Evaluation of peripapillary atrophy in early open-angle glaucoma using autofluorescence combined with optical coherence tomography

Purpose To quantitatively analyze α -zone and β -zone peripapillary atrophy (PPA) in patients having early primary open-angle glaucoma (POAG) using fundus autofluorescence (FAF) in conjunction with spectral domain optical coherence tomography, colored photography and perimetry. Design This is an observational cross-sectional case–control study. Methods This study included 100 eyes (54 patients) of early to moderate POAG and 100 normal eyes (50 subjects). Ophthalmological examination, OCT for the optic nerve and FAF were performed. The extent of α-PPA and β-PPA was measured. Results The extent of α -PPA and β -PPA as measured by FAF had higher values in POAG group as compared to control group ( p values 0.003 and ≤ 0.001 for the total nasal and temporal extents, respectively). However, the nasal alpha and temporal beta zones showed more values in POAG patients as compared to normal controls ( p values 0.002 and 0.024). The difference between the total extents of either zones alone was not significant. B-scan OCT was able to positively detect both zones. Detecting the alpha zone was significantly higher in the control group, while beta zone detection was significantly higher in the POAG group ( p values ≤ 0.001). Conclusion The sensitivity of alpha zone detection was equal using colored photographs, FAF and B-scan OCT. FAF showed superior results in estimating the beta zone extent although OCT was more accurate in the anatomical delineation of Bruch’s membrane and RPE termination. The nasal alpha and temporal beta zone extents could be taken as early indices for evaluating early glaucomatous optic neuropathy.