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Biomedical subjects

F L Ferris

Publications and source records attributed to F L Ferris.

At least 55 records · Page 3Linked to original sources
PubMed1989

Factors associated with visual outcome after photocoagulation for diabetic retinopathy. Diabetic Retinopathy Study Report #13.

Six risk factors for severe visual loss despite panretinal (scatter) photocoagulation were identified by analyzing data collected during the first 5 years after randomization in the Diabetic Retinopathy Study. Proportional hazards regression revealed NVD (neovascularization on/around the optic disc) to be the most important risk factor. The risk of severe visual loss rose with increasing NVD, hemorrhages/microaneurysms, retinal elevation, proteinuria, and hyperglycemia and fell with increasing "treatment density." These results are similar to previous DRS findings on untreated eyes. The importance of "treatment density" as an independent predictor of visual outcome is a new finding and lends support to the common clinical practice of repeating photocoagulation if initial treatment does not reduce or stabilize retinal neovascularization.

Aged↗
PubMed1988

Transient severe visual loss after panretinal photocoagulation.

Seven diabetic patients experienced severe but transient visual loss after panretinal photocoagulation for proliferative diabetic retinopathy. In all patients, visual acuity decreased shortly after treatment to levels ranging from 5/200 to no light perception. In five of the patients, no observable ocular disease or surgical complications could explain the degree of visual loss. The other two patients developed exudative macular detachments, although it was not clear that this change accounted for their severe visual loss. Vision improved in all patients over a period ranging from nine days to nine months. In five patients, visual acuity returned to within two Snellen lines of the pretreatment level.

Adult↗
PubMed1988

Optic disk neovascularization and retinal vessel diameter in diabetic retinopathy.

We measured retinal vessel diameter before and after panretinal photocoagulation in 59 eyes with diabetic retinopathy and moderate to severe optic disk neovascularization. Treatment significantly reduced mean arteriolar and venular diameter. The diameter of the retinal arterioles after treatment correlated significantly with the amount of regression in disk neovascularization. Eyes with large diameter vessels after treatment usually had little or no regression of proliferative retinopathy, whereas regression was more frequently seen in eyes with smaller diameter vessels after treatment.

Arterioles↗
PubMed1988

Diabetic retinopathy and cardiovascular disease in type II diabetics. The Framingham Heart Study and the Framingham Eye Study.

Data from the Framingham Heart Study and the Framingham Eye Study were used to examine the association between diabetic retinopathy and the occurrence of cardiovascular events (coronary heart disease, intermittent claudication, congestive heart failure, and stroke). Among the 206 persons with Type II diabetes in the Framingham Eye Study, the odds ratios for diabetic retinopathy and cardiovascular disease were 14.3 (95% confidence interval (CI) = 2.7-101.9), 2.0 (95% CI = 0.5-8.1), and 0.3 (95% CI = 0.05-1.3) for ages 52-64, 65-74, and 75-85 years, respectively. The test for homogeneity indicated highly significant differences for the odds ratios across age groups. The associations were similar when sex, duration of diabetes, age at diagnosis of diabetes, and history of insulin treatment were accounted for by logistic regression. Our data suggest an association in younger diabetics between diabetic retinopathy, a small vessel complication of diabetes, and a group of cardiovascular events commonly thought to result from large vessel disease. The finding may merely indicate that diabetics with large vessel disease are also more likely to have small vessel disease. However, it is also consistent with the hypothesis, suggested by histologic data, that a more generalized microangiopathy affecting not only the eye but also organs such as the heart may play a role in the pathogenesis of cardiovascular disease in diabetics.

Age Factors↗
PubMed1987

Intraocular pressure following panretinal photocoagulation for diabetic retinopathy. Diabetic Retinopathy Report No. 11.

Data collected during the first five years after randomization in the Diabetic Retinopathy Study were analyzed to determine the effect of panretinal photocoagulation on intraocular pressure (IOP). At each follow-up visit, median IOP was identical for the treated and untreated eyes. Mean IOP rose slightly in each group. The proportion of untreated eyes with IOP above 30 mm Hg at two consecutive visits was twice that of the treated eyes (2% vs 1%). These data show that panretinal photocoagulation reduces the risk of subsequent intraocular hypertension, apparently by preventing the development of neovascular glaucoma.

Argon↗
PubMed1987

Macular thickening and visual acuity. Measurement in patients with cystoid macular edema.

Cystoid macular edema (CME) is commonly associated with many ocular conditions. The presence of CME on fluorescein angiographic examination need not, however, preclude good visual acuity. The hypothesis that the degree of macular thickening is associated with visual acuity was tested. Ten consecutive stereoscopic fluorescein angiograms were graded by 13 ophthalmologists using a set of four standards. Linear regression showed a significant relationship between mean macular thickening and the visual acuity recorded at the time of angiography. However, no significant relationship could be made between the estimation of visual acuity and the amount of fluorescein staining measured in the posterior pole. Although the observation of fluorescein leakage is indispensable for documenting a breakdown in the blood-retinal barrier, the observation of retinal thickening is important for identifying the sites of edema accumulation, and may be the useful parameter to follow when trying to assess improvement or worsening of retinal edema and in cases of uveitis when the cause of poor vision may be multifactorial.

Adult↗
PubMed1987

Macular edema in Diabetic Retinopathy Study patients. Diabetic Retinopathy Study Report Number 12.

Results from the Diabetic Retinopathy Study (DRS) demonstrate that scatter photocoagulation is associated with some loss of visual acuity soon after treatment. This visual loss is especially prominent in eyes with preexisting macular edema. It is also associated with the intensity of treatment. Reducing macular edema by focal photocoagulation before initiating scatter treatment and dividing scatter treatment into multiple sessions with less intense burns may decrease the risk of the visual loss associated with photocoagulation.

Diabetic Retinopathy↗
PubMed1986

Evaluation of medical data: role of clinical trials.

Over the centuries, methods have been developed to evaluate diseases and their treatments. One systematic method is the case series, in which groups of patients are followed over time to estimate the likelihood of various disease outcomes, either with or without treatment. A more efficient method for assessing treatment effectiveness is the clinical trial. Both methods have been used for evaluating current treatments of macular diseases. the combination of case series and clinical trials has been used to advantage for many of these diseases. However, when one wants to be certain that a treatment is effective, there is no substitute for the clinical trial.

Clinical Trials as Topic↗
PubMed1986

Comparability of ophthalmic diagnoses by clinical and Reading Center examiners in the Visual Acuity Impairment Survey Pilot Study.

Technologic advances in ophthalmic equipment offer the possibility of replacing direct clinical examinations with Reading Center evaluations of data recorded in epidemiologic studies. Clinical and Reading Center examiners made independent ophthalmic diagnoses of 133 right and 132 left eyes of 138 adults in the Visual Acuity Impairment Survey Pilot Study, carried out in three US cities, Boston, Detroit, and Minneapolis, in August 1981-December 1982. The Reading Center diagnosed eye conditions using only photographic and visual field data collected at the time of the clinical examination. In the comparisons of clinical and Reading Center evaluations reported here, only eyes judged by the examiners to have pathology severe enough to reduce visual acuity to 6/9 or worse were classified as having pathology. (No visual acuity criterion was required for the diagnosis of glaucoma or diabetic retinopathy.) There was agreement in diagnostic assessments between clinical and Reading Center examiners in about 80% of eyes. The kappa statistic, which adjusts for chance agreement, was in the fair to good range: 0.60 for 133 right eyes and 0.62 for 132 left eyes. When the Reading Center examiners were provided with additional information on medical history, refractive error and best corrected visual acuity, the agreement between clinical and Reading Center assessments among the subset of eyes with 6/9 or worse vision again was in the fair to good range, with kappas of 0.61 for 45 right eyes and 0.68 for 48 left eyes. Inter-observer agreement between Reading Center examiners in diagnosing pathology was in the good to excellent range. Use of Reading Centers in future epidemiologic studies should be considered, but elimination of the clinical examinations is not recommended until modifications in the protocol described here have been made and shown to improve levels of agreement between clinical and Reading Center examiners.

Eye Diseases↗
PubMed1984

Age-related macular degeneration and blindness due to neovascular maculopathy.

Age-related macular degeneration (AMD) is one of the four most common causes of blindness in the United States. Retinal manifestations of AMD can be categorized as either atrophic or neovascular/exudative. To the best of our knowledge, the proportion of patients legally blind due to the neovascular/exudative manifestations of this disease has not been previously reported. Data from two studies, the Framingham Eye Study and a large case-control study, demonstrate that the vast majority of patients with legal blindness due to AMD have the neovascular/exudative form of the disease. Seventy-nine percent of eyes legally blind due to AMD in the Framingham population and 90% of eyes legally blind due to AMD in the case-control study had neovascular/exudative retinopathy. This is in spite of the fact that neovascular/exudative retinopathy is a relatively infrequent complication of AMD.

Aged↗
PubMed1984

Macular edema. A complication of diabetic retinopathy.

Diabetic macular edema is the leading cause of decreased vision from diabetic retinopathy. This decreased vision is caused by an increase in extracellular fluid within the retina distorting the retinal architecture and frequently taking on a pattern of cystoid macular edema. This fluid accumulates within the retina because of the breakdown of the barriers within the retinal blood vessels and possibly the pigment epithelium. Diabetic macular edema tends to be a chronic disorder. Although spontaneous recovery is not an uncommon occurrence, over one-half of diabetics with macular edema will lose two or more lines of visual acuity within two years. The most promising treatment for diabetic macular edema has been photocoagulation. It is recommended that in all patients with diabetic macular edema attempts be made to normalize elevated blood glucose, decrease elevated blood pressure, and improve cardiac or renal status. Reduction of serum lipids by diet or pharmacologic means is an unproven treatment at this time. The Early Treatment Diabetic Retinopathy Study hopefully will provide more definitive information as to whether photocoagulation is effective in various subgroups of patients with diabetic macular edema.

Blood Glucose↗
PubMed1984

Site visits in a multicenter ophthalmic clinical trial.

Site visits were conducted to 19 clinical centers in a large multicenter ophthalmologic clinical trial, the Early Treatment Diabetic Retinopathy Study (ETDRS). The purpose of these site visits was to ensure the consistency of study procedures among clinics and to verify that these procedures were being carried out in accordance with the ETDRS Manual of Operations. The five major aspects of this quality control program are as follows: To monitor and review each clinical center's organization and procedures; To promote comparability of participating centers in all important aspects of the clinical trial; To gain more understanding about special problems facing individual clinical centers; To establish good rapport between the site visitor and clinic staff to aid future clinic monitoring; To promote and maintain enthusiasm for the study. The ETDRS clinical center site visits were conducted by using an observational approach. Presite visit preparations included the formation of a site visit agenda and the design of a site visit form, providing a guide for the site visitor, and a list of the topics that were to be reviewed at each center. Important concerns common to all site visits proved beneficial in the ETDRS.

Attitude of Health Personnel↗
PubMed1983

Senile macular degeneration: review of epidemiologic features.

Senile macular degeneration is a leading cause of visual loss in the United States, England, and probably many other industrialized countries. The clinical manifestations of this disease include: drusen, atrophy of the retinal pigment epithelium, serous detachment of the retinal pigment epithelium, subretinal neovascularization, and disciform scars. Standardized techniques for defining these manifestations of senile macular degeneration are necessary for epidemiologic study of this disease. Such standardization is facilitated by the use of fundus photographs. If a visual acuity deficit is included in the definition of senile macular degeneration, care must be taken to assure that senile macular degeneration is responsible for the decreased vision. The Framingham Eye Study provides the best senile macular degeneration prevalence data. The rapid increase in prevalence of senile macular degeneration after the fifth decade is demonstrated in this study and is consistent with other studies. In fact, increasing age has the strongest association with senile macular degeneration of any of the risk factors considered to date. Many other possible risk factors have been identified but further investigation is necessary to verify these associations.

Aged↗
PubMed1983

Senile macular degeneration: a case-control study.

Senile macular degeneration, although a leading cause of visual loss in the United States, remains a poorly understood disease. To assess the effects of host and environmental factors on this condition, a study of 228 cases and 237 controls matched by age and sex, who had visited any of 34 Baltimore ophthalmologists between September 1, 1978 and March 31, 1980, was conducted. Study participants were interviewed for past medical, residential, occupational, smoking and family histories, as well as social and demographic factors. Diagnoses were validated by means of fundus photographs. The 162 cases and 175 controls who met the study diagnostic criteria for cases and controls were included in the analysis. Statistically significant associations were demonstrated between senile macular degeneration and family history of macular disease (odds ratio (OR) = 2.9), chemical work exposures (OR = 4.2), blue or medium pigmented eyes (OR = 3.5), history of one or more cardiovascular diseases (OR = 1.7), decreased hand grip strength, and hyperopia. The risk of macular degeneration in cigarette smokers was significant for males only (OR = 2.6). The study results suggest that the development of macular degeneration is mainly influenced by familial, genetic, and personal characteristics, rather than by the few environmental factors studied. Additional studies are needed to further evaluate the role of environmental factors.

Aged↗
PubMed1983

An ocular clinicopathologic correlative study of six patients from the Diabetic Retinopathy Study.

The authors studied the eyes postmortem from six patients who were enrolled in the multicenter Diabetic Retinopathy Study and treated by photocoagulation. All were patients of the Wilmer Institute, The Johns Hopkins Hospital. Of these six patients, four had equal or better vision in the treated eye at their last visit. Two patients had worse vision, due primarily to cystoid macular edema. All but one patient had clinically significant field loss in the treated eye, and this correlated with the retinal damage induced by photocoagulation. This treatment produced local retinal and choroidal effects and did not alter the histopathologic appearance of the anterior segment of the eye.

Adult↗