Despite the widespread use of OCT to derive objective measurements of the circumpapillary retinal nerve fiber layer (cpRNFL) and macula for assessing glaucoma detection and progression, significant challenges remain regarding the applicability and usefulness of these measurements because of inherent variances between individuals and suspected effects from variables including age, optic nerve head size, axial length, and other comorbidities.

In high myopia, because of enlarged optic nerves with tilted discs associated with peripapillary atrophy, glaucomatous changes of the optic nerve head are difficult to characterize with confidence, and a clinician often relies on other structural measures to distinguish early glaucoma from normal eyes.