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Epidemiology of Keratoconus in an Iranian Population

Ziaei, Hossein MD; Jafarinasab, Mohammad Reza MD; Javadi, Mohammad Ali MD; Karimian, Farid MD; Poorsalman, Hossein MD; Mahdavi, Manijeh MD; Shoja, Mohammad Reza MD; Katibeh, Marzieh MD, MPH

doi: 10.1097/ICO.0b013e31823f8d3c
Basic Investigation

Purpose: To determine the incidence of clinical keratoconus (KCN) in an Iranian population.

Methods: This prospective surveillance study was conducted in Yazd province in central Iran (population 990,818). During 1 year (July 2008 to June 2009), all new patients with KCN were registered and referred. Diagnosis was based on the topographic pattern, and indices were measured and eye examination was done by anterior segment subspecialists.

Results: Of the 564 eligible patients referred, 28 did not attend their topography session (95% response rate). Topographic figures showed suspect or definite patterns of KCN in 47.8% of participants (256/536 subjects). Based on topographic images and clinical examination, KCN was confirmed in 221 patients, and in addition, 26 patients were categorized as having suspected KCN and 9 had non-KCN corneal diseases; therefore, the annual incidence rate of KCN was estimated as 22.3 (95% confidence interval, 19.5–25.4) and 24.9 (95% confidence interval, 21.9–28.2) per 100,000 population, excluding and including suspected KCN cases, respectively.

Conclusion: The incidence of KCN in our context is apparent and comparable with rates in other studies on Asian ethnic populations. This is much higher than the incidence in European Caucasians and warrants further genetic and environmental studies.

*Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Department of Ophthalmology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

Reprints: Marzieh Katibeh, Ophthalmologic Research Center, Labbafinejad Medical Center, Boostan 9, Pasdaran, Tehran 16666, Iran (e-mail:

The authors have no financial or conflicts of interest to disclose.

Received February 7, 2011

Accepted July 18, 2011

Copyright © 2012 Wolters Kluwer Health, Inc. All rights reserved.