Glaucomatous visual field loss rates correlate better with rates of GCL thinning than with rates of RNFL thinning.  Photo: James Fanelli, OD. Click image to enlarge.

In a presentation Monday morning at ARVO 2023 in New Orleans, researchers assessed the correlation between 24-2 visual field (VF) rates of progression and retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) rates of change, and found, somewhat surprisingly, that glaucomatous visual field loss rates correlate better with rates of GCL thinning than with rates of RNFL thinning, which is routinely used in most OCT analyses of glaucoma.

A database of 78,298 VF and 49,559 macula and disc OCT scans from 11,234 eyes (6,495 patients) was generated of consecutive patients seen in a university-based glaucoma division between February 2020 and May 2022. All eyes with same-day reliable (false positive <15%) 24-2 VFs and OCT exams from at least five visits and a minimum of five years follow-up were included. The global, superior and inferior 24-2, RNFL and GCL scans were obtained from the Forum Structure-Function Glaucoma Progression Analysis.

A total of 499 eyes from 292 patients met inclusion criteria. Baseline global 24-2 mean deviation, RNFL and GCL were -3.9±4.9dB, 77.5±12.8µm and 69.4±11.1µm, respectively. All correlations between rates of progression of 24-2, RNFL and GCL were statistically significant. The 24-2 had a stronger correlation with the GCL than with the RNFL. Similarly, the superior 24-2 better correlated with the inferior GCL than with the RNFL of the inferior quadrant rates of change, and the inferior 24-2 better correlated with the superior GCL than with the RNFL of the superior quadrant.

Due to the results of this study, the authors suggest GCL thinning may be a better marker of functional loss in glaucoma than the RNFL.

Original abstract content © Association for Research in Vision and Ophthalmology 2023.