Abstract
Purpose: :
1. To assess the risk of CNV due to age–related macular degeneratiom following cataract surgery. 2. To assess the presence of known risk factors such as smoking, family history, high Body Mass Index (BMI), hypertension, and raised cholesterol in these patients.
Methods: :
We assessed whether unilateral pseudophakia was a risk factor for the development of CNV. A group of patients presenting to a UK, Photodynamic therapy (PDT) center, between April–Oct 2005 was analysed. Patients were identified from a PDT and a Fundus Fluorescein Angiogram database. Those who had developed CNV within 5 years of unilateral cataract surgery were selected. We compared the incidence of CNV between the two eyes using un–operated fellow eyes as controls. Stastical analysis was done using Fishers exact test.
Results: :
One hundred and ninety three patients with CNV (105 classic; 88 occult) were identified. Patients were aged between 76–94 years (Mean, 84 yr), male to female ratio; 1:3. Twenty–eight eyes (20 patients) had undergone cataract surgery in previous five years; 22 of these eyes developed CNV (78.5%); among the 15 un–operated eyes, 3 eyes developed CNV during the same period (20%). Operated eyes were statistically more likely to develop CNV than the control eyes (p= 0.0003). Average time interval between surgery and development of CNV was 27 months (range: 1–60 months). Silicone, Hydrogel, and Acrylic lenses were used in these patients. There was no statistical difference in the incidence of CNV between these lenses (p=0.4). All the study and control eyes had pre–existing age–related maculopathy. One–third of patients were either current or ex–smokers. 11 patients had higher BMI (>25). 14 patients were hypertensive controlled on medication. Three patients were on cholesterol lowering agents.
Conclusions: :
Our study shows that CNV will typically present in the pseudophakic eye of patients with unilateral cataract surgery. As the patients’ non–operated eye acts as a control, this study suggests cataract surgery is associated with increased risk of developing CNV. All the intra ocular lenses in this study had UV filters; none had a yellow tint. Increased BMI, hypertension and smoking are potential risk factors.
Keywords: age-related macular degeneration • choroid: neovascularization • cataract