Retinal nerve fiber layer (RNFL) thickness assessment, a staple of glaucoma work-up for years, may remain a better parameter than newer metrics like Bruch’s membrane opening minimum rim width (BMO-MRW) when identifying preperimetric glaucomatous damage, a recent study suggests.

This observational cohort study evaluated 113 eyes of 81 glaucoma suspects. Using SD-OCT, a team measured RNFL thickness and BMO-MRW and classified eyes as glaucomatous or nonglaucomatous based on evidence of progressive change in the appearance of the optic nerve or retinal nerve fiber layer.

The investigators found that 52 eyes (46%) showed progressive optic nerve changes and were classified as preperimetric glaucoma, while the remainder did not and were classified as normal. With the sensitivity pre-set at 95% for both measures, and specificity was 60% for RNFL thickness and 40% for BMO-MRW. Each RNFL thickness measure (global, superotemporal, inferotemporal, superonasal) all had notable areas under the curve of at least 0.80, while the only BMO-MRW parameter that reached 0.80 or more was inferotemporal.

The authors conclude that this may make RNFL thickness measures more useful than BMO-MRW measures when evaluating glaucoma suspects.