Abstract
Purpose: :
To study the association between functional measure (light sensitivity) and structural measures of peripapillary nerve fiber layer (pNFL) and macular ganglion cell complex (mGCC) thickness using spectral-domain optical coherence tomography (OCT) in early and advanced glaucoma.
Methods: :
Thirty six eyes of 22 subjects diagnosed with glaucoma were included in the study. Based on Humphrey visual field mean deviations (MD), 15 and 21 eyes were classified as early (MD better than -6 dB) or advanced stage (MD worse than -6 dB) glaucoma, respectively. Exclusion criteria were significant media opacity, macular pathology or unreliable visual field data. The RTVue OCT (Optovue, Inc, Fremont, CA) commercial software was used to measure mGCC (NFL+ ganglion cell layer + inner plexiform layer) and pNFL thickness. Humphrey visual field testing provided functional measure of light sensitivity. Means for functional and structural measures were calculated in each hemifield. Pearson’s correlations between structure-function and structure-structure measures were computed for early and advanced stages of glaucoma.
Results: :
Structure-function correlations (Table 1) showed that pNFL thickness highly correlated with light sensitivity for both early and advanced glaucoma (p < 0.01). In contrast, mGCC thickness showed a significant correlation with light sensitivity in only early glaucoma (p < 0.01). Structure-structure (mGCC vs pNFL) correlations were highly significant in early glaucoma (p < 0.01), and less significant in advanced glaucoma (p = 0.04) (Table 2).
Conclusions: :
In our cohort of patients with advanced glaucoma, using the commercially available RTVue software, the pNFL thickness better correlated with function than mGCC thickness averaged over hemifields.
Keywords: imaging/image analysis: clinical