Does Ganglion Cell Complex Scan Predict Glaucoma Earlier Than Retinal Fiber Layer Thickness Map in Suspects and Glaucoma Patients Using Fourier Domain OCT?

Abstract

Purpose: : To compare the ganglion cell complex scan (GCC) with retinal fiber layer thickness map (RNFL) in suspects and glaucoma patients.

Methods: : 40 patients [20 glaucoma suspects (GS; normal SAP, C/D ratio > 0.5 or asymmetry > 0.2 and/or ocular hypertension), and 20 glaucoma patients (MD < -12 dB, glaucomatous optic neuropathy)] were prospectively enrolled. GCC and RNFL map protocols [Fourier Domain OCT,RT Vue, Optovue Inc.] were performed in both eyes of each patient in the same visit. Exclusion criteria SAP was performed with the Octopus 3.1.1 Dynamic 24-2 program. The statistical analysis was performed with the SPSS 10.1 (SPSS Inc. Chicago, IL, EUA). Results were expressed as mean ± standard deviation and a p value of 0.05 or less was considered significant.

Results: : There was a statistical significant difference in average RNFL thickness (p=0.004), Superior RNFL thickness (p=0.006), Inferior RNFL thickness (p=0.0005) and average GCC (p=0.03) between suspects and glaucoma patients. There was no difference in Optic Disc area (p=0.35) and vertical Cup/Disc ration (0.234) comparing both groups. 15 of 40 (38%) eyes had an abnormal GCC and 5 of 40 eyes (13%) had an abnormal RNFL thickness in the suspect glaucoma group. 39 of 40 eyes (98%) had an abnormal GCC and 36 of 40 eyes had an abnormal RNFL thickness in the glaucoma group.

Conclusions: : Although RNFL thickness has been used for diagnose of glaucoma, the GCC protocol is indicative of earlier structural glaucoma damage. The GCC printout is comparable to the visual field defect in most of glaucoma patients.

Keywords: ganglion cells • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • visual fields