​​Retinal Volume Increases in Macular, Peripheral Regions in DME

Retinal volume increases in both macular and peripheral regions in DME, particularly as NPDR severity progresses. This scan from the study shows a 74-year-old man with severe NPDR. The macular area exhibits a volume of 12.4mm3, while the peripheral area measures 78.4mm3. Photo: Chiku Y, et al. Ophthalmol Sci. July 16, 2025. Click image to enlarge. The evolution of retinal imaging continues to enable the evaluation of a larger section of the retina and enhance optometrists’ ability to assess progression risk in diabetic retinopathy (DR). Recent advancements in imaging technology have introduced ultra-widefield (UWF) imaging, capable of capturing up to 82% of the retinal surface in a single shot. With ocular steering, UWF can image 100% of the retina, providing a panoramic view that significantly enhances the detection and assessment of peripheral retinal lesions. Researchers in Japan evaluated retinal volume in both the macular and peripheral retina in patients with nonproliferative (NP) DR with and without diabetic macular edema (DME) using widefield swept-source OCT (SS-OCT). Their recent study demonstrated a significant increase in macular and peripheral retinal volumes in patients with NPDR and DME compared with patients with the same type of DR without DME and with controls.This retrospective study, which was published last week in Ophthalmology Science, included a total of 98 eyes: 30 from patients with NPDR without DME, 38 from patients with NPDR with DME and 30 from age- and sex-matched healthy controls. OCT examinations used SS-OCT (Xephilio OCT-S1; Canon) to capture 23x20mm (1024x128 A-scans) cube images. Retinal volume was calculated for each sector in a nine-sector grid defined by concentric circles (1mm, 6mm and 20mm in diameter) centered on the fovea and divided into four quadrants: superior, inferior, nasal and temporal. The macular region was defined within a 6mm diameter, while the peripheral retina spanned 6mm to 20mm.Macular retinal volume was 8.46mm3 in the control group, 8.79mm3 in the NPDR without DME group and significantly higher at 10.53mm3 in the NPDR with DME group. Peripheral retinal volume was 64.5mm3 in the control group, 62.2mm3 in the NPDR without DME group and significantly higher at 68.7mm3 in the NPDR with DME group. In the NPDR with DME group, severe NPDR showed greater volumes (macula: 11.2mm3; periphery: 71.9mm3) than mild-to-moderate NPDR (macula: 9.67mm3; periphery: 65.1mm3).“In our study, the peripheral retina was defined as the annular region extending from 6mm to 20mm from the foveal center, encompassing a broader retinal area,” the study authors wrote in their paper. “This broader definition may enable the detection of edema that is less apparent when using narrower peripheral criteria and may better capture the continuum of retinal involvement in DME.”These findings support the notion that retinal edema in advanced disease may extend beyond the macula and involve the peripheral retina.Click here for the journal source. Chiku Y, Hirano T, Hoshiyama K, Murata T. Evaluation of retinal edema in nonproliferative diabetic retinopathy using widefield swept-source optical coherence tomography. Ophthalmol Sci. July 16, 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.