الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Ocular allergy especially VKC has been associated as one of the factors predisposing to keratoconus. Significant number (34%) of VKC cases and (8%) of seasonal allergy cases were found to have topographical abnormalities suggestive of initiation of keratoconus. Astigmatism is usually the first manifestation of corneal disfigurement. Average corneal astigmatism was found to be significantly more in VKC cases as compared to other allergic groups. Central corneal power of some corneas was significantly higher than others. Also, the I-S value (>1.4) was positive in 20 eyes, suggesting superior or central steepening.
These results highlight the importance of using a simple corneal topography system in screening the patients with VKC for keratoconus which is relatively cheap and easy to interpret as compared with more expensive topography systems. It is recommended that patients with VKC, especially of long duration, severe VKC, and with decreased vision, should undergo topography for early detection of keratoconus and further preventive follow-up and management
There was a higher prevalence of keratoconus like topography in patients with VKC. However, owing to the small sample size, being hospital based study lack of population based randomized study, the data have limited role in extrapolation to the general population. So, patients with ocular allergy especially VKC should be advised to have corneal topography, especially when presentation of VKC is of long duration, a significant proportion of high refractive error is present, and BSCVA is decreased.