The following is the summary of “Association of Optic Nerve Head and Macular Optical Coherence Tomography Measures With Glaucoma-Related Disability,” published in the May 2023 issue of Glaucoma by Bonham, et al.
Optical coherence tomography (OCT) may provide more patient-relevant disability information beyond what is collected by routine VF testing since it estimates retinal nerve fiber layer (RNFL) thickness associated with glaucoma-related impairment independently of the visual field (VF) loss. To determine if there is an independent relationship between VF damage and two OCT metrics (peripapillary RNFL thickness and macular ganglion cell/inner plexiform layer (GCIPL) thickness) that are related to the quality of life (QoL) and disability.
This cross-sectional research measured the RNFL and GCIPL thickness using OCT scans of 156 patients with glaucoma or suspected glaucoma who underwent VF testing. The Glaucoma Quality-of-Life 15 was used to evaluate QoL, and additional impairment indicators such as fear of falling, reading speed, and daily steps were measured. The correlations between disability indicators and the thickness of the less-impaired eye’s RNFL and GCIPL were examined using multivariate regression models that controlled for relevant factors and considered the presence or absence of VF damage.
Poorer quality of life (95% CI=0.4-1.4; P<0.001) and slower reading speed (CI=-0.06 to -0.02; P<0.001) are linked to more significant VF damage. When controlling for VF damage, the correlation between QoL scores and RNFL and GCIPL thicknesses disappeared. However, post hoc analyses in individuals with improved eye thicknesses between 55 and 75 µm showed relationships between thinner RNFL and poorer quality of life (CI=-2.2 to -0.1; P=0.04) and increased fear of falling (CI=-6.1 to -0.4; P=0.03), even after taking VF damage into account. For GCIPL thickness, no such correlations were found.
Multiple indices of impairment related to OCT RNFL thickness, but not GCIPL thickness, are correlated with VF injury severity.
