Abstract
Purpose: :
Neuronal changes are thought to precede microvascular changes in diabetes. So this study compared retinal thickness (RT) in diabetic subjects compared to controls in a multiethnic cohort using Spectral Domain Optical Coherence Tomography (SD-OCT).
Methods: :
This is a retrospective study on 72 diabetic subjects (with no or minimal retinopathy) and 46 normal subjects. Subjects were from three ethnic groups (Asian, Afro-Caribbean and Caucasian); with age range 20-86 years and best corrected visual acuity 20/20 or better. The OCT scans were performed using a standard protocol on the Heidelberg Spectralis SD-OCT as part of routine medical care. Retinal thickness (RT) in 9 Early Treatment Diabetic Retinopathy Study (ETDRS) subfields, including central subfield was compared between the two groups after adjusting for age, gender and ethnicity.
Results: :
There is no difference in mean retinal thickness between diabetics and non-diabetics after adjusting for age, gender and ethnic origin. In the control subjects, the mean central sub-field thickness (CST) was 261.87 ± 22.24µm, being thickest in Caucasians followed by Asians and then Afro-Caribbeans (p=0.024). There was significant change in RT with age (p<0.01) and males having thicker CST than females (p=0.013).
Conclusions: :
Neuronal changes in diabetes are not detected by measuring RT on OCT. These results also suggest that studies comparing OCT measurements should carefully control for age, race, and gender-based variations in retinal thickness.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina • diabetic retinopathy