Associations between macular retinal vasculature and severity of idiopathic epiretinal membrane

BACKGROUND

To demonstrate the associations between the morphology of macular retinal vasculature and disease severity of idiopathic epiretinal membrane (ERM).

METHODS

Macular structures were assessed using optical coherence tomography (OCT), and were classified as "with pseudohole" or "without pseudohole". The 3 × 3 mm macular OCT angiography images were analyzed using the Fiji software to obtain the vessel density, skeleton density, average vessel diameter, vessel tortuosity, fractal dimension, and foveal avascular zone (FAZ)-related parameters. The correlations between these parameters and ERM grading as well as visual acuity were analyzed.

RESULTS

For ERM with or without a pseudohole, increased average vessel diameter, decreased skeleton density, and decreased vessel tortuosity were all associated with inner retinal folding and thickened inner nuclear layer, indicating more severe ERM. In 191 eyes without a pseudohole, the average vessel diameter increased, fractal dimension decreased and vessel tortuosity decreased with increasing ERM severity. The FAZ was not associated with ERM severity. Decreased skeleton density (r = -0.37), vessel tortuosity (r = -0.35), and increased average vessel diameter (r = 0.42) were correlated with worse visual acuity (All P < 0.001). In 58 eyes with pseudoholes, a larger FAZ was associated with a smaller average vessel diameter (r = -0.43, P = 0.015), higher skeleton density (r = 0.49, P < 0.001), and vessel tortuosity (r = 0.32, P = 0.015). However, none of the retinal vasculature parameters correlated with visual acuity and central foveal thickness.

CONCLUSION

Increased average vessel diameter, decreased skeleton density, decreased fractal dimension and decreased vessel tortuosity were good indicators of ERM severity and associated visual impairment.

Early macular and peripapillary vasculature dropout in active thyroid eye disease

PURPOSE

To compare macular and peripapillary vasculatures in active thyroid eye disease (TED), not active not compressive (NANC) TED, and control eyes.

METHODS

Twenty-one eyes of 12 active TED patients, 77 eyes of 43 NANC patients, and 65 eyes of 35 healthy normal subjects were recruited in this observational study. The participants underwent optical coherence tomography (OCT) and OCT angiography (OCT-A) of the peripapillary and macular areas. Macular ganglion cell complex (GCC) was measured in addition to peripapillary and macula superficial and deep vasculatures.

RESULTS

Linear mixed models accounting for inter-eye correlation showed that whole macular and parafoveal superficial vessel densities were significantly lower in the active TED with values of 50.6 ± 4.3% and 52.7 ± 4.8%, respectively, compared with control group values of 53.7 ± 3.0% and 56.3 ± 3.2% (P = 0.03, P < 0.001, respectively). In contrast, only the nasal sector of parafoveal vasculature value was significantly lower in the NANC TED than in control eyes (P = 0.03) and in the active group than in the NANC group (P < 0.001). Similarly, the average peripapillary vessel density was lower in the active TED than in the NANC and control groups. No significant differences were observed in GCC thickness among active, NANC, and control groups. Whole superficial macular and parafoveal vessel densities were significantly correlated with visual field MD (r = 0.32, r = 0.30, respectively, both P < 0.001).

CONCLUSIONS

OCT-A findings of lower peripapillary and macular vessel density values in the active TED eyes show subclinical retinal and optic nerve involvement.