PACG patients have a higher rate of blindness. Photo: Michael Cymbor, OD.
PACG patients have a higher rate of blindness. Photo: Michael Cymbor, OD. Click image to enlarge.

While glaucoma remains the leading cause of blindness worldwide, certain forms of the disease may pose a higher risk than others. Studies have reported that blindness is a more common patient outcome in primary angle-closure glaucoma (PACG) than in primary open-angle glaucoma (POAG), given that PACG is a more destructive disease form and involves pupillary block. Researchers recently performed a meta-analysis on POAG and PACG patients and concluded that the latter form of the disease is more likely to result in blindness.

The analysis gathered data from 23 studies on diverse populations published on PubMed between 2000 and 2020, totaling 78,434 participants. Of these, 1,702 were diagnosed with POAG, while 724 were diagnosed with PACG. In the POAG group, 8.9% of patients reported blindness, while in the PACG group, more than one in every four patients was blind (27%).

“The risk ratio of blindness in PACG to POAG varied from 0.73 to 10.6 among the studies,” the researchers noted in their paper. “The cumulative risk ratio was 2.39. This corresponds with what has been suspected in clinical practice. Intermittent spikes or acute elevations in intraocular pressure may cause greater optic nerve damage than the more gradual elevation in IOP seen in POAG.”

The findings of this meta-analysis support what has been proven in previous studies with smaller and more homogeneous cohorts: overwhelmingly, PACG is more likely to be associated with blindness. Treat patients with this form of glaucoma aggressively and monitor them closely to look out for signs of disease progression or vision loss.

George R, Panda S, Vijaya L. Blindness in glaucoma: primary open-angle glaucoma versus primary angle-closure glaucoma-a meta-analysis. Eye (Lond). October 13, 2021. [Epub ahead of print].