The Spectrum of Central Choriocapillaris Abnormalities on Swept-Source Optical Coherence Tomography Angiography in the Fellow Eye of Unilateral Exudative Age-Related Macular Degeneration Patients: From Flow Deficits to Subclinical Non-Exudative Neovascularization

The Impact of Diabetic Retinopathy on the Choriocapillaris in Neovascular AMD

Purpose

To investigate the impact of diabetic retinopathy (DR) on morphological choriocapillaris (CC) modifications in eyes with type 1 macular neovascularization (MNV) secondary to AMD using optical coherence tomography angiography (OCTA).

Methods

Eyes with AMD-related type 1 MNV with and without DR were prospectively included. We performed 3 × 3 mm OCTA scans at two visits: before the loading phase of intravitreal injections of aflibercept (T1) and 1 month after the last injection (T2). OCTA En face flow images of the CC were analyzed for flow deficit percentage (FD%), FD average area and FD number in a 500-µm-wide ring surrounding the dark halo (DH) around type 1 MNV.

Results

A total of 65 eyes, out of which 30 eyes had mild DR, were included. In the group without diabetes, there was a gradual reduction in FD% in the CC ring around the DH after antiangiogenic therapy, indicating reperfusion of the CC (P = 0.003). However, in the DR group, there were no significant changes in CC parameters between the two study visits. Specifically, the FD% in the CC ring around the DH did not show a significant reduction at T2 compared with T1 values (P > 0.05). Furthermore, the comparison of the variation in FD% between the two groups was statistically significant. The nondiabetic group exhibited a gradual CC reperfusion after the loading phase of aflibercept, whereas the diabetic eyes did not show significant changes (P = 0.029).

Conclusions

The CC surrounding the DH associated to type 1 MNV exhibited greater hypoperfusion in diabetic eyes compared with eyes without diabetes, both before starting therapy and after the loading phase. Hence, DR may be a potential risk factor in the development and progression of late-stage AMD and may also influence the response to antiangiogenic therapy.

Age-Related Macular Degeneration: New Insights in Diagnosis, Treatment, and Prevention

Age-related macular degeneration (AMD) is an aging-related ocular disease that can be responsible for severe loss of visual acuity and loss of autonomy in patients [...]

INFLUENCE OF HIGH MYOPIA ON CHORIOCAPILLARIS PERFUSION AND CHOROIDAL THICKNESS IN DIABETIC PATIENTS WITHOUT DIABETIC RETINOPATHY

PURPOSE

To investigate the impact of high myopia on choriocapillaris (CC) perfusion and choroidal thickness (CT) in diabetic patients without diabetic retinopathy.

METHODS

Healthy subjects and patients with diabetes mellitus were recruited from communities in Guangzhou. They were divided into four groups according to the presence of diabetes and high myopia: healthy control (n = 77), diabetes (n = 77), high myopia (n = 77), and diabetes with high myopia (n = 77). Swept-source optical coherence tomography angiography (SS-OCTA) measured CC perfusion and CT. CC perfusion was quantified using the choriocapillaris perfusion index (CPI).

RESULTS

A total of 308 subjects (308 eyes) were included in the study. The average CPI was 91.11 ± 0.84, 90.16 ± 1.46, 89.80 ± 1.42, and 89.36 ± 1.19% in the control, diabetes, high myopia, and diabetes with high myopia groups, respectively (p < 0.001); the average CT was 227.55 ± 43.13, 205.70 ± 59.66, 158.38 ± 45.24, and 144.22 ± 45.12μm, respectively (p < 0.001). After adjusting for age and sex, the average CPI decreased 0.95 ± 0.20% (p < 0.001) in the diabetes group, 1.33 ± 0.20% (p < 0.001) in the high myopia group, and 1.76 ± 0.20% (p < 0.001) in the diabetes with high myopia group relative to the control group; the average CT decreased 23.53 ± 8.12 (p = 0.004), 70.73 ± 9.41 (p < 0.001), and 85.90 ± 8.12 μm (p < 0.001), respectively. Further adjustment for other risk factors yielded a similar result.

CONCLUSION

Diabetes and high myopia significantly impact CPI and CT, and the presence of both conditions is more damaging to CPI and CT than diabetes or high myopia alone.