Projecting the Growth of Cataract Surgery During the Next 25 Years

Cataract surgery is the most frequent surgical procedure performed in many countries, providing significant improvements in quality of life to seniors at a low cost.^1,2 While the aging population is expected to burden all areas of health care, ophthalmologists provide approximately 90% of their procedure-based services to seniors, making this specialty particularly vulnerable.³ Further, among surgical specialties, ophthalmology will experience the greatest growth in demand for services in coming years.^3,4 As a result, projecting future cataract surgery needs is vital for health human resource, hospital, and surgical center management and planning. However, in many jurisdictions including the United States, predicting the number of operations needed to meet population demand is difficult because of a lack of population-based surgery data and because unmet demand—as reflected by growing wait times—is generally unknown.

In Ontario, Canada, the cost of cataract surgery is covered by universal health care insurance, and a recent government-mandated Wait Time Strategy (WTS) has provided population-based analyses of wait times for cataract surgery. Evidence suggests that the surgery rates achieved by the WTS are appropriate to meet population needs.⁵ We used this information to forecast cataract surgery rates needed in Ontario during the next 25 years. Because current and forecasted demographic characteristics in the United States and Ontario are very similar—with the number of seniors projected to more than double between 2010 and 2036^6,7—our predictions for Ontario can be used as a template to predict the need for cataract surgery in the United States as well.

Future cataract surgery rates were estimated by direct standardization of age- and sex-specific cataract surgery rates, obtained from the Ontario Health Insurance Plan Database, to Ontario's population projections.⁶ Ontario is Canada's largest province, with a population of about 13 million. Population projections were produced using a cohort-component method incorporating births, deaths, immigration, and emigration.⁶ In sensitivity analyses, we combined surgery rates from both 2004-2005 (before WTS) and 2006-2007 (during WTS) with 3 population projection scenarios (low, medium, and high growth). The study was approved by the Queen's University Research Ethics Board.

In the base case analysis, which combined medium population growth projections and 2006-2007 surgical rates, the number of cataract operations in Ontario was projected to increase from about 143 000 in 2006-2007 to 326 000 (128% growth) by 2036 (Figure 1). Projected increases in surgery ranged from 72% to 144% by 2036 (Figure 1). The proportion of cataract operations provided for older patients was projected to increase significantly, with the number of operations for patients aged 85 years and older more than tripling by 2036 (Figure 2).

Our findings suggest that maintaining cataract surgery rates provided under the Ontario WTS (2006-2007), a level consistent with meeting population demand⁵ will require a 128% growth in surgical volume in 25 years. Extrapolating this increase to the US population translates into approximately 4.3 million additional cataract operations per year needed in the United States by 2036.

Our most conservative estimate, which used pre-WTS base surgery rates and the low population growth projection scenario, forecasted a 72% increase by 2036. However, before the WTS, 10% of patients waited approximately a year for cataract surgery in Ontario.⁸ Therefore, calculating future needs using pre-WTS cataract surgery rates yields a considerable underestimate. Our projections also indicate that the proportion of operations provided for older patients will increase significantly. Because age is a risk factor for cataract surgical complications, this could lead to higher rates of adverse events.⁹ A limitation of our study is that our projection models did not consider changes in the threshold or indications for cataract surgery¹⁰ or population-level changes in risk factors for cataract other than age, such as UV radiation, smoking, heredity, and diabetes mellitus.

The need for cataract surgery in Ontario is likely to more than double during the next 25 years. Because demographic characteristics in the United States and other developed nations are similar to those in Ontario, analogous dramatic increases can be anticipated in the United States, the United Kingdom, Australia, and numerous other countries.¹¹ Strategies will need to be in place to meet the demand for this common, important, and cost-effective procedure, which helps to maintain the independence of seniors.

Correspondence: Dr R. J. Campbell, Department of Ophthalmology, Queen's University, Hotel Dieu Hospital, 166 Brock St, Kingston, Ontario, Canada K7L 5G2 (rob.campbell@queensu.ca).

Author Contributions: Drs Hatch and R. J. Campbell had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Funding/Support: Dr Bell is supported by a Canadian Institutes of Health Research and Canadian Patient Safety Institute chair in Patient Safety and Continuity of Care. Dr R. J. Campbell is supported by a Clinician Scientist Award from the Southeastern Ontario Academic Medical Organization and Queen's University. Drs Bell and R. J. Campbell are affiliated with the Institute for Clinical Evaluative Sciences, which is funded by an annual grant from the Ontario Ministry of Health and Long-term Care.

Role of the Sponsors: The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; or preparation, review, or approval of the manuscript.

Disclaimer: The opinions, results, and conclusions reported in this article are those of the authors and are independent from the sponsors. No endorsement by the Institute for Clinical Evaluative Sciences or the Ontario Ministry of Health and Long-term Care is intended or should be inferred.