Macular thickness changes in glaucomatous optic neuropathy detected using optical coherence tomography

Abstract

Objective: To correlate macular thickness and retinal nerve fiber layer (RNFL) thickness in normal and glaucomatous eyes using optical coherence tomography.

Methods: Complete examination, automated achromatic perimetry, and optical coherence tomography of the peripapillary RNFL and macula were performed. Exclusion criteria were visual acuity of less than 20/40, diseases other than glaucoma, and unreliable automated achromatic perimetry. Macular thickness measurements were generated using 6 radial optical coherence tomographic scans (5.9 mm) centered on the fovea, and mean and quadrantic macular thickness values were calculated.

Results: Fifty-nine eyes of 59 patients (29 normal and 30 glaucomatous) were enrolled (mean +/- SD age, 56.7 +/- 20.3 years; range, 20-91 years). All eyes with glaucoma had associated visual field loss (mean +/- SD mean defect, -8.4 +/- 5.8 dB). Mean macular thickness was significantly associated with visual field mean defect (R2 = 0.47; P<.001), pattern standard deviation (R2 = 0.32; P<.001), and mean RNFL thickness (R2 = 0.38; P<.001). In glaucomatous eyes with visual field loss localized to 1 hemifield (n = 11), mean +/- SD macular thickness in the quadrant associated with the field defect (277 +/- 28 micro m) was significantly less (P =.005) than in the unaffected quadrant (286 +/- 27 micro m). Mean RNFL thickness in the affected quadrant (89 +/- 53 micro m) was significantly thinner (P =.009) than in the unaffected quadrant (121 +/- 39 micro m).

Main outcome measures: Mean total and quadrantic macular and RNFL thickness measurements.

Conclusions: Macular thickness changes are well correlated with changes in visual function and RNFL structure in glaucoma and may be a surrogate indicator of retinal ganglion cell loss.