To evaluate levels of complement factors in human vitreous of eyes with retinal detachments (RDs) and proliferative diabetic retinopathy (PDR) eyes.
Human vitreous samples were collected from eyes undergoing routine vitrectomy at the University of Colorado Health Eye Center (Aurora, CO). Complement factor D, component C5/C5a, and component C9 levels were measured using enzyme-linked immunosorbent assay and multiplex assays. Retinal detachment and PDR eyes were compared with controls, which were defined as eyes with macular holes or epiretinal membranes.
The levels of complement factor D in PDR (mean = 2,110.0 ng/mL, P = 0.001) and RD (mean = 660.9 ng/mL, P = 0.03) eyes were statistically significantly higher than controls (mean = 290.5 ng/mL). The levels of complement component C9 were also more elevated in PDR (P = 0.004) compared with control but not in RD eyes.
Elevated complement factors, particularly of the alternative pathway, were noted in PDR and RD eyes compared with controls. One potential explanation for this is that the oxidative stress in RD and PDR eyes leads to complement dysregulation and alternative complement upregulation.
Complement factor levels were measured from human vitreous aspirates from patients undergoing routine vitrectomy for various retinal pathology. Markedly elevated complement factors, particularly of the alternative pathway, were noted in patients with proliferative diabetic retinopathy and retinal detachment.
Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado.
Reprint requests: Niranjan Manoharan, MD, Rocky Mountain Lions Eye Institute, 1675 Aurora Court, Mailstop F731, Aurora, CO 80045; e-mail: Niranjan.Manoharan@ucdenver.edu
Supported in part by a challenge grant from Research to Prevent Blindness to the Department of Ophthalmology. No other specific grant was received from any funding agency in the public, commercial, or not-for-profit sectors.
None of the authors has any conflicting interests to disclose.