SD-OCT-A Shows Good Reproducibility in Most Retinal Layers in Glaucoma

SD-OCT-A shows good reproducibility for quantifying macular and optic nerve head peripapillary vessel densities among patients with glaucoma, according to a study published in Archivos de la Sociedad Española de Oftalmología.

Investigators included patients with glaucoma (n=33) and control group participants without glaucoma (n=30) in the cross-sectional study. Study participants underwent a complete ophthalmic examination followed by 2 consecutive SD-OCT-A scans. The team calculated intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) for various optic nerve head peripapillary vessel density and macular vessel density measurements and compared them among the control group and individuals with mild (n=11), moderate (n=11), and severe (n=11) glaucoma.

Overall, SD-OCT-A showed good reproducibility between the 2 scans in both the control group and in patients with glaucoma. In the control group, the ICCs ranged between 0.916 (P <.001) for deep capillary plexus measurements to 0.991 (P <.001) for nerve fiber layer vascular plexus measurements. The CVs ranged between 1.65% and 10.33%. Among the glaucoma group, the best reproducibility was observed for superficial vascular plexus (ICC, 0.971; P <.001) and poorest for nerve fiber layer vascular plexus (ICC, 0.936; P <.001) and the CV ranged between 2.01% and 10.33%.

Glaucoma severity affected reproducibility for macular and optic nerve head peripapillary vessel density measurements. The measures with the best reproducibility were nerve fiber layer vascular plexus density in mild (ICC, 0.869; P <.001) and moderate (ICC, 0.972; P <.001) glaucoma and deep capillary plexus density in advanced glaucoma (ICC, 0.968; P <.001). The poorest reproducibility was observed for deep vascular complex density in mild glaucoma (ICC, 0.856; P <.001), deep capillary plexus density in moderate glaucoma (ICC, 0.832; P <.001), and superficial vascular plexus density in advanced glaucoma (ICC, 0.864; P <.001). Overall, CV ranged between 3.14% and 8.66%.

SD-OCT-A showed good reproducibility for macular vessel density as well in patients with glaucoma with ICCs ranging from 0.961 (P <.001) in moderate glaucoma to 0.747 (P =.003) in mild glaucoma for deep vascular plexus density. The CV ranged between 2.20% and 10.94%.

This study may have been limited as the original cohort comprised 75 study participants, but images were of poor quality for 16% and were removed from the study.

“It is relevant studying reproducibility with different OCT-A devices because each device has its own algorithm and results which are not interchangeable,” the study authors explain. “Also, for clinical applicability [it] is important to know the variability of the measures of the retina, which can be different according to the degree of glaucomatous damage.”