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Dive into the research topics where John G. Walt is active.

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Featured researches published by John G. Walt.


Ophthalmology | 2003

Utility assessment among patients with dry eye disease

Rhett M. Schiffman; John G. Walt; Gordon Jacobsen; John Doyle; Gary Lebovics; Walton Sumner

PURPOSE To determine utilities (patient preferences) for dry eye disease. DESIGN Survey study. PARTICIPANTS Fifty-six patients with mild, moderate, or severe dry eye treated by ophthalmologists in the Eye Care Services department of Henry Ford Health Care System. TESTING Patients completed interactive software utility assessment questionnaires by the time trade-off (TTO) method. Utility scores were scaled such that a score of 1.0 = perfect health and 0 = death. Dry eye severity was independently classified using clinical parameters and physician/patient assessments. Global health status, visual functioning, and ocular symptoms were assessed by the Short Form-36 Health Survey, 25-Item National Eye Institute Visual Function Questionnaire (NEI VFQ-25), and Ocular Surface Disease Index survey instruments. MAIN OUTCOME MEASURES Utility scores for a range of dry eye severity states. These utilities were compared with utilities reported for other disease states. Correlations with the general and vision-related health status measures were conducted. RESULTS Fifty-six patients completed the utility assessments with acceptable reliability. Mean utilities for moderate (0.78) and severe dry eye (0.72) by TTO were similar to historical reports for moderate (0.75) and more severe (class III/IV) angina (0.71), respectively. Utility scores correlated with the NEI VFQ-25 composite score (rho = 0.32; P = 0.037) and with components of other health measures. CONCLUSIONS Utilities for the more severe forms of dry eye are in the range of conditions like class III/IV angina (0.71) that are widely recognized as lowering health utilities. Our results underscore how significantly dry eye impacts patients compared with other medical conditions.


Archives of Ophthalmology | 2010

Minimal Clinically Important Difference for the Ocular Surface Disease Index

Kimberly L. Miller; John G. Walt; David R. Mink; Sacha Satram-Hoang; Steven E. Wilson; Henry D. Perry; Penny A. Asbell; Stephen C. Pflugfelder

OBJECTIVE To assess the minimal clinically important difference (MCID) for the Ocular Surface Disease Index (OSDI; Allergan Inc, Irvine, California, holds the copyright), a 12-item patient-reported outcome questionnaire designed to quantify ocular disability due to dry eye disease. METHODS Study data were collected within the Restasis Review of Efficacy and Safety vs Tears in the Relief of Dry Eye (RESTORE), an observational registry. A clinician global impression (CGI) and a subject global assessment (SGA) served as anchors to estimate the MCID for the overall OSDI score (range, 0-100). The overall OSDI score defined the ocular surface as normal (0-12 points) or as having mild (13-22 points), moderate (23-32 points), or severe (33-100 points) disease. RESTORE patients were included if they completed the OSDI at the baseline visit and at a follow-up visit and had a global change rating (SGA or CGI). RESULTS Three hundred ten patients were included (82.3% white and 81.6% female [mean age, 57.8 years]). The CGI and SGA correlated with the OSDI score change for all OSDI categories except the normal category. The MCID ranged from 7.0 to 9.9 for all OSDI categories. The MCID ranged from 4.5 to 7.3 for mild or moderate disease and from 7.3 to 13.4 for severe disease. CONCLUSIONS Using observational data, we estimated the MCIDs for different baseline OSDI categories of dry eye disease. These results will assist clinicians and researchers when interpreting OSDI score changes.


Journal of Glaucoma | 2009

Assessing quality of life in patients with glaucoma using the Glaucoma Quality of Life-15 (GQL-15) questionnaire.

Ivan Goldberg; Colin I. Clement; Tina H. Chiang; John G. Walt; Lauren J. Lee; Stuart L. Graham; Paul R. Healey

PurposeTo measure and compare quality of life in patients with and without glaucoma using the Glaucoma Quality of Life-15 Questionnaire, and to determine the association between glaucoma-related quality of life and clinical indices of glaucoma. Patients and MethodsUsing a prospective, cross-sectional study, we collected demographic information via interviews and administered the questionnaire to assess glaucoma-related quality of life in 121 patients with glaucoma and 31 subjects without glaucoma. Visual function was measured objectively by clinical examination. Group differences and the association between questionnaire scores and clinical indices were evaluated using nonparametric analysis of variance and correlation coefficients, respectively. The relationship between the likelihood of reporting vision-related dysfunction and glaucoma severity was examined using logistic regression. ResultsPatients with glaucoma had significantly poorer glaucoma-related quality of life than controls (P<0.001). Summary scores differed significantly among patients with mild, moderate, and severe glaucoma demonstrating a trend of poorer quality of life with increasing disease severity. Activities involving glare and dark adaptation were most problematic for all, but patients with glaucoma felt significantly more compromised in central and near vision, peripheral vision, and outdoor mobility (all P<0.001). Glaucoma-related quality of life scores correlated moderately and significantly with visual acuity, disease severity, and visual field measurements, but only severe glaucoma was a significant predictor of self-perceived deficits in glaucoma-related quality of life (P=0.038). ConclusionsThe Glaucoma Quality of Life-15 Questionnaire correlated well with objective measures of visual function and discriminated between quality of life in patients with glaucoma and subjects without glaucoma.


Archives of Ophthalmology | 2008

Impact of Vision Loss on Costs and Outcomes in Medicare Beneficiaries With Glaucoma

Thomas J. Bramley; Patti Peeples; John G. Walt; Marta Juhasz; Jan Hansen

OBJECTIVE To assess the impact of vision loss severity on costs and health outcomes among Medicare beneficiaries with glaucoma. METHODS A retrospective cohort analysis was conducted using Medicare claims. Patients were stratified into 4 categories: no vision loss, moderate vision loss, severe vision loss, and blindness. Outcomes of interest were mean annual medical costs by category, component costs, and frequency of depression, falls and/or accidents, injury, femur fracture, and nursing home placement. RESULTS Multivariate regression analysis showed that patients with any degree of vision loss had 46.7% higher total costs compared with patients without vision loss. Mean total and component costs increased with onset and severity (


Current Medical Research and Opinion | 2005

Analytic review of bimatoprost, latanoprost and travoprost in primary open angle glaucoma

Stefan Holmstrom; Patricia Buchholz; John G. Walt; Jannie Wickstrøm; Mark Aagren

8157 for no vision loss to


Journal of Glaucoma | 2004

Trends in glaucoma surgery before and after the introduction of new topical glaucoma pharmacotherapies.

David R. Strutton; John G. Walt

18,670 for blindness). Patients with vision loss were significantly more likely to be placed in a nursing home (odds ratio = 2.18; 95% confidence interval, 2.06-2.31), develop depression (odds ratio = 1.63; 95% confidence interval, 1.54-1.73), fracture a femur (odds ratio = 1.67; 95% confidence interval, 1.53-2.83), or experience a fall or accident (odds ratio = 1.59; 95% confidence interval, 1.50-1.68) vs patients without vision loss. CONCLUSIONS Vision loss in glaucoma is costly, and costs increase with severity. There is significantly increased risk of nursing home admission, depression, falls and/or accidents, injury, or femur fracture with vision loss compared with no vision loss.


Ophthalmology | 1993

The Efficacy of Brimonidine in Decreasing Elevations in Intraocular Pressure after Laser Trabeculoplasty

Howard S. Barnebey; Alan L. Robin; Thom J. Zimmerman; John C. Morrison; Stanley B. Hersh; Richard A. Lewis; Anne L. Coleman; Donald J. Cinotti; John G. Walt; Kuankuan S. Chen; Elaine P. Kelley

ABSTRACT Objective: The objective of this review was to evaluate different measures of efficacy of the intraocular pressure (IOP) lowering lipid class agents bimatoprost, latanoprost and travoprost in the treatment of primary open angle glaucoma. Study arms of timolol in trials including the above mentioned lipid class drugs were also included. Methods: MEDLINE and EMBASE were searched for randomized clinical trials including one or more of the lipid class drugs bimatoprost, latanoprost and travoprost. The study results were pooled, and the simple, weighted IOP-lowering efficacy was compared among the lipid class drugs and timolol, where data were available. Efficacy parameters were reviewed, including mean reduction of IOP and percentage of patients achieving different levels of IOP. Results: 161 articles were identified of which 42 were included in the analysis. A total of 9295 patients participated in the included trials. Based on all studies, timolol on average had a weighted mean IOP reduction of 22.2%, while latanoprost, travoprost and bimatoprost had a weighted mean IOP reduction of 26.7%, 28.7% and 30.3%, respectively. Analysis of target achievement to various IOP levels shows that bimatoprost seems more efficacious than latanoprost. The direct comparisons (head-to-head studies) also show that bimatoprost is the most efficacious treatment, however it is not conclusive whether latanoprost or travoprost is better in reducing IOP. Conclusions: This review shows that bimatoprost seems to be the most efficacious treatment in lowering IOP. Head-to-head studies confirm this.


Health and Quality of Life Outcomes | 2005

The reliability, validity, and preliminary responsiveness of the Eye Allergy Patient Impact Questionnaire (EAPIQ)

Michael Alexander; William Berger; Patricia Buchholz; John G. Walt; Caroline Burk; Jeffrey T. Lee; Rob Arbuckle; Linda Abetz

Objective:Recent advances in pharmacotherapy that have improved the ability to effect sustained reductions in intraocular pressure may delay or obviate the need for surgery for open-angle glaucoma. This analysis explored this possibility by evaluating the frequency of surgeries for open-angle glaucoma in the US Medicare population before and after the 1996 introduction of latanoprost, a topical prostaglandin analogue with potent ocular antihypertensive efficacy and a better safety profile than older topical glaucoma medications. Methods:Data from the Medicare 5% Standard Analytical File were used to develop national estimates of the frequency of glaucoma surgeries in the US yearly from 1994 through 1999. Results:While the number of US Medicare patients with a diagnosis of glaucoma remained constant from 1994 through 1999, the number of inpatient and outpatient glaucoma surgeries declined with a particularly sharp drop between 1996 and 1997. In 1999 relative to 1994, the number of annual glaucoma surgeries among unique patients with a diagnosis of glaucoma was reduced by 72% for inpatient procedures and 42% for outpatient procedures. Conclusions:The number of glaucoma surgeries among US Medicare patients markedly decreased from 1994 to 1999, during which time the prevalence of glaucoma remained stable in this population. The decrease in surgeries coincided with the introduction of improved topical pharmacotherapies for the management of glaucoma. Although the ability to infer a causal relationship between introduction of new pharmacotherapy and the decrease in surgeries is limited, the consistency of these data with those of several other studies renders the findings compelling.


Journal of Glaucoma | 2007

Glaucoma in the United States and europe: predicting costs and surgical rates based upon stage of disease.

Paul P. Lee; Simon P. Kelly; Richard P. Mills; Carlo Traverso; John G. Walt; John Doyle; Laura M. Katz; Lisa R. Siegartel

PURPOSE The authors explored the empirical dosing requirement for administration of an alpha 2-adrenoceptor agonist, brimonidine, and determined its efficacy in decreasing elevations in intraocular pressure (IOP) after 360 degrees argon laser trabeculoplasty (ALT). METHODS This vehicle-controlled, double-masked, multicenter trial evaluated three dosing regimens of brimonidine. Two hundred thirty-two patients for whom 360 degrees ALT was indicated were randomized into one of four treatment groups: 0.5% brimonidine both before and after ALT; brimonidine before but vehicle after ALT; vehicle before but brimonidine after ALT; or vehicle at both times. RESULTS During the first 3 hours after 360 degrees ALT, the overall incidence of IOP elevations of 5 mmHg or greater was 38% (23 of 60 eyes) in the group receiving vehicle only, and it ranged from 3% to 9% (2 of 62 to 5 of 53 eyes) in the groups receiving any brimonidine treatment. There was little difference in efficacy between the three dosing regimens of brimonidine. Brimonidine was well tolerated by the patients. CONCLUSION Based on this large, controlled, multicenter study, 0.5% brimonidine was an effective agent for reducing elevations in IOP after 360 degrees ALT. Only one dose, administered either before or after 360 degrees ALT, was required.


Current Medical Research and Opinion | 2009

Glaucoma medication persistence with a fixed combination versus multiple bottles

Eve J. Higginbotham; Jan Hansen; Elizabeth J. Davis; John G. Walt; Angela Guckian

BackgroundThe Eye Allergy Patient Impact Questionnaire (EAPIQ) was developed based on a pilot study conducted in the US and focus groups with eye allergy sufferers in Europe. The purpose of this study was to present the results of the psychometric validation of the EAPIQ.MethodsOne hundred forty six patients from two allergy clinics completed the EAPIQ twice over a two-week period during the fall and winter allergy seasons, along with concurrent measures of health status, work productivity, and utility. Construct validity, reliability (internal consistency and test-retest), concurrent, known-group, and clinical validities, and responsiveness of the EAPIQ were assessed. Known-group validity was assessed by comparing EAPIQ scale scores between patients grouped according to their self-rating of ocular allergy severity (no symptoms, very mild, mild, moderate, severe, very severe). Clinical validity was assessed by assessing differences in EAPIQ scores between groups of patients rated by their clinician as non-symptomatic, mild, moderate, and severe.Results and DiscussionResults from the validation study suggested the deletion of 14 of 43 items (including embedded questions) that required patients to complete the percentage of time they were troubled by something (daily activity limitations/emotional troubles). These items yielded a significant amount of missing or inconsistent data (50%). The resulting factor analysis suggested four domains: symptoms, daily life impact, psychosocial impact, and treatment satisfaction. When included as separate scales, the symptom-bother and symptom-frequency scales were highly correlated (> 0.9). As a consequence, and due to superior discriminative validity, the symptom bother and frequency items were summed. All items met the tests for item convergent validity (item-scale correlation = 0.4). The success rate for item discriminant validity testing was 97% (item-scale correlation greater with own scale than with any other). The criterion for internal consistency reliability (alpha coefficient ≥ 0.70) was met for all EAPIQ scales (range 0.89–0.93), as was the criterion for test-retest reliability (intraclass correlation [ICC] ≥ 0.70). Largely moderate correlations between the scales of the EAPIQ and the mini Rhinoconjunctivitis Quality of Life Questionnaire (miniRQLQ) and low correlations with the Health Utilities Index 2/3 (HUI2/3) were indicative of satisfactory concurrent validity. The EAPIQ symptoms, Daily Life Impact, and Psychosocial Impact scales were able to distinguish between patients differing in eye allergy symptom severity, as rated by patients and clinicians, providing evidence of satisfactory known-group and clinical validities, respectively. Preliminary analyses indicated the EAPIQ Symptoms, Daily Life Impact, and Psychosocial Impact scales to be responsive to changes in eye allergies.ConclusionFollowing item reduction, construct validity, reliability, concurrent validity, known-group validity, and preliminary responsiveness were satisfactory for the EAPIQ in this population of ocular allergy patients.

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Paul P. Lee

University of Michigan

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Richard G. Fiscella

University of Illinois at Chicago

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Jacob T. Wilensky

University of Illinois at Chicago

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