Incidence of cataract surgeries in people with and without Alzheimer's disease

Purpose To investigate the incidence of cataract surgeries in relation to Alzheimer's disease (AD) diagnosis and to compare it with that in people without AD. Methods The MEDALZ-study includes community-dwelling Finnish persons who received clinically verified AD diagnoses (n = 70718) during 2005-2011 and a matched comparison cohort without AD (n = 70718). The cataract surgeries were identified from the Care Register for Healthcare (1996-2015) using NOMESCO surgical procedure codes CJE (10,15,20,25,99), CJF (00,10,20,30,40,45,50,55,99) and CJG (00,05,10,15,20,25,99). The incidence rates for surgeries per 100 person-years were calculated from 10 years before to 3 years after the index date (date of AD diagnosis from the Special Reimbursement Register). Results 25 763 cataract procedures were performed on persons with AD and 26 254 on persons without AD during the follow-up. The incidence of surgery increased similarly in both groups before the index date of AD diagnosis, and the rate of surgery was similar in people with and without AD (3.5 and 3.3/100 person-years, respectively). The incidence diminished steeply in the AD group already one year after the index date, whereas the slow increase continued in the non-AD group. After the index date, the rates were 3.7 and 4.7/100 person-years in people with and without AD. Conclusion The diminishing surgery rate very soon after AD diagnosis is concerning. The stigma of AD diagnosis may lead to fewer referrals to surgery, although these patients are expected to benefit from surgery.