Evaluation of the Macular Ganglion Cell-Inner Plexiform Layer and the Circumpapillary Retinal Nerve Fiber Layer in Early to Advanced Stages of Glaucoma: Correlation with Central Visual Function and Visual Field Indexes

was found between the RTvue and the Cirrus OCT device in various parameters in different severity levels ( p = 0.42). Even in discriminating the advanced stage of glaucoma from the rest, RNFL performed better than the macular parameters. Elbendary and Mohamed Helal [2] studied RNFL thickness parameters between different stages of glaucoma in 3D OCT 2000 (Topcon, Tokyo, Japan) and concluded that average, superior, and inferior RNFL thicknesses were the best parameters to discriminate normal from early glaucoma (AUC 0.91–86), early from moderate (AUC 0.77–0.70), and moderate from advanced (AUC 0.85– 0.83). There is a paucity of literature on the discriminating ability of OCT devices in different stages of glaucoma. Most of the studies conducted previously discriminate normal from early glaucoma subjects using OCT, with few studies concluding that RNFL parameters perform similar to macular parameters, while others suggest that average RNFL measurement is superior to global GCIPL measurement for the detection of early glaucoma [3, 4] . We would like to add that it would be extremely advantageous to calculate and compare the AUC in your study for different parameters in different severity groups of glaucoma as this test can be performed even on nonparametric distribution of data [5] . We acknowledge your work which has enlightened our minds and directed our future research studies on OCT and glaucoma.