Prevalence of subclinical keratoconus in children presenting with refractive errors: A cross-sectional study

Abstract

Background: Keratoconus is a progressive noninflammatory condition that often starts to develop at the age of puberty. The subclinical disease remains unexplored geographically for its prevalence in children. This study was aimed to determine the prevalence of subclinical keratoconus in children presenting with refractive errors. Methods: A cross-sectional study was conducted among children (below 14 years of age) with refractive errors. Corneal topography indices such as Belin/Ambrosio enhanced ectasia total deviation value (BAD_D), index of vertical asymmetry (IVA), and index of surface variance (ISV) of both eyes were selected from the medical records. The prevalence of subclinical keratoconus was identified using the parameters BAD_D = 1.54–2.38, IVA >0.14, and ISV >22. The incidence was calculated and statistically analyzed. Results: Total 726 eyes (354 right and 372 left eyes) from 363 children (190 males and 173 females) were included in the study. Among the total 726 eyes studied, 132/726 (18.18%) showed subclinical keratoconus with 58/132 (43.93%) in right eyes and 74/132 (53.06) in left eyes (P = 0.3411). Definite keratoconus was observed in total 37/726 eyes only (5.09%) with 23/37 in right eyes (62.16%) and 14/37 left eyes (37.83). No statistically significant (P = 0.1678) difference was found between the incidence of definite or subclinical keratoconus with cases of normal indices. Conclusion: The incidence of subclinical keratoconus among children presenting with refractive errors was 18.18%. Corneal topography and tomography may be recommended for children presenting with refractive errors for identifying subclinical keratoconus and to arrest its progression at the onset.

Keywords

• belin/ambrosio enhanced ectasia total deviation value
• corneal topography
• index of surface variance
• index of vertical asymmetry
• keratoconus
• mean keratometry