Purpose: To analyze intraocular growth factor and cytokine concentrations in eyes with different stages of age-related macular degeneration (AMD) compared with controls.
Methods: The Clinical Age-Related Maculopathy Staging (CARMS) system was used for assignment of patients into the respective categories. Aqueous humor specimens were taken before cataract surgery in 21 controls (CARMS 1) and in 17 early (CARMS 2) and 16 intermediate (CARMS 3) AMD patients. In 18 neovascular (CARMS 5) AMD patients, specimens were taken immediately before anti–vascular endothelial growth factor intravitreal therapy. Luminex multiplex bead assays were conducted for endostatin, angiogenin, vascular endothelial growth factor, platelet-derived growth factor AA, placental growth factor, thrombospondin 2, and fibroblast growth factor a.
Results: Vascular endothelial growth factor concentrations were elevated in CARMS 3 (P = 0.037) and tended to be elevated in CARMS 5 (P = 0.093), whereas levels in CARMS 2 (P = 0.425) were similar to CARMS 1. Platelet-derived growth factor levels were diminished in CARMS 2 (P = 0.020), with a trend to lower levels for CARMS 3 (P = 0.099) and CARMS 5 (P = 0.082) compared with CARMS 1. For CARMS 5, antiangiogenic endostatin was elevated (P < 0.002), while antiangiogenic thrombospondin 2 was reduced (P = 0.029).
Conclusion: Clinical Age-Related Maculopathy Staging 3 dry AMD was associated with higher vascular endothelial growth factor levels than CARMS 5 neovascular AMD. Therefore, intraocular vascular endothelial growth factor concentrations do not seem to reflect choroidal neovascularization activity in neovascular AMD directly. Platelet-derived growth factor was decreased in most forms of AMD. The antiangiogenic endostatin was exclusively elevated in neovascular AMD, while thrombospondin 2 was reduced. Age-related macular degeneration disease seems to be associated with a generally altered cytokine system.
Higher vascular endothelial growth factor levels were found in intermediate dry age-related macular degeneration (AMD) than in active neovascular AMD compared with controls. Reduced platelet-derived growth factor (PDGF) levels were associated with most forms of AMD, whereas endostatin was exclusively elevated in neovascular AMD. Age-related macular degeneration disease seems to be associated with an altered cytokine system.
*Department of Vitreoretinal Surgery, Center of Ophthalmology, University of Cologne, Cologne, Germany; and
†Eye Department, Red Cross Hospital, Munich, Germany.
Reprint requests: Philipp S. Muether, MD, Department of Vitreoretinal Surgery, Center of Ophthalmology, University of Cologne, 50924 Cologne, Germany; e-mail: firstname.lastname@example.org
Supported by the Koeln Fortune Program/Faculty of Medicine, University of Cologne. Additional support was provided by Gilen, Nolting, and Imhoff Foundation.
The authors have no conflict of interest to disclose.