Biomedical subjects

John G Ferraro

Publications and source records attributed to John G Ferraro.

6 recordsLinked to original sources

PubMed2006

Evaluation of an eye health program: the vision initiative.

PURPOSE: The aim of this study was to develop an innovative, rapid and economical assessment methodology to determine the knowledge, attitudes and behaviours regarding eye health and to determine the rates of the most common causes of visual impairment and undiagnosed eye disease. METHODS: Letters were posted to Seniors Card holders aged 70-79 in 18 randomly selected areas, stratified by socio-economic status. A questionnaire was developed to measure knowledge, attitudes and behaviours regarding eye health. Uncorrected refractive error was determined by measuring presenting and best-corrected visual acuity (VA). Diabetic retinopathy and age-related macular degeneration were assessed using digital non-mydriatic retinal photography. Glaucoma was assessed using Frequency Doubling Technology (FDT) and digital images of the optic nerve head. Cataract was determined using digital retro-illumination images of the lens taken with a non-mydriatic camera. The cost for recruiting, examining and grading images for each participant was calculated by dividing the total study cost by the number of participants examined. RESULTS: Of the 13,483 participants invited to participate in the study, appointments were made for 1860 (13.8%) people with 1,701 (91%) actually attending. Overall, missing data from the 1,695 questionnaires represented less than 1.0% and all participants attended the vision screening over a three-month period. Presenting and best-corrected visual acuity and FDT results on both eyes were obtained on 99% of the sample. The proportion of gradable digital images of the fundus in both eyes in the sample was 89%, while 90% of participants with bilateral presenting VA<6/12 had assessable lens images. The cost for recruiting, examining and grading images for each participant was approximately 150 AUS dollars. CONCLUSION: The recruitment from a mailing obtained the required sample size for the study, allowing a large sample of participants to be examined efficiently over a short period of time. It is important that the most common causes of visual impairment and undiagnosed eye disease can be determined using this rapid assessment methodology.

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PubMed2006

Utilization of eye care services in Victoria.

PURPOSE: To determine baseline eye care utilization by older Victorians in order to assess change in 2 years after an eye health promotion campaign. METHODS: A letter of invitation to participate was sent to all people aged 70-79 years in randomly selected Melbourne postcode areas. A questionnaire was designed to allow gathering of eye health-related information. Eye exams included autorefraction, frequency doubling technology and non-mydriatic fundus photography. Results were compared with the Melbourne Vision Impairment Project . RESULTS: A total of 1695 people with a mean age of 74 years were recruited. The overall proportion with visual impairment was 8% (134/1695), of which 27% (36/134) was due to non-refractive causes. Only 31% (11/36) of visually impaired people knew about low-vision services, of whom 20% (7/36) had used them. Of all people with diabetes, only 52% (96/184) had a dilated eye exam within the recommended 2 years (Melbourne Vision Impairment Project 44%). CONCLUSIONS: Compliance rates with recommendations for 2-yearly eye exams for people with diabetes have not improved since the last major eye health study in Victoria 10 years ago. The same is true for the rate of undiagnosed glaucoma, suggesting that messages about eye examinations need to be promoted for older people at high risk of vision loss, for example, those with diabetes and at risk of vision loss from glaucoma.

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PubMed2006

Rapid and cost-effective method to assess vision disorders in a population.

PURPOSE: The aim was to develop a means of rapidly assessing eye health in a cost- and time-effective way to monitor changes over time. METHODS: Key features of the five main eye diseases that cause vision loss in Australia were assessed. Participation was volunteer-based from randomly selected Melbourne suburbs. Recruitment was by mail. Anterior segments and fundi were photographed with a digital non-mydriatic fundus camera. Visual fields were tested with Frequency Doubling Technology. A questionnaire collected information about demographics, general health and lifestyle. Findings from this rapid assessment were compared with those from a population-based study. RESULTS: A total of 1695 people, aged between 70 and 79 years (mean 74), were recruited. The rates and causes of visual impairment were similar between the rapid assessment method and the population-based study. Among the 134 people (8%) with visual impairment at presentation, 98 (73%) had undercorrected refractive error, 17 (13%) had age-related macular degeneration, 11 (8%) had cataract, 2 (2%) had diabetic retinopathy and 2 (2%) had glaucoma. Screening costs per participant were only about AU$145, compared with AU$433 in the Melbourne Visual Impairment Project (VIP). The application of Frequency Doubling Technology as well as the use of a non-mydriatic digital camera for fundus and lens photography resulted in an average examination time of less than half the time needed in the VIP. Data collection took 3 months rather than 4 years in the VIP. CONCLUSION: The rapid assessment method was efficient in time and cost and produced results comparable to a normal population-based survey. Repeating the study design for a similarly sampled group every 2 years would allow the assessment of changes in the prevalence of undiagnosed eye disease.

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PubMed2006

The agreement between the Heidelberg Retina Tomograph and a digital nonmydriatic retinal camera in assessing area cup-to-disc ratio.

PURPOSE: To determine the repeatability and agreement between a digital camera (monoscopic and stereoscopic images) and the Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Heidelberg, Germany) in determining cup-to-disc ratio. A secondary purpose was to determine the monoscopic and stereoscopic thresholds that maximize specificity and sensitivity when compared with the HRT. METHODS: Community living participants aged between 70 and 79 years had their optic discs imaged with a digital nonmydriatic retinal camera (NMRC) and the HRT. Intraclass correlation coefficients (ICCs) and 95% tolerance limits of change were used to determine repeatability characteristics of the instruments. The agreement between the HRT- and NMRC-derived area cup-to-disc ratios was assessed using weighted kappa statistics and receiver operator characteristic (ROC) curves. RESULTS: The agreements between the monoscopic and stereoscopic images and HRT were assessed for 1238 and 1173 eyes, respectively. The reliability measures for both NMRC techniques and HRT were almost perfect (ICC = 0.84-0.99) with narrow tolerance limits of change (9.2%-18.4%) and very small systemic biases (P < 0.05). The agreement between the HRT and both NMRC techniques was substantial, with a weighted kappa = 0.83. The HRT gave a marginally larger area cup-to-disc ratio than the monoscopic and stereoscopic images by 0.008 and 0.006, respectively (P < 0.001). The areas under the ROC curves for both NMRC techniques were 0.98, indicating excellent discriminating characteristics (P < 0.001). An area cup-to-disc ratio cutoff of > or =0.5 for the monoscopic and stereoscopic NMRC was highly specific (94.1% and 91.6%) and sensitive (87.5% and 97.2%, respectively) in determining an HRT-derived area cup-to-disc ratio >0.6. CONCLUSIONS: The monoscopic and stereoscopic digital images showed excellent repeatability and demonstrated substantial agreement with the HRT. The results indicate that the digital NMRC could be a reliable and useful instrument for assessing area cup-to-disc ratio and screening for glaucoma-suspect eyes in the community.

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PubMed2005

Detecting cataract causing visual impairment using a nonmydriatic fundus camera.

PURPOSE: To assess the validity of a digital nonmydriatic fundus camera in detecting cataract as a cause of visual impairment. DESIGN: Diagnostic test comparison. METHODS: Photos of the anterior segment of 72 eyes were taken with a nonmydriatic fundus camera and assessed for cataract by two graders. Dilated biomicroscopy examination of the anterior segment of the same 72 eyes was then performed and cataract graded using the Wilmer scale. RESULTS: Grader 1 and 2 reported 90% and 94% sensitivity and 82% and 77% specificity, respectively, when the digital photos were compared with slit-lamp biomicroscopy in determining visually significant cataract. In addition, both graders showed similar substantial agreement between the digital photos and slit-lamp biomicroscopy when assessed for cataract (unweighted kappa 0.87 and 0.92, respectively, for graders 1 and 2). CONCLUSION: The nonmydriatic fundus camera may be an alternative method for screening for visually significant cataract in the community.

Cataract↗

PubMed2005

Assessment of optic disc cupping with digital fundus photographs.

PURPOSE: To determine the agreement between the assessment of retinal digital images by using an overlay transparency sheet and the Heidelberg retinal tomograph (HRT) in determining cup-disk ratios greater than 0.6. DESIGN: Diagnostic test comparison. METHODS: Computerized topographic and monoscopic digital images of the optic disk of 628 people aged 70 to 79 years were assessed. A grader (M.C.) defined the disk margin on HRT images, and the operation software computed the area cup-disk ratio. The same grader also determined whether the vertical cup-disk ratio on retinal images was greater than 0.6 by superimposing a transparency overlay sheet over the images. Findings of a second grader (J.G.F.) were used to establish reliability measures. RESULTS: The intragrader reliability for the overlay method and HRT was almost perfect (intraclass correlation coefficient [ICC] = 0.96 and 0.99, respectively), whereas the intergrader reliability was good (ICC = 0.77 and 0.92, respectively). A perfect agreement was found on 28 (85%) of 33 eyes between the overlay and HRT methods in determining cup-disk ratios greater than 0.6. CONCLUSIONS: The overlay transparency method appears to be a reliable and promising alternative in determining cup-disk ratios greater than 0.6 in a community screening setting.

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