Systematic review of Purtscher's and Purtscher-like retinopathies.

PURPOSE: (1) To describe the clinical characteristics of Purtscher and Purtscher-like retinopathies, including etiologies, fundoscopic signs, results of complementary investigation, treatments, and outcomes. (2) To compare visual acuity (VA) of patients receiving corticosteroids for PuR compared with observation. METHODS: Systematic review of several databases (1980-2010): Medline, EMBASE, ISI, EBSCO, Science Direct and Google Scholar. Study selection criteria included: (A) Studies of PuR with ophthalmology assessments; (B) ≥3 of 5 diagnostic criteria of PuR; (C) Quantified VA at presentation. For quantitative assessment (purpose 2), we selected only studies that reported whether corticosteroids were administered, and with vision assessments after at least 1 month. RESULTS: (1) From 670 studies initially found, 40 were included (68 cases, 110 eyes): 1 prospective, 5 case series, and 34 case reports. Mean VA at presentation was 1.3 logMAR (logarithm of the minimum angle of resolution) (<20/200; range: 20/20-light perception). Purtscher flecken were underreported. Trauma and acute pancreatitis were the most frequent etiologies. There were six deaths, all with systemic associations. (2) There was no statistically significant difference between VA improvement for patients treated with corticosteroids compared with observation. Visual prognostic factors identified included etiology (pancreatitis and trauma were associated with higher probability of visual improvement) and male gender. CONCLUSION: Due to limitations of case reports and series, the presented data are only useful as broad characterizations of the clinical course of PuR. Further studies, possibly including trials to assess the effectiveness of corticosteroids use, and larger prospective cohort studies, are necessary, but may not be feasible to conduct.

Comparison of the potential acuity meter and the visometer in cataract patients.

PURPOSE: To compare the Guyton-Minkowski Potential Acuity Meter (PAM) and the Haag-Streit Lotmar Visometer (Visometer) in their ability to predict postoperative best corrected visual acuity (BCVA) in cataract surgery. SETTING: University of British Columbia/Vancouver General Hospital Eye Care Center, Vancouver, British Columbia, Canada. METHODS: In total, 292 eyes (223 patients) of subjects with cataracts and no known macular or optic nerve pathology were recruited over 6 months. Preoperative predictions of postoperative BCVA were compared with actual postoperative BCVA. The usefulness of these instruments as a 'diagnostic test' for predicting true surgical success (defined as postoperative BCVA of 20/40 or better) from predicted surgical success (PAM or Visometer predicted acuity 20/40 or better) was analysed. RESULTS: Neither the PAM nor the Visometer predictions were statistically significant predictors of postoperative BCVA. The sensitivities of PAM and Visometer for predicting surgical success were 84.7% and 96.1%, respectively. The specificity of the PAM and Visometer for predicting surgical success was 27.3% and 9.1%, respectively. Overall, 92.7% of patients had 'successful surgery'. Given a predicted success from the PAM or Visometer the post-test probability of success was 93.5% and 93.1%, respectively. Given a predicted failure from the PAM or Visometer there was a post-test probability of surgical success of 87.5% and 84.6%, respectively. CONCLUSION: We found no clinical benefit to support using the PAM or Visometer in the preoperative assessment of cataract patients with no known retinal or optic nerve pathology.

The prevalence of low vision and blindness in a Canadian inner city.

PURPOSE: To ascertain the prevalence and primary causes of visual impairment in a sample of patients from Vancouver's downtown eastside (VDES). MATERIALS AND METHODS: A total of 200 patients seeking nonophthalmic medical care at the Vancouver Native Health Society (VNHS) clinic in Vancouver's inner city (downtown eastside) participated in this observational case-series study. For each participant, we obtained demographic information, a medical and ocular history, and performed a complete eye exam. The prevalence of visual disability using standard North American criteria was reported. Causes of visual loss were also reported based on Canadian National Institute for the Blind (CNIB) guidelines. RESULTS: A total of 200 patients participated in our study. The median age of our sample was 46 years, 69% were male. There were very high rates of comorbid medical conditions including HIV, Hepatitis B/C, IV drug use, and diabetes. The raw prevalence of visual disability based on best-corrected visual acuity (BCVA) was 500 per 10,000; this was over nine times greater than in the general Canadian population. The raw prevalence rate of 'presenting visual disability' based on presenting visual acuity (PVA) was 2400 per 10,000. Major causes of visual disability were cataract and retinal disease. Although age-related macular degeneration and diabetic retinopathy represent major causes of vision loss in North America, no cases were noted in our sample. CONCLUSION: The overall prevalence of visual disability was alarmingly high in this disadvantaged community. These results identify both ophthalmic disease and access to refraction and prescription spectacles as a significant health concern among people living in the VDES.

The prevalence of low vision and blindness in Canada.

PURPOSE: The purpose of this study was to ascertain the prevalence and primary causes of visual impairment in a representative Canadian population. METHODS: We reviewed a representative sample of patients who attended ophthalmologists' offices in a medium-sized Canadian city between 1996 and 2001 in order to estimate the prevalence of visual impairment. Demographic data, visual diagnoses, best-corrected visual acuities (BCVA), and visual field information were recorded. Visual status was categorized based on accepted World Health Organization (WHO) and North American criteria. Population data were obtained from the Canadian census. RESULTS: The prevalence of low vision and blindness in our population was 35.6 and 3.8 per 10 000 individuals, according to the WHO classification, and 71.2 and 23.6 per 10 000 individuals, using the North American definition. Among individuals with some vision loss (vision worse than 20/40), cataract and visual pathway disease were the most common causes, together accounting for 40% of visual impairment. Age-related macular degeneration and other retinal diseases were the next most common causes of vision loss. Diabetic retinopathy and glaucoma were less frequently encountered as causes of visual impairment. CONCLUSION: The overall prevalence of low vision and blindness in Canada are in keeping with data from large population-based studies from other developed nations. Cataract, visual pathway disease, and macular degeneration are the leading causes of visual impairment. These results are important for enhancing our understanding of the scope of vision health in Canada and may direct future health planning and cost-utilization research.

An evaluation of photographic screening for neovascular age-related macular degeneration.

BACKGROUND: Photographic screening for neovascular age-related macular degeneration (AMD) is not commonly employed because the prevalence of treatable disease is low and fluorescein angiography is considered necessary for the diagnosis of this form of AMD. However, there may be a role for colour retinal imaging in assisting with the diagnosis and triage of subjects with neovascular AMD. The purpose of this study was to evaluate the utility of colour fundus photographs for identifying subjects with potentially treatable neovascular AMD. METHODS: A total of 74 stereo pairs of Kodachrome colour slides of subjects with AMD were evaluated (i) nonstereoscopically, (ii) stereoscopically, and (iii) stereoscopically with visual acuity and visual symptom data. Two retina specialists read the images to identify active exudative lesions. RESULTS: The kappa statistic comparing the retinal specialists diagnosis of treatable neovascular AMD from color slides was excellent. The sensitivity and specificity of nonstereo images for the appropriate categorization of lesions was 0.95 and 0.90 respectively. The evaluation of stereo pairs was more sensitive, but less specific, 0.98, 0.83, as was the evaluation of stereo-pairs with clinical histories and visual acuities, 1.00, 0.77. CONCLUSIONS: The evaluation of colour images for subjects with suspected exudative macular degeneration can be diagnostic for neovascular AMD and may expedite the appropriate referral of patients for more timely angiography and treatment. Incorporating more clinical information for the image evaluators ((i) stereo image pairs and/or (ii) presenting symptomatology and visual acuity data) led to a decrease in the false-negative rate, but also decreased the screening specificity.