Prevalence of keratoconus in refractive surgery cases in Western India

Abstract

Purpose: To report the prevalence of keratoconus (KCN) in patients presenting for refractive surgery in western India. METHODS: A cross-sectional, observational, retrospective study performed at a tertiary eye care center. A total of 2902 cases, aged 18–40 years who presented in the refractive surgery department between January 2014 and December 2018 were included. Records of all the included cases were reviewed. Patients showing KCN pattern on topography were noted and divided into KCN and KCN suspects. Annual and overall 5-year prevalence were calculated at 95% confidence interval (CI). Demographic details of KCN and non-KCN participants were compared. RESULTS: Of the 2902 cases, 25 (0.86%) had clinical KCN and 22 (0.76%) were KCN suspects. The combined 5-year prevalence of all these 47 KCN cases was 1.61% (95% CI: 1.15%-2.07%), with an annual prevalence range of 0.97%–2.43%. The mean age of non-KCN cases was 24.60 ± 4.91 years and KCN cases was 24.62 ± 5.37 years ( P = 0.98). Among the KCN cases, there were more females (30; 63.83%), and the gender ratio was significantly different than non-KCN cases ( P = 0.004). CONCLUSION: The prevalence of KCN in refractive surgery cases was 1.61% which is higher than those found in the western population and lower than those found in the Middle East (Saudi Arabia and Iran). Furthermore, topographic examination performed during the routine screening of patients for refractive surgery can be a useful tool to diagnose new cases of KCN in asymptomatic patients.

Estimated prevalence of keratoconus in the largest metropolitan area of Italy

“…25 A comparable disease prevalence (pooled 2.3%; range: 0.9% to 2.4%) has been found in India. 13,26,27 A significantly higher prevalence than reported in this study was found in Saudi Arabia, Iran and Africa. 13,16,28 In a prospective, observational, multicenter study, the keratoconus prevalence was 4.8% in a pediatric population ( n = 522) living in Riyadh 28 ; it was 3.6% in a large population-based study in Iran ( n = 3314).…”

Prevalence of Corneal Topographic Patterns in Ectatic Corneal Diseases

“…The pathfinder corneal analysis detection system in the Atlas topographer shows keratoconus pattern probability of ≥40% along with an anterior elevation of ≥12 μm and a posterior elevation of ≥25 μm on the Scheimpflug analyzer. 15,16 The eyes showing keratoconus probability on pathfinder corneal analysis with anterior elevation <12 μm and posterior elevation <25 μm on the Scheimpflug analyzer without clinical signs were considered as suspected cases and those with no clinical and topographical signs as forme fruste ectasia. 15,16 The pathfinder corneal analyzer was described in a previous article.…”

“…15,16 The eyes showing keratoconus probability on pathfinder corneal analysis with anterior elevation <12 μm and posterior elevation <25 μm on the Scheimpflug analyzer without clinical signs were considered as suspected cases and those with no clinical and topographical signs as forme fruste ectasia. 15,16 The pathfinder corneal analyzer was described in a previous article. 15 The pattern analysis included only the right eyes of patients with clinical ectasia.…”

“…15,16 The pathfinder corneal analyzer was described in a previous article. 15 The pattern analysis included only the right eyes of patients with clinical ectasia. In patients who had forme fruste or suspected keratoconus in their right eye, the fellow eye was considered.…”

“…The pathfinder corneal analysis detection system in the Atlas topographer shows keratoconus pattern probability of ≥40% along with an anterior elevation of ≥12 μm and a posterior elevation of ≥25 μm on the Scheimpflug analyzer 15,16 …”