Retinal inter vascular arcade area and susceptibility to diabetic maculopathy

Abstract

Purpose : There is variation in the extent of the area delineated by the second-generation superior and inferior temporal retinal vascular arcades. It is also not known if there is an association between the size of this area and a susceptibility to diabetic maculopathy. It is possible that a larger retinal inter vascular arcade area (RIVAA) may be more prone to develop diabetic maculopathy due to extended network geometry and effects on vascular hemodynamics.
This hypothesis was investigated in this retrospective, observational, proof of concept study.

Methods : The RIVAA measurements were made on the infra-red reflectance image obtained with Heidelberg spectralis OCT with the aid of image analysis software.
The RIVAA was obtained by drawing a best fit circle within the arcade with the limits of the circle specified by the temporal edge of the optic disc and upper and lower second generation retinal arteries. Two independent measurements were taken and mean used. In a subset of patients and controls vascular density and flow indices will be determined with OCT angiography.
Thirty-three diabetic patients with exudative diabetic maculopathy (EDM) and 28 non-diabetic controls (NDC) were identified and images analyzed and RIVAA calculated. The results were analyzed via the two-tailed t-test using GraphPad Prism software.

Results : Data was collected form 48 eyes of 31 patients with EDM and 45 eyes of 28 NDC patients. The average age of the EDM group was 62 (age range 31-90) and that of NDC group was 78 (63-94). Of the EDM patients selected 75% were males and 25% females; and of the NDC patients, 39% were males and 61% were females.
The patients with EDM had a mean RIVAA of 77.05 mm² (SD 21.68 and SEM 3.13) and the NDC patients had a mean RIVAA of 63.75 mm² (SD 23.12 and SEM 3.45). There was a significant difference in RIVAA between EDM patients and NDC patients (p=0.005).

Conclusions : There was a significant difference in the RIVAA between the EDM group and the NDC group, which could imply an association.
This association may require more robust evaluation as it could allow identification of individuals with more susceptibility to diabetic maculopathy, particularly in screening programs.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.