Patients with narrow-angle normal-tension glaucoma (NTG) may be more prone to disease progression than those with wide-angle NTG, according to the findings of a recent study in JAMA Ophthalmology.

In an effort to find out if anterior chamber angle width played a role in NTG disease progression, researchers at Seoul National University Hospital conducted a retrospective analysis of data from 2004 to 2009, which included 104 patients, 52 with wide-angle NTG and 52 with narrow-angle NTG. Non-indentation gonioscopy was used to grade anterior chamber angles.

The cumulative probability of both structural and functional progression was significantly greater in the narrow-angle than in the wide-angle group, researchers noted.

Over the course of the approximate seven-year follow-up, 25 of the 52 narrow-angle eyes (48.1%) and 13 of the 52 wide-angle eyes (25.0%) showed structural progression. Additionally, 21 of the 52 narrow-angle eyes (40.3%) and nine of the 52 wide-angle eyes (17.3%) showed functional progression.

The baseline diurnal intraocular pressure (IOP) was approximately 1.38x greater in the narrow-angle group than in the wide-angle group. In the follow-up, the narrow-angle group showed an approximate 1.75x greater difference in IOP fluctuation, which the researchers noted could be linked to a greater chance of disease progression.

 “Further studies determining whether augmented or differentiated treatment strategies would be beneficial for patients with narrow-angle NTG are warranted,” the investigators said.