Visual axis opacity following IoL implantation in children aged under 2 years: Findings from the IoLunder2 cohort study

Abstract Objective/ Purpose Appropriate correction of aphakia is key to good outcomes. There may be clinical settings and populations where accessing or managing aphakic contact lenses is challenging. Strategies to target the increased risk of visual axis opacity (VAO) following primary IoL implantation in infancy are necessary. We describe the predictors of VAO following primary IoL implantation for unilateral or bilateral congenital or infantile cataract in children aged under 2 years. Design Population based (UK and Ireland) prospective inception cohort study undertaken through a national clinical network. Participants 105 children (57 bilateral cataract, 48 unilateral, total 162 eyes) undergoing primary IoL implantation in the first two years of life between January 2009 and December 2010. Methods Observational longitudinal study with multilevel, multivariable modelling to investigate associations between outcome of interest, and child and treatment specific factors including age, axial length, socioeconomic status, IoL model, and post operative steroid use. Main outcome measures Post operative proliferative and / or inflammatory visual axis opacity (VAO) requiring surgical correction. Results Visual axis opacity occurred in 67 eyes (45%), typically within the first post-operative year. Use of a three piece IoL model (odds ratio/OR 0.3, 95% confidence interval/CI 0.09 – 0.99, p=0.03), and increasing age at surgery (OR 0.97, 95% CI 0.95-0.99, p=0.02), were each independently protective against the development of proliferative VAO. Inflammatory VAO was independently associated with socioeconomic deprivation (OR 5.39, 95%CI 1.46 – 19.89, p=0.01). Conclusions Visual axis opacification is common following IoL implantation in early childhood. The findings of this prospective cohort study suggest that the use of three piece IoL models may reduce the risk of pseudophakic VAO in children aged under 2 years.