Abstract
Purpose :
To identify factors impacting retinal thickness in type 1 DM patients across a wide range of age, DM duration and DR severity.
Methods :
Images were obtained from 50-Year Medalists and shorter DM duration patients at Joslin Diabetes Center without central-involved diabetic macular edema on OCT [central subfield thickness (CST) <305µm females, <320µm males]. Blood pressure (BP), BMI and lipids were recorded. Retinal layers on spectral domain OCT (SDOCT) were segmented and CSTs of Medalists with time domain (TD) OCT converted to TD equivalents and combined with SDOCT data.
Results :
For 692 subjects (625 Medalists, 67 non-Medalists), mean±SD age was 64±9 [range: 26-88]yrs, DM duration 52±10 [1-78]yrs, A1c 7.3±1.1 [4.8-15.2]% and 57% female. Overall, 17%, 34%, 9%, 1%, and 39% had no DR; mild, moderate, and severe nonproliferative DR (NPDR); and proliferative DR (PDR), respectively. In bivariate analyses (Table 1), increased CST was associated with greater age (p<0.0001), male gender (p<0.0001), greater age at DM diagnosis (p< 0.0001), lower A1c (p=0.002), lower BMI (p=0.03) and PDR (p=0.0003), but not with DM duration, BP or lipids. With multivariate modelling, CST remained correlated with age (p=0.03), gender (p<0.0001), age at DM diagnosis (p=0.008), BMI (p=0.03) and PDR (p<0.0001). In eyes with no-mild NPDR, age, gender and age at DM diagnosis were associated with CST (all p<0.0001). In eyes with PDR, neither panretinal photocoagulation (N=491) nor macular laser (N=61) was related to CST or central individual layer thickness. There were no significant differences in layer thickness between Medalists and non-Medalists. In the full cohort, after adjusting for age, gender, age at DM diagnosis, and BMI, PDR was associated with increased CST for retinal nerve fiber (p=0.008), ganglion cell (p=0.008), inner nuclear (p=0.0002) and outer plexiform (p=0.01) layers, but decreased CST for outer nuclear (p=0.04), and photoreceptor (p<0.0001) layers.
Conclusions :
Across a wide range of age, DM duration and DR severity, factors most closely associated with CST are age, gender, age at DM diagnosis and the presence of PDR. Individual thickness of central retinal layers does not change substantially with increasing DM duration or laser. There is a strong association between PDR and increased CST, although opposing effects on inner versus outer layer thickness are observed.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.