Does cataract surgery (CSG) increase the risk of incident age-related macular degeneration (AMD)?

Abstract

Purpose : Population-based studies have reported equivocal findings of the impact of CSG on AMD development. We examined whether CSG increased the risk of incident AMD in a well-characterized population-based cohort of Singapore Malays, Indians and Chinese.

Methods : We included 3,561 adults (48.2% males, mean age [SD]: 55.8 [9.2] years) from the Singapore Epidemiology of Eye Diseases Study, with gradable retinal photographs and relevant data at baseline and follow-up examinations (mean [SD] follow-up duration: 6.3 [0.9] years). CSG was defined as the presence of intraocular implant (pseudophakia) or absence of crystalline lens (aphakia) recorded on slit lamp lens assessments by the study ophthalmologists. Where CSG was absent at baseline but present at follow-up, we classified such eyes as having received CSG in the primary analysis, but examined how their exclusion impacted conclusions. Fundus photographs were graded for AMD severity using the modified Wisconsin Age-Related Maculopathy Grading System into no, early or late AMD. Based on baseline and follow-up presentation, we defined three outcomes, incident any AMD (no to early/late), incident early AMD (no to early) and incident late AMD (no/early to late). Eye-level data with general estimating equations were used to determine the relationship of CSG with these outcomes, adjusting for early AMD signs such as drusen and risk factors that may have been indicators for initiating CSG, such as undercorrected refractive error.

Results : Out of 6,682 eyes with no AMD at baseline, 244 (3.7%) eyes developed any AMD, of which 229 (3.3%) had incident early AMD. Out of 6,879 eyes with no/early AMD at baseline, 29 (0.4%) eyes developed late AMD. CSG was present in 352 (5.1%) eyes at baseline and 469 (6.8%) eyes had incident CSG. In multivariable-adjusted models, CSG was associated with higher risk of incident late AMD (relative risk 3.41, 95% confidence interval [CI]: 1.35-8.62). After excluding eyes with incident CSG, CSG at baseline was independently associated with higher risk of any, early and late AMD (relative risk of 1.62 (95% CI: 1.03-2.55), 1.63 (95% CI: 1.02-2.58) and 4.00 (95% CI: 1.11-14.37), respectively).

Conclusions : CSG is associated with higher risk of incident any, early, and late AMD, independent of traditional risk factors. This may guide clinicians advising patients considering CSG, particularly those at high risk of developing late-stage AMD.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.