Multidimensional Functional and Structural Evaluation Reveals Neuroretinal Impairment in Early Diabetic Retinopathy

Abstract

PurposeTo test whether quantitative functional tests and optical coherence tomography (OCT)-defined structure can serve as effective tools to diagnose and monitor early diabetic neuroretinal disease.MethodsFifty-seven subjects with diabetes (23 without diabetic retinopathy [no DR], 19 with mild nonproliferative diabetic retinopathy [mild NPDR], 15 with moderate to severe [moderate NPDR]), and 18 controls underwent full ophthalmic examination, fundus photography, spectral-domain optical coherence tomography (SD-OCT), e-ETDRS (Early Treatment Diabetic Retinopathy Study) acuity, and the quick contrast sensitivity function (qCSF) method. Perimetry testing included short-wavelength automated perimetry (SWAP), standard automated perimetry (SAP), frequency doubling perimetry (FDP), and rarebit perimetry (RBP).ResultsETDRS acuity and RBP were not sensitive for functional differences among subjects with diabetes. AULCSF, a metric of qCSF, was reduced in diabetics with moderate compared to mild NPDR (P = 0.03), and in subjects with no DR compared to controls (P = 0.04). SWAP and SAP mean deviation (MD) and foveal threshold (FT) were reduced in moderate compared to mild NPDR (SWAP, MD P = 0.002, FT P = 0.0006; SAP, MD P = 0.02, FT P = 0.007). FDP 10-2 showed reduced MD in moderate compared to mild NPDR (P = 0.02), and FDP 24-2 revealed reduced pattern standard deviation (PSD) in mild NPDR compared to no DR (P = 0.02). Structural analysis revealed thinning of the ganglion cell layer and inner plexiform layer (GCL+IPL) of moderate NPDR subjects compared to controls. The thinner GCL+IPL correlated with impaired retinal function.ConclusionsThis multimodal testing analysis reveals insights into disruption of the neuroretina in diabetes and may accelerate the testing of novel therapies.

Reading deficits in diabetic patients treated with panretinal photocoagulation and good visual acuity

“…; Joltikov et al. ). The minimum contrast threshold of the 5° diameter stimulus was measured at each of 55 test locations (Joltikov et al.…”

“…The minimum contrast threshold of the 5° diameter stimulus was measured at each of 55 test locations (Joltikov et al. ). The testing time was approximately 5 min per eye.…”

Optic Nerve Changes in Diabetic Retinopathy

“…Moreover, besides VA tests, some experts suggested that psychophysical tests, such as visual field and contrast sensitivity test, should also be evaluated in DR patients with optic nerve complication. They found that those examinations were more sensitive than VA test only [13].…”

“…Chronic hyperglycemia damages the retinal blood vessels and causes pericyte loss due to elevated sorbitol level. These result in involution of the vascular changes in microcirculation and loss of normal capillary exchange [12][13][14]. Microvascular anomalies and chronic inflammation may develop dysfunctional barriers permitting leakage of inflammatory molecules and immune cells from systemic circulation and cause further deterioration of the tissue [12,41].…”

“…Such processes are metabolic alteration, oxidative stress, and ischemia [10]. These changes could be detected via modalities such as visual evoked potential, biomicroscopy, and fundus photography [11][12][13]. These changes usually occur after persistent metabolic alterations, which may lead to late detection [2,14].…”