Association of baseline optical coherence tomography angiography with the development of glaucomatous visual field defects in preperimetric glaucoma eyes

AimsTo evaluate whether baseline vessel density (VD) parameters derived from optical coherence tomography angiography (OCT-A) is associated with the development of glaucomatous visual field (VF) defects in preperimetric glaucoma (PPG) patients.MethodsOne eye from each of 200 consecutive PPG patients with a normal standard automated perimetry and OCT-A at baseline was retrospectively analysed. OCT-A was used to measure the circumpapillary VD (cpVD) and the parafoveal and perifoveal VD. The retinal nerve fibre layer (RNFL) and macular ganglion cell-inner plexiform layer thicknesses were measured as reference standards. Two patient groups were stratified based on the development of repeatable glaucomatous VF loss. A Cox proportional hazards model was constructed to determine the predictive ability of OCT-A parameters for VF defects. The correlation between these baseline OCT-A parameters and the rate of global VF sensitivity loss (dB/year) was calculated using linear regression analysis.ResultsDuring a 3.1-year average follow-up period, 18 eyes (9.0%) developed glaucomatous VF defects. At baseline, the lower inferior temporal cpVD (HR (95% CI)=0.934 (0.883 to 0.988); p=0.017) and thinner inferior RNFL (HR (95% CI)=0.895 (0.839 to 0.956); p=0.001) were predictive of glaucomatous VF loss. A lower inferior temporal cpVD and thinner RNFL at baseline were associated with faster rate of global VF sensitivity loss (β=0.015; p=0.001).ConclusionIn PPG eyes, a lower baseline inferior temporal cpVD is significantly associated with glaucomatous VF defect development and a faster rate of global VF loss.