Prevalence and clinical characteristics of Keratoconus amongst school children in Mumbai.

Abstract

Purpose: To determine the prevalence and characterize the clinical profile of keratoconus [KC] among Mumbai schoolchildren.

Methods: A sample of 2 042 students aged 9-17 years was selected from schools in Mumbai through stratified random sampling. Selected participants underwent ocular assessments of visual acuity [VA], auto keratorefractometry [ARK], retinoscopy, ophthalmoscopy, and corneal topography. Descriptive and inferential statistical analyses were conducted utilizing SPSS software version 25.

Results: The prevalence of KC was 3.6% [n = 74], with a mean age of 12.47 ± 1.7 years and 70% being female. Amongst the KC group, 58% were Hindus and 41% Muslims, with consanguinity being significantly associated with KC amongst Muslims (<0.001). In both topography [48.22D vs. 43.58D] and ARK [47.58D vs. 43.16D], K2 [steep keratometry] was higher in the KC as compared to the non-KC group. The I-S index was elevated [2.0D vs. 0.71D], unaided VA worse by 0.35 log units, and myopia [-5.27D vs. -1.89D] and irregular astigmatism [-1.88D vs. -0.68D] more severe in the KC group. Significant asymmetry was noted in the surface asymmetry index, flat and mean K values, myopia, and astigmatic refractive errors [p < 0.001] when comparing better and worse eyes. Retinoscopy showed strong associations with refractive error and topographical findings.

Conclusion: This first population-based study among schoolchildren in Mumbai [aged 9-17] found a significant KC prevalence. A more comprehensive screening approach, incorporating key diagnostic indicators such as topographical indices [mean K, I-S index, an asymmetric bow-tie pattern], positive scissors reflex on retinoscopy, myopia [≥ - 5 D], irregular astigmatism [>1.5 D], VA of 0.35 log units or worse and marked asymmetry between better and worse eyes, proved effective in identifying KC cases. Findings highlight the need to integrate KC detection protocols into school vision programs in Mumbai for early diagnosis and intervention, ultimately improving long-term visual and ocular health outcomes of affected children.