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Biomedical subjects

W C Steinmann

Publications and source records attributed to W C Steinmann.

At least 37 records · Page 2Linked to original sources
PubMed1989

Risk factors for the development of Tenon's capsule cysts after trabeculectomy.

Tenon's capsule cysts (TCCs) are a complication of glaucoma filtering surgery. They are frequently associated with substantial elevations in intraocular pressure (IOP) beginning 2 to 8 weeks postoperatively. To determine the incidence and possible risk factors for the development of TCCs, case records of all patients who received trabeculectomy over a 4-year period at the Wills Eye Hospital were reviewed. The incidence of TCCs was 28% in those who underwent trabeculectomy. Characteristics of patients after trabeculectomy in whom TCCs developed were compared with patients after trabeculectomy in whom TCCs did not develop. Both univariate and multivariate techniques were used to assess the association of characteristics associated with the development of TCCs. Factors associated with increased risk (P less than 0.05) were: history of prior TCCs, argon laser trabeculoplasty, male gender, and the use of preoperative sympathomimetics. The use of a compression shell was associated with decreased risk (P less than 0.05).

Adult↗
PubMed1989

Visual field change in low-tension glaucoma over a five-year follow-up.

There is some evidence that the nature and progression of disease in low-tension glaucoma may be distinct from other open-angle glaucomas. The authors assessed visual field change by retrospective case review of all patients treated for low-tension glaucoma by the Glaucoma Service, Wills Eye Hospital, for at least 5 years. Sixty-two glaucomatous eyes of 36 patients were identified. All eyes were treated medically and 40 (65%) underwent at least one surgical procedure. Twenty-eight eyes (47%) had initial field loss confined to a single hemi-field and in the remainder both hemi-fields were involved. Thirty of 57 eyes (53%) showed progression at 3 years and 38 (62%) of 57 had progressed by 5 years. A dense scotoma extending from the nasal periphery toward fixation was the most common visual field defect. The rate of field change in this population is significantly greater than in a cohort of primary open-angle glaucoma patients also seen at Wills Eye Hospital, but who had elevated intraocular pressures. Patterns of field loss and rate of progression in this low-tension glaucoma population suggest that the natural history of low-tension glaucoma differs from high-tension open-angle glaucoma.

Aged↗
PubMed1989

The effect of chronic miotic therapy on the results of posterior chamber intraocular lens implantation and trabeculectomy in patients with glaucoma.

We reviewed the charts of 18 patients (20 glaucomatous eyes) who had not used pilocarpine prior to undergoing trabeculectomy combined with or performed later with posterior chamber lens implantation. We then compared postoperative results and complications in these patients with those in 35 other patients (40 glaucomatous eyes) in two age- and stage-matched groups who had used pilocarpine prior to undergoing the same procedures. All patients had a minimum follow-up of 6 months. There was no significant difference between these groups in terms of postoperative intraocular pressure and required glaucoma medications. However, in the pilocarpine-treated groups, there was a significantly higher incidence of complications, especially intraocular lens capture (P less than 0.05), and of worse visual outcomes (P less than 0.01).

Aged↗
PubMed1989

A comparative evaluation of three methods of analyzing optic disc topography.

Topographical evaluations of the optic discs of 17 eyes obtained using a clinical planimeter, the Rodenstock video-ophthalmograph, and the IS 2000 image analyzer were compared. The parameters studied were vertical and horizontal cup-to-disc ratios, cup volumes, rim areas, disc areas, and rim area-to-disc area ratios. There was good correlation between the measurements obtained by the three methods (correlation coefficients ranged from 0.46 to 0.88). For various parameters, the correlations between clinical planimetry and image analysis were higher than either those between image analysis and video-ophthalmography, or those between clinical planimetry and video-ophthalmography. The mean horizontal cup-to-disc ratios and rim areas as measured by clinical planimetry were significantly higher than those measured by image analysis. Image analysis measured significantly higher disc area and rim areas and lower cup volumes than video-ophthalmography.

Aged↗
PubMed1988

Variability in digital analysis of optic disc topography.

We determined the magnitude of variability in optic disc topographical parameters on digital analysis of the optic disc using the IS 2000. The variability introduced by the system, the observer, the observer and patient, and by clinically different types of discs was assessed in the measurement of the vertical cup-to-disc ratio, horizontal cup-to-disc ratio, cup area-to-disc area, cup volume, neuroretinal rim area, and neuroretinal rim area-to-disc area. The system itself accounted for no variability. The variability introduced by one observer for the parameters ranged from 1% to 7%, and by one observer and patient from 1% to 28%. The variation among five observers ranged from 1% to 55%. Direct image acquisition (using video cameras) gave results that were no different from those obtained by digitizing the slides. Contrast-enhancement techniques did not decrease observer variability. A change in the flash intensity level at which optic disc images were acquired from 94.5 to 15.0 Watt-seconds introduced a variability of 3% to 21%. These results are less variable than those obtained on clinical observation and comparable to those of the Rodenstock image analyzer in evaluating these aspects of optic disc topography.

Adult↗
PubMed1988

Surgical therapy of chronic glaucoma in aphakia and pseudophakia.

Most glaucoma surgical procedures are less successful in aphakic or pseudophakic eyes. The authors reviewed 91 consecutive initial glaucoma procedures in aphakic patients from 1979 to 1986 to determine successful outcomes and complications. Success was defined as an intraocular pressure (IOP) of at least 30% below the preoperative value and less than 21 mmHg, less than 2 lines of Snellen acuity loss, and no further surgical intervention. At 9 months, success rates were: trabeculectomy, 4 of 15 patients; cyclodialysis, 3 of 20 patients; neodymium:YAG (Nd:YAG) cyclophotocoagulation, 1 of 8 patients; cyclocryotherapy, 9 of 22 patients; anterior chamber tube shunt (Schocket procedure), 3 of 6 patients; and argon laser trabeculoplasty, 2 of 20 patients. Severe complications included phthisis bulbi in 11% of cyclocryotherapy and severe visual loss in 20% with cyclodialysis and 14% with cyclocryotherapy. Results confirm the difficulty of surgical therapy in these patients.

Aged↗
PubMed1988

The clinical effectiveness of pneumococcal vaccine in the elderly.

The effectiveness of pneumococcal vaccine in the immunocompetent elderly remains controversial. We report the results of a multicenter, case-control study of 244 controls and 122 patients, aged 55 years and older, hospitalized during a 5-year period with pneumococcal bacteremia, meningitis, or other bacteriologically confirmed pneumococcal infection. Two controls per patient were matched on the basis of admission date, hospital records, and underlying diseases. All subjects were selected without knowledge of immunization status with pneumococcal vaccine, and were excluded if there was evidence for immunosuppression due to disease or iatrogenic causes. The clinical effectiveness of the vaccine was calculated to be 70% (95% confidence intervals [CI], 37% to 86%) in this population, based on a Mantel-Haenszel point estimate of the odds ratio of 0.30 (95% CI, 0.14% to 0.63%; P less than 0.005). The clinical effectiveness of pneumococcal vaccine in preventing pneumococcal infection in the immunocompetent elderly approximates the vaccine's effectiveness in the general immunocompetent population.

Aged↗
PubMed1987

Positional changes in the vasculature of the optic disk in glaucoma.

We analyzed 34 sets of optic disk photographs from 19 patients with glaucoma who had been followed up for ten years to evaluate changes in the position of the vasculature of the optic disks over time. Each photograph was analyzed by an image analyzer's edge-defining program for optic disk analysis and by three experienced clinicians. Image analysis of the blood vessels in 16 optic disks showed positional centrifugal shifts. The clinicians consistently noted changes in the appearance of seven optic disks. The difference between the results obtained using the image analyzer and those obtained by clinical observation was significant (P less than .05).

Adult↗
PubMed1987

Cysts of Tenon's capsule following filtration surgery. Medical management.

Cysts of Tenon's capsule (encapsulated blebs) developed postoperatively in 77 (13%) of 607 eyes that underwent filtration surgery between 1980 and mid-1985. The annual incidence was not uniform, increasing markedly throughout the period. Seventy-four eyes were treated with medical therapy only. At a mean follow-up of 19 months, the success rate for these eyes, defined as an intraocular pressure (IOP) of 21 mm Hg or less, was 92%. The three eyes that underwent surgical revision subsequently failed clinically by the study criteria. Those patients in whom cysts of Tenon's capsule developed were compared with an age-matched control group to assess for possible differences in long-term outcome. There was a significantly higher IOP in the Tenon's cyst group at one and three months after surgery, and an increased proportion of IOPs above 30 and 40 mm Hg. At a six-month and later follow-up, there was no significant difference in the mean IOP or in progression of visual field loss. Causative factors were sought for the development of these cysts of Tenon's capsule. Prior conjunctival surgery, or previous cyst formation in the other eye, were the significant risk factors noted.

Adolescent↗
PubMed1987

Pupillary dilation with tropicamide 1% for funduscopic screening. A study of duration of action.

Primary care practitioners omit pupillary dilation from funduscopic examination, possibly because of time constraints, poor patient compliance, or fear of adverse reactions. Nevertheless, the omission of this procedure may lead to the inadequate visualization of the fundus for screening. We administered a topical solution of 1% tropicamide to 30 adults to determine the course of pupillary dilation over time and whether adequate dilation could be attained within a routine clinic visit. Pupil diameters were measured every 5 minutes in a 30-minute period. The initial mean pupillary diameter was 2.4 mm and the endpoint was 5.5. Dilation was significantly slower in those older than 50 years of age. However, at 15 minutes 87% of the patients, regardless of age, had achieved dilation to at least 4 mm, which should be sufficient for screening under most circumstances. We conclude that adequate pupillary dilation in adults usually can be achieved within the time frame of a routine office visit and thus should not be a deterrent to routine funduscopic screening by primary care practitioners.

Adult↗
PubMed1984

Procedural skills training in the internal medicine residency.

To determine whether there was agreement on a core of procedural skills that all internal medicine residents should be able to perform, faculty members and residents at the University of Pennsylvania and the University of Nebraska were surveyed regarding 72 procedures. Nineteen procedures were indicated by 90 percent or more of the respondents as those that should be learned by the graduates. In response to a second survey, many senior residents said they did not feel competent to perform these 19 procedures, and many did not recall that their performance on procedures had been evaluated. Thus, despite any regional or institutional influences, there was agreement on a core of procedural skills that should be required of all physicians completing the general internal medicine residency. It is important that training programs assess whether or not the procedures they consider essential are being mastered by their residents.

Clinical Competence↗
PubMed1982

Screening for glaucoma by general medicine residents.

A screening-training program to teach Schiötz tonometry to internal medicine residents was completed. A large number of previously undiagnosed glaucoma cases were detected. Most of the residents had never before performed tonometry. None had previously screened patients in their clinics. Following training, most of the physicians believed themselves to be competent to perform tonometry, although many had not fully mastered the instrument technically. They believed that glaucoma screening should be done by general internists. Although the residents indicated plans to screen their patients for glaucoma, few continued to do so. General internists may be willing to learn to perform tonometry. However, earlier training and more effective role modelling are probably necessary to effect routine screening for glaucoma.

Family Practice↗