The prevalence of keratoconus in children with allergic eye disease in an Egyptian population

Abstract

Purpose: To determine the prevalence of keratoconus (KC) among children with ocular allergy. Methods: A cross-sectional study was conducted on all children presenting with ocular allergic disease from September 2017 to September 2018. All study participants were subjected to history taking (a specially designed questionnaire), routine ophthalmological examination, and corneal tomography. Results: A total of 79% of the study patients had vernal keratoconjunctivitis (VKC) while the remaining had perennial allergic conjunctivitis (10%), seasonal allergic conjunctivitis (9%) and atopic keratoconjunctivitis (2%). Manifest KC was seen in 7% of cases, suspect KC was found in 27% of cases, and 66% had no evidence of KC. For the manifest KC, 56% had clinical signs, while 44% were diagnosed by tomography. For the purpose of statistical analysis, the cohort was divided into group KC (manifest or suspicious KC) and group non-KC (no KC). The mean age was 11.2 years in group KC, and 9 years in group non-KC ( p < 0.001). The mean duration of allergic symptoms was 3.75 years in group KC, and 2.5 years in group non-KC ( p = 0.001). The mean duration of eye rubbing was 2.5 years in group KC, and 0.83 years in group non-KC ( p = 0.02). Systemic atopy was present in 35.3% of group KC, and in 12.5% in group non-KC ( p = 0.005). Conclusion: The overall prevalence of KC was 34%. Risk factors for the development of KC in patients with ocular allergy were age, duration of symptoms specially eye rubbing, systemic atopy and VKC. Tomographic diagnosis of KC can be present in absence of clinical signs.