Ferdi A, Nguyen V, Kandel H, et al. - The authors used data from 34 centres across Australia, New Zealand, Spain and Italy to find risk factors for development in untreated keratoconus patients. Study participants were divided into ‘progressors’ and ‘stable’ patients for each clinical parameter: visual acuity (VA), steepest keratometry (maximum keratometry (Max-K)) and thinnest corneal thickness (TCT). From 2,283 patients, there were 3,994 untreated eyes. The most clinically useful baseline predictors of progression were a steeper Max-K and a younger age, as they were linked to worsening of two clinical parameters. Every 1D steeper Max-K was related to a 7% and 3% greater risk of worsening VA and thinning TCT, respectively. Each 1 year younger was linked to a 4% and 2% increase in the risk of steepening Max-K and thinning TCT, respectively.