OCT helps determine GCC thinning to better predict glaucoma progression. Photo: Brian Fisher, OD. Click image to enlarge.

Whether rapid ganglion cell complex (GCC) thinning during initial follow-up is associated with rates of central visual field loss over time is unclear,  but it is still important to understand as informed risk of glaucoma progression can help guide treatment intensity. Looking into this potential association, researchers recently found that initial rapid GCC thinning is associated with faster rates of central visual field decline.

The retrospective cohort study assessed 202 eyes of 139 patients older than 18 with glaucoma at a tertiary glaucoma care center who were followed for four and a half years. Initial rates of GCC thinning were obtained from global GCC thickness values of the first three OCT scans. Rates of central visual field loss were assessed through the change in central (10-2) visual field mean deviation during the five-year follow-up period by univariable and multivariable linear mixed-effects models. Eyes were categorized as slow (>-1μm/year) or fast (≤-1μm/year) progressors based on rates of GCC thinning.

The rate of GCC change was -0.56μm/year during a mean initial follow-up of 1.8 years. A total of 163 eyes (80.7%) were slow OCT progressors, and 39 (19.3%) were fast OCT progressors, with rates of GCC thinning of -0.3μm/year and -1.6μm/year, respectively. The rates of 10-2 visual field mean deviation worsening among slow and fast OCT progressors were -0.10dB/year and -0.34dB/year, respectively.

“These findings support use of longitudinal macular OCT scans assisting clinical decision-making for glaucoma and also may guide possible intensification of therapy in high-risk patients,” the study authors concluded in their paper.

Mahmoudinezhad G, Moghimi S, Nishida T, et al. Association between rate of ganglion cell complex thinning and rate of central visual field loss. JAMA Ophthalmol. November 23, 2022. [Epub ahead of print].