Degree of loss in the tissue thickness, microvascular density, specific perimetry and standard perimetry in early glaucoma.

Objective: To identify the degree of loss of the circumpapillary retinal nerve fibre layer (cpRNFL), the layer from the macular RNFL to the inner plexiform layer (mGCL++), circumpapillary (cpVD) and macular vascular density (mVD), Pulsar perimetry and standard perimetry in early glaucoma.

Methods: In this cross-sectional study, one eye from each of 96 healthy controls and 90 eyes with open-angle glaucoma were measured with cpRNFL, mGCL++, cpVD, mVD, Pulsar perimetry with Octopus P32 test (Pulsar) and standard perimetry with Humphrey field analyser 24-2 test (HFA). For direct comparison, all parameters were converted to relative change values adjusted in both their dynamic range and age-corrected normal value.

Results: The degree of loss in mGCL++ (-24.7%) and cpRNFL (-25.8%) was greater than that in mVD (-17.3%), cpVD (-14.9%), Pulsar (-10.1%) and HFA (-5.9%) (each p<0.01); the degree of loss in mVD and cpVD was greater than that in Pulsar and HFA (each p<0.01); and the degree of loss in Pulsar was greater than that in HFA (p<0.01). The discrimination ability between glaucomatous and healthy eyes (area under the curve) was higher for mGCL++ (0.90) and cpRNFL (0.93) than for mVD (0.78), cpVD (0.78), Pulsar (0.78) and HFA (0.79).

Conclusion: The degree of loss of cpRNFL and mGCL++ thickness preceded by approximately 7%-10% and 15%-20% compared with the micro-VD and visual fields in early glaucoma, respectively.

Trial Registration Number: UMIN Clinical Trials Registry (http://www.umin.ac.jp/; R000046076 UMIN000040372).