Abstract
Purpose :
The choroidal layer supplies blood to the outer layers of the retina and may play a key role in the pathophysiologic mechanism of diabetic macular edema (DME). Swept source-optical coherence tomography (SS-OCT) allows for faster scanning speed and its longer wavelength enables deeper penetration in the choroid and a better layer segmentation. The objective of the present study was to compare the macular choroidal thickness between patients with DME and age-matched healthy individuals.
Methods :
The Institutional Review Board approved the study protocol. From December 2015 to July 2016, 71 normal eyes and 48 eyes with DME were consecutively selected. Subfoveal (SF) choroidal thickness, and choroidal thickness at 500-µm intervals up to 2500 µm nasal and temporal from the fovea were measured using the SS-OCT Topcon Triton (Topcon Corporation, Tokyo, Japan). Choroidal thicknesses were compared between groups using Student’s t-test. Additionally, Pearson correlations were calculated between diabetes duration, glycosylated hemoglobin (HbA1c) levels, and choroidal thickness. For all analyses, p<0.05 was considered statistically significant.
Results :
The DME group comprised 33 moderate non-proliferative diabetic retinopathy (NPDR) eyes, 10 severe NPDR eyes and 5 proliferative diabetic retinopathy eyes. Mean age was 68.0±8.4 and 67.8±7.0 years (p=0.87), while SF choroidal thickness was 228.2±78.9 and 183.6±72.9 µm (p=0.002) in the control and DME groups, respectively. In the DME group, mean HbA1c was 7.6±1.1% and DM duration was 14.9±8.6 years. Differences were observed in all of the choroidal thicknesses between healthy and DME eyes, except at 2000 and 2500-µm nasal positions. No significant correlation was detected between choroidal thickness and DM duration in DME patients. HBA1c level neither correlated significantly with choroidal thickness.
Conclusions :
Macular choroidal thickness was reduced in DME patients. Further studies are needed to clarify the effect of diabetes on this layer and the relationship between choroidal thickness and DME.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.