Abstract
Purpose :
Visual acuity potential in diabetic retinopathy can be hard to predict in the context of distorted macular anatomy. The papillomacular bundle, located in the nerve fiber layer (NFL) between the fovea and the optic nerve, carries signals for central vision and may be thinned in eyes with reduced visual acuity. We tested this hypothesis by conducting a retrospective, observational clinical study in eyes with a history of proliferative diabetic retinopathy to examine the relationship between visual acuity and optical coherence tomography (OCT)-measured papillomacular bundle thickness.
Methods :
Eyes with a history of proliferative diabetic retinopathy referred to the vitreoretinal clinic between July and December 2023 were included. Cirrus OCT (Carl Zeiss Meditec AG, Germany) 6 x 6 mm macular cube scans were acquired with the 512 x 128 protocol. The most recent readable OCT for each eye and the corresponding Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity from the medical record were used for analyses. Eyes were excluded if accurate OCT measurements could not be obtained. Papillomacular bundle thickness (PBT) was measured as the NFL thickness at a point halfway between the fovea and the center of the optic disc. Central subfield thickness (CST) was recorded using the Cirrus review software. Summary statistics and linear regression were performed using Stata (StataCorp LLC, TX).
Results :
Thirty seven eyes of 22 patients were studied. Seventeen eyes (46%) were from male patients. Twenty nine eyes (78%) were from patients with type 2 diabetes. The mean (SD) age and ETDRS visual acuity of eyes were 55.2 (14.7) years and 60.1 (19.2) letters, respectively. Mean (SD) PBT and CST were 38 (13) micrometers and 293 (95) micrometers, respectively. Multiple linear regression found that PBT was associated with ETDRS visual acuity (p = 0.001), whereas CST was not (p = 0.32). For each 1 micrometer decrease in PBT, visual acuity decreased by approximately 0.9 letters (95% confidence interval: 0.4 - 1.4 letters).
Conclusions :
In eyes with proliferative diabetic retinopathy, thinning of the papillomacular bundle is associated with reduced visual acuity. This provides information on the visual potential of these eyes and could help guide treatments such as intravitreal injections, laser and intraocular surgery.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.