Foveal avascular zone area analysis in juvenile-onset type 1 diabetes using optical coherence tomography angiography

Optical coherence tomography angiography (OCTA) was performed on patients with juvenile-onset type 1 diabetes (T1DM) but with no diabetic retinopathy to measure the foveal avascular zone (FAZ) area.

Retrospective single-facility study METHODS: Twenty-nine patients (58 eyes) with juvenile-onset T1DM were studied. Images (3 mm x 3 mm cube centered on the fovea) were acquired using an OCTA device. Age at examination was 16.1 ± 8.7 years; onset age was 6.4 ± 3.5 years; duration of diabetes was 9.7 ± 8.3 years. Twenty-four age-matched healthy individuals were studied as controls.

FAZ area was significantly larger in T1DM patients than in controls (0.29 ± 0.09 vs. 0.25 ± 0.08 mm², P = 0.0234). Parafoveal vessel density was not significantly different between patients and controls (50.43 ± 4.24 vs. 50.07 ± 4.64, P = 0.8842). By generalized linear model analysis, annual HbA1c (P = 0.0190), number of serious hypoglycemic attacks (P = 0.0210), and onset age (P = 0.0447) were identified as variables significantly associated with FAZ area. Age, gender, duration of disease, total cholesterol, high or low-density lipoprotein, triglycerides, and body mass index were not significantly associated with FAZ area.

Patients with juvenile-onset T1DM and no diabetic retinopathy had increased FAZ, but no significant difference in parafoveal vessel density compared to healthy controls. Larger FAZ area was associated with higher annual HbA1c, more episodes of severe hypoglycemic attacks, and older onset age.