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J A Sorenson

Publications and source records attributed to J A Sorenson.

At least 19 recordsLinked to original sources
PubMed2001

Tamoxifen retinopathy in a male patient.

PURPOSE: To report a case of tamoxifen retinopathy in a male patient. METHODS: Case report. A 68-year-old man, who had received a cumulative tamoxifen dose of 60 g over 33 months for unresectable hepatocellular carcinoma, was evaluated. RESULTS: A peculiar, bilateral, symmetric, inner retinal crystalline deposition associated with mild macular edema was discovered. No other ocular toxicity of tamoxifen was observed. CONCLUSION: To our knowledge, this is the first report of tamoxifen retinopathy in a male.

Aged↗
PubMed2001

Endoscopic vitreoretinal surgery for complicated proliferative diabetic retinopathy.

PURPOSE: To evaluate the indication for endoscopic vitreoretinal surgery in proliferative diabetic retinopathy (PDR). METHODS: Chart review of consecutive cases of vitreoretinal surgery for PDR performed by one of the authors (Y.L.F.) over a 2-year period. RESULTS: Endoscopic vitreoretinal surgery was performed in 8 of 41 (19.5%) eyes. The surgical indications were small pupil (3), hyphema (3), pseudophakia with fibrotic posterior capsule (1), and pars plana neovascularization with anterior tractional retinal detachment (6). CONCLUSION: Endoscopic vitreoretinal surgery, by enhancing the visualization of the retroirideal space, is a useful technique in PDR with opaque ocular media and/or neovascularization of the pars plana and ciliary body.

Adult↗
PubMed2000

Retinal choroidal anastomoses and occult choroidal neovascularization in age-related macular degeneration.

OBJECTIVE: This study was designed to identify the incidence of retinal choroidal anastomoses in patients with occult choroidal neovascularization (CNV) and focal hot spots on indocyanine green (ICG) angiography, to identify the clinical and angiographic features that would assist in their identification, and to determine if the presence of these anastomotic lesions affect the outcome of laser therapy. DESIGN: Combined prospective and retrospective cross-sectional study. PARTICIPANTS: One hundred fifty consecutive patients with newly diagnosed occult CNV secondary to exudative age-related macular degeneration and focal hot spots on ICG angiography were evaluated prospectively. In addition, a retrospective review was performed on 79 eyes previously reported to have undergone laser photocoagulation treatment with ICG guidance. METHODS AND TESTING: In all cases, stereo color and red-free photographs, and stereo fluorescein and digital ICG angiograms were obtained for evaluation. MAIN OUTCOME MEASURES: Images obtained by all four techniques were evaluated for the presence of a retinal choroidal anastomosis. Associated clinical and angiographic findings were noted. In the retrospective review, the success rate of laser treatment was correlated with the presence or absence of a retinal choroidal anastomosis. RESULTS: Of the 150 eyes evaluated prospectively, 31 (21%) were found to have a retinal choroidal anastomosis. Retinal choroidal anastomoses were found in 27% of patients with associated serous pigment epithelial detachment (PED), whereas 13% were found in those without an associated elevation of the retinal pigment epithelium. Seventy-one percent of eyes had multiple anastomotic connections. Ninety percent of eyes had at least one retinal vein involved in the anastomotic connection. Clinical evidence of preretinal and intraretinal hemorrhage and cystic edema coupled with angiographic evidence of intraretinal dye leakage were key features of retinal choroidal anastomoses. In the retrospective review, seven patients were found to have retinal choroidal anastomoses with associated serous PED and demonstrated a very low (14%) success rate for laser treatment. CONCLUSIONS: Retinal choroidal anastomoses can present as a primary manifestation of the exudative process in age-related macular degeneration. They may be seen in eyes with and without detachment of the retinal pigment epithelium. Specific clinical and angiographic features have been identified that can aid in the diagnosis of these vascular anomalies. Their presence represents a poor prognostic sign for successful ICG-guided laser treatment.

Arteriovenous Anastomosis↗
PubMed2000

Polypoidal choroidal vasculopathy masquerading as central serous chorioretinopathy.

OBJECTIVE: To differentiate polypoidal choroidal vasculopathy (PCV) from central serous chorioretinopathy (CSC). DESIGN: A retrospective, observational case series. PARTICIPANTS: Thirteen patients originally diagnosed with CSC proved to have PCV after more extensive evaluation and follow-up. METHODS: A clinical and angiographic review of patients with manifestations of CSC, including macular detachment. MAIN OUTCOME MEASURES: Demographic data, funduscopic examination, and fluorescein and indocyanine green (ICG) angiographic findings. RESULTS: Thirteen patients initially suspected of having CSC were ultimately diagnosed as having PCV. These eyes had exudative macular detachments secondary to a small caliber, polypoidal choroidal vascular abnormality or so-called polypoidal choroidal neovascularization. The clinical manifestations in the fundus varied. They included multiple, variably sized serous pigment epithelial detachments, neurosensory retinal detachment, lipid deposition, patchy atrophy of the pigment epithelium and indistinct staining from decompensation of the posterior blood-retinal barrier on fluorescein angiography. In reality, the suspected PEDs proved to be polypoidal lesions of PCV when imaged with ICG angiography. CONCLUSIONS: The clinical diagnosis of CSC or PCV generally poses little challenge to the experienced retinal specialist. However, in CSC with persistent and/or recurrent exudation, a myriad of retinal pigment epithelial changes may evolve that make it difficult to differentiate these two entities. In such patients, ICG angiography is useful in differentiating CSC from PCV. An accurate clinical diagnosis is important since each of these entities, CSC and PCV, may differ in terms of their risk factors, natural course, and visual prognosis.

Adult↗
PubMed2000

Compensation of susceptibility-induced signal loss in echo-planar imaging for functional applications.

Functional magnetic resonance imaging favors the use of multi-slice gradient-recalled echo-planar imaging due to its short image acquisition times, whole brain coverage and sensitivity to BOLD contrast. However, despite its advantages, gradient-recalled echo-planar imaging also is sensitive to static magnetic field gradients arising primarily from air-tissue interfaces. This can lead to image artifacts such as voxel shifts and complete signal loss. A method to recover signal loss by adjusting the refocusing gradient amplitude in the slice-select direction, preferably axially, is proposed. This method is implemented as an automated computer algorithm that partitions echo-planar images into regions of recoverable signal intensities using a histogram analysis and determines each region's proper refocusing gradient amplitude. As an example, different refocusing gradient amplitudes are interleaved in a fMRI acquisition to maximize the signal to noise ratio and obtain functional activation in normal and dropout regions. The effectiveness of this method is demonstrated by recovering signal voids in the orbitofrontal cortex, parahippocampal/amygdala region, and inferior visual association cortex near the cerebellum.

Algorithms↗
PubMed1999

Polypoidal choroidal vasculopathy and neovascularized age-related macular degeneration.

OBJECTIVE: To determine the nature and frequency of polypoidal choroidal vasculopathy (PCV) in a series of patients suspected of having neovascularized age-related macular degeneration (AMD). METHODS: A prospective analysis of 167 consecutive, newly diagnosed patients aged 55 years or older with presumed neovascularized AMD was performed. All patients were examined with fundus biomicroscopy as well as fluorescein and indocyanine green angiography. RESULTS: Choroidal neovascularization secondary to AMD was diagnosed in 154 (92.2%) of 167 patients; 13 (7.8%) patients had PCV. The patients affected by PCV were younger than those with AMD (P = .01). Peripapillary choroidal neovascularization was seen in 3 (1.9%) of 154 patients with AMD and 3 (23.1%) of 13 patients with PCV (P = .006). Significant drusen were present in 63 (70%) of 90 fellow eyes with unilateral AMD compared with only 1 (16.7%) of 6 eyes with PCV (P = .02). Only 5 patients with AMD (3.2%) were nonwhite compared with 3 patients with PCV (23.1%) (P = .02). CONCLUSIONS: A measurable number of elderly patients with findings suggestive of neovascularized AMD and serosanguineous macular manifestations will instead have PCV. Polypoidal choroidal vasculopathy can occur in any sex or race, but is more commonly seen in the peripapillary area, without associated drusen, and in nonwhite patients. It is important to differentiate AMD from PCV because there are significant differences in the demographic risk profile, natural course, visual prognosis, and management of these patients.

Aged↗
PubMed1999

Systemic findings associated with central serous chorioretinopathy.

PURPOSE: To determine systemic factors associated with central serous chorioretinopathy. METHODS: In a retrospective study, 230 consecutive patients with central serous chorioretinopathy examined in a referral setting were compared with a historical gender-matched and age-matched control group of 230 patients with ocular findings who were examined in the same referral setting. RESULTS: The median age of the patients was 49.8 years, and of the control subjects, 50.0 years. The male-female ratio for both groups was 2.7:1. Patients with central serous chorioretinopathy were more likely to use psychopharmacologic medications (odds ratio = 2.6; 95% confidence interval = 1.30 to 5.19; P = .0049) and corticosteroids (odds ratio = 3.17; 95% confidence interval = 1.30 to 7.70; P = .0067) and were more likely to have hypertension (odds ratio = 2.25; 95% confidence interval = 1.39 to 3.63; P = .0008) than were the control subjects. CONCLUSIONS: This study identified psychopharmacologic medication use, corticosteroid use, and hypertension as factors associated with central serous chorioretinopathy. These findings reinforce the concept that stress and adaptations to stress play a role in this disorder. The findings of possible associations between central serous chorioretinopathy and both hypertension and corticosteroid usage suggest that these modifiable factors may influence morbidity of central serous chorioretinopathy.

Adult↗
PubMed1999

Radiation-associated choroidal neovasculopathy.

PURPOSE: To characterize a newly discovered choroidal vascular abnormality in patients who have received radiation therapy for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration. DESIGN: Two-center cross-sectional study. PARTICIPANTS: In the United States, there were 95 patients who were treated with 10 or 12 Gy of external beam photons. In Belgium, 98 patients were treated with 20 Gy. These patients were examined retrospectively for the presence of a specific CNV abnormality. RESULTS: During the follow-up period, an unusual vascular growth pattern was identified in 12 patients (12.6%) of those treated in the United States and in 7 (7.1%) of those treated in Belgium. These patients developed round or oval vascular blebs along the outer border of their neovascular lesions. These blebs profusely leaked fluorescein dye and could be imaged best by indocyanine green angiography. Patients with these blebs appeared to have a marked propensity for loss of visual acuity. CONCLUSION: An unusual pattern of new vessel growth occurred in 19 of the 193 patients with CNV treated with radiation. This new entity, termed radiation-associated choroidal neovasculopathy, is a recognizable disorder that appears to have a particularly poor prognosis.

Aged↗
PubMed1998

Functional connectivity in single and multislice echoplanar imaging using resting-state fluctuations.

A previous report of correlations in low-frequency resting-state fluctuations between right and left hemisphere motor cortices in rapidly sampled single-slice echoplanar data is confirmed using a whole-body echoplanar MRI scanner at 1.5 T. These correlations are extended to lower sampling rate multislice echoplanar acquisitions and other right/left hemisphere-symmetric functional cortices. The specificity of the correlations in the lower sampling-rate acquisitions is lower due to cardiac and respiratory-cycle effects which are aliased into the pass-band of the low-pass filter. Data are combined for three normal right-handed male subjects. Correlations to left hemisphere motor cortex, visual cortex, and amygdala are measured in long resting-state scans.

Adult↗
PubMed1998

External beam radiation therapy for choroidal neovascularization.

OBJECTIVE: This study aimed to determine the effect of external beam radiation therapy on choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). DESIGN: The study design was a nonrandomized clinical trial with an historic control group. PARTICIPANTS: A total of 91 patients were treated with external beam radiation. These patients were compared retrospectively to the 119 patients in a control group. INTERVENTION: Patients with subfoveal CNV who did not meet the criteria for laser treatment defined by published reports from the Macular Photocoagulation Study Group or who did not want laser treatment were considered for radiation therapy in a nonrandomized, prospective clinical trial. Additional entry criteria for this prospective study included visual acuity better than or equal to 20/320 on the Early Treatment Diabetic Retinopathy Study chart and a lesion size less than 12 disc areas. The patients were treated with 5 fractions of 200 cGy 6 MV external beam photons. MAIN OUTCOME MEASURES: The visual acuity measured at baseline was compared to the visual acuity after 1 year of follow-up. RESULTS: The mean baseline visual acuity of the 91 patients entered into the Radiation Study was 20/80. After 1 year, 83 patients (91.2%) completed follow-up, and their mean visual acuity dropped to 20/200. By comparison, the mean baseline visual acuity of the control patients also was 20/80, and after 1 year, the control subjects had a mean visual acuity of 20/125. At 1 year of follow-up, 49.4% of patients treated with radiation and 38.1% of the control subjects lost 3 or more lines of visual acuity (P = 0.16). CONCLUSIONS: This study found that external beam radiation using 1000 cGy in 5 fractions, a dose similar to that used in previous studies, was not effective in the treatment of CNV secondary to AMD. These results suggest that patients should not be treated with this dose of external beam radiation for CNV secondary to AMD.

Aged↗
PubMed1998

Wide-angle indocyanine green angiography.

BACKGROUND: Evaluation of the vasculature and blood flow in the fundus is limited by the small field of view of conventional fundus cameras. We sought to develop an easy method to image wide areas of the fundus. METHODS: Wide-angle contact fundus lenses with antireflective coatings in the infrared range were placed on the eye and indocyanine green angiography was done on the fundus through the contact lenses. More than 50 patients with varying fundus pathology have been examined. RESULTS: The angular field of view using this method can reach 160 degrees. Obtaining angiograms where the field of view extended anterior to the ora serrata was simplified, and studying the choroidal vasculature in detail was possible. In addition, imaging of entities such as peripheral choroidal neovascularization and choroidal tumors was enhanced with the present technique as compared with conventional techniques. CONCLUSIONS: Angiography through wide-angle fundus lenses is an easy and inexpensive method of visualizing large areas of the fundus. This technique may help improve our ability to image the angioarchitecture, hemodynamics, and pathologic changes in the retina and choroid.

Choroid↗
PubMed1998

Basic concepts of functional arteriovenous MR imaging malformations.

This article reviews the technical features of functional MR imaging. Examples are presented demonstrating how MR imaging may be used to identify primary cortical regions adjacent to AVMs. Preliminary results suggest that cortical functions may undergo translocation when the AVM involves eloquent cortex. This finding underscores the importance of cortical mapping prior to surgical excision.

Brain Mapping↗
PubMed1997

Spatially filtering functional magnetic resonance imaging data.

When constructing MR images from acquired spatial frequency data, it can be beneficial to apply a low-pass filter to remove high frequency noise from the resulting images. This amounts to attenuating high spatial frequency fluctuations that can affect detected MR signal. A study is presented of spatially filtering MR data and possible ramifications on detecting regionally specific activation signal. It is shown that absolute activation levels are strongly dependent on the parameters of the filter used in image construction and that significance of an activation signal can be enhanced through appropriate filter selection. A comparison is made between spatially filtering MR image data and applying a Gaussian convolution kernel to statistical parametric maps.

Magnetic Resonance Imaging↗
PubMed1997

Indocyanine green angiography of multifocal choroiditis.

PURPOSE: The purpose of the study is to determine indocyanine green (ICG) angiographic characteristics of patients with multifocal choroiditis (MC) and to identify features that may assist in the differentiation of MC from other ocular inflammatory diseases. METHODS: After complete ophthalmologic examination, fluorescein angiography and ICG angiography were performed in a series of 14 patients with MC. The ICG findings were then correlated with the clinical and fluorescein angiographic appearance of these patients to determine specific characteristics and distinguishing features of the entity. These findings then were compared with those of angiographic patterns observed in patients with ocular histoplasmosis syndrome to determine whether differentiating features could be identified. RESULTS: Fourteen (50%) of the 28 eyes were found to have large hypofluorescent spots in the posterior pole on ICG angiography, which, in most cases, did not correspond to clinically or fluorescein angiographically detectable lesions. Seventeen (61%) had smaller hypofluorescent lesions (approximately 50 pm in size) in the posterior pole on the ICG study. In seven eyes exhibiting enlarged blind spots on visual field testing, ICG angiography showed confluent hypofluorescence surrounding the optic nerve. The ICG angiogram was found useful in evaluating the natural course in two patients with MC as well as a response to oral prednisone therapy in four others. The ICG angiographic findings differed from those seen in patients with ocular histoplasmosis. CONCLUSIONS: Indocyanine green angiography can provide information that is not detectable by clinical or fluorescein angiographic examination in patients with MC. This information may prove useful in differentiating this condition from the ocular histoplasmosis syndrome, provide a better understanding of the natural course and progression of the disease, and provide a potential adjunct in the clinical evaluation of patients undergoing therapeutic regimens for active inflammatory lesions.

Adolescent↗
PubMed1997

Treatment of experimental methicillin-resistant Staphylococcus epidermidis endophthalmitis with intravitreal vancomycin and intravitreal dexamethasone.

The use of intravitreal steroids to treat bacterial endophthalmitis remains controversial. The efficacy of intravitreal vancomycin alone (group 1), intravitreal dexamethasone alone (group 2), and a combination of intravitreal vancomycin and dexamethasone (group 3) in the treatment of experimental methicillin-resistant Staphylococcus epidermidis endophthalmitis was evaluated in a rabbit model: 24 h after bacterial inoculation of all eyes, right eyes were treated and left eyes served as infected controls. Vitreal aspirations and grading of vitreal inflammatory reaction were done regularly until sacrifice. Group 2 eyes demonstrated more inflammation histologically than control eyes. Vitreal aspirations demonstrated no growth by 5 days from groups 1 and 3 eyes. Although the clinical appearance was not significantly different between groups 1 and 3, the histologic appearance of group 3 eyes showed less intense intraocular inflammation. Treatment with dexamethasone in the absence of appropriate antibiotics was more harmful than no treatment at all (P < .05). Therapy with both intravitreal vancomycin and dexamethasone results in less inflammation than intravitreal vancomycin alone in this model.

Animals↗