Retinal Neural Layer Thickness and Contrast Sensitivity in Type 2 Diabetes Without Clinical Retinopathy: A Cross-Sectional Study
DOI:
https://doi.org/10.37275/bsm.v10i7.1660Keywords:
Contrast sensitivity, Diabetic retinal neurodegeneration, Ganglion cell-inner plexiform layer, Optical coherence tomography, Retinal nerve fiber layerAbstract
Background: Retinal neural dysfunction may occur in type 2 diabetes mellitus (T2DM) before clinically visible diabetic retinopathy.
Objective: We evaluated whether retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCL-IPL) thickness were associated with contrast sensitivity in adults with T2DM without clinical retinopathy.
Methods: This cross-sectional study included 30 eyes from 16 participants examined from September 2024 to June 2025. Swept-source optical coherence tomography measured average and quadrant RNFL thickness and macular GCL-IPL thickness. Monocular contrast sensitivity was assessed with the Pelli-Robson chart. Source-reported analyses included exploratory Spearman correlations, generalized estimating equations (GEE) for inter-eye clustering, and exploratory receiver operating characteristic (ROC) analysis.
Results: Mean RNFL thickness was 101.3 ± 12.55 µm, GCL-IPL thickness was 81.53 ± 7.34 µm, and contrast sensitivity was 1.773 ± 0.227 logCS. Eye-level correlations with contrast sensitivity were ρ=0.758 for GCL-IPL and ρ=0.640 for average RNFL (both source-reported p<0.001). In the exploratory GEE model, coefficients were 0.0104 logCS per µm for GCL-IPL (95% CI 0.001-0.019) and 0.0062 for RNFL (95% CI 0.001-0.011). Exploratory AUCs were 0.872 and 0.804, respectively.
Conclusion: Thicker GCL-IPL and RNFL measurements were associated with better contrast sensitivity in this small cohort. The estimates are hypothesis-generating and require confirmation with participant-level data, larger samples, and external validation before clinical use.
Authors
- Ramzi Amin1*
- Ririn Rahayu1
- Petty Purwanita1
- Muhammad Aulia Molid Ogest Putra Calisanie1
- 1Department of Ophthalmology, Faculty of Medicine, Universitas Sriwijaya / Dr. Mohammad Hoesin Central General Hospital, Palembang, Indonesia
Corresponding author Ramzi Amin — ramzi.amin26@gmail.com
Article history
- Submitted
- Accepted
- Published
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Ramzi Amin, Ririn Rahayu, Petty Purwanita, Muhammad Aulia Molid Ogest Putra Calisanie

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
As our aim is to disseminate original research article, hence the publishing right is a necessary one. The publishing right is needed in order to reach the agreement between the author and publisher. As the journal is fully open access, the authors will sign an exclusive license agreement.
The authors have the right to:
- Share their article in the same ways permitted to third parties under the relevant user license.
- Retain copyright, patent, trademark and other intellectual property rights including research data.
- Proper attribution and credit for the published work.
For the open access article, the publisher is granted to the following right.
- The non-exclusive right to publish the article and grant right to others.
- For the published article, the publisher applied for the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.













