| Table 3: Summary of manoeuvres, effectiveness, levels of evidence and recommendations for screening for visual impairment among elderly patients | |||
| Manoeuvre | Effectiveness | Level of evidence* | Recommendation* |
| Snellen sight chart | Use of chart reliably detects reduced visual acuity in community studies
Population screening can lead to useful improvements in vision | Cohort study [11,12] (II-2) Cohort study [15] (II-2) |
Fair evidence to include in the periodic health examination (PHE) (B) |
| Funduscopy or retinal photography in diabetic patients | Funduscopy and retinal photography are sensitive for detecting retinopathy; early detection preserves vision
Photocoagulation in proliferative diabetic retinopathy preserves vision | Expert opinion [96] (III) Randomized controlled trials [85-87,89] (I) |
Fair evidence to include in the PHE of diabetic patients (B) |
| Funduscopy to detect age-related macular degeneration (ARMD) | ARMD can be detected by those trained in ophthalmoscopy
Photocoagulation preserves vision in patients with neovascular changes from ARMD | Expert opinion [38] (III) Randomized controlled trials [37-40] (I) |
Insufficient evidence to include in or exclude from the PHE (C) |
| Funduscopy, tonometry or automated perimetry to detect glaucoma | Examination of optic disc (fundoscopy) is sensitive for detecting glaucoma
Schiötz tonometry has poor sensitivity and specificity for early detection of glaucoma Automated perimetry (Humphrey) is sensitive for detecting glaucoma Topical application of beta-adrenergic blocker lowers IOP and may retard vision loss | Cohort study [37] (II-2) Case series [42,53,54] (III) Case series [60] (III) Randomized controlled trials [62-70] (I) |
Insufficient evidence to include in or exclude from the PHE (C) |
*For descriptions of the other levels of evidence and classification of recommendations see Appendix 1 in part 1 of the 1992 update (CMAJ 1992; 147: 443)