Abstract
Purpose: :
Genetic changes in the complement cascade have been associated with AMD and rare renal diseases such as membranoproliferative glomerulonephritis type 2. Since complement mediated inflammation and renal status may correlate with disease severity and progression in age-related macular degeneration (AMD), we investigated renal function and C-reactive protein levels in patients with dry AMD enrolled in the COMPLement Inhibition with Eculizumab for the Treatment of Non-Exudative Age-Related Macular Degeneration (COMPLETE) Study.
Methods: :
Two cohorts of dry AMD patients were enrolled in the COMPLETE Study. Cohort-1 was comprised of eyes with GA measuring from 1.25 mm2 to 18 mm2 based on SDOCT fundus imaging. Cohort-2 was comprised of eyes with drusen in the absence of GA, and the drusen had a volume of at least 0.03 mm3 within a 3 mm diameter circle centered on the fovea based on SDOCT imaging. Drusen volume maps were obtained using SDOCT imaging (Cirrus, Carl Zeiss Meditec Inc.), the 200x200 scan pattern, and a proprietary algorithm. Ophthalmologic exams, ETDRS visual acuity testing, serologic testing, and imaging studies were performed at baseline and at follow-up months 3, 6, 9, and 12. Serologic testing included assessment of glomerular filtration rate (GFR), and C-reactive protein. Statistical analysis was performed using two-sample t-tests,Pearson correlations,and analysis of covariance.
Results: :
A total of 60 patients were enrolled in the study. Only one eye of each patient was included as a study eye, although fellow eyes meeting entry criteria were evaluated as a secondary endpoint. In Cohort-1, mean age 80 (SD=6) years, a total of 49 eyes met entry criteria: 30 study eyes and 19 fellow eyes. In Cohort-2, mean age 71 (SD=7) years, a total of 43 eyes met entry criteria: 30 study eyes and 13 fellow eyes. Mean GFR at baseline was 64.3 mL/min/1.73m2 (SD=17.0) in Cohort-1 and 78.3 mL/min/1.73m2 (SD=19.3) in Cohort-2 (p=0.004) but was not significant after adjusting for age (p=0.15). Mean C-reactive protein value at baseline was 0.57 mg/dL (SD=0.50) in Cohort-1 and 0.60 mg/dL (SD=0.86) in Cohort-2 (p=0.84). There were no significant correlations between the renal function parameters or C-reactive protein levels and baseline area of GA or baseline drusen volume (all p>0.25). The correlations between renal function and C-reactive protein and growth rates of lesions are currently being evaluated.
Conclusions: :
At baseline, disease severity did not correlate with renal function or C-reactive protein levels in each cohort. Whether these parameters are predictive of disease progression in each cohort remains to be determined.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00935883
Keywords: age-related macular degeneration