[Year:2021] [Month:January-June] [Volume:10] [Number:1] [Pages:6] [Pages No:4 - 9]
Objective: This cross-sectional study aimed to determine the prevalence of keratoconus (KC) among young individuals in the Omani population, covering the entire country. Additionally, the severity of keratoconus was investigated after detection of the disease.
Materials and methods: A total of 2750 participants were included in the study. The screening was conducted using retinoscopy (Phase 1) by well-trained optometrists, and those with a positive scissoring reflex underwent further assessment with corneal tomography to confirm the presence of keratoconus and assess its severity (Phase 2). Visual acuity and demographic data, such as age, sex, governorate, and village of residence, were collected during Phase 1, while corneal curvature parameters (K-Max, K-Mean, corneal thickness, back elevation) and keratoconus staging data were collected during Phase 2.
Results: Out of the 2750 participants screened, 184 individuals between the ages of 20 and 34 were found to have a positive scissoring reflex. Among them, 96 cases were confirmed to have keratoconus in one or both eyes through corneal tomography, regardless of the severity stage. This yielded a prevalence rate of 3.49% among the study population. Among the positive keratoconus cases, 38 were males and 58 were females, with only 15 individuals aware of their keratoconus condition. Analysis of positive cases revealed the highest prevalence in the Al Batinah North governorate. Severity analysis based on topographic keratoconus classification displayed five eyes in stage 3–4, indicating advanced disease. Additionally, 75 cases had corneal parameters suspected of keratoconus on corneal tomography but did not meet the diagnostic criteria (based on the KSS score, This system grades the severity of keratoconus from 0 (suspect) to 5 (severe) based on two corneal topographic indices (i.e., anterior corneal higher order aberration RMS error and mean central keratometry), and 13 cases were confirmed as false-positive scissoring reflex.
Conclusion: This study revealed a significant prevalence of keratoconus among young individuals in the Omani population. Compared with similar studies conducted in other parts of the world and neighboring countries, Oman appears to have a higher prevalence. Notably, a significant proportion of cases were already in advanced stages upon detection. Certain regions in Oman showed a higher prevalence, suggesting a potential relationship with geographic location and environmental factors. These findings warrant further investigation into the causative factors of keratoconus among the Omani population in the planned Phase 3 of the study. Close follow-up is recommended for cases suspected of having keratoconus but not meeting diagnostic criteria. Additionally, the lack of awareness among individuals with keratoconus, even in advanced stages, highlights the importance of population-based educational programs to promote early detection and intervention, ultimately preventing permanent visual disability.