Analysis of macular volume in normal and glaucomatous eyes using optical coherence tomography

Purpose To evaluate macular volume in normal and glaucomatous eyes using optical coherence tomography (OCT). Design Case control study. Methods The authors assessed 272 eyes of 164 subjects as part of an institutional study at New England Eye Center in Boston, Massachusetts; 202 eyes were in the study group and 70 eyes in the control group. Eyes were categorized as normal (70 eyes of 43 subjects), glaucoma suspect (70 eyes of 44 subjects), early glaucoma (70 eyes of 47 subjects), or advanced glaucoma (62 eyes of 43 subjects). Subjects underwent analysis with the commercially available OCT1 unit. Optical coherence tomography macular neurosensory retinal thickness maps were used to calculate macular volume for comparison to Humphrey visual field testing, intraocular pressure measurement, and stereo biomicroscopy of the optic nerve head and nerve fiber layer. Results Using repeated measures regression, macular volume in normal (2.37 ± 0.11 mm 3 ) glaucoma suspect (2.33 ± 0.16 mm 3 ), and early glaucoma eyes (2.27 ± 0.13 mm 3 ) was significantly greater than in eyes with advanced glaucoma (2.12 ± 0.23 mm 3 , P = .0001, P = .0001, and P = .0008, respectively). Macular volume in normal eyes was significantly greater than in early glaucoma eyes ( P = .01). Conclusions Optical coherence tomography retinal macular volume correlates with known structural defects of glaucoma, providing a potential objective and quantitative parameter for evaluation. Our data show a significant difference in macular volume between normal, glaucoma suspect, and early glaucoma eyes, compared with advanced glaucomatous eyes as well as between normal and early glaucomatous eyes. This correlates with a trend of decreasing macular volume in eyes with more advanced disease.