Abstract
Purpose :
To evaluate the anatomical versus functional change in diabetic retinopathy by studying the correlation of retinal vascular perfusion density and dark adaptation.
Methods :
Optical coherence tomography angiograms (OCTA) and dark adaptation (DA) were performed in diabetic patients and nondiabetes controls. Diabetic patients were classified into no diabetic retinopathy (no DR), non proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR). Dark adaptation was measured by AdaptDx dark adaptometer and the rod intercept time was recorded. Macular OCTA images were acquired using the RTVue XR Avanti with AngioVue. Superficial and deep layers of retinal vascular perfusion density were quantified.
Results :
Eighty six eyes from 57 type 2 diabetes patients (19 patients had no DR, 19 had NPDR and 19 had PDR with photocoagulation) and 10 eyes from 10 nondiabetes patients were enrolled. Decreased vascular density and prolonged dark adaptation time and were found as DR severity progresses with statistical significance (p < 0.01). Negative trend was found between vascular density and dark adaptation time. The negative trend in the deep vascular layer (Spearman’s rank correlation ρ = -0.50) was more substantial than the superficial (Spearman’s rank correlation ρ =-0.39). Trends of prolonged DA were found in associated with elevated HbA1C (ρ = 0.30) and decreasing visual acuity (ρ = 0.63).
Conclusions :
The vascular density of macula could be assessed by OCTA and the outer retina functional change could be measured by DA non-invasively. The severities of decreasing vascular density and prolonged DA are proportional to the DR progression. Decreased deep retinal vascular perfusion density and impaired dark adaptation time are strongly correlated and have a negative trend in DR severity.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.