In a new study published in Ophthalmology, a team of South Korean researchers found OCT guided progression analysis (GPA) was an effective approach to evaluate the topographic patterns of progressive macular ganglion cell-inner plexiform layer (GCIPL) thinning in glaucomatous eyes.

Researchers included 292 eyes of 192 patients with primary open-angle glaucoma with a mean follow-up of six years in this longitudinal, retrospective observational study.

The investigators performed macular GCIPL imaging and visual field (VF) examination at six-month intervals for approximately three years. They evaluated progressive GCIPL thinning through Cirrus HD-OCT (Carl Zeiss Meditec) imaging and the GCIPL thickness change maps. They also compared the baseline GCIPL thickness deviation maps and the final GCIPL thickness change maps. VF progression was determined by Early Manifest Glaucoma Trial criteria and linear regression of the VF index.

The researchers found 72 eyes of 62 participants showed progressive GCIPL thinning in the thickness change map, and progressive thinning was detected most frequently at 2.08mm from the fovea and extended in an arcuate shape in the inferotemporal region. VF progression was accompanied by progressive GCIPL thinning in 56.9% of the eyes tested.

“Progression of GCIPL thinning occurred before apparent progression on standard automated perimetry in most glaucomatous eyes,” the researchers said. “Understanding specific patterns and sequences of macular damage may provide important insights in the monitoring of glaucomatous progression.”