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).