Subspecialization in glaucoma surgery

Purpose: To evaluate trends in glaucoma surgery subspecialization.

Design: Population-based analysis of incisional glaucoma surgery and laser trabeculoplasty practice patterns among all ophthalmologists in Ontario, Canada, from 1995 through 2010.

Participants: All ophthalmologists in Ontario, Canada, providing universal health care for the provincial population of approximately 12 million.

Methods: The province of Ontario provides government-funded universal health care insurance to all citizens through the Ontario Health Insurance Plan (OHIP). Anonymized physician services data were obtained from the OHIP database, which has excellent accuracy for procedure performance.

Main outcome measures: Proportion of ophthalmologists providing incisional glaucoma surgery and laser trabeculoplasty and the distribution of these surgical and laser procedures among ophthalmologists.

Results: Between 1995 and 2010, the median number of ophthalmologists in Ontario was 427 (35.1 per 1 million population), ranging from 417 to 453 (32.9-40.3 per 1 million population). The percentage of ophthalmologists providing incisional glaucoma surgery dropped from 35% in 1995 to 19% in 2010, a 47% decline. Over the same period, the mean number of incisional glaucoma surgeries performed per surgeon doubled, and the percentage of incisional glaucoma operations provided by high-volume surgeons rose from 23% to 59%. The percentage of ophthalmologists performing laser trabeculoplasty was relatively stable (48% in 1995 to 50% in 2010).

Conclusions: Over the past 16 years, the proportion of ophthalmologists providing incisional glaucoma surgery has declined significantly. At the same time, the proportion of incisional glaucoma surgery provided by high-volume glaucoma surgeons has more than doubled. These trends will have important implications for stakeholders from policy makers and hospitals to academic departments and residency education programs.