Demographic profile, clinical, and topographic characteristics of keratoconus patients attending at a tertiary eye center

PURPOSE: To evaluate the demographic profile, clinical, and topographic characteristics of keratoconus (KCN) patients attending at a subspecialty eye hospital in Tehran, Iran. METHODS: In this cross-sectional study, all patients who attended Noor Eye Hospital between March 2011 and March 2017 and had a diagnosis of KCN were identified, and the required number of patients was randomly selected. The following data were extracted from patient's records: age, sex, visual acuity, refraction, keratometry, pachymetry, and treatment procedures. The data of KCN laterality, severity, morphology, and cone location were also extracted by analyzing the corneal imaging maps. RESULTS: The records of 1080 eyes of 540 patients were evaluated. The mean age of the participants was 31.04 ± 8.54 years (range, 13–63 years), and 69.3% of the patients were male. The highest and lowest frequency of KCN was seen in the age group 20–30 years and above 50 years, respectively. Bilateral KCN was detected in 93.3% [95% confidence interval (CI): 91.68–94.75] of the subjects. 43.7% (95%CI: 32.88–54.48), 55.6% (95%CI: 44.73–66.38), and 0.8% (95%CI: 0.75–0.78) of the cases had nipple, oval, and globus cones, respectively. The cone was central in 52.1% (95%CI: 41.10–63.11), paracentral in 43.6% (95%CI: 36.13–51.04), and peripheral in 4.3% (95%CI: 00.76–7.86) of the cases. The frequency percentage of KCN according to severity was 15.2% (95%CI: 13.09–17.46), 56.4% (95%CI: 53.37–59.37), and 28.4% (95%CI: 25.75–31.21) for mild, moderate, and severe KCN, respectively. Among different parameters, only cone location had a significant association with age as the frequency of paracentral and peripheral cones increased with ageing (P = 0.002). CONCLUSIONS: The mean age of KCN patients in our study was higher than similar studies in other Asian countries. KCN was bilateral in most cases with an oval morphology and central cone location. Most of the patients had moderate to severe KCN.