Charles Wright and colleagues1 are to be commended for the model of health outcome measures that they have developed for examining the appropriateness of elective surgical procedures. However, we have some concerns about the tool used to assess cataract surgery. The VF-14 index is very sensitive when used appropriately, but it was not designed to determine who needs surgery. Previous studies of preoperative visual function have obtained findings similar to those of the Wright study, that is, that about 20% to 30% of people have a high score on the visual function test.2 However, such results do not necessarily mean that these patients do not need surgery. The VF-14 index is a composite measure for reading, driving, playing sports, watching television and other activities, and as such it does not clearly identify people with a significant deficit in just one of these domains who would benefit from surgery.
Ocular comorbidity, which was present in up to 50% of all cataract patients in the cohort studied (Ken Bassett, Associate Professor, Department of Ophthalmology, University of British Columbia: personal communication, 2003), predicts poor outcomes. So does old age. Such comorbidity does not mean that surgery is inappropriate, but the VF-14 index does not capture patient satisfaction after surgery in such cases.
Finally, the authors did not emphasize that ophthalmologists have reported visual improvement in 92.4% (786/851) of patients at the University of British Columbia Eye Care Centre (essentially the same patients as were included in the Regional Evaluation of Surgical Indications and Outcomes study), whereas in 4.9% they reported no change in visual acuity (Ken Bassett: personal communication, 2003). Similarly, Wright and colleagues were not able to report the level of satisfaction that could have been determined by asking “Do you think this surgery was helpful and has it added to the quality of your life?” We are disappointed that these issues were not fully addressed in the Interpretation section of this paper, nor, apparently, was such a discussion requested by the peer reviewers.
Raymond P. LeBlanc Chair National Coalition on Vision Health Toronto, Ont.
References
- 1.Wright CJ, Chambers GK, Robens-Paradis Y. Evaluation of indications for and outcomes of elective surgery. CMAJ 2002;167(5):461-6. [PMC free article] [PubMed]
- 2.Steinberg EP, Tielsch JM, Schein OD, Javitt JC, Sharkey P, Cassard SD, et al. The VF-14. An index of functional impairment in patients with cataract. Arch Ophthalmol 1994;112:630-8. [DOI] [PubMed]