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Frederick L Ferris

Publications and source records attributed to Frederick L Ferris.

23 records · Page 2Linked to original sources
PubMed2003

A computerized method of visual acuity testing: adaptation of the early treatment of diabetic retinopathy study testing protocol.

PURPOSE: To develop a computerized method of visual acuity testing for clinical research as an alternative to the standard Early Treatment for Diabetic Retinopathy Study (ETDRS) testing protocol, and to evaluate its test-retest reliability and concordance with standard ETDRS testing. DESIGN: Test-retest reliability study. METHODS: Multicenter setting of a study population of 265 patients at three clinical sites. Visual acuity was measured with both the electronic visual acuity testing algorithm (E-ETDRS) and standard ETDRS protocol (S-ETDRS) twice on one eye of each patient. E-ETDRS testing was conducted using the electronic visual acuity tester (EVA), which utilizes a programmed Palm (Palm, Inc, Santa Clara, California, USA) hand-held device communicating with a personal computer and 17-inch monitor at a test distance of 3 meters. RESULTS: For the E-ETDRS protocol, test-retest reliability was high (r = 0.99; with 89% and 98% of retests within 0.1 logMAR and 0.2 logMAR of initial tests, respectively) and comparable with that of S-ETDRS testing (r = 0.99; with 87% and 98% of retests within 0.1 logMAR and 0.2 logMAR of initial test, respectively). The E-ETDRS and S-ETDRS scores were highly correlated (r = 0.96 for initial tests and r = 0.97 for repeat tests). Based on estimates of 95% confidence intervals, a change in visual acuity of 0.2 logMAR (10 letters) from a baseline level is unlikely to be related to measurement variability using either the E-ETDRS or the S-ETDRS visual acuity testing protocol. CONCLUSIONS: The E-ETDRS protocol has high test-retest reliability and good concordance with S-ETDRS testing. The computerized method has advantages over the S-ETDRS testing in electronically capturing the data for each tested letter, requiring only a single distance for testing from 20/12 to 20/800, potentially reducing testing time, and potentially decreasing technician-related bias.

Adolescent↗
PubMed2003

Proposed international clinical diabetic retinopathy and diabetic macular edema disease severity scales.

PURPOSE: To develop consensus regarding clinical disease severity classification systems for diabetic retinopathy and diabetic macular edema that can be used around the world, and to improve communication and coordination of care among physicians who care for patients with diabetes. DESIGN: Report regarding the development of clinical diabetic retinopathy disease severity scales. PARTICIPANTS: A group of 31 individuals from 16 countries, representing comprehensive ophthalmology, retina subspecialties, endocrinology, and epidemiology. METHODS: An initial clinical classification system, based on the Early Treatment Diabetic Retinopathy Study and the Wisconsin Epidemiologic Study of Diabetic Retinopathy publications, was circulated to the group in advance of a workshop. Each member reviewed this using e-mail, and a modified Delphi system was used to stratify responses. At a later workshop, separate systems for diabetic retinopathy and macular edema were developed. These were then reevaluated by group members, and the modified Delphi system was again used to measure degrees of agreement. MAIN OUTCOME MEASURES: Consensus regarding specific classification systems was achieved. RESULTS: A five-stage disease severity classification for diabetic retinopathy includes three stages of low risk, a fourth stage of severe nonproliferative retinopathy, and a fifth stage of proliferative retinopathy. Diabetic macular edema is classified as apparently present or apparently absent. If training and equipment allow the screener to make a valid decision, macular edema is further categorized as a function of its distance from the central macula. CONCLUSIONS: There seems to be a genuine need for consistent international clinical classification systems for diabetic retinopathy and diabetic macular edema that are supported with solid evidence. The proposed clinical classification systems provide a means of appropriately categorizing diabetic retinopathy and macular edema. It is hoped that these systems will be valuable in improving both screening of individuals with diabetes and communication and discussion among individuals caring for these patients.

Diabetic Retinopathy↗
PubMed2003

The long-term effects of laser photocoagulation treatment in patients with diabetic retinopathy: the early treatment diabetic retinopathy follow-up study.

OBJECTIVES: To evaluate the long-term natural history and effects of laser photocoagulation treatment in patients with diabetic retinopathy. DESIGN: Follow-up study of the 214 surviving patients enrolled originally at the Johns Hopkins Clinical Center for the Early Treatment Diabetic Retinopathy Study (ETDRS), which was a clinical trial designed to evaluate the role of laser photocoagulation and aspirin treatment in patients with diabetic retinopathy. METHODS: Early Treatment Diabetic Retinopathy Study patients enrolled in the Johns Hopkins Clinical Center had complete eye examinations, including best-corrected visual acuity measurements, fundus photographs, and medical questionnaires throughout the 7-year study. They had the same examinations at the final long-term follow-up visit at the National Eye Institute, National Institutes of Health, 13 to 19.5 years after the initial laser photocoagulation (median, 16.7 years). MAIN OUTCOME MEASURES: The major outcomes were mortality and the rates of moderate and severe vision loss. The secondary outcomes were progression of diabetic retinopathy and need for other eye surgery. RESULTS: Of the 214 patients who were alive at the end of the original ETDRS in 1989, 130 (61%) were deceased at the time of the re-examination. Of the 84 who were alive, 71 (85%) were examined at their long-term follow-up visit at the National Institutes of Health. At the long-term follow-up examination, 42% had visual acuity of 20/20 or better, and 84% had visual acuity of 20/40 or better in the better eye. Compared with baseline, 20% of patients had moderate vision loss (loss of 3 lines or more vision) in the better eye at follow-up. Only one patient had visual acuity of 20/200 bilaterally. He had visual acuity loss secondary to age-related macular degeneration. No patient had severe vision loss (worse than 5/200). All the initially untreated eyes of patients who had severe nonproliferative diabetic retinopathy or worse by the time of the ETDRS closeout visit of the original study received scatter photocoagulation treatment. Focal photocoagulation was performed in 43% bilaterally and 22% unilaterally. Cataract surgery was performed in 31% of the patients, vitrectomy in 17%, and glaucoma surgery in one patient. CONCLUSIONS: As previously reported, the mortality rate of patients with diabetic retinopathy is much higher than that of the general population. For those who survived, aggressive follow-up, with treatment when indicated, seems to be associated with maintenance of good long-term visual acuity for most patients. The need for laser scatter photocoagulation with long-term follow-up seems to be high.

Adult↗
PubMed2003

Who should receive oral supplement treatment for age-related macular degeneration?

Oxidative damage to the retina has been proposed as a risk factor for age-related macular degeneration (AMD). Dietary or supplemental antioxidants may play a protective role. The Age-Related Eye Disease Study (AREDS), a randomized, multicenter, placebo-controlled clinical trial designed to test the effect of pharmacologic doses of antioxidants and zinc on the incidence and progression of AMD, reported a beneficial effect of high-dose supplements, taken for approximately 6 years, in delaying the progression of intermediate AMD to advanced AMD. AREDS and subsequent research on dietary intake or supplement use have not indicated a protective role of antioxidant or zinc intake or supplement use in the incidence or prevalence of early AMD. Numbers of cases were insufficient to investigate effects on late AMD. Persons with intermediate AMD and without contraindications should consider using antioxidant and zinc supplements. There is no evidence to date that earlier use conveys benefit.

Administration, Oral↗