An internationally renowned working group of retina specialists, ocular imaging experts, and ocular pathologists have suggested standardizing definitions for age-related macular degeneration (AMD) and its subtypes.
For neovascular lesion nomenclature, the CONAN group proposed specific terms be used:
- Type 3 neovascularization is to be used when the vascular complex originates in the retina.
- Type 1 neovascularization is applied when the vessels originate from the choroid and remain under the RPE.
- Type 2 neovascularization is denoted if neovascularization that originates in the choroid breaks through the RPE to reach the subretinal space.
The CONAN group followed the lead of the Classification of Atrophy Meetings group and adapted their definitions for non-neovascular AMD to describe atrophy in the context of neovascular disease.
However, the group was unable to come to a consensus on all definitions, despite acknowledging that the current nomenclature must change.
For example, CONAN notes that the term “polypoidal choroidal vasculopathy” is imprecise because a polyp is not a vascular aberration—it’s a solid tissue growth. A new, more accurate term—aneurysmal type 1 neovascularization—was suggested to replace polypoidal choroidal vasculopathy, but the group could not reach an agreement beyond the general inaccuracy of the current term.
Importantly, CONAN notes that ocular coherence tomography (OCT) and OCT-angiography (OCT-A) should not replace fluorescein angiography or color photography; rather, OCT and OCT-A should be considered complimentary imaging, providing clinicians with additional data to help classify disease type and staging.
The group also recommends diagnosing AMD by patient and not by eye because measures to stave-off AMD development and progression, such as vitamin supplements, are given to the whole person.
Finally, the CONAN group acknowledges that to keep pace with advances in imaging modalities, these standardized definitions must be updated as clinician understanding of AMD pathology improves.
1. Spaide RF, Jaffe GJ, Sarraf D, et al. Consensus Nomenclature for Reporting Neovascular Age-Related Macular Degeneration Data: Consensus on Neovascular Age-Related Macular Degeneration Nomenclature Study Group. Ophthalmology 2019 Nov 14. pii: S0161-6420(19)32243-2. doi: 10.1016/j.ophtha.2019.11.004. [Epub ahead of print]
2. Ferris FL, Wilkinson CP, Bird A, et al. Clinical classification of age‐related macular degeneration. Ophthalmology 2013; 120: 844–851.