Simultaneous GA and CNV/MNV: incidence, characteristics, and treatments

Understanding the clinical characteristics and underlying mechanisms of simultaneous geographic atrophy (GA) and choroidal neovascularization (CNV)/macular neovascularization (MNV) is necessary for the long-term management of late age-related macular degeneration (AMD) in clinical practice.

The authors reviewed the literature on the incidence, risk factors, and clinical characteristics of simultaneous GA and CNV/MNV and developed consensus recommendations for the diagnosis, assessment, and management of simultaneous GA and CNV/MNV in clinical practice.

The incidence rate of CNV/MNV in eyes with GA is reported as 7.4% per patient-year or 13.8% in 4.1 years, while that of macular atrophy (MA) subsequent to CNV/MNV is reported as 24.4% to 37% in 24 months. Recent studies using optical coherence tomography angiography (OCT-A) revealed the presence of subclinical CNV/MNV in 11% to 16% of eyes with GA. Fundus autofluorescence is used to detect MA; optical coherence tomography (OCT) and OCT-A are useful for detecting MA, especially around the fovea, with OCT-A offering high sensitivity and specificity in the detection of both MA and CNV/MNV. GA and CNV/MNV share the genetic risk factors of HTRA1, complement factor H, complement factors 3 and 2, and ARMS2, and clinical risk factors of large drusen, cuticular drusen, intraretinal hyperreflective foci, and subretinal drusenoid deposits, suggesting that simultaneous GA and CNV/MNV represents a continuum of AMD. Anti-vascular endothelial growth factor therapy for CNV/MNV is reported to have no impact on the speed or magnitude of MA development or enlargement. An association has been observed between CNV subtype and MA progression, with the latter being slower in the presence of type 1 CNV/MNV.

These findings suggest there is a high probability of coexistence of GA and CNV/MNV and that they should not be considered separately. Future clinical studies should assess the two conditions simultaneously using OCT and OCT-A.

What is known Owing to differences in their clinical characteristics, geographic atrophy (GA) and choroidal neovascularization (CNV)/macular neovascularization (MNV) have historically been regarded as two separate entities; however, several cases of coexistent GA and CNV/MNV have been reported recently in the published literature. What is new The findings of this review confirm that GA and CNV/MNV share common genetic risk factors and clinical characteristics, and suggest that these two entities are part of a continuum of late-stage age-related macular degeneration (AMD). The potential for GA and CNV/MNV to coexist should be considered in any discussion of the long-term management of late AMD; moreover, clinicians should assess for CNV/MNV in patients with GA, and for GA in those with CNV/MNV, using multimodal imaging.