Changes in drusen and retinal layer volumes prior to CNV development
Reviewed by Ed Rule

This retrospective longitudinal study looked at patients with wet age-related macular degeneration (AMD) in one eye who subsequently developed wet AMD in the fellow eye. The aim was to discover whether drusen characteristics or volumes of retinal layers correlate with the development of either classic or occult choroidal neovascularisation (CNV) in the fellow eye. The authors identified 49 patients with unilateral wet AMD who developed classic or occult CNV in the fellow eye, and who had at least two years of follow-up. Three OCT scans were used from the two years prior to CNV development; at baseline, year one and year two. OCT data was analysed to determine the number of drusen, their area and volume, and the volume of retinal layers. There was no difference in the number, area or volume of drusen between eyes that developed classic versus occult CNV. However, eyes that developed occult CNV had a significantly greater increase in drusen area and volume between year one and two compared to eyes that developed classic CNV. Eyes that developed classic CNV also had significantly thinner outer nuclear layers compared to those that developed occult CNV. This study is limited by being retrospective and having a small sample size. It does, however, add weight to the possibility of using OCT as a prognostic indicator of different subtypes of CNV.

Association of longitudinal changes in drusen characteristics and retinal layer volumes with subsequent subtype of choroidal neovascularisation.
Lamin A, El Nokrashy A, Chandra S, Sivaprasad S.
OPHTHALMIC RESEARCH
2020;63(4):375-82.