CTF Structured Abstract: Visual problems

Periodic health examination, 1995 update: 3. Screening for visual problems among elderly patients

Christopher Patterson, MD, FRCPC, Professor and Head, Division of Geriatric Medicine, McMaster University, Hamilton, Ontario

Objective
To provide recommendations to family physicians for screening elderly patients (over 65 years of age) for visual impairment and its common clinical causes.

Burden of Suffering
Visual impairment of some form affects 13% of elderly people; almost 8% of them have severe impairment (blindness in both eyes or inability to read newsprint even with glasses). About 1% of people over 40 years have bilateral blindness. In 1989, there were 63 576 people registered as legally blind in Canada. The leading causes of visual impairment in elderly people are presbyopia, cataracts, age-related macular degeneration (ARMD), glaucoma and diabetic retinopathy.

Options
Visual acuity screening with Snellen sight chart, funduscopy, retinal photography, tonometry and perimetry.

Outcomes
Delay or prevention of visual deterioration or blindness.

Evidence
MEDLINE was searched for articles published between January 1986 and December 1993 with the use of the following
headings and key words: glaucoma, glaucoma, suspect screening or vision screening, clinical trial, glaucoma-drug therapy, intraocular pressure-drug effect, timolol-administration and dosage, vision disorders, aged, diabetic retinopathy, age-related macular degeneration, cataract and retinal diseases.

Values
The 13-member Task Force of experts in family medicine, geriatric medicine, pediatrics, psychiatry and epidemiology used an evidence-based method for evaluating the effectiveness of preventive health care interventions. Recommendations were not based on cost-effectiveness of options. Patient preferences were not discussed.

Background papers providing critical appraisal of the evidence and tentative recommendations prepared by the chapter author were pre-circulated to the members. Evidence for this topic was presented and deliberated upon in 1- to 2-day meetings. Consensus was reached on final recommendations.

Preservation of vision was given the highest value in accordance with other guidelines regarding eyesight.

Benefits, Harms, and Costs
Potential benefits are to maintain or improve visual acuity.

Complications of cataract surgery with intraocular lens implantation include infection, which occurs in up to 3% of cases. Macular edema occurs as a late complication in about 4%, retinal detachment in about 2% and lens dislocation in about 1%. Opacification of the posterior capsule, most commonly seen in posterior-chamber IOL implantation, occurs in up to 5% of cases and may be treated with laser capsulotomy.

Perimetry has been used as a screening test for glaucoma. However, the equipment is costly and not generally available to primary care physicians.

Recommendations
Recommendation grade [A, B, C, D, E] and level of evidence [I, II-1, II-2, II-3, III] are indicated after each recommendation. Citations in support of individual recommendations are identified in the guideline text.

There is fair evidence to include the use of the Snellen sight chart in the periodic health examination to detect reduced visual acuity [B, II-2]
There is fair evidence to include fundoscopy or retinal photography in the PHE of diabetic patients [B, I, III]
There is insufficient evidence to include or exclude fundoscopy to detect age-related macular degeneration (ARMD) [C, I, III]
There is insufficient evidence to include or exclude fundoscopy, tonometry or automated perimetry to detect glaucoma [C, I, II-2, III]

Validation
This report was externally reviewed. The recommendations differ from those of the American Academy of Ophthalmology and the American Optometric Association. Those for glaucoma screening are similar to the recommendations of the US Preventive Services Task Force. The American Academy of Ophthalmology recommends that ophthalmoscopy and tonometry be performed annually among all people over age 40. A complete ocular examination by an ophthalmologist is recommended at least once between the ages of 35 and 45 and should be repeated every 5 years after age 50. The American Optometric Association recommends a complete eye and vision examination, including tonometry, for people over 35. The US Preventive Services Task Force suggests advising people at high risk for glaucoma (e.g., those aged 65 or more) to be tested by an eye specialist. The optimal frequency is left to clinical discretion. Schiötz tonometry should no longer be recommended as a technique for the early detection of glaucoma.

Sponsors
The Canadian Task Force on Preventive Health Care developed this guideline with funding from Health Canada and the National Health
Research Development Program. Dr. Christopher Patterson was supported in part by the Educational Centre for Aging and Health, McMaster University, Hamilton, Ont.