Cataract Surgery More Common in Patients With Parkinson Disease Prior to Diagnosis

An elevated incidence of cataract surgery was shown to precede diagnosis of Parkinson disease, according to study findings published yesterday in Archives of Gerontology and Geriatrics.

Among the motor and nonmotor symptoms involved in the pathophysiology of PD, visual dysfunction is a common issue for patients, including decreased visual acuity, contrast sensitivity, and color discrimination. Patients with PD additionally have higher prevalence of cataract compared with the general older population, which if left untreated can result in poor vision and vision loss.

“People with PD may be less likely to be referred for cataract surgery, although early management increases chances for successful cataract surgery in patients. Previous studies have shown that people with cognitive disorders are less likely to receive cataract surgery, with steep decrease in surgery rates after Alzheimer disease diagnosis,” said the study authors.

“Prevention of visual loss is important, because poor vision is associated with cognitive decline, and cataract surgery might also improve cognitive functioning in persons with cognitive disorders. Visual impairment also increases the risk of falls and reduces life expectancy among persons with PD.”

With no available evidence on whether cataract surgery rates differ between people with and without PD, or when the difference emerges, they examined these associations via data from the nationwide register-based Finnish study on PD (FINPARK), which includes 22,189 persons with clinically confirmed PD diagnosis between 1996 and 2015 who were community dwelling at the time of diagnosis.

Of this cohort, individuals who were younger than 45 years at the beginning of follow-up were excluded, resulting in 17,546 persons with PD who were compared with 114,817 controls matched for age, sex, and hospital district on the date of PD diagnosis (index date). More than half of the study cohort were women (53%) and the average age at the beginning of follow-up was 64.4 years. The median follow-up times in the PD and comparison cohorts were 13.2 and 14.2 years, respectively.

Incidence of cataract surgeries was assessed from 10 years before to 10 years after the index date, with information on cataract surgeries and comorbidities extracted from several nationwide health care registers.

“The rate of surgery per 1000 person-years was calculated for the entire follow-up, and separately for time periods before the index date and after the index date using stptime command of STATA,” explained the study authors.

During the entire follow-up, a total of 5882 cataract procedures were performed on persons with PD and 38,854 on persons without PD, with a slightly higher incidence rate in the PD cohort (20.4 surgeries per 1000 person-years) than in the comparison group (18.7 surgeries per 1000 person-years; incident rate ratio [IRR], 1.09; 95% CI, 1.06-1.12; P < .001).

A minority of the procedures (2723 and 15,070 on persons with and without PD, respectively) were performed before the index date. The rate of surgeries was more than 20% higher in people with PD vs controls (incidence rate, 16.5 vs 13.7 surgeries per 1000 person-years; IRR, 1.21; 95% CI, 1.16-1.26) before the index date.

After the index date, 3159 and 23,784 cataract surgeries were performed on persons with and without PD, respectively. No difference in the incidence rate was observed after PD diagnosis for those with and without PD (28.7 vs 29.0 surgeries per 1000 person-years; IRR, 0.99; 95% CI, 0.95-1.03).

“Persons who had undergone cataract surgery were older and had more eye diseases and other comorbidities compared to those without surgery,” noted researchers. “In addition, other comorbidities such as cardiovascular diseases and hearing problems were more common among those who underwent cataract surgery.”

The generalizability of the results and lack of detailed individual-level data available in traditional longitudinal studies were cited as limitations of the analysis. Researchers concluded that the possibility of developing PD should be considered in older persons with unexplained eye symptoms.

Reference

Lampela P, Tolppanen AM, Kaarniranta K, Hokkinen K, Hartikainen S. Incidence of cataract surgeries in relation to diagnosis of Parkinson’s disease. Arch Gerontol Geriatr. Published online October 17, 2022. doi:10.1016/j.archger.2022.104842