Abstract
Purpose:
Diabetic Macular Oedema (DME) is a vision threatening complication of diabetes. Anti-vascular endothelial growth factor (anti-VEGF) treatments can improve the visual outcomes for patients with an effective reduction in retinal thickness. Choroidal thickness (CT) changes are undetermined. In this prospective, non-intervention, observation-only study, CT changes were evaluated using Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT) in patients undergoing anti-VEGF treatment for DME.
Methods:
Twenty-four patients with DME (any severity) were recruited from medical retina clinics in a tertiary eye hospital. At baseline, all patients had visual acuity (VA), retinal photos, axial length, random blood glucose, HbA1c, lipids, eGFR and OCT performed. At one month follow up, only VA, retinal and OCT images were assessed. Central macular thickness (CMT) was the automated value from the platform’s analysis protocol. The average value for sub-foveal CT for each scan was manually measured three times by two masked graders. Each scan was given a score on the visibility of the choroidal/scleral interface: 0 for border not gradable, 1 for uncertain, 2 for clear border. Confidence intervals, Pearson’s correlation and paired comparisons were calculated.
Results:
Of 24 treatment naïve recruited participants, 16 (66.7%) were male, with mean age 61.5 years (range:40-78). At baseline, the mean VA, using ETDRS method, was 59.0 letters (95%CI:55.6 -62.5) and the mean duration of diabetes 18.5 years (95%CI:14.0-23.0). The mean CMT values were 461µm (95%CI:412-509) and 411µm (95%CI:362-459; p=0.043), at baseline and follow up visits, respectively. The mean change in CMT was -50.5µm (95%CI:-96.7- -4.2). The border for subfoveal CT measurements was not discernible for 2 patients. Mean baseline subfoveal CT was 262µm (95%CI:233-290) with a mean follow up of 36.2 days. Mean follow up subfoveal CT measurements were 268µm (95%CI:241-294). There was no significant change in subfoveal CT, mean 5.9µm (95%CI:-0.3-12.0), p=0.076. Except for age (r=-0.50, p=0.018) there were no clinically significant correlations with baseline parameters and baseline CT (r=-0.29-0.35, p>0.107).
Conclusions:
In DME patients receiving anti-VEGF treatment, there is a significant reduction on CMT but no significant effect on CT in the short term. Longitudinal studies are needed to establish if anti-VEGF therapy has long-term effects on CT.