Purpose: The aim of the study was to compare the diagnostic ability of macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (pRNFL) thickness in high-tension glaucoma (HTG) and low-tension glaucoma (LTG).
Patients and methods: Glaucoma was defined as glaucomatous optic neuropathy and reproducible visual field defects. Patients were classified as having LTG if untreated intraocular pressure was ≤21 mm Hg on 2 different occasions. Only eyes with early glaucoma (mean deviation <-6 dB) were included. All patients underwent spectral-domain optical coherence tomography (SDOCT) imaging.
Results: A total of 56 normal subjects, 64 HTG patients, and 35 LTG patients were enrolled. Overall, after adjusting for mean deviation and age, the average pRNFL thickness in eyes with LTG was 18.7 µm thinner than in eyes with HTG (17% difference, P<0.01). In the HTG group, no significant difference was found between areas under the receiver operating characteristic curve (AUCs) for average GCC and average pRNFL thicknesses (0.77 vs. 0.68, P=0.06). In the LTG group, average pRNFL thickness had a significantly larger AUC compared with average GCC thickness (0.95 vs. 0.81, P<0.001). Comparing AUCs between HTG and LTG groups, although the average GCC had similar AUCs in both groups (P=0.47), the average pRNFL thickness had a significantly larger AUC in the LTG group (P<0.001).
Conclusions: In eyes with early glaucoma, the pRNFL thickness scan seems to be a more accurate SDOCT protocol to identify those with LTG compared with the GCC thickness scan.