To evaluate the glaucoma discriminating ability of macular inner layers measured by SD-OCT (Cirrus HD-OCT, Carl Zeiss Meditec (CZM) Dublin, CA, USA).Methods
Our study concerns 252 primary open angle glaucoma (POAG) eyes (early, moderate and advanced glaucoma) and 337 normal eyes which underwent a visual field testing (Humphrey Field Analyser, SITA-Standard 24-2, CZM), and Cirrus HD-OCT imaging (macular and optic disc cube 200x200). OCT macular scans were segmented into macular nerve fibre layer (mNFL), ganglion cell layer with inner plexiform layer (GCIPL) and ganglion cell complex (GCC=GCIPL+mNFL). Area under the receiver operator characteristic curve (AUC) for macular parameters and mean circumpapillary retinal nerve fibre layer (cpRNFL) were used.Results
There is a statistically significant difference between glaucomatous and control eyes for all parameters (p <0.05). For early POAG group the best AUCs were respectively minimum GCIPL (0.747), average GCIPL (0.716), GCC (0.71), cpRNFL (0.704), minimum mNFL (0.673) and average mNFL (0.655). For moderate POAG group the best AUCs were respectively minimum GCIPL (0.864), GCC (0.858), cpRNFL (0.853), average GCIPL (0.838), average mNFL (0.82) and minimum mNFL (0.815). For advanced POAG group the best AUCs were respectively minimum GCIPL (0.938), GCC (0.928), minimum mNFL (0.92), average GCIPL (0.908), cpRNFL (0.854) and average mNFL (0.854).Conclusion
Minimum GCIPL would have the highest sensitivity to diagnosis glaucoma. It may represent an interesting complementary parameter to cpRNFL thickness.