To identify macular neovascularization (MNV) of wet age-related macular degeneration (AMD), ophthalmologists should first use optical coherence tomography angiography (OCT-A), according to new research from Annals of Medicine and Surgery. The study explains that OCT-A can be used as a noninvasive option to identify lesion patterns of MNV in AMD, reflecting their active or inactive status.
The researchers evaluated 70 eyes of 50 patients with MNV secondary to wet AMD in a cross-sectional study. They used OCT-A imaging to assess MNV and detect degenerative lesions, subretinal fibrosis, pigment epithelial detachment (PED), subretinal hyperreflective material, intraretinal hyperreflective dots, and outer retinal atrophy.
In examining OCT-A’s sensitivity in detecting MNV, the researchers studied the branching pattern, vessel termination, morphologic shape, any presence of a dark perilesional halo, and visibility of the feeder vessel. They designated MNV lesions as following “pattern I” or “pattern II” based on those characteristics.
Sensitivity of detection with OCT-A was highest (100%) for type 2 (n=15), mixed (n=1), and type 3 (n=1) lesions. It was 92% for unclassified fibrotic MNV (n=13), and 85% for type 1 (n=40). It was 84.6% for active lesions (55.7% of the cohort) and 96.8% for inactive lesions (44.3% of the cohort).
The researchers identified 41.3% (n=26) of lesions as “pattern I” and 58.7% (n=37) as “pattern II.” Lesion activity on multimodal imaging (MI) was associated with “pattern I” on OCT-A, with a correlation rate of 84.8%. Inactive lesions (mean area of 3.86 mm2) were larger than active lesions (mean area of 2.92 mm2).
“Indicating an antiangiogenic treatment based on OCT-A alone can sometimes be quite challenging, especially for recurrent neovascular lesions,” according to researchers. “Comparing en face and cross-sectional OCT-angiograms in order to identify exudative signs could help assess the activity status of the lesion without recourse to conventional dye-injection imaging techniques. OCT-A should be performed first-line in the presence of any macular lesion suggestive of AMD in order to identify the neovascular complex and to assess its morphological characteristics. The absence of a neovascular network on OCT-A should lead to further investigations using conventional dye-injection imaging techniques in order to confirm or rule out the diagnosis.”
Limitations of the study include inability to assess OCT-A for long-term monitoring and some lack of cooperation of patients during OCT-A.
Ahmed M, Syrine BM, Nadia BM, et al. Optical coherence tomography angiography features of macular neovascularization in wet age-related macular degeneration: A cross-sectional study. Annals of Med and Surgery. Published online September 8, 2021. doi:10.1016/j.amsu.2021.102826