Progression to bilaterality in unilateral primary congenital glaucoma

To evaluate the incidence of rise in intraocular pressure (IOP) in fellow eyes of patients with unilateral primary congenital glaucoma (PCG) and to identify risk factors for IOP increase over long-term follow-up.

The medical records of unilateral PCG patients who had completed at least 5 years of follow-up were reviewed retrospectively. The incidence of developing ocular hypertension / glaucoma in fellow eyes was analyzed. Fellow eye progressors were those which showed an increase in optic nerve cupping by at least 0.2 since the first presentation or had IOP of >21 mm Hg on two occasions. The risk factors for progression that were analyzed included IOP, visual acuity, axial length, central corneal thickness (CCT), corneal diameters (CD), presence or absence of angle dysgenesis on high-resolution anterior segment optical coherence tomography (AS-OCT), and morphology of aqueous outflow pathways.

After a median follow-up of 8.2 years (range, 5-25.5) progression to bilateral disease was found in 17 of 54 patients (32%), of whom 8 (15%) developed ocular hypertension and 9 (17%) developed glaucoma in the fellow eye. Among the unaffected fellow eyes, those with a larger CD (>12 mm), measured after at least 5 years' follow-up, were ten times more likely to progress (P = 0.01; OR = 9.5 [95% CI, 1.7-54.3]). The presence of a patent supraciliary channel was significantly more frequently associated in fellow eyes compared with affected eyes on AS-OCT (OR = 1.4 [95% CI, 0.46-4.68]).

One-third of unaffected fellow eyes of unilateral PCG eventually progress over time, most often after 5 years. Larger CD at follow-up in the fellow eye is strongly predictive for progression.