Intensified Multifactorial Intervention in Patients With Type 2 Diabetes Mellitus: Phenotypes of Retinopathy Progression

Abstract

Abstract: : Purpose: We carried out a prospective randomised two–year follow up study to compare the effect of stepwise intensive treatment versus standard treatment on the progression of preclinical retinopathy in type 2 diabetes mellitus. Methods: Forty type 2 diabetic patients were allocated in this open, parallel trial to either standard (n=20) or intensive (n=20) treatment. Thirty–five patients completed the two–year period of follow–up. The age at inclusion was 55±6 years old (mean ± SD) and a mean known duration of their diabetes of 9±5 years. Intensive treatment was a stepwise implementation of behaviour modification and pharmacological therapy. The endpoints were: number of new red dots, alteration of the Blood–Retinal Barrier (BRB), capillary closure, measurements of retinal thickness and retinal capillary blood flow. Results: There was retinopathy progression of one level of Wisconsin grading in 32 out of 35 eyes that completed the study. No differences in retinopathy progression were found between the intensive and nonintensive treatment groups, or between the groups that showed HbA_1C values ≤7,1% or >7,1% throughout the 2–year follow–up period. Overall, the alteration of the BRB remained stable whereas there were significant increases in retinal thickness (p<0,001) and retinal capillary blood flow (p=0,042). Capillary closure developed in 5 of the 35 eyes. Two groups of eyes showed 2 well defined patterns of retinopathy progression. Ten eyes showing higher levels of leakage (>10% over mean +2SD) had higher increases of retinal thickness (p=0,030) and higher values of retinal capillary blood flow (p=0,020). The 5 eyes that developed capillary closure showed low levels of leakage, thickness and capillary blood flow. Conclusions: Retinopathy progression appears to follow different patterns in eyes of different patients independently of metabolic control. Two different patterns characterized by more rapid progression were identified in this study, one associated with marked alterations of the BRB and the other with the development of capillary closure.

Keywords: clinical (human) or epidemiologic studies: natural history • diabetic retinopathy • imaging/image analysis: clinical