Visual field loss patterns differ between open-angle, angle-closure glaucoma

SINGAPORE — The pattern of visual loss differs between open-angle and angle-closure glaucoma, according to a prospective study.

Patients with primary angle-closure glaucoma (PACG) have more severe visual loss overall than those with primary open-angle glaucoma (POAG) when the decision is made to operate, the comparative study concluded. The patterns of visual field loss differ between the two forms of glaucoma as well. The study authors suggest that these differences may offer insights into the pattern of visual field loss in predominantly pressure-dependent glaucomatous optic neuropathy.

Gus Gazzard, FRCOphth, and colleagues at the Singapore National Eye Center and elsewhere assessed 234 patients with primary glaucoma who were at least 30 years old. Patients with previous symptomatic angle-closure, normal-tension glaucoma, visually significant cataract or previous intraocular surgery were excluded.

Of the patients enrolled, 129 had POAG and 105 had PACG. Mean deviations indicated patients with PACG had more severe visual loss than patients with POAG. Patients with POAG were more severely affected in the superior hemifield than the inferior.

“We detected differences between POAG and PACG in retinal sensitivity between the superior and inferior hemifields, independent of severity of damage,” the study authors report in the December issue of Archives of Ophthalmology.

Cases with moderate field loss had more negative mean pattern deviation values in the superior sectors than did the severe cases in both groups, the study authors said. “This could be the result of a more uniform visual field loss in the severely affected groups,” they said.