The delisting of routine eye exams from the Ontario Health Insurance Plan (OHIP) for healthy adults under age 65 has resulted in lower rates of recommended eye screening for people with diabetes, states a study published in CMAJ - even though eye exams for people with diabetes are still covered (Canadian Medical Association Journal).

Medical guidelines recommend that people with diabetes have a dilated eye exam every 1-2 years to screen for diabetic retinopathy. Diabetic retinopathy is the major cause of blindness in adults and is the result of damage caused by diabetes. Early detection and treatment of retinopathy through regular eye exams in which the pupil is dilated can significantly reduce the likelihood of blindness.

"Health policy experts suggest that delisting services from insurance schemes can have unpredictable effects," writes Dr. Tara Kiran, a family doctor and researcher at St. Michael's Hospital and research fellow at the Institute for Clinical Evaluative Sciences in Toronto. "Understanding the effect of delisting on care is particularly important as governments face fiscal pressures and contemplate further reductions in what is publicly insured."

As of Nov. 1, 2004, OHIP no longer funded annual eye exams for adults aged 20-64 years, although they are still fully funded for children and seniors. Adults with diabetes, those with other conditions that affect the eyes and people receiving social assistance are still eligible for annual exams.

Researchers looked at data on publicly funded eye exams of adults aged 40 and over with diabetes in Ontario, Canada's largest province, to determine whether delisting annual exams for healthy middle-aged adults affected screening for retinopathy in patients with diabetes. They found that eye exam rates for people aged 40-65 years remained steady at 69% between 1998 and 2004 but dropped after delisting to 61% in 2006 and remained low at 57% in 2010.

"We found a marked and persistent decrease in publicly funded eye examinations for residents of Ontario with diabetes aged 40-65 years after routine eye examinations were delisted from OHIP for healthy adults in that age group," write the authors. "This trend was seen even though examinations continued to be insured for these patients."

The drop in eye exams was mostly due to fewer exams being done by optometrists. The authors hypothesize that this was likely due to a misunderstanding by patients and health care providers who may have thought that eye exams done by an optometrist were not covered for people with diabetes. Patients may also have been inadvertently or inappropriately charged for a publicly insured service, something the authors were not able to study. The number of eye exams did not decrease in people over the age of 65 years, a group not affected by delisting.

"The decision to delist routine eye examinations for healthy adults in Ontario was made ostensibly to reduce public expenditure on nonessential health services; however, it had the unintended consequence of reducing appropriate use of publicly funded health services," state the authors.

"In this time of fiscal restraint, policy-makers will increasingly debate which services are 'medically necessary' and warrant coverage. Some limitations of services may be rational and justified, but policy-makers will need to be mindful of the unintended consequences of delisting services from insurance schemes and the potential impact on health equity. Policy changes need to be accompanied by better and more effective communication strategies to decrease misunderstanding among patients and health care providers," conclude the authors.