Abstract
Purpose :
To assess the peripapillary and macular vessel density (VD) with Optical Coherence
Tomography Angiography (OCT-A) in a cohort of glaucomatous patients with single-hemifield defect and to evaluate associations with the severity of visual field (VF) damage.
Methods :
Observational, cross-sectional study. Glaucomatous patients with single-hemifield VF loss and healthy subjects underwent a comprehensive ocular examination including VF and Retinal Nerve Fiber Layer (RNFL), Ganglion Cell Complex (GCC), peripapillary (ppVD) and macular (mVD) analysis using the RTVue-XR Avanti. Paired and unpaired t tests were performed to evaluate differences between the perimetrically affected and intact hemiretinae and healthy subjects.
Results :
48 glaucomatous (18 mild, 16 moderate, 14 severe) and 16 healthy eyes were included. In glaucomatous eyes, mean ppVD, mVD, RNFL, GCC and VF mean sensitivity (MS) were lower than in healthy eyes (p<0.001). As compared to the intact, the affected hemiratinae presented significant differences in terms of OCT-A ppVD (48.53±8.39% vs 55.9±6.21%) and mVD (45.15±5.46% vs 47.58±5.59%), RNFL (67.13±11.09% vs 81.87±17.21%) and GCC thicknesses (68.01±10.38 vs 84.57±12.34), p<0.001 for all comparisons. Compared with healthy eyes, reduced ppVD, RNFL and GCC thicknesses were observed in the intact hemiretinae of glaucomatous eyes (p<0.001for all comparisons). The difference in ppVD was not significant for mild VF damage. Within the corresponding hemiretinae, VF MS was significantly correlated with ppVD (r=0.70), GCC (r=0.58) and RNFL (r=0.54).
Conclusions :
In patients with moderate to severe VF defect, OCT-A seems able to discriminate the intact from the pathological hemifield. Moreover, the highest correlation with VF damage in the corresponding hemiretinae was found with ppVD.
As well as RNFL and GCC, ppVD was different between healthy subject and the intact hemiretinae of glaucomatous patients, being a possible precursor of VF damage.
The use of OCT-A in the analysis of glaucoma could provide further evidence on the possible vascular pathogenesis of glaucomatous defect.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.