Choroidal Thickness Greater in NPDR vs. Healthy Eyes

This study’s findings reinforce the value of careful retinal and choroidal assessment in patients with type 2 diabetes, even when visible retinopathy appears limited. Increased choroidal thickness may reflect early diabetic choroidopathy, vascular dysregulation, inflammation or autoregulatory dysfunction, the authors posit. Photo: Kou J, et al. Open Ophthalmol J. 2025;19:e18743641367379. Click image to enlarge. New evidence suggests that choroidal changes occur early in diabetic eye disease, even before advanced retinal complications develop. Using swept-source OCT (SS-OCT), researchers compared macular choroidal thickness between individuals with nonproliferative diabetic retinopathy (NPDR) and healthy controls, finding that the measurement was significantly greater in patients with NPDR.The study, published recently in Open Ophthalmology, included 52 patients with NPDR (104 eyes) and 31 healthy volunteers (62 eyes). Patients ranged from 45 to 75 years old, and the mean age was higher in the NPDR group than in controls (56.00 ± 9.08 years vs. 38.94 ± 10.92 years). To minimize confounding, the researchers excluded patients with prior ocular surgery, retinal laser therapy, intravitreal anti-VEGF injections, hypertension, diabetic nephropathy, cardiovascular disease and other ocular conditions that might affect the choroid. All participants underwent slit-lamp and fundus examinations, BCVA testing, intraocular pressure measurement, fundus photography and SS-OCT imaging of a 6x6mm macular area.The results showed that the NPDR group had significantly thicker choroids in the central foveal region and most peripheral sectors. Mean central foveal choroidal thickness was 343.21 ± 107.84µm in the NPDR group compared with 282.56 ± 92.81µm in controls.In the inner ring, all four quadrants were thicker in NPDR eyes: superior 333.71 ±110.01µm vs. 294.98 ±97.47µm, inferior 334.71 ±107.92µm vs. 284.48 ±97.40µm, nasal 326.00 ±124.51µm vs. 261.16 ±96.75µm and temporal 339.75 ±96.61µm vs. 292.97 ±92.12µm. In the outer ring, the inferior quadrant was thicker in NPDR eyes at 313.03 ±94.87µm vs. 281.31 ±93.19µm, and the nasal quadrant showed the largest difference at 282.10 ±113.68µm vs. 219.85 ±88.94µm. Superior and temporal outer-ring sectors were numerically thicker but not significantly different. After age adjustment, all major regional differences remained significant.“Taken together, the results suggest that in patients with NPDR, the choroid has undergone corresponding changes, even without noticeable retinal lesions,” the researchers explained in their paper. They argued that these findings “underscore the critical role played by the choroid in the pathogenesis of DR,” noting that “while paying adequate attention to the retinal changes, the importance of the choroid should also be recognized.”Click here for the journal source. Kou J, Pang J, Zhou Y, et al. Choroidal thickness in non-proliferative diabetic retinopathy vs healthy eyes using SS-OCT. Open Ophthalmol J. 2025;19:e18743641367379.  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.