Abstract
Purpose :
Long-term Type One Diabetes Mellitus (T1DM) complications can lead to diabetic retinopathy, macular edema, and vision loss. Early signs may include reductions in contrast sensitivity due to Ganglion Cell Complex (GCC) and Nerve Fiber Layer (NFL) thinning. The American Academy of Ophthalmology recommends a full ocular screening at age 15 or 5 years post-diagnosis of T1DM. We hypothesize Optical Coherence Tomography (OCT) may be an early predictor of GCC and NFL changes in T1DM.
Methods :
We retrospectively evaluated changes in posterior pole GCC thickness in 15 T1DM participants (age 22 ± 7.7 years, 66.7% male, T1DM duration 16.4 ± 7.6 years) over a 3-year period. We analyzed the GCC measurement using OCT (Avanti, Optovue, Fremont, California). Measurements were taken in 2016, 2017, and 2018 at an annual conference for T1DM (Orlando, FL). Participants were categorized by age, sex, duration of diabetes, HbA1C, duration of insulin pump use, and body mass index. Analysis of variance (ANOVA) tests using SPSS 24 were conducted to identify groups with significant changes.
Results :
One-way ANOVA tests were completed and slopes in the superior, inferior, and overall portion of the GCC in each eye were measured for all participants and for each category. All categories had a positive average slope across the 3 years (OD average slope = 0.58 μ/year, OS average slope = 0.68 μ/year). We hypothesize this is due to fluctuations in retinal thickness, potentially caused by macular edema. The major determining factors in these fluctuations appear to be HbAIC levels and duration of diabetes. There were no significant differences noted in the group overall or when split by category. However, there were lower slopes noted in females, those with lower HbAIC values, those who used an insulin pump for 15 – 20 years, and those who had diabetes for over 18 years.
Conclusions :
GCC and NFL changes precede vision changes and can be used as early markers for intervention with blood glucose control (HbA1C) to minimize retinal damage caused over the lifetime of the disease. Further investigation will be done to follow trends and correlations between GCC, NFL, and T1DM duration. Individuals with T1DM should have imaging when diagnosed to establish baseline values and accurately analyze GCC and NFL changes. With advancements in technology such as OCT, the standard of care for T1DM may change in the area of vision preservation tools.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.