Most patients diagnosed with unilateral glaucoma will eventually develop it bilaterally, according to a study published last week in JAMA Ophthalmology. The investigators added that bilateral development is especially likely in cases with progression in the first eye.

The team conducted a post-hoc analysis of 607 participants in the Collaborative Initial Glaucoma Treatment Study. These patients all had newly diagnosed open-angle glaucoma in one or both eyes. They were followed for up to 11 years (1993 to 2004), and the data was analyzed from 2012 to 2018. In 47.9% of cases, the fellow eye was treated at baseline; 31.8% of fellow eyes never received treatment and 20.3% were eventually treated.

The report listed age, hypertension, large cup-to-disc ratio and worse mean deviation as predictors of the need for treatment in the fellow eye. These factors were more predictive than either family history or race, both of which have been associated with greater glaucoma risk in the past.

Although the research found race lacked predictive significance for fellow eye development, it did find that black patients in the study had a significantly higher prevalence of hypertension (47.6%) than patients of other races (30.6%) and that they were also more likely to have their fellow eyes treated initially (55%) than other races (44%).

Niziol L, Gillespie B, Musch D. Association of fellow eye with study eye disease trajectories and need for fellow eye treatment in collaborative initial Glaucoma Treatment Study (CIGTS) participants. JAMA Ophthalmol. August 9, 2018. [Epub ahead of print].