Keratoconus higher among Asians than white patients, study in Britain finds

Asians were significantly more likely than white patients to have keratoconus in a retrospective study at an English hospital.

T. Georgiou and colleagues in Leeds, England, conducted a retrospective study of new patients diagnosed with keratoconus or malformation of the cornea at their hospital between 1994 and 2000. A catchment population of 176, 774 for the hospital was used to calculate the incidence of keratoconus in three ethnic populations: white (82%), Asian (17%) or other (1%).

A total of 74 cases of keratoconus were diagnosed in this 6-year period. Of these patients, 29 (39%) were white and 45 (61%) were Asian. This factored to an incidence of keratoconus of 1 in 4,000 per year for Asians, compared with 1 in 30,000 per year for whites (P < .001), the researchers said. Asians presented with keratoconus significantly younger than white patients. The incidence of atopic disease was found to be significantly higher in whites compared to Asian keratoconic patients, according to the study.

The researchers said that Asians, mostly of northern Pakistani origin, were significantly more likely to present with keratoconus than whites. The authors noted that this community has a tradition of interfamilial relationships, especially first-cousin marriages. The higher incidence in this population was highly suggestive of a genetic factor being significant in the etiology of keratoconus, the researchers said. The incidence of keratoconus was higher than in previous studies, the researchers said.

Atopic disease was significantly less common in Asians than white people, supporting the theory of a different etiology in these patients, the authors said.

The study is published in the April issue of the Eye.