Abstract
Purpose:
Whether cataract surgery affects the progression of age-related macular degeneration (AMD) is controversial. This study tests whether the grade of AMD and the number of mitochondrial (mt) DNA lesions, which has been shown to be increased in more advanced AMD, differ in human donor eyes that have undergone cataract surgery compared to those that have not.
Methods:
Human donor eyes (n=99) were obtained from the Minnesota Lions Eye Bank, as approved by the Institutional Review Board at the University of Minnesota. Donor age, gender, race, smoking status, and history of cataract surgery were obtained from Eyebank records. The stage of AMD was determined using the Minnesota Grading System. mtDNA analysis was performed on DNA isolated from macular punches of retinal pigment epithelium (RPE). The associations between (1) cataract surgery and AMD grade and (2) cataract surgery and mtDNA lesions were tested with regression models and analysis of variance (ANOVA). Models were adjusted for known risk factors for AMD (age, Caucasian race, female gender, and smoking status).
Results:
There is no significant difference in mtDNA lesions in donor eyes based on prior cataract surgery (p=0.70). A regression model with mtDNA lesions as the dependent variable and cataract surgery status, AMD grade, age, smoking, and gender as the independent variables shows that AMD grade is the only studied variable with a statistically significant association with mtDNA lesions (p<0.001). A regression model with AMD grade as the dependent variable and cataract surgery status, mtDNA lesions, age, smoking, and gender as the independent variables shows that only age (p=0.01) and mtDNA lesions (p<0.001) have a statistically significant association with AMD grade.
Conclusions:
In this study, (1) cataract surgery is not associated with an increase in mtDNA damage, and (2) cataract surgery, after adjusting for age, is not associated with increased stage of AMD. These results provide additional support to the growing body of evidence that concerns about AMD progression should not preclude cataract surgery.