Diagnostic accuracy of posterior pole asymmetry analysis parameters of spectralis optical coherence tomography in detecting early unilateral glaucoma

Abstract

Purpose:To report the diagnostic ability of posterior pole asymmetry analysis (PPAA) parameters of spectralis optical coherence tomography (OCT) in detecting early unilateral glaucoma.Methods:A prospective, cross-sectional study which included 80 eyes of 80 normal subjects and 76 eyes of 76 patients with unilateral early primary open-angle glaucoma by Hodapp-Anderson-Parrish classification. All subjects were of age more than 18 years, best-corrected visual acuity 20/40 or better, and a refractive error within ± 5 diopter (D) sphere and ± 3 D cylinder. Control subjects had a normal ocular examination, intraocular pressure (IOP) <22 mmHg, no past history of high IOP, no family history of glaucoma, normal optic disc morphology, and visual field in both eyes. One eye of the control subject was randomly included. All eyes underwent OCT for retinal nerve fiber layer (RNFL) analysis and PPAA. The number of continuous black squares was noted in the asymmetry analysis (right-left + hemisphere asymmetry). The area under curve (AUC) was calculated for all OCT parameters.Results:The best value for AUC for RNFL analysis was 0.858 for the inferotemporal quadrant thickness. This was similar to the best value for AUC for PPAA which was 0.833 for the inferior macular thickness parameter (P = 0.5). The AUC for the right-left and the hemisphere asymmetry part of PPAA was 0.427 and 0.499, respectively.Conclusion:The macular thickness PPAA parameters were equally good as the RNFL parameters. However, the asymmetry analysis parameters performed poorly and need further refinement before its use in early unilateral glaucoma diagnosis.

Clinical Utility of Optical Coherence Tomography in Glaucoma

“… 135 Posterior pole asymmetry analysis, although not presently having a built-in normative database, is highly reproducible and matches circumpapillary RNFL measurements in terms of diagnostic accuracy of early glaucoma. 136 – , 138 Spectral-domain OCT may also be superior to SS-OCT in detecting GCIPL thinning in the outer temporal zone, 119 where the glaucomatous damage commonly occurs. 100 However, SD-OCT and SS-OCT have similar glaucoma diagnosis abilities based on macular inner layer thickness analysis.…”

Regional Relationship between Macular Retinal Thickness and Corresponding Central Visual Field Sensitivity in Glaucoma Patients

“…By using the device employed in the present study (i.e., the Spectralis OCT), Rolle et al divided the posterior pole into 4 quadrants and identified the highest discriminating power in the inferior nasal quadrant (AUROC = 0.82) [10]. Dave et al also found the highest AUROC for the average inferior macular thickness (AUROC = 0.833) [19]. However, in these 2 studies, the 24-2 VF was used for central field sensitivity.…”

Diagnostic Capability of Three-Dimensional Macular Parameters for Glaucoma Using Optical Coherence Tomography Volume Scans

“…However, several studies comparing the diagnostic ability of the macular parameters to those of the traditional RNFL thickness with the different platforms showed contrasting results. 24 – 38 Specifically, studies using the Cirrus HD-OCT 26 – 30 and RTVue 31 – 34 instruments, comparing healthy subjects with patients with different stages of glaucoma, showed equivalent glaucoma diagnostic abilities of macular parameters (GCIPL or GCC, respectively) compared to peripapillary RNFL thickness (i.e., AUROC of the average GCIPL and GCC ranged from 0.735–0.964, and of average RNFL thickness from 0.735–0.972). 26 – 34 In other studies using RTVue OCT, average RNFL thickness performed better than the GCC in patients with preperimetric 35 and perimetric 36 glaucoma (i.e., AUROC of the average RNFL thickness ranged from 0.89035 to 0.91936 vs. 0.79035 to 0.86136 for GCC).…”

“… 24 , 25 For all of these 3 commonly used SD-OCT platforms, a literature review generally suggests that the current commercially available SD-OCT macular software has the same or worse diagnostic potential as the traditional RNFL thickness parameter. 24 – 38 …”

“…Because a review of the currently available macular software for glaucoma patients suggests that macular analysis is no better than the most commonly used RNFL thickness parameter, 24 – 38 this study had two specific aims. The first aim was to develop customized glaucoma software for macular analysis in the clinic to see if a macular parameter could be developed that is better than the traditional RNFL thickness parameter.…”