Progression detection capability of macular thickness in advanced glaucomatous eyes

To evaluate the progression rate of macular and circumpapillary retinal nerve fiber layer (RNFL) thickness in advanced glaucomatous eyes using spectral domain optical coherence tomography (Cirrus HD-OCT, Carl Zeiss Meditec, Dublin, CA).

Longitudinal, observational study.

A total of 98 eyes of 98 patients with advanced glaucoma (visual field [VF] mean deviation [MD] <-10 dB) with a mean follow-up time of 2.2 years.

Three glaucoma experts independently reviewed optic disc and RNFL photographs and classified patients into 3 groups: progressed, stable, and undetermined (criterion 1). Patients in the undetermined group could not be evaluated because of advanced optic disc cupping. The eyes were also classified into 2 groups, progressed and stable, by serial VF data (criterion 2).

Progression rates as determined by linear regression analysis against patient age using serial macular and RNFL thickness parameters were compared among different groups.

By criterion 1, 25 eyes (25.5%) were classified as stable, 13 eyes (13.3%) were classified as progressed, and 60 eyes (61.2%) were classified as undetermined. By criterion 2, 86 eyes (87.8%) were classified as stable, and 12 eyes (12.2%) were classified as progressed. By criterion 1, the mean progression rate of average macular thickness was significantly higher in the progressed group than in the stable and undetermined groups (-4.74±4.40, -0.53±1.44, and -2.72±4.75 μm/year, respectively; P = 0.01). The undetermined group showed a higher progression rate than the stable group (P = 0.045). However, the progression rate of average RNFL thickness did not differ significantly among the 3 groups (-1.19±2.62, -0.33±1.29, and -1.21±2.75 μm/year, respectively; P = 0.34). By criterion 2, the mean progression rate of average RNFL thickness did not differ significantly between the stable and progressed groups (-0.90±2.42 and -2.08±2.85 μm/year; P = 0.459). However, the progression rate as revealed by average macular thickness was significantly different between the 2 groups (-2.22±4.33 and -5.12±2.40 μm/year, respectively; P = 0.039).

Exploration of changes over time in macular thickness may improve detection of progression in patients with advanced glaucoma.