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Clinical & Experimental Optometry May 2014Uncorrected refractive error is the leading cause of global visual impairment. Given resource constraints in developing countries, the gold standard method of refractive... (Review)
Review
Uncorrected refractive error is the leading cause of global visual impairment. Given resource constraints in developing countries, the gold standard method of refractive error correction, custom-made spectacles, is unlikely to be available for some time. Therefore, ready-made and recycled spectacles are in wide use in the developing world. To ensure that refractive error interventions are successful, it is important that only appropriate modes of refractive error correction are used. As a basis for policy development, a systematic literature review was conducted of interventional studies analysing visual function, patient satisfaction and continued use outcomes of ready-made and recycled spectacles dispensed to individuals in developing countries with refractive errors or presbyopia. PubMed and CINAHL were searched by MESH terms and keywords related to ready-made and recycled spectacle interventions, yielding 185 non-duplicated papers. After applying exclusion criteria, eight papers describing seven studies of clinical outcomes of dispensing ready-made spectacles were retained for analysis. The two randomised controlled trials and five non-experimental studies suggest that ready-made spectacles can provide sufficient visual function for a large portion of the world's population with refractive error, including those with astigmatism and/or anisometropia. The follow-up period for many of the studies was too short to confidently comment on patient satisfaction and continued-use outcomes. No studies were found that met inclusion criteria and discussed recycled spectacles. The literature also notes concerns about quality and cost effectiveness of recycled spectacles, as well as their tendency to increase developing countries' reliance on outside sources of help. In light of the findings, the dispensing of ready-made spectacles should be favoured over the dispensing of recycled spectacles in developing countries.
Topics: Disposable Equipment; Eyeglasses; Humans; Patient Satisfaction; Refraction, Ocular; Refractive Errors; Visual Acuity
PubMed: 24397254
DOI: 10.1111/cxo.12126 -
Survey of Ophthalmology 1996The monovision concept of correcting one eye for distance and the other for near may be utilized in presbyopes undergoing refractive surgery. We have performed a... (Review)
Review
The monovision concept of correcting one eye for distance and the other for near may be utilized in presbyopes undergoing refractive surgery. We have performed a systematic review of published literature to evaluate the factors influencing monovision success, and to determine the visual outcome in patients with monovision. Articles in MEDLINE and published bibliographies reporting monovision prescription for correction of presbyopia were systematically identified and reviewed. Pertinent data were abstracted and, when feasible, statistically analyzed. The mean success rate was 73%. The success in monovision correlated with distance correction on dominant eye, alternating dominance, less than 50 seconds of are stereoacuity reduction, and less than 0.6 prism diopter of distance esophoric shifts. Monovision resulted in significant reduction of binocular contrast sensitivity function at spatial frequencies higher than 4 cycles per degree, and 2-6% reduction in task performance, but resulted in minimal reduction of binocular visual acuity, peripheral vision, visual field width and binocular depth of focus. The published literature indicates that monovision is an effective and reasonable therapeutic modality for correcting presbyopia. Proper patient selection and clinical screening are essential for monovision success.
Topics: Adult; Aged; Anisometropia; Contact Lenses; Contrast Sensitivity; Depth Perception; Female; Humans; Male; Middle Aged; Presbyopia; Vision, Binocular; Vision, Monocular; Visual Acuity; Visual Fields
PubMed: 8724641
DOI: 10.1016/s0039-6257(96)82015-7