A number of studies report monocular treatment trials of glaucoma medications to assess efficacy, where the untreated eye is used as a control for comparison.30,31 However, anti-VEGF is known to exit the eye via the conventional outflow tracts and can be measured systemically following intravitreal injection.32,33 Therefore, unilateral injections still could have effects on the contralateral eye. The gene discussed is VEGFA; the disease is glaucoma.