Abstract
Purpose :
Wet Age-related Macular Degeneration (AMD) encompasses a broad spectrum of chorio-retinal disease. Wet AMD has a variable presentation, variable response to therapy, and variable prognosis. Retinal Angiomatous Proliferation (RAP) results from neovascularization originating within the retina in contrast to the more common presentation of neovascularization that originates within the choroid. We have previously identified differences in the vitreous proteome between eyes with RAP and CNV. Given these differences, we now ask whether the total protein levels of the vitreous might also differ between RAP and CNV.
Methods :
We analyzed vitreous samples of patients undergoing intravitreal injection for wet AMD during an IRB approved study. Each vitreous sample was acquired immediately prior to intravitreal injection. Total protein levels were calculated using the Pierce 660 nm Protein Assay (Thermo Scientific, NanoDrop 2000). Spectral Domain-OCT, Fundus Fluorescein Angiography, Indocyanine Green Angiography, Fundus Autofluorescence and Infrared Fundus Photography were conducted preceding each treatment. 2283 samples were collected from 518 eyes of 441 patients between the period from 1/1/07 to 9/15/15. We examined the clinical presentation of eyes observed to have a total protein level of 4.0mg/mL or greater to determine the presence or absence of a RAP lesion.
Results :
The average vitreous total protein found in 2283 samples from 518 eyes of 441 patients with wet AMD was 0.81 mg/mL. A total vitreous protein level > 4.0 mg/mL was identified 25/518 (5%) of eyes. Of those eyes with elevated vitreous protein 14/25 (56%) were found to have angiographically, tomographically, or photographically demonstrable RAP lesions.
Conclusions :
Patients with elevated vitreous total protein levels were found to have RAP lesions at an incident rate well above that reported in nAMD. The influence of RAPs upon the vitreous proteomome supports the hypothesis that RAPs are an aggressive vascular proliferation of inner retinal origin and thus in close proximity to the vitreous body. This association further suggests the potential utility of vitreous proteomics that might assist in the understanding of AMD and other retinal disorders.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.