Assessment of retinal fiber layer thickness (RNFLT) may be better suited for monitoring progression than visual field (VF) parameters for different baseline classifications in primary open-angle glaucoma, according to the results of a study published in the Journal of Glaucoma.
For the study, the investigators compared the detection of glaucoma progression by RNFLT, using optical coherence tomography (OCT), and VF, static automated perimetry (SAP), assessments for different baseline classifications of primary open-angle glaucoma.
Overall, 194 eyes from 194 patients with a minimum of 9 follow-up visits were examined and classified according to baseline clinical signs (ocular hypertension, n=39; glaucomatous optic neuropathy only, n=60; glaucomatous visual field loss only, n=39; and definite glaucoma, n=56). The investigators assessed glaucoma progression statistically, using global and sectorial mean deviations values generated for RNFLT (RNFLT-MD) and VF data (VF-MD). They then compared the proportion of eyes identified as progressing within each classification.
The investigators were able to identify glaucoma progression across the different classifications using both RNFLT and VF parameters, and the 2 methods performed similarly among eyes with glaucomatous optic neuropathy only and those with definite glaucoma. However, compared with global VF-MD, the rate of positive identification was significantly higher using global RNFLT-MD for eyes with ocular hypertension, by 33.3%, and for eyes with glaucomatous visual field loss only, by 30.8% (P <.01 for both).
The major limitations of the study were the lack of standardized treatment across eyes with the different baseline classifications and the approach used to generate age-corrected optical coherence tomography and static automated perimetry parameters, which is not available to clinicians; however, the authors note that the latter does not limit the clinical applicability of their findings because not applying the age correction would lead to even greater sensitivity of RNFLT.
“Both RNFLT and VF assessments can identify progression in patients with different baseline classification of [primary open-angle glaucoma]. RNFLT assessment, however, tended to identify more eyes as progressing compared with VF assessment in all baseline classifications,” researchers report. “Our results suggest that although both assessments are capable of detecting progression in patients with different baseline clinical signs, preference may be given to RNFLT assessment when prevailing circumstances permit for only a single test.”
Abu SL, Marín-Franch I, Racette L. Detecting progression in patients with different clinical presentations of primary open-angle glaucoma. J Glaucoma. 2021;30(9):769-775. doi:10.1097/IJG.0000000000001843