GCC Thickness at the Central 1mm Might Help Predict Visual Outcomes in DME

The persistent DME group exhibited the most significant GCC thickness, which may be attributed to inflammatory processes and the presence of macular edema associated with early activation of glial cells. Using the “binarization” technique of converting grayscale to black and white, the researchers calculated the choroidal vascularity index (CVI), as seen in these images from the study. The original SD-OCT image (A) was binarized (B)  and then combined with the total choroidal area segmentation image (C). Then, an overlay of the region of interest  (D) was added to the original SD-OCT image. The researchers saw promising results with this approach but note that larger studies are necessary for confirmation. Photo: Condelipes A, et al. Comput Biol Med. 2025;198(Pt A):111192. Click image to enlarge. Due to the highly complex pathogenesis and the involvement of various biochemical pathways, such as neuroinflammation, cellular permeability alteration and retinal cell apoptosis, some patients with diabetic retinopathy (DR) exhibit persistent diabetic macular edema (DME) even after months of anti-VEGF therapy. Recognizing this situation is essential not only to predict treatment response but also to guide therapeutic decisions.Researchers based in Portugal believe that the integrity of the ganglion cell complex (GCC) of the retina is crucial for visual function maintenance, and its thickness may reflect diverse pathophysiological behaviors. Their recent study in Computers in Biology and Medicine characterized the anatomical profile of the GCC and choroidal parameters—thickness, area and choroidal vascularity index (CVI)—in patients with distinct anti-VEGF treatment response patterns. CVI is a newer OCT technique that converts grayscale scans to black and white in order to render the choroid’s vascular integrity in sharp contrast. The team found a moderate negative correlation was observed between best-corrected visual acuity (BCVA) and 1mm GCC thickness. These findings suggest that 1mm GCC thickness could be an interesting parameter for predicting visual outcomes after treatment.This cross-sectional study included 27 patients with type 2 diabetes in three different groups based on their response to anti-VEGF therapy and classifications in the Early Treatment Diabetic Retinopathy Study: the control group with no DR (n=11), the responder DME group (n=9) and the persistent DME group (n=7).In the overall characterization of the sample, a significant difference was observed only in BCVA. There was a significant difference in average retinal thickness (1mm, 3mm and 6mm) between the three groups and in GCC thickness at the central 1mm. BCVA was negatively correlated with mean retinal thickness, while CVI showed a potential positive correlation with BCVA.The study found statistically significant differences in the analyses of the total choroidal area and the vascular area between the persistent DME and responder DME groups. However, the CVI did not reach statistical significance. Analysis of correspondence between BCVA and CVI suggested that a larger sample size could reveal statistically significant associations.“Future studies should adopt a longitudinal approach to assess CVI and choroidal thickness changes before, during and after treatment,” the study authors wrote in their paper. “Such an approach would provide insights into the temporal dynamics of these parameters and their utility in monitoring treatment response.”Click here for the journal source. Mihalache A, Huang RS, Zajner C, et al. Mental health and vision difficulty in adults: a population-based analysis. Can J Ophthalmol. October 15, 2025. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.