Keratoconus is an ectatic corneal disorder for which exciting therapeutic and diagnostic technologies are emerging. However, its pathogenesis is still heterogeneous and elusive. We researched overlooked Asian keratoconus data by literature review of databases (PubMed, MEDLINE, Ovid, Google Scholar, Cornea, and Cochrane) using key words “keratoconus, Asia, epidemiology, treatment, risk factors, genes” and names of Asian countries. Articles and their references were analyzed. Studies showed that keratoconus may be more prevalent, have earlier onset, and have greater disease progression in certain Asian and non-Asian ethnicities, particularly Indians, Pakistanis, Middle Easterners, and Polynesians, compared with white populations. Epidemiological risk factors include ethnicity, age (younger than 30 years), gender (male), positive family history, and eye rubbing. Genetic and disease risk factors include atopy, vernal keratoconjunctivitis, Down syndrome, pellucid marginal corneal degeneration, VSX1 (visual system homeobox 1) gene, and Leber congenital amaurosis. Differentiation of heterogeneous keratoconus subsets with detailed genotype–phenotype characterization may advance understanding. Comprehensive multiethnic population studies with valid large-scale data are needed. New effective treatments (deep anterior lamellar keratoplasty, intrastromal corneal ring segments, and corneal collagen cross-linking with riboflavin) are succeeding previous treatments.
*Department of Ophthalmology,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
†Department of Ophthalmology, National University Hospital, Singapore, Singapore.
The authors state that they have no financial or conflicts of interest to disclose.
Reprints: Dr Loon Seng Chee, Department of Ophthalmology, National University Hospital, 5 Lower Kent Ridge Rd, Kent RidgeWing 2, Level 3, Singapore 119074 (e-mail: email@example.com).
Received May 16, 2010
Accepted December 19, 2010