Campbell and colleagues have provided a valuable study evaluating trends in glaucoma surgery in the most populated province of Canada. The number of incisional glaucoma surgeries remained fairly stable from 1995 to 2010, but the proportion of ophthalmologists performing these procedures declined by 47%. In contrast, the percentage of ophthalmologists providing laser trabeculoplasty remained relatively unchanged during the same time period. The study's findings suggest that comprehensive ophthalmologists are progressively limiting their scope of practice and referring glaucoma surgical cases to subspecialists. However, a specific breakdown of the number of procedures performed by glaucoma specialists and general ophthalmologists is not presented to confirm this assumption (and may not be available from the Ontario Health Insurance Plan database). The apparent shift in practice patterns may relate to a greater availability of glaucoma specialists in Ontario. It would be interesting to know whether there was a rise in the number of graduating ophthalmology residents in Canada who sought glaucoma fellowship training during the same time period. A trend towards increasing subspecialty training in glaucoma would be consistent with a wider availability of glaucoma specialists in this region. Alternatively, many general ophthalmologists may have chosen to avoid performing glaucoma surgery for other reasons. Trabeculectomy and aqueous shunt surgery (the two procedures examined in this study) are known to be associated with a significant risk of complications and require intensive postoperative care. Surgeons may have elected to not perform these glaucoma procedures in favor of less labor-intensive operations with lower medico-legal exposure.
The recent introduction of micro-invasive glaucoma surgery (MIGS) may dramatically affect the observed trends. These procedures were excluded from the present study because they were infrequently performed, but this may change over the next several years. MIGS have a lower risk of surgical complications and require less rigorous follow-up care than traditional glaucoma surgery. These newer procedures may be adopted by comprehensive ophthalmologists and redistribute the provision of glaucoma surgical treatment. It should also be remembered that Ontario offers government-funded universal health care insurance to all citizens, and the results of this study may not be applicable to other countries with different health care systems. Furthermore, health care reform is occurring at a rapid pace in many areas of the world raising questions about how glaucoma care will be delivered in the future.