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Reduced Vision (reduced + vision)
Selected Abstracts4424: Visual acuity loss with healthy ageing: can it be reversed by wavefront laser?ACTA OPHTHALMOLOGICA, Issue 2010D ELLIOTT Purpose To consider what levels of "super acuity" might be achieved by the correction of ocular aberrations in older patients by wavefront corrected ophthalmic surgery. Note that when comparing visual acuity (VA) of older patients with VA in the young, the average optimal monocular visual acuity of a young subject is about 6/4 (decimal VA 1.50) and not the often quoted ,normal' figure of 20/20 (6/6 or 1.0 decimal). Methods Studies that attempted to isolate the cause(s) of deterioration in visual function with age in normal, healthy eyes were reviewed. Results The majority of studies suggest that the deterioration in visual function with age is primarily due to changes within the neural system rather than optical factors. In addition, several studies have shown increases in ocular aberrations with age, but this is only found when comparisons are made across age groups with fixed pupil sizes. When natural pupil sizes are considered, there is no change in aberrations with age because of age-related pupillary miosis Conclusion There appears to be little scope for ocular aberration correction to be used to counteract the loss of vision with age. Reduced vision in patients with cataract is primarily due to increased forward light scatter, and aberrations play a minor role in reducing vision. Intra-ocular lenses (IOLs) should be designed to keep ocular aberrations at a minimum after cataract surgery, but given that vision loss with age appears to be primarily due to neural changes, there seems little scope for IOLs to improve on the vision of phakic subjects under natural pupil conditions. [source] Vision screening of older peopleOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 6 2007Zahra Jessa Abstract A recent systematic review found that between 20% and 50% of older people in the UK have undetected reduced vision and in most cases this is caused by refractive error or cataracts, and is correctable. Two approaches to improve the detection of these problems are to better publicise optometric services and to carry out community-based vision screening of older people. Screening programmes should pass the Wilson criteria and a consideration of these highlights three inter-related questions: ,Is vision screening effective at detecting correctable low vision in older people?'; ,Which tests should be included?' and ,Which venues are most appropriate?' We carried out a systematic review to investigate these questions. For the first question, only one study was found which met our selection criteria. The ,gold standard' eye examination in this study lacked several important components, and the vision screening method that was used was not found to be very effective. The review revealed other studies, which, although not meeting our selection criteria, included relevant information. The screening studies highlight the lack of agreement on the content of a gold standard eye examination and of the test(s) that should be used to screen vision. Visual function in older people is not adequately described by high contrast visual acuity (VA), nor by self-reports of visual difficulties. Other tests that may be relevant include visual field testing, low contrast VA, contrast sensitivity and stereo-acuity. The pinhole test has often been used in attempts to detect uncorrected refractive errors, but results from this test can be problematic and possible reasons for this are discussed. Appropriate venues for vision screening are contingent upon the format of the vision screening programme. There is still uncertainty over the battery of vision tests that are most appropriate. This, and optimum venues for screening, require further research before it can be fully determined whether vision screening of older people meets the Wilson criteria. If a vision screening programme using a battery of vision tests, perhaps computerised, can be established, then this should be tested to determine the sensitivity and specificity for detecting the target conditions. Ultimately, longitudinal studies are necessary to determine whether such a screening programme will lead to improved visual performance and quality of life in older people. [source] 4243: Capsular peeling in premium IOLs to improve visual outcomeACTA OPHTHALMOLOGICA, Issue 2010MJ TASSIGNON Purpose To demonstrate that capsular peeling may improve quality of vision of patients who experienced reduced vision in the short postoperative period after premium IOL implantation due to decentration of the IOL secondary to PCO. Methods Patients who were refered to our centre because of unsatisfactory quality of vision after premium IOL implantation (more specifically after multifocal IOLs) were scheduled for surgery aiming at peeling the capsular bag. The conditions which the patient needed to meet were: increased higher order aberrations, evidence of tilt or decentration of the IOL, important fibrotic proliferation in the capsular bag, no YAG laser capsulotomy performed. Results After capsular peeling, it was possible to demonstrate that the quality of vision of the patient improved, the higher order aberrations reduced and it was often unnecessary to explant the premium IOL. Although there was an obvious improvement of the quality of vision, this improvement still did not reached the high standard of vision as measured after monofcal IOLs. Conclusion This paper shows how important the role is of PCO on quality of vision. Because contrast sensitivity is already reduced after premium IOL implantation, patients will be very sensitive to an additional reduction as it appears after PCO. [source] Operated and unoperated cataract in AustraliaCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 2 2000Catherine A McCarty PhD MPH ABSTRACT Purpose: To quantify the prevalence of cataract, the outcomes of cataract surgery and the factors related to unoperated cataract in Australia. Methods: Participants were recruited from the Visual Impairment Project: a cluster, stratified sample of more than 5000 Victorians aged 40 years and over. At examination sites interviews, clinical examinations and lens photography were performed. Cataract was defined in participants who had: had previous cataract surgery, cortical cataract greater than 4/16, nuclear greater than Wilmer standard 2, or posterior subcapsular greater than 1 mm 2. Results: The participant group comprised 3271 Melbourne residents, 403 Melbourne nursing home residents and 1473 rural residents. The weighted rate of any cataract in Victoria was 21.5%. The overall weighted rate of prior cataract surgery was 3.79%. Two hundred and forty-nine eyes had had prior cataract surgery. Of these 249 procedures, 49 (20%) were aphakic, 6 (2.4%) had anterior chamber intraocular lenses and 194 (78%) had posterior chamber intraocular lenses. Two hundred and eleven of these operated eyes (85%) had best-corrected visual acuity of 6/12 or better, the legal requirement for a driver's license. Twenty-seven (11%) had visual acuity of less than 6/18 (moderate vision impairment). Complications of cataract surgery caused reduced vision in four of the 27 eyes (15%), or 1.9% of operated eyes. Three of these four eyes had undergone intracapsular cataract extraction and the fourth eye had an opaque posterior capsule. No one had bilateral vision impairment as a result of cataract surgery. Surprisingly, no particular demographic factors (such as age, gender, rural residence, occupation, employment status, health insurance status, ethnicity) were related to the presence of unoperated cataract. Conclusions: Although the overall prevalence of cataract is quite high, no particular subgroup is systematically under-serviced in terms of cataract surgery. Overall, the results of cataract surgery are very good, with the majority of eyes achieving driving vision following cataract extraction. [source] | ||||||||||