A clinical study to describe the corneal topographic pattern and estimation of the prevalence of keratoconus among diagnosed cases of vernal keratoconjunctivitis

Abstract

BackgroundAssociation of keratoconus with vernal keratoconjunctivitis is well known, but there are few topographic studies describing actual prevalence especially in India where it is a common condition. There is also scarce literature on the topographic patterns and subclinical topographic anomalies in cases of vernal catarrh and their relationship with various subtypes. This study was conducted to estimate the prevalence of subclinical keratoconus among Indian subjects with vernal keratoconjunctivitis and describe the various topographic abnormalities which can help in screening for these cases. MethodsIn the cross-sectional study conducted at a tertiary care center, 76 established cases of vernal keratoconjunctivitis were evaluated with placido disc–based videokeratography for topographic abnormalities and early keratoconus based on modified Rabinowitz–McDonnell criteria. ResultsSeventeen (11.2%) eyes satisfied both the modified Rabinowitz–McDonnell criteria of keratoconus. Corneal topographic pattern analysis showed asymmetric bowtie with inferior steepening in 17.11% of the patients. None of these patients had clinical evidence of keratoconus. ConclusionsThe study showed 11.2% prevalence of keratoconus in patients suffering from vernal keratoconjunctivitis. The findings highlight the importance of using a simple placido disc–based corneal topography system for screening the patients with vernal keratoconjunctivitis for keratoconus. This can help in early detection and preventive intervention.