The Auckland keratoconus study: identifying predictors of acute corneal hydrops in keratoconus.

Background: The aim was to identify potential factors associated with acute corneal hydrops in a New Zealand population with keratoconus referred to a hospital eye service.
Methods: In a single hospital centre, in a retrospective review, demographic and clinical features of subjects with keratoconus and corneal hydrops over a 17-year period were compared with an age- and gender-matched control group of subjects with keratoconus but no history of corneal hydrops.
Results: One hundred and one eyes of 101 subjects (mean age 24.6 ± 8.4 years) were identified with keratoconus-related corneal hydrops. Subjects were more likely to be of Pacific but less likely to be of New Zealand European ethnicity than control subjects (n = 101). In comparison, Maori ethnicity was not found to have a significantly positive or negative association with hydrops. The pre-hydrops visual acuity (VA) of affected eyes was poorer than that of controls (p < 0.001) at first presentation to our tertiary referral corneal and contact lens service. Hydrops typically developed approximately four years after diagnosis of keratoconus. Subjects with hydrops were more likely to have a history of eye-rubbing (p = 0.011) but less likely to have a family history of keratoconus (p = 0.05). In 31 cases, the acute hydrops event was their first optometric/ophthalmologic contact. There were no statistically significant differences in the prevalence of atopic disease, contact lens wear or overall corneal transplantation rate between the two groups.
Conclusions: Pacific ethnicity, history of eye-rubbing, poor VA at first hospital presentation and lack of family history were statistically associated with developing acute corneal hydrops in keratoconus in a New Zealand population. Greater understanding of such predisposing risk factors may help develop early management strategies to delay or prevent progression of this disease.
(© 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.)