Case-control study of risk factors for acute corneal hydrops in keratoconus

PurposeTo determine risk factors for the development of acute corneal hydrops in keratoconus in the UK in a case-controlled study.MethodsBetween November 2009 and December 2010, we prospectively identified 73 individuals who developed acute corneal hydrops. We then identified 174 controls from nine regions in the UK with keratoconus who had not had hydrops. For cases and controls we recorded demographics and clinical features. Univariate and multivariable logistic regressions were performed to identify risk factors.ResultsUnivariate analysis suggested strong associations between the odds of hydrops and each of vernal keratoconjunctivitis (OR 4.08, 95% CI 1.45 to 11.49, p=0.008), asthma (OR 2.70, CI 1.34 to 5.47, p=0.006), atopic dermatitis (OR 3.13, CI 1.50 to 6.56, p=0.002), learning difficulties (OR 7.84, CI 2.86 to 21.46, p