Evaluation of Macular Ganglion Cell Layer Thickness vs Peripapillary Retinal Nerve Fiber Layer Thickness for Glaucoma Detection Using Spectral-domain Optical Coherence Tomography in a Tertiary Philippine Hospital

AIM AND OBJECTIVE: To appraise the validity of measuring macular ganglion cell layer (mGCL) thickness as an indicator of early glaucoma, as compared to measurement of peripapillary retinal nerve fiber layer (pRNFL) thickness. MATERIALS AND METHODS: This was a single-center, single-observer, cross-sectional, retrospective study. Records included Filipino adult patients seen from January 2017 onward. Patients underwent testing of both automated visual field (VF) testing with either Humphrey Visual Field Analyzer (24-2 SITA program) or Octopus 311 (G1 program), and standard Spectral-Domain Optical Coherence Tomography (Cirrus HD-OCT 5000). Modified Hodapp–Anderson–Parrish criteria were used to classify subjects as either healthy, suspect, or early glaucomatous eyes. Thickness changes were directly observed through optical coherence tomography. Area under receiver operating curve (AUC) analysis was used to determine ability of mGCL and pRNFL to discriminate between healthy and early glaucomatous states. RESULTS: A total of 96 eyes were included. Progressive thinning for all parameters was noted for both pRNFL and mGCL from healthy to suspect to early glaucomatous eyes. The highest AUC of 0.744 was seen in average pRNFL of healthy vs early glaucomatous eyes. However, AUC values for both pRNFL and mGCL were all above 0.500. CONCLUSION: Measurements of mGCL thickness in Filipino patients exhibit comparable performance to pRNFL measurements in detecting early anatomic glaucomatous change. It is a tool that can be utilized for early glaucoma detection in addition to current standard diagnostic tests. CLINICAL SIGNIFICANCE: This study, the first to be performed on Filipino patients, validates using mGCL thickness as a good parameter in discriminating between normal and early glaucoma patients for this particular population and Ethnic group. HOW TO CITE THIS ARTICLE: Aquino LG, Aquino NM. Evaluation of Macular Ganglion Cell Layer Thickness vs Peripapillary Retinal Nerve Fiber Layer Thickness for Glaucoma Detection Using Spectral-domain Optical Coherence Tomography in a Tertiary Philippine Hospital. J Curr Glaucoma Pract 2020;14(2):50–56.