirror like structure, called Cornea, become weak, leading to progressive thinning and stretching which gradually progresses. Gradually, the Cornea bulges forwards, leading to an irregular cone shape. This causes distortion and blurring of the image formed by the cornea. Usually the disease is bilateral, though the severity may vary between the two eyes. Keratoconus affects about 1 in 7000 people.

SYMPTOMS

It may present as frequent change in spectacles power. When the disease progresses, vision deteriorate and may not improve with spectacles. It also causes distortion in vision with multiple images, glare and sensitivity to light.

TREATMENT

Rigid Gas Permeable Contact Lenses: Early Keratoconus can be managed by giving rigid gas permeable contact lens to the patient, which corrects the irregularity of the cornea and provide better quality of vision. In advanced keratoconus, these lenses may not fit the eye optimally and become difficult to wear.

Rose K Contact Lens/Scleral Boston Contact Lens: Theses are special custom made contact lenses which give better fit and superior vision quality. These are ordered after taking various measurements of cornea.

C3R (Corneal Collagen Cross Linking wit Riboflavin): This is the only treatment to stop the progression of Keratoconus. It is based on collagen cross- linking with ultra-violet A (UVA, 365 nm) and Riboflavin (Vitamin B2, a photo sensitizing agent). This increase in corneal strength has shown to arrest the progression of Keratoconus in almost all cases and it can reverse the Keratoconus changes by 20 to 30 percent.

Cornea Transplant: This is a surgical treatment, which is reserved for advance cases of Keratoconus, where the vision cannot be improved with glasses or contact lenses. Here the central portion of the cornea is removed and replaced with a donor cornea of similar size. Since there is high possibility of complications and graft rejection, this surgery is done for selected cases.

Intacs: These are acrylic rings inserted in the corneal stroma to decrease corneal irregularity in cases of Keratoconus. They can improve uncorrected vision without contact lenses. These can also be combined with C3R.

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Optometry : open access

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