Seven-Year FAZ Trend Analysis of OCT-A Across COVID-19 in Type 1 Diabetes Mellitus

Abstract

Purpose : Type 1 Diabetes Mellitus (T1DM) is a chronic condition that may cause vision loss if patients lack glycemic control. T1DM is associated with Foveal Avascular Zone (FAZ) deterioration and decreases in Foveal Density (FD). We evaluated FAZ health using OCT-A trend analysis in T1DM patients to determine the relationship between glycemic control and the health of the ocular vasculature.

Methods : Fifty-four patients (41% male, average 26 years old and 16.9 years since T1DM diagnosis) from the annual Children with Diabetes Conference were imaged with OCT-Angiography five times using the Optovue Avanti RTVue OCT over seven years (2016-2022). Patients were not screened from 2020-2021 due to COVID-19. We used Optovue’s Trend Analysis, which provides linear regression models to analyze patient progress. Changes in FAZ area, FAZ perimeter, and foveal density (FD) were recorded, and patients were stratified by controlled (A1c≤7) and uncontrolled glucose (A1c>7). T-tests were utilized to assess statistical associations using SPSS.

Results : Trend Analysis measures change over time (slope) in FAZ area, FAZ perimeter, and FD. No differences were observed between males and females. On average, patients with uncontrolled T1DM had more negative slopes in all variables, indicating more retinal deterioration than patients with controlled T1DM. Patients with uncontrolled T1DM had worse FAZ area (p=0.0696) and significantly worse FAZ perimeter (p=0.0473) and FD (p=0.0076) as compared to a baseline of no change (slope=0). Patients with controlled T1DM saw improvement in FAZ area (0.002 mm²/year), while they had slight decreases in FAZ perimeter (-0.0044 mm/year) and foveal density (-0.1354%/year).

Conclusions : In patients with uncontrolled diabetes, FAZ and FD values declined significantly compared to baseline. This underscores the importance of annual retinal screening and education in patients with T1DM, even during the pandemic. Longitudinal analysis of OCT-A may be an important tool to track, triage, and prioritize patients when healthcare may be limited.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Table 1. The average changes in FAZ area, perimeter, and foveal density were calculated by Trend Analysis^TM in well-controlled and uncontrolled T1DM patients over seven years. Progress was compared to a baseline of no change (slope=0).

 

Figure 1. OCT-A Trend Analysis report of FAZ area, perimeter, and foveal density