Incidence of cataract surgeries in relation to diagnosis of Parkinson's disease

Background: Parkinson's disease (PD) causes also visual dysfunction including decreased visual acuity, even already at the prodromal phase of disease. Still, it has been suggested that persons with PD may be less likely to be referred for cataract surgery, although early management increases the chances for successful cataract surgery.

Methods: Data from nationwide register-based Finnish Study on Parkinson's Disease (N=22189) was used. This study included 17546 persons with PD diagnosed in 1996-2015 and 114817 comparison persons who were at least 45 years old. Comparison persons were matched for age (+/-1 year, sex and hospital district on the date of PD diagnosis (index date). Incidence of cataract surgeries was investigated from ten years before to ten years after the index date. Information on cataract surgeries and comorbidities were extracted from several nationwide healthcare registers.

Results: The incidence rate of cataract surgeries was 20.4/1000 and 18.7/1000 person-years (PY) for persons with or without PD, respectively. Before PD diagnosis, rate of surgeries was higher in persons with PD (incidence rate 16.5 vs 13.7 /1000PY, IRR, 95%CI 1.21, 1.16-1.26). After PD diagnosis there was no difference in the incidence rate. Persons who had undergone cataract surgery were older and had more eye diseases and other comorbidities compared to those without surgery.

Conclusions: Diagnosis of PD does not decrease the incidence of cataract surgeries. Conversely, the incidence may be increased prior to PD diagnosis, probably due to other eye diseases and prodromal symptoms of PD.