Comparison between deviation map of circumpapillary retinal nerve fiber layer and macular ganglion cell-inner plexiform layer measurements using high-definition optical coherence tomography in the detection of early glaucoma

Abstract

Purpose: To compare the sensitivity and specificity of the deviation map of circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell-inner plexiform layer (GCIPL) measurements using high-definition optical coherence tomography (Cirrus HD-OCT) for discriminating between healthy control and early glaucoma patients.

Methods: We prospectively enrolled 171 early glaucoma patients confirmed by two reliable visual field tests (mean deviation > -6 dB) and 114 healthy control subjects. Abnormal cpRNFL and macular GCIPL deviation maps corresponding to visual field defects represented as red (P < 1%) or yellow (P < 5%) superpixels were used to calculate the sensitivity and specificity (%). We used three different criteria for deviation map abnormality: a cluster of three or more contiguous yellow in the same hemifield on the deviation map, including one or more red ones (criteria 1): a cluster of five or more yellow superpixels, including three or more red (criteria 2): a cluster of ten or more yellow superpixels, including five or more red (criteria 3). Sensitivity differences were determined by McNemar test.

Results: The early glaucoma detection sensitivities of the cpRNFL deviation map were 92.7% (95% confidence interval (CI): 88.5 - 96.9%) for criteria 1, 90.1% (95% CI: 85.7 - 94.5%) for criteria 2, and 88.0% (95% CI: 83.1 - 92.9%) for criteria 3. The specificities were 54.4% (95% CI: 45.1 - 63.7 %), 64.9% (95% CI: 56.0 - 73.8%), and 76.3% (95% CI: 68.4 - 84.2%), respectively. The sensitivities of the macular GCIPL deviation map were 90.4% (95% CI: 86.1 - 94.7%) for criteria 1, 87.4% (95% CI: 82.5 - 92.3%) for criteria 2, and 85.1% (95% CI: 79.8 - 90.4%) for criteria 3. The specificities were 59.6% (95% CI: 50.5 - 68.7%), 69.3% (95% CI: 60.7 - 77.9%), and 76.3% (95% CI: 68.4 - 84.2%), respectively. The sensitivity difference between the cpRNFL and macular GCIPL deviation maps was not statistically significant for any of the three abnormality criteria (P > 0.05).

Conclusions: The deviation map of macular GCIPL measurement by Cirrus HD-OCT showed similar early glaucoma detection sensitivities to that of the cpRNFL deviation map. On this basis, the macular GCIPL deviation map can be considered to be a complementary glaucoma diagnostic test.

Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 531 ganglion cells