Vision screening in primary care: Flawed methodology, dangerous recommendations.

Guidelines in medicine can be very powerful. They consolidate vast amounts of knowledge – the magnitude of which may be difficult if not impossible for an individual physician to do – into concise recommendations. The process requires input from many experts, including those who understand the subject of interest; individuals with a knowledge of health-care delivery in the geographic region where the guidelines apply; and experts in data analysis. When done well, guidelines can result in more efficient and uniform delivery of health care that is evidence-based.

The Canadian Ophthalmological Society, which represents all ophthalmologists in Canada, recognizes the importance of guidelines but also appreciates the challenges around them. For guidelines to be effective, they need to involve a variety of stakeholders with varying expertise from the beginning to ensure inclusion of all the evidence and consideration of issues where there may not be published data. Failure to do this may result in recommendations that are potentially dangerous and create confusion among health-care providers if guidelines are in conflict.

This occurred with the 2018 Canadian Task Force on Preventative Health Care guideline on vision screening for adults. Its recommendation was against screening for impaired vision in primary health care for adults aged 65 or older, including simply inquiring about a patients’ vision. Given the importance of preventative health and the increased prevalence of eye disease with aging, it is difficult to understand how such a strong conclusion could have been made for an intervention of minimal cost and risk.

Literature to support the recommendation came partly from studies outside of Canada and from misinterpretation of Canadian data. Since health-care delivery is different in Canada, this needs to be considered when interpreting studies performed elsewhere. Those making the recommendations were not aware that routine eye exams for seniors are not covered in several provinces. This has resulted in an increased role for primary care providers in vision care since more than 50 per cent of the population aged 65+ in these provinces are not seeing an eyecare professional. This is a significant issue as the prevalence of eye disease is known to increase with age.

The task force states that physicians are too conflicted to make recommendations related to health care. For this reason, ophthalmologists were excluded from the process that ultimately resulted in flawed methodology, inaccurate data interpretation and dangerous recommendations. Although there may be a degree of conflict of interest, this should be able to be managed without excluding an important physician resource.

Excluding physicians who manage the disease of interest in guideline development is, for lack of a better word, very shortsighted.