Showing papers by "Oliver D. Schein published in 1994"

The VF-14. An index of functional impairment in patients with cataract.

Abstract: Objective: To describe the development and the performance of a brief questionnaire designed to measure functional impairment caused by cataract (the VF-14). Design: Observational cross-sectional study. Patients were recruited between July 15 and December 15, 1991. Setting: Patients were recruited from the practices of 70 ophthalmologists, located in Columbus, Ohio (N=21), St Louis, Mo (N=26), and Houston, Tex (N=23). Patients: Seven hundred sixty-six patients undergoing cataract surgery for the first time. Main Outcome Measures: Preoperative best corrected visual acuity in each eye; scores on the VF-14, a new index of functional impairment in patients with cataract; patient reports of overall trouble and satisfaction with their vision; and scores on the Sickness Impact Profile, a measure of general health status. Results: The VF-14 has high internal consistency (Cronbach's α=.85) and correlates more strongly with the overall self-rating of the amount of trouble and satisfaction patients have with their vision than do several measures of visual acuity or the Sickness Impact Profile score. The VF-14 score is moderately correlated with visual acuity in the better eye. Conclusions: The VF-14 is a reliable and valid measure of functional impairment caused by cataract and provides information not conveyed by visual acuity or a general measure of health status.

Synthesis of the Literature on Visual Acuity and Complications Following Cataract Extraction With Intraocular Lens Implantation

Abstract: Objective: To better define the effectiveness and risks of modern cataract surgery Design: Meta-analysis (formal systematic identification, selection, review, and synthesis) of published literature Patients: Patients described in 90 studies published between 1979 and 1991 that addressed visual acuity (n=17 390 eyes) or complications (n=68 316 eyes) following standard extracapsular cataract extraction with posterior chamber intraocular lens implantation, phacoemulsification with posterior chamber intraocular lens implantation, or intracapsular cataract extraction with flexible anterior chamber intraocular lens implantation Main Outcome Measures: The proportion of eyes with postoperative Snellen visual acuity of 20/40 or better and the proportion of eyes with each of 18 complications Results: The pooled percentage of eyes (weighted by sample size) with postoperative visual acuity of 20/40 or better was 955% (95% confidence interval [CI], 951% to 959%) among eyes without preexisting ocular comorbidity and 897% (95% CI, 893% to 902%) for all eyes The pooled percentage of eyes experiencing complications (weighted by sample size and, when pertinent, by quality score of the individual studies but not adjusted for variation in duration of follow-up) ranged from 013% for endophthalmitis to 197% for posterior capsule opacification Pooled proportions of eyes with other complications were as follows: bullous keratopathy, 03%; intraocular lens malposition/dislocation, 11%; clinically apparent cystoid macular edema, 15%; and retinal detachment, 07% Pooled results for postoperative Snellen visual acuity and most complications were similar for surgery performed via phacoemulsification vs standard extracapsular cataract extraction, although comparisons of the outcomes between these procedures should be interpreted with caution Conclusions: The published literature indicates that modern cataract surgery yields excellent visual acuity and, although not free of complications, is a very safe procedure regardless of the extraction technique used

Functional Status and Quality of Life Measurement Among Ophthalmic Patients

Abstract: Objectives: Assessment of the relationship between visual function and functional status/quality of life in clinical research involving patients with eye disease by investigating whether the scores of four existing functional status/quality of life patient questionnaires are sensitive to differences in visual acuity and studying whether selected subscales of the questionnaires provide similar information concerning the relationship between functional status/quality of life and visual acuity as do the respective full-length questionnaires. Design, Setting, Participants: Case patients consisted of 86 consecutive patients seen at The Wilmer Ophthalmological Institute Retinal Vascular Center, Baltimore, Md. Controls consisted of 51 individuals with normal visual acuity and no known ocular disease and were frequency-matched to the case patients by age (±5 years), sex, and race. Subjects were interviewed in person using each of the following questionnaires: the Sickness Impact Profile, the vision-specific Sickness Impact Profile, the Community Disability Scale, and the General Health Questionnaire. Results: Scores of all four questionnaires and their subscales were significantly associated with visual acuity. The vision-specific Sickness Impact Profile and the Community Disability Scale were independently significant predictors of visual acuity. Regression analysis revealed that in our study, selected subscales of the respective full-length questionnaires were able to demonstrate the association between vision and functional status/quality of life. Conclusions: Ophthalmic patients are at high risk for decreased functional status/quality of life. Subscales of existing questionnaires potentially may be substituted for the full-length questionnaires, thereby increasing the efficiency of functional status/quality of life measurement in such patients.

The Impact of Overnight Wear on the Risk of Contact Lens—Associated Ulcerative Keratitis

Abstract: Objective: To assess the relative risk of contact lens—associated ulcerative keratitis by lens type and related lenswearing behavior. Design: Case-control study. Setting/Participants: Forty practice-based case patients with contact lens—associated ulcerative keratitis and 180 control patients matched to the case patients' dispensing practitioner and date of contact lens prescription. Results: Compared with users of daily-wear soft lenses, users of disposable soft contact lenses had a 13.33-fold (95% confidence interval [CI], 5.35 to 33.20) excess risk of ulcerative keratitis. However, after adjusting for overnight wear, the excess risk associated with disposable contact lenses is reduced to 3.21 (95% CI, 1.22 to 14.36). Overall, overnight wear of contact lenses conferred an 8.25-fold excess risk (95% CI, 3.33 to 25.58) of ulcerative keratitis after controlling for lens type. No protective effect of standard compared with substandard lens hygiene was found. The risk of ulcerative keratitis attributable to overnight wear was estimated at 49% for users of daily-wear lenses and 74% for users of lenses approved for overnight wear. Conclusion: Overnight wear of contact lenses is the overwhelming risk factor for ulcerative keratitis among contact lens users. We estimate that 49% to 74% of cases of contact lens—associated ulcerative keratitis could be prevented by eliminating overnight wear.

Cortical lenticular opacification: distribution and location in a longitudinal study.

Abstract: PURPOSE: To examine the distribution of cortical opacification of the lens by lens quadrant in a longitudinal study. METHODS: In 1990, a follow-up assessment of a cohort of Chesapeake Bay watermen, initially studied in 1985, was performed. Four hundred thirty-seven subjects (834 eyes) had gradable cortical photographs for at least one eye in both 1985 and 1990. Cortical photographs were graded by both estimating total area and determining the quadrant with the greatest degree of cortical opacification. RESULTS: The prevalence and severity of cortical opacification increased with age with a high degree of concordance (84%) between eyes. For the 47 eyes with cortical opacification > or = 1/8 at baseline, the principal locations of opacification were: inferonasal 63.8%, inferotemporal 17.0%, superonasal 6.4%, and superotemporal 12.8% (P < 0.001, compared with equal distribution by quadrant). Five-year development of new cortical opacification and five-year progression of existing cortical opacification showed even greater preferential occurrence in the inferonasal quadrant of the lens. CONCLUSIONS: In this population, the inferonasal quadrant of the lens is the principal site of cortical opacification in both cross-sectional and longitudinal assessment. This finding is consistent with the hypothesis that sunlight exposure is a significant risk factor for cortical opacification.

Variation in Ophthalmic Testing Before Cataract Surgery: Results of a National Survey of Ophthalmologists

Abstract: Little information is available either for the clinical value of many ophthalmic tests performed preoperatively in the evaluation of patients for cataract surgery or for variation in ophthalmologists' use of such tests. To assess variation in ophthalmologists' use of ophthalmic tests, we conducted a national survey of American Academy of Ophthalmology members. Thirty-three percent, 17%, 37%, and 19% of the respondents reported that they "frequently" or "always" perform glare testing, contrast sensitivity testing, potential acuity measurement, and specular microscopy, respectively, in patients being considered for cataract surgery who have no history of eye disease other than cataract. In contrast, 27%, 54%, 24%, and 48% of respondents reported that they never perform each of these four tests in such patients. Two ophthalmologist characteristics—a surgical volume of greater than 200 cataract extractions per year and performance of surgery in an ambulatory surgical center or private office (as opposed to a hospital)-were independently associated with an increased probability of performing each of these four tests frequently or always. Ten percent or less of the respondents reported that they frequently or always perform electroretinography, visual evoked response testing, photography of fundus or anterior segment, B-scan ultrasonography, formal color vision testing, and formal visual field testing in such patients. Thus, there is considerable variation in ophthalmologists' use of glare testing, contrast sensitivity testing, potential acuity measurement, and specular microscopy. A small percentage of ophthalmologists may be overusing several other tests in the evaluation of patients being considered for cataract surgery.

Primary graft failure: a case control investigation of a purported cluster.

Abstract: Primary graft failure is a rare but major complication of penetrating keratoplasty. An apparent clustering of four cases during a 1-month period led to a review of all 778 keratoplasties performed by nine surgeons at Massachusetts Eye and Ear Infirmary from July 1, 1986 to June 30, 1988. The objectives of this study were (a) to investigate the possibility that cases of primary graft failure occurred in clusters within their physical environment of space, time, and personnel and (b) to determine the frequency of and evaluate possible risk factors for primary graft failure. Twenty-one cases of primary graft failure were found, resulting in an incidence rate of 2.7% during this period. A 13.3% incidence of primary graft failure was found in donor mates, suggesting improper tissue preparation. The charts and eye bank records of the 21 cases and 84 age-matched controls, randomly selected from the group of all keratoplasties, were reviewed for donor-, recipient-, surgeon-, and surgery-related characteristics. Improper tissue preparation was not associated with primary graft failure. An individual surgeon was the most significant risk factor [odds ratio = 6 (95% CI: 2.1-17.0)].

Rigor of research methods in studies of the effectiveness and safety of cataract extraction with intraocular lens implantation. Cataract Patient Outcome Research Team.

Abstract: OBJECTIVE: To assess the rigor of research methods reported in studies of the safety or effectiveness of contemporary cataract surgery. DESIGN: Formal systematic identification of pertinent studies and critical appraisal of each study's research methods. SUBJECTS: From 6113 unique, potentially relevant citations that we identified, 90 original studies published between 1979 and 1991 that addressed visual acuity or complications following standard extracapsular cataract extraction with posterior chamber intraocular lens implantation, phacoemulsification with posterior chamber intraocular lens implantation, or intracapsular cataract extraction with flexible anterior chamber intraocular lens implantation. MAIN OUTCOME MEASURES: Strength of study design, performance, and reporting in 11 methodologic areas assessed with a standardized abstraction form by two reviewers masked to authors, their institutions, and the journal of publication. Results of reviews were tallied to produce an overall quality score (measure of rigor in research methods) for each study. RESULTS: The mean (+/- SD) quality score was 43.1 +/- 20.1 out of a maximum possible score of 100. Studies received intermediate scores on description of baseline ocular disease and low scores on descriptions of other characteristics of enrolled patients, standardization of outcome assessment and follow-up duration, and handling of patient attrition. Eighty-three studies (92%) lacked a comparison group. The rigor of research methods in studies varied by the journal of publication, did not improve over time, and was no greater for studies with larger vs smaller sample sizes. CONCLUSIONS: The rigor of research methods in studies of cataract surgery can be improved if more attention is paid to fundamental principles of study design, data analysis, and reporting.