Assessment of Retinal Structural Characteristics in Eyes with Diabetic Retinopathy

Abstract

Purpose : To compare retinal layer thicknesses of patients with diabetes with (DR) and without diabetic retinopathy (DWR), and subjects with no known ocular pathology (controls) using spectral- domain optical coherence tomography (SD-OCT).

Methods : SD-OCT (Heidelberg Spectralis®) raster scans of patients with DWR and DR were obtained. Eyes with macular edema and other macular pathologies that preclude segmentation of individual retinal layers were excluded. The Heidelberg Heyex™ 5.2 software was used to segment retinal layers along a 5 mm horizontal scan passing through the fovea. Retinal layers analyzed include: full retinal thickness (FRT), retinal pigment epithelium (RPE), photoreceptor layer (PRL), inner nuclear layer (INL), combined ganglion cell, inner plexiform layers and nerve fiber layers (GCL+/NFL). Changes in thicknesses of the layers were assessed in 0.5 mm increments along the B-scan in the nasal and temporal regions. These recorded values were compared to corresponding values of 51 eyes from 51 subjects with no known ocular pathology.

Results : Twenty four consecutive subjects from a retina clinic at a tertiary care center (45 eyes) (DWR: 15 patients/29 eyes; DR: 9 patients/16 eyes) were included in the analysis. The median age was 62.8 years (range: 36 to 87), with 16 males (67%). Among the 51 controls, median age was 52 (range: 40 to 75), with 26 males (51%). The mean duration of diabetes was 6.1 years in subjects with DWR and 11.6 years in subjects with DR. Table 1 reports the differences among the three groups for various retinal layers. Figure 1 represents the thickness of various retinal layers across the B-scan.

Conclusions : Conclusion: Retinal layer thinning may be observed in patients with diabetes even in the absence of diabetic retinopathy. Progression of RPE thinning may correlate with disease severity and duration. Thinning of the RPE may be more pronounced in eyes with retinopathy.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

Changes of individual layers in diabetic eyes with (DR) and without (DWR) retinopathy in comparison with subjects with no known ocular pathology (Control)

 

Figure 1: Thickness of retinal layers across the B-scan in diabetic eyes with and without retinopathy in comparison with controls