Hannah Kersten, Hilary Goh, Lisa Gossage, Helen Danesh-Meyer

Purpose: Systemic vascular dysfunction has been well-established in primary open angle glaucoma (POAG). The aim of this study was to identify nailfold capillary abnormalities in POAG, and their association with glaucomatous visual field loss.
Methods: This single site, case-control study included 83 POAG patients with visual field loss on at least two consecutive tests, and 40 healthy con- trols with no known ocular pathology. The DinoLite Capillary Scope was used to acquire images from the digits of the non-dominant hand. Four non-overlapping images for each participant were evaluated by two masked independent graders. Images were evaluated for capillary density, avascu- lar zones (>100 μm), capillary crossings, dilated cap- illary loops (>50 μm), capillary distribution and haemorrhages.
Results: Inter-rater agreement for capillary variables was high. After controlling for demographic factors, hypertension, Raynaud’s and cholesterol, lower mean capillary density (OR = 0.6; 95% CI, 0.4 – 0.8), a higher number of avascular zones (OR = 1.3; 95% CI, 1.1-1.6), and higher capillary distribution scores (OR = 4.6; 95% CI, 2.2-10.8) were signifi- cantly associated with POAG. Among POAG cases only, after controlling for age, avascular zones (b =
−1.9; 95% CI, −3.7 to −0.06), haemorrhages (b =
−11.0; 95% CI, −17.9 to −4.2) and capillary distri-
bution scores (b = −8.2; 95% CI, −14.2 to −2.2) were all significantly negatively associated with visual field index.
Conclusion: Patients with POAG had significant derangement of capillary structure, in particular, lower capillary density, more avascular zones and more irregular capillary distribution. This study pro- vides further evidence to support non-ocular vascu- lar dysfunction in POAG.