One-Year Progression of Diabetic Subclinical Macular Edema in Eyes with Mild Nonproliferative Diabetic Retinopathy: Location of the Increase in Retinal Thickness

Abstract

Purpose: To characterize the 1-year progression of retinal thickness (RT) increase occurring in eyes with subclinical macular edema in type 2 diabetes. Methods: Forty-eight type 2 diabetic eyes/patients with mild nonproliferative diabetic retinopathy (NPDR; levels 20 and 35 in the Early Treatment Diabetic Retinopathy Study) classified as presenting subclinical macular edema at baseline completed the 1-year follow-up period, from a sample of 194 followed in a 12-month observational and prospective study (ClinicalTrials.gov identifier: NCT01145599). Automated segmentation of the retinal layers in these eyes was performed, followed by verification and correction by a human grader. Results: The highest increase in RT over the 1-year follow-up period for the 48 eyes/patients with subclinical macular edema was found in the inner nuclear layer (INL). Progression to clinical macular edema was also associated with increased thickening of other retinal layers aside from the INL. The microvascular disease activity shown by microaneurysm (MA) turnover ≥6 was associated with progression from subclinical to clinical macular edema. Conclusions: Increases in RT occurring over a period of 1 year in diabetic eyes with mild NPDR and subclinical macular edema occur mainly in the INL. The development of clinical macular edema appears to be associated with increased thickening of other retinal layers and microvascular disease activity.

Single Retinal Layer Evaluation in Patients with Type 1 Diabetes with No or Early Signs of Diabetic Retinopathy: The First Hint of Neurovascular Crosstalk Damage between Neurons and Capillaries?

“…Indeed, while previous experimental studies [32,33] reported an activation and hypertrophy (swelling) of Muller cells in the earlier stages of DR, other studies [18,34] showed an increased retinal thickness, which mainly occurs at the INL level, in the early stages of subclinical macular edema. This is likely related to the pathological alteration of the deep capillary plexus and extracellular accumulation of fluid.…”

Thickening of inner retinal layers in the parafovea after bariatric surgery in patients with type 2 diabetes

“…) or thickening of the INL in patients with subclinical macular oedema (Tejerina et al. ). In early diabetic macular oedema, the ONL is prone to the earliest thickening (Antcliff & Marshall ) and longitudinally the peripapillary RNFL has been reported to decrease with preceding intravitreal antivascular endothelial growth factor (Hwang et al.…”

Relevance of Retinal Thickness Changes in the OCT Inner and Outer Rings to Predict Progression to Clinical Macular Edema: An Attempt of Composite Grading of Macular Edema

“…The study was an investigator-driven observational study sponsored by the European Vision Institute Clinical Research Network (EVICR.net) [2]. Results of this study and procedures have been previously described [3,4,5]. …”