According to a study published in the Survey Of Ophthmalogy, cataract surgery is directly related to the progression of age related macular degeneration (AMD). The study reviewed previous published literature on both cataract surgery and macular degenertion in making the conclusion.
The literature review examined all scientific literature published on both cataract surgery and macular degeneration. Only seven research studies were found that were deemed suitable for the literature review.
Of the seven studies, none were randomized control trials, but according to the researchers, there were ethical conditions that led to the lack of randomized control trials. Conducting such tests would have meant depriving patients of cataract surgery, and the benefit of performing the surgery outweighed the need for randomized control trials. Given this, the studies selected were probably the best possible research necessary when examining the question of how cataract surgery impacts the progression of macular degeneration from early to late stage macular degeneration.
Of the seven studies, two were small observational studies with several methodological or analytical deficiences. One of these studies did however find an increased risk of developing late stage macular degeneration after cataract surgery.
Two other studies were clinical trials that examined whether or not macular degeneration worsened as a result of cataract surgery. These studies followed patients for only 1 year following the surgery and had several other methodological deficiencies that limited their scientific value. Neither of these studies concluded that cataract surgery increased the risk of macular degeneration progression.
However, given all the deficiencies, the authors of the literature review were able to conclude that the best available scientific evidence available indicates that cataract surgery does increase the risk of macular degeneration progressing from early to late stage macular degeneration.
Source: Survey of Ophthalmology, 2008 Jul-Aug;53(4):359-67