[Ultrasound biomicroscopy--microscopic resolution imaging].
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Diagnostic Imaging↗
Biomedical subjects
D Weinberger
Publications and source records attributed to D Weinberger.
A comparative study of two dose regimens of latanoprost in patients with elevated intraocular pressure.
OBJECTIVE: The purpose of the study was to determine whether latanoprost (13,14-dihydro-17-phenyl-18,19,20-trinor PGF2a-isopropyl ester), a new prostaglandin analogue that has been found effective in reducing intraocular pressure (IOP) in humans, is equally effective at lower concentrations than those currently employed. DESIGN AND PARTICIPANTS: Fifty patients with glaucoma or ocular hypertension were treated in a randomized, crossover, double-masked fashion with 1 drop of latanoprost (50 microg/ml once daily and 15 microg/ml twice daily) in the affected eye(s) for 3 weeks on each concentration. Tonometry was obtained at 8:00, 13:00, and 17:00 hours at baseline (untreated) and after 3 weeks on each concentration. Placebo (a buffer solution of latanoprost eye drop) was administered for complete masking of the study. RESULTS: Mean baseline (untreated) diurnal IOP for the entire sample was 24.7 mmHg. Intraocular pressure was reduced by 6.1 mmHg with latanoprost 15 microg/ml twice daily, and by 7.5 mmHg with 50 microg/ml once daily. Results with both regimens were significant (P < 0.001 each, Student's t-test). However, the 50 microg/ml dose was significantly more effective than the 15 microg/ml dose, with a difference of 1.4 mmHg (P < 0.001, ANOVA). Both dose regimens were well tolerated, with little, predominantly mild, ocular discomfort. The higher dose did not cause more hyperemia at 3 weeks than the lower one, i.e., the lower dose yielded a slightly higher score (1.8 mm) on the visual analogue scale (P < 0.29, ANOVA). CONCLUSIONS: Latanoprost administered at a concentration of 50 microg/ml once daily effectively reduces IOP in patients with elevated IOP. Administration of a lower concentration (15 microg/ml) twice daily is less effective, but still significant.
Adult↗
Sulfur hexafluoride injection for Descemet's membrane detachment in cataract surgery.
Extensive Descemet's membrane detachment persisted after small incision cataract surgery in three patients. Unfolding and repositioning of Descemet's membrane by sodium hyaluronate (Healon) were followed by injection of sulfur hexafluoride 20% gas mixed with air to fill the anterior chamber. Initially, the gas bubble filled most of the anterior chamber; it disappeared over 7 to 9 days. Descemet's membrane remained attached, and the corneal edema cleared.
Aged↗
Kinetic modeling of [11C]raclopride: combined PET-microdialysis studies.
The in vivo binding of D2 receptor ligands can be affected by agents that alter the concentration of endogenous dopamine. To define a more explicit relation between dopamine and D2 receptor binding, the conventional compartment model for reversible ligands has been extended to account for a time-varying dopamine pulse. This model was tested with [11C]raclopride positron emission tomography and dopamine microdialysis data that were acquired simultaneously in rhesus monkeys. The microdialysis data were incorporated into the model assuming a proportional relation to synaptic dopamine. Positron emission tomography studies used a bolus-plus-infusion tracer delivery with amphetamine given at 40 minutes to induce dopamine release. The extended model described the entire striatal time-activity curve, including the decrease in radioactivity concentration after an amphetamine-induced dopamine pulse. Based on these results, simulation studies were performed using the extended model. The simulation studies showed that the percent decrease in specific binding after amphetamine measured with the bolus-plus-infusion protocol correlates well with the integral of the postamphetamine dopamine pulse. This suggests that changes in specific binding observed in studies in humans can be interpreted as being linearly proportional to the integral of the amphetamine-induced dopamine pulse.
Animals↗
Rhegmatogenous retinal detachment operation after radial keratotomy.
Radial keratotomy has recently been introduced for the correction of myopia. This procedure does not hinder progression of the pathophysiological changes in the myopic eye. We hereby describe a case of rhegmatogenous retinal detachment operation after radial keratotomy and present the operative considerations and refractive results.
Cornea↗
Three-dimensional measurements of central serous chorioretinopathy using a scanning laser tomograph.
PURPOSE: To evaluate the topographic three-dimensional mapping of retinal elevation in central serous chorioretinopathy using the Heidelberg Retina Tomograph and to correlate the measured parameters with the fluorescein angiographic findings. METHODS: Seventy-six consecutive patients with central serous chorioretinopathy (63 men, 13 women), between 26 and 54 years of age, were examined to identify areas of neurosensory retinal detachment and fluorescein leakage. In areas of retinal detachment, the parameters measured were the area, volume, maximal height, and diameters of the retinal elevation, which were statistically analyzed, and the correlations between these parameters were evaluated. RESULTS: Mean +/- SD area of elevation was 9.6 +/- 5.22 mm2 (range, 2.7 to 21.5 mm2); mean volume was 1.16 +/- 1.3 mm3 (range, 0.11 to 4.73 mm3); mean maximal height was 238 +/- 108 microns (range, 97 to 450 microns); mean x-axis was 3.4 +/- 1.1 mm (range, 1.6 to 5.6 mm); and mean y-axis was 3.03 +/- 0.98 mm (range, 1.6 to 4.7 mm). Most of the retinal elevations were oval (the x-axis longer than the y-axis); the maximal height was in the geometric center in the smaller blebs and below the geometric center in the larger blebs. There were statistically significant correlations between area, volume, and height of the sensory elevation. No correlation was found between the location and the shape of leakage on fluorescein angiography and the Heidelberg Retina Tomograph measurements. CONCLUSIONS: Confocal laser tomography is potentially useful as a noninvasive diagnostic technique for quantitative measurements of the neurosensory retinal detachment in central serous chorioretinopathy.
Adult↗
Diabetic retinopathy during pregnancy.
PURPOSE: The purpose of the study is to evaluate the incidence, prevalence, progression, and risk factors of diabetic retinopathy during pregnancy. METHODS: Sixty-five patients who were pregnant and had insulin-dependent diabetes mellitus were evaluated before pregnancy, in every trimester during the pregnancy, and 12 months postpartum. The medical data included age, diabetes duration, glycohemoglobin, fructosamine, hemoglobin, creatinine, uric acid, and systolic and diastolic blood pressure. RESULTS: Progression of the retinopathy occurred in 77.5% of the patients who presented with diabetic retinopathy at conception; proliferative diabetic retinopathy occurred in 22.5%. Only 26% of the patients who started the pregnancy without diabetic retinopathy had some progression of the retinopathy. Duration of the diabetes was longer in the progressive group compared with the nonprogressive group (P = 0.007). The glycohemoglobin was higher in the progressive group than in the nonprogressive group at each time point, but only in the third trimester was the difference statistically significant (P = 0.04). The hemoglobin level was lower in the progressive group than in the nonprogressive group (P < 0.01). The systolic blood pressure was higher in the progressive group (P < 0.005). CONCLUSION: Understanding the risk factors contributing to the aggravation of diabetic retinopathy during pregnancy is helpful in designing criteria for the team management of pregnant patients with diabetes.
Adult↗
Extracapsular cataract extraction and intraocular lens implantation in eyes filled with silicone oil.
Extracapsular cataract extraction with posterior chamber intraocular lens implantation was performed in five phakic eyes filled with silicone oil following vitreoretinal surgery. Silicone oil migration was prevented during surgery using an anterior chamber maintaining system and a self-sealed corneoscleral tunnel incision. The posterior capsule opacified within 3 months in all patients, and neodymium:YAG capsulotomy or surgical discission was performed in a diamond-shaped pattern. No silicone-related complications were found, including silicone oil migration into the anterior chamber. There were no difficulties visualizing the peripheral retina during funduscopy.
Cataract↗
Retinal detachment after noncontact pneumatic tonometry.
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Air↗
Predictors of recurrence for patients with small (one centimeter or less) localized breast cancer (T1a,b N0 M0).
BACKGROUND: The frequency of small (< or = 1 cm) axillary lymph node negative invasive breast cancers (T1a,b N0 M0) is increasing because of wider implementation of breast cancer screening. Identification of prognostic factors for these patients has been based largely on retrospective pathology review. The authors analyzed histologic factors recorded in the original pathology reports to determine predictors of recurrence for patients with T1a,b N0 M0 breast cancer. METHODS: Two hundred eighteen patients were studied. Potential prognostic factors including measured millimeter tumor size in three dimensions, histologic grade, nuclear grade, and presence or absence of lymphatic vessel invasion were documented prospectively in routine surgical pathology reports of a large community (nonuniversity based) hospital. Follow-up was performed annually by the tumor registry. RESULTS: With a median follow-up of 6.9 years (range, 3-15.8 years), overall recurrence free survival was 93%. Poor nuclear grade (hazard ratio, 5.8; 95% confidence interval, 1.70-19.82; P = 0.004) and lymphatic vessel invasion (hazard ratio, 4.6; 95% confidence interval, 1.34-15.61; P = 0.01) were independent predictors of recurrence. Only 10% of patients had cancers with both poor nuclear grade and lymphatic vessel invasion and their 67% 7-year recurrence free survival (RFS) rate was significantly lower than the 92% RFS rate observed for patients with one of these two factors (P = 0.007) and the 99% RFS for patients with neither poor risk factor (P = 0.0001). CONCLUSIONS: The combination of poor nuclear grade and lymphatic vessel invasion identifies a very small subset (10%) of patients with T1a,b N0 M0 breast cancer with a significant relapse risk that warrants consideration of adjuvant systemic therapy. However, the majority of patients with T1a,b N0 M0 breast cancer have an exceptionally good prognosis.
Adult↗
Three-dimensional measurements of idiopathic macular holes using a scanning laser tomograph.
PURPOSE: The diagnosis of macular holes is difficult. Confocal laser tomographic analysis of the retina permits the precise measurements of the macular surface. The authors used this technique to study the macular area of patients with full-thickness macular holes. The purposes of these studies is to perform three-dimensional measurements of the macular holes and their rims and to search for a correlation between these parameters. METHODS: Thirty-one eyes with idiopathic full-thickness macular holes underwent scanning of their affected macular area using the Heidelberg retinal tomograph (HRT). The authors evaluated the following parameters: area of the hole and its elevated rim, the maximal depth of the hole, and the maximal elevation of the rim at 12, 3, 6, and 9 o'clock. RESULTS: The average hole area was 0.33 mm2, and the rim area average was 2.99 mm2. The average area of the rim was found to be 9.06 times larger than that of the hole (P < 0.001). The depth of the hole averaged 144 microns. CONCLUSIONS: The area of the rim is usually bigger than that of the hole and in direct correlation to it. Also, the bigger the hole area, the greater its depth. The average height in each of the four quadrants (12, 3, 6, and 9 o'clock) correlates to the other quadrant heights (P < 0.001).
Aged↗
Intraocular intrusion of sutures after retinal detachment buckling surgery.
BACKGROUND: Intraocular intrusion of tight encircling silicone band is a major complication of retinal detachment surgery leading to subretinal and vitreous hemorrhage, retinal detachment, and phthisis bulbi. Intrusion of the sutures into the eye has only been reported as an adjunct to buckle intrusion. METHODS: Seven patients (9 eyes) are presented in whom intrusion of sutures occurred as a late complication of retinal detachment surgery using the extrascleral buckling technique. Their complications and treatments are discussed. RESULTS: Eleven anchoring sutures were observed under the retina and two sutures penetrated into vitreous cavity. In five eyes (55.5%), small subretinal or vitreous hemorrhages were noted and in one of them perforation with total detachment occurred. In four eyes, no complications were detected. In four eyes, the silicone band was cut and left in place and the hemorrhages were spontaneously absorbed. The perforated eye underwent replacement of the silicone band with a wide silicone sponge, followed by vitrectomy and silicone oil injection. CONCLUSIONS: Intrusion of sutures into the eye can rarely be seen years after retinal detachment surgery and usually do not require surgical intervention. When hemorrhage occurs, cutting of the silicone band only, with no attempt to remove the band or the sutures, is recommended.
Foreign-Body Migration↗
Non-retinovascular leakage in diabetic maculopathy.
BACKGROUND: Diabetic macular oedema is the leading cause of vision deterioration in diabetic retinopathy. Extracellular fluid within the retina, which distorts the retinal architecture, was assumed to be strictly of retinal vasculature origin. However, there is some experimental evidence supporting clinical observations suggesting a possible role of the retinal pigment epithelium (RPE). An unusual form of diabetic maculopathy is presented in which the RPE and the subretinal space play the main role. METHODS: Fluorescein angiograms of 1850 non-proliferative diabetic retinopathy (NPDR) patients were examined. Nineteen eyes (14 patients, 1% of NPDR patients) met the criteria-mainly having minimal diabetic retinopathy with only a few microaneurysms and no clinically significant macular oedema (CSMO). Early phase angiograms were compared with late phase angiograms. RESULTS: It was found that in all 19 eyes the area of diffuse RPE late phase leakage was spread around the macular area. No cystic changes or cystoid macular oedema were present in any of the eyes and the visual acuity was 6/10 or better in all the eyes. CONCLUSIONS: Possible changes occur in the RPE that may be responsible for the late leakage in NPDR patients-namely, diabetic retinal pigment epitheliopathy. These changes are associated with a breakdown of the outer blood-retinal barrier, consisting of leakage through RPE cells. No focal or diffuse leakage across the RPE has been reported in the literature related to the fluorescein angiograms in diffuse diabetic maculopathy.
Aneurysm↗
Pigmented epithelial tumours of the conjunctiva.
Two out of 60 conjunctival epithelial tumours reviewed between 1973 and 1989 were found to be pigmented. One tumour was a pigmented papilloma and the other a pigmented squamous cell carcinoma. The melanin pigment was found in epithelial tumour cells as well as in macrophages, dendritic melanocytes, and Langerhans cells. The distinction between the latter two types of cells was possible in one of the tumours only. Both tumours were found in dark-skinned white patients without any evidence of conjunctival acquired melanosis.
Adult↗
The treatment of foveal central serous choroidopathy by krypton red laser.
We present 24 patients with recent foveal central serous choroidopathy. Only those in whom the leakage site was located within a radius of 250 microns from the foveal center were included in this study. All patients were treated with the krypton red laser (647 nm) within a week of the clinical diagnosis. At the end of the follow-up, 70.8% of the patients had a visual acuity of 6/8.5 or better, and an overall visual improvement was found in 83.3%. In 90% of the patients whose vision improved, significant absorption of subretinal fluid was seen within three weeks and in 10% within four weeks. No evidence of any macular pathology complicating the laser treatment was found at the end of the follow-up period of at least 36 months.
Adult↗
Magnetoelectric stimulation of human motor cortex: normal values and potential safety issues in spinal cord injury.
Upon magnetoelectric stimulation (MES) of the motor cortex, maximal amplitude and minimal latency of compound muscle action potentials were recorded for four limbs in 20 able-bodied volunteers after ten sequential stimulations. The ratio of maximal cortical to maximal peripheral compound muscle action potential was calculated. Standard statistical parameters were calculated for values from each limb. A paired t-test revealed a statistically significant difference in lower extremity side-to-side amplitude. Regression analysis of patient height vs upper extremity and lower extremity latency demonstrated a strong correlation: r = .720 and r = .601, respectively. A pendulum model demonstrated that a miniscule amount of energy is imparted onto metallic fixation devices by the magnetic coil, but no significant paraspinal activity could be measured in any of five volunteers upon stimulation of the motor cortex. This study has established a normal MES data base that might be useful in evaluating spinal cord injured patients. It has also demonstrated that initial safety concerns about the use of MES in this population are likely unfounded.
Adult↗
Air travel with intraocular gas. I. The mechanisms for compensation.
The absolute intraocular pressure of the gas-containing eye of a rabbit fell with the fall in cabin pressure during a simulated airplane ascent but lagged behind. The lag was manifested clinically as a relative rise in transscleral pressure. The amount of lag depended on the amount of gas in the eye at takeoff. As there is no significant transfer of gas out of the eye during the ascent, the fall in absolute intraocular pressure could only be mediated by expansion of the bubble. The enabling mechanisms for expansion are choroidal compression, scleral expansion, and accelerated aqueous outflow.
Aerospace Medicine↗
Air travel with intraocular gas. II. Clinical considerations.
The patient with a residual intraocular gas volume of 0.6 mL, approximately 10% of the volume of the eye, can compensate for the decrease in cabin pressure as an airplane ascends without a symptomatic rise in intraocular pressure. Larger volumes may be accommodated in aircraft that decompress to less than 8000 ft or that take off from altitudes above sea level. The patient with residual intraocular gas who experiences pain or dimness of vision in an ascending airplane can obtain relief if the cabin altitude is decreased by 2000 ft. This will require a modest adjustment in the altitude of the airplane.
Aerospace Medicine↗