Cataracts and age-related macular degeneration are common causes of vision loss that often coexist in patients over 65 years of age. With the aging of the population, the prevalence of these pathologies increases. This highlights the importance of understanding the relationship between cataract surgery and AMD.
Cataract surgery is one of the most common procedures in the United States, the effectiveness of this procedure in improving visual acuity and quality of life of patients has been widely demonstrated.
Although effective treatments for atrophic AMD continue to be investigated, the introduction of anti-vascular endothelial growth factor agents revolutionized the treatment of neovascular AMD and its outcomes.
The relationship between cataract surgery and AMD has been studied extensively, although the results obtained in crossover studies report an increased risk of late AMD after cataract surgery, those based on clinical results have not found an association.
The present study attempts to provide a brief summary of the latest evidence related to this association, to facilitate decision-making by professionals.
Although it is not proven , there are theoretically two mechanisms that could lead to the development or progression of AMD after cataract surgery: blue light toxicity and inflammation.
Ultraviolet or blue light causes macular phototoxicity; cataracts absorb most short waves of light, protecting the macula from its harmful effects.
After cataract surgery, this natural filter is replaced with the implant of IOLs that provide less protection against ultraviolet light. This led to the use of yellow IOLs that block blue light, however there is no evidence to date that this works.
Inflammation plays an important role in the pathogenesis of AMD. Iatrogenic inflammation induced during cataract surgery could favor the development or progression of AMD. This theory would have been more likely with the old technique of cataract surgery with extracapsular extraction, which caused greater inflammation than modern phacoemulsification.
It is important to keep in mind that crossover studies cannot determine a cause-effect relationship; however, in the latest crossover studies with at least 5 years of follow-up, there is no information that supports an association between cataract surgery and AMD.
The discrepancy between these studies and the first ones may be due to different surgical technique, advances in diagnostic technology (OCT), and differences between the populations studied.
A 2015 systematic review and meta-analysis of four studies by Kessel et al indicated that visual acuity was significantly better in AMD eyes undergoing cataract surgery than unoperated AMD eyes.
In patients with wet AMD and cataracts, there is concern that fluctuating IOP and inflammation associated with surgery could affect preexisting choroidal neovascular membranes and stimulate their development.
The studies consulted did not find major differences in the results of operated and non-operated patients, although the topic should continue to be investigated in greater depth.
The AREDS study reported a significant improvement in visual acuity in eyes undergoing cataract surgery with different levels of AMD. AREDS reported on the risk of advanced AMD after cataract surgery in 8050 eyes and the data showed no clear effect.
Although it is known that quality of life improves markedly after cataract surgery, it is not known if patients with AMD can expect the same benefits.
Stock et al found that cataract surgery in eyes with AMD improved visual function associated with visual quality, although vision recovery was less than in controls. Patients with preoperative visual acuity of 20/40 or better showed similar improvement to patients without retinal pathology.
Conclusions:
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