Detection of glaucomatous progression by spectral-domain optical coherence tomography

Purpose: To compare the rate of change of circumpapillary retinal nerve fiber layer (cRNFL) thickness, macular volume and thickness, and optic nerve head (ONH) parameters assessed using spectral-domain optical coherence tomography (SD-OCT) between eyes with progressing and nonprogressing glaucoma.

Design: Longitudinal, observational study.

Participants: Two hundred seventy-nine eyes from 162 glaucoma patients followed for an average of 2.2 years.

Methods: Eyes were classified as progressors and nonprogressors according to assessment of optic disc and RNFL photographs and visual field progression analysis. Linear mixed effects models were used to evaluate the overall rate of change of cRNFL thickness, macular volume and thickness, and ONH parameters after adjustment for age, spherical equivalent, signal strength, and baseline SD-OCT measurements.

Main outcome measures: The rate of change of cRNFL thickness, macular volume, and thickness and ONH parameters.

Results: Sixty-three eyes (22.6%) from 52 subjects were identified as progressors. Average, inferior quadrant, and 6- and 7-o'clock sector cRNFL thickness decreased faster in progressors than in nonprogressors (-1.26 vs -0.94, -2.47 vs -1.75, -3.60 vs -2.52, and -2.77 vs -1.51 μm/year, respectively; all P<0.05). The ONH rim area decreased faster, and average and vertical cup-to-disc ratio increased faster in progressors than in nonprogressors (-0.016 vs -0.006 mm(2)/year, and 0.004 vs 0.002 and 0.006 vs 0.004 per year, respectively; all P<0.05). Macular cube volume and the thickness of temporal outer and inferior inner macular sectors decreased faster in progressors than in nonprogressors (-0.068 vs -0.048 mm(3)/year, and -2.27 vs -1.67 and -2.51 vs -1.73 μm/year, respectively; all P<0.05).

Conclusions: Serial measurement of parameters in all 3 areas (cRNFL, macula, and ONH) by SD-OCT may permit identification of progression in glaucomatous eyes.

Financial disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article.