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Ophthalmologists who perform more cataract surgeries have better patient outcomes


A new Institute for Clinical Evaluative Sciences (ICES) study shows that Ontario cataract patients who are treated by ophthalmologists that perform a high volume of the surgeries are less likely to experience post-operative complications.

“There are few volume-outcome studies in the field of ophthalmology compared with other surgical specialties, despite the relatively large surgical volume of these physicians,” said Dr. Chaim Bell, ICES adjunct scientist and lead author of the study.

In order to take a more detailed look at this issue, investigators identified Ontarians 20 years and older who underwent cataract surgery between April 2001 and March 2004, as well as ophthalmologists who performed more than 50 cataract surgeries annually during this time period. They examined whether there was an association between the number of cataract surgeries performed and the rate of post-operative complications within the first two weeks following the surgery.

The number of cataract surgery procedures in Ontario increased from 89,556 in 2001/02 to 99,333 in 2003/04, and the number of ophthalmologists who performed more than 50 cataract operations annually in Ontario ranged from 231 to 243 over the three years. In each year during the study period, less than one in 200 patients experienced a complication. The rate of complications varied between eight per 1,000 patients treated by surgeons who performed 50 to 250 cataract surgeries per year, to one per 1,000 patients treated by surgeons who performed more than 1,000 cataract surgeries per year.

These better outcomes for patients of ophthalmologists who perform higher volumes of cataract surgeries were also present when complications were analyzed separately, and were not explained on the basis of variations in patient age or gender.

“It is important to note that these findings describe a general trend and may not be applicable to some individual surgeons. Patients are encouraged to speak with their surgeon or ophthalmologist regarding his/her rate of surgical complications,” said Dr. Bell.

“Nevertheless, our results may be helpful for professional organizations and policy makers to formulate recommendations about the appropriate number of cataract surgeries required for surgeons to maintain a high level of proficiency.”

The study, “Surgeon volumes and selected patient outcomes in cataract surgery”, is in the March 2007 issue of the journal Ophthalmology.

Author affiliations: ICES (Drs. Bell, Cernat and Urbach), Department of Medicine (Dr. Bell), Department of Health Policy, Management and Evaluation (Drs. Bell and Urbach), Department of Ophthalmology and Vision Sciences (Dr. Hatch), and Department of Surgery (Dr. Urbach), University of Toronto; St. Michael’s Hospital (Dr. Bell); University Health Network (Drs. Urbach and Hatch); Cancer Care Ontario (Dr. Urbach).

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.      


  • Julie Dowdie
  • Media Relations Officer, ICES
  • (416) 480-4780 or cell (416) 432-8143


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