PubMed Health⌕ Search

Biomedical subjects

E Z Blumenthal

Publications and source records attributed to E Z Blumenthal.

At least 19 recordsLinked to original sources
PubMed2001

Discriminating between normal and glaucomatous eyes using the Heidelberg Retina Tomograph, GDx Nerve Fiber Analyzer, and Optical Coherence Tomograph.

OBJECTIVE: To compare the ability of 3 instruments, the Heidelberg Retina Tomograph (HRT), the GDx Nerve Fiber Analyzer (GDx), and the Optical Coherence Tomograph (OCT), to discriminate between healthy eyes and eyes with early to moderate glaucomatous visual field loss. SUBJECTS AND METHODS: Forty-one patients with early to moderate glaucomatous visual field loss and 50 healthy subjects were included in the study. The HRT, GDx, and OCT imaging and visual field testing were completed on 1 eye from each subject within a 6-month interval. Statistical differences in sensitivity at fixed specificities of 85%, 90%, and 95% were evaluated. In addition, areas under the receiver operating characteristic (ROC) curve were compared. RESULTS: No significant differences were found between the area under the ROC curve and the best parameter from each instrument: OCT thickness at the 5-o'clock inferior temporal position (mean +/- SE, 0.87 +/- 0.04), HRT mean height contour in the nasal inferior region (mean +/- SE, 0.86 +/- 0.04), and GDx linear discriminant function (mean +/- SE, 0.84 +/- 0.04). Twelve HRT, 2 GDx, and 9 OCT parameters had an area under the ROC curve of at least 0.81. At a fixed specificity of 90%, significant differences were found between the sensitivity of OCT thickness at the 5-o'clock inferior temporal position (71%) and parameters with sensitivities less than 52%. Qualitative assessment of stereophotographs resulted in a sensitivity of 80%. CONCLUSION: Although the area under the ROC curves was similar among the best parameters from each instrument, qualitative assessment of stereophotographs and measurements from the OCT and HRT generally had higher sensitivities than measurements from the GDx.

Adult↗
PubMed2001

Assessment of the retinal nerve fiber layer in clinical trials of glaucoma neuroprotection.

Assessment of the retinal nerve fiber layer (RNFL) is appealing for use in clinical trials of glaucoma neuroprotection, as it is directly correlated with loss of ganglion cells, which is assumed to be a primary event in glaucomatous damage. Qualitative assessment of the RNFL includes ophthalmoscopy, color stereophotography, and red-free monochromatic photography. In contrast, confocal scanning laser ophthalmoscopy (CSLO), scanning laser polarimetry (GDx), optical coherence tomography (OCT), and retinal thickness analysis (RTA) objectively and quantitatively measure the RNFL thickness. These latter techniques are still in evolution. Continuing meticulous objective validation is necessary to assess the usefulness and limitations of these powerful tools. Nevertheless, there are excellent prospects for using longitudinal assessment of the RNFL in clinical trials of glaucoma neuroprotection.

Cell Survival↗
PubMed2001

Using optical imaging summary data to detect glaucoma.

PURPOSE: To evaluate the sensitivity and specificity for discriminating between early to moderate glaucomatous and normal eyes using summary data reports from the Heidelberg Retina Tomograph (HRT), the GDx Nerve Fiber Analyzer (GDx), and the Optical Coherence Tomograph (OCT). DESIGN: Comparative cross-sectional study PARTICIPANTS: One eye each of 50 normal subjects and 39 glaucoma patients with early to moderate visual field damage (mean deviation, -5.04 +/- 3.32 dB; range, -0.85 to -13.2 dB). METHODS: Three experienced graders masked to patient identity and diagnosis evaluated each summary data report from the HRT, GDx, and OCT independently. MAIN OUTCOME MEASURES: Each summary report was classified as either normal or glaucomatous. Sensitivity and specificity are reported for each grader, and agreement between graders is reported. RESULTS: For the HRT, sensitivity and specificity ranged from 64% to 75% and 68% to 80%, respectively. Agreement (kappa +/- standard error [SE]) between observers one and two, two and three, and one and three was 0.73 +/- 0.07, 0.77 +/- 0.07, and 0.67 +/- 0.08, respectively. For the GDx, sensitivity and specificity ranged from 72% to 82% and 56% to 82%, respectively. Agreement (kappa +/- SE) between observers one and two, two and three, and one and three was 0.66 +/- 0.08, 0.66 +/- 0.08, and 0.50 +/- 0.09, respectively. For the OCT, sensitivity and specificity ranged from 76% to 79% and 68% to 81%, respectively. Agreement (kappa +/- SE) between observers one and two, two and three, and one and three was 0.73 +/- 0.07, 0.58 +/- 0.08, and 0.51 +/- 0.09, respectively. CONCLUSIONS: When used alone, HRT, GDx, and OCT summary data reports can differentiate between normal and glaucomatous eyes with mild to moderate visual field loss. However, none of the instruments provided sensitivity and specificity that justify summary data reports being used as a screening tool for early to moderate glaucoma.

Adult↗
PubMed2001

Detecting early glaucoma by assessment of retinal nerve fiber layer thickness and visual function.

PURPOSE: To compare the abilities of scanning laser polarimetry (SLP), optical coherence tomography (OCT), short-wavelength automated perimetry (SWAP), and frequency-doubling technology (FDT) perimetry to discriminate between healthy eyes and those with early glaucoma, classified based on standard automated perimetry (SAP) and optic disc appearance. To determine the agreement among instruments for classifying eyes as glaucomatous. METHODS: One eye of each of 94 subjects was included. Healthy eyes (n = 38) had both normal-appearing optic discs and normal SAP results. Glaucoma by SAP (n = 42) required a repeatable abnormal result (glaucoma hemifield test [GHT] or corrected pattern standard deviation [CPSD] outside normal limits). Glaucoma by disc appearance (n = 51) was based on masked stereoscopic photograph evaluation. Receiver operating characteristic (ROC) curve areas, sensitivities, and specificities were calculated for each instrument separately for each diagnosis. RESULTS: The largest area under the ROC curve was found for OCT inferior quadrant thickness (0.91 for diagnosis based on SAP, 0.89 for diagnosis based on disc appearance), followed by the FDT number of total deviation plot points of < or =5% (0.88 and 0.87, respectively), SLP linear discriminant function (0.79 and 0.81, respectively), and SWAP PSD (0.78 and 0.76, respectively). For diagnosis based on SAP, the ROC curve area was significantly larger for OCT than for SLP and SWAP. For diagnosis based on disc appearance, the ROC curve area was significantly larger for OCT than for SWAP. For both diagnostic criteria, at specificities of > or =90% and > or =70%, the most sensitive OCT parameter was more sensitive than the most sensitive SWAP and SLP parameters. For diagnosis based on SAP, the most sensitive FDT parameter was more sensitive than the most sensitive SLP parameter at specificities of > or =90% and > or =70% and was more sensitive than the most sensitive SWAP parameter at specificity of > or =70%. For diagnosis based on disc appearance at specificity of > or =90%, the most sensitive FDT parameter was more sensitive than the most sensitive SWAP and SLP parameters. At specificity > or = 90%, agreement among instruments for classifying eyes as glaucomatous was poor. CONCLUSIONS: In general, areas under the ROC curve were largest (although not always significantly so) for OCT parameters, followed by FDT, SLP, and SWAP, regardless of the definition of glaucoma used. The most sensitive OCT and FDT parameters tended to be more sensitive than the most sensitive SWAP and SLP parameters at the specificities investigated, regardless of diagnostic criteria.

Diagnostic Techniques, Ophthalmological↗
PubMed2000

Short-wavelength automated perimetry and standard perimetry in the detection of progressive optic disc cupping.

OBJECTIVE: To compare progression in short-wavelength automated perimetry (SWAP) and white-on-white (standard) perimetry in eyes with progressive glaucomatous changes of the optic disc detected by serial stereophotographs. METHODS: Forty-seven glaucoma patients with at least 2 disc stereophotographs more than 2 years apart, along with standard perimetry and SWAP examinations within 6 months of each disc photo of the same eye, were included in the study. The mean follow-up time was 4.1 years (range, 2.0-8.9 years). Baseline and follow-up stereophotographs were then graded and compared for the presence of progression. Progression in standard perimetry and SWAP, using the Advanced Glaucoma Intervention Study scoring system and a clinical scoring system, was compared between eyes with progressive change on stereophotographs and those without. RESULTS: Twenty-two of 47 eyes showed progressive change by stereophotographs. There was a statistically significant difference in the mean change in Advanced Glaucoma Intervention Study scores for both standard perimetry (P<.004) and SWAP (P<.001) between the progressed and nonprogressed groups. The sensitivity, specificity, and area under the receiver operator characteristic curve were higher using SWAP than standard perimetry when evaluated by either algorithm. This was statistically significant only in the area under the receiver operator characteristic curve for the Advanced Glaucoma Intervention Study scoring system (P =.04). CONCLUSIONS: Short-wavelength automated perimetry identified more patients than standard perimetry as having progressive glaucomatous changes of the optic disc. Compared with standard perimetry, SWAP may improve the detection of progressive glaucoma. Arch Ophthalmol. 2000;118:1231-1236

Aged↗
PubMed2000

Comparison of long-term variability for standard and short-wavelength automated perimetry in stable glaucoma patients.

PURPOSE: To quantify and compare, on a point-by-point basis, the long-term variability of standard and short-wavelength automated perimetry in a group of stable glaucoma patients. METHODS: From a group of 53 glaucoma patients experienced in visual field testing, we identified one eye, randomly chosen, from each of 25 glaucoma patients whose condition was found to be stable, based on both standard and short-wavelength automated perimetry visual field criteria. On each of three visits during a period of up to 3 months, each patient performed one standard and one short-wavelength automated perimetry 24-2 visual field in a random order on a Humphrey visual field analyzer. The long-term variability (also referred to as test-retest variability) was defined as the SD of the three threshold decibel values at each test location. The long-term variability for each test point (mean +/- SD) was determined separately for both standard visual fields and short-wavelength automated perimetry. RESULTS: With all 52 test locations of the 24-2 field averaged, the global long-term variability, mean (+/- SD) for standard visual fields and short-wavelength automated perimetry was 2.37 +/- 2.03 dB (95% confidence interval, 2.26-2.48 dB) and 2.92 +/- 2.03 dB (95% confidence interval, 2.81-3.03 dB), respectively (P <.0001). In 16 of the 52 visual field locations, long-term variability on short-wavelength automated perimetry was significantly higher than long-term variability on standard visual fields. In addition, the long-term variability increased with greater distance from the point of fixation for both standard visual fields and short-wavelength automated perimetry. The long-term variability decreased closer to fixation, more for standard visual fields than for short-wavelength automated perimetry. CONCLUSIONS: In a group of stable glaucoma patients, mean long-term variability was 0.55 dB higher for short-wavelength automated perimetry than for standard visual fields. This needs to be taken into consideration when serial visual fields are evaluated for change.

Adult↗
PubMed2000

Reproducibility of nerve fiber layer thickness measurements by use of optical coherence tomography.

OBJECTIVE: To evaluate the reproducibility of optical coherence tomograph (OCT) retinal nerve fiber layer (RNFL) measurements in normal and glaucomatous eyes by means of the commercially available OCT 2000 instrument (Humphrey Systems, Dublin, CA). DESIGN: Prospective instrument validation study. PARTICIPANTS: One eye each from 10 normal subjects and 10 glaucoma patients. METHODS: Twenty subjects underwent a total of eight scanning sessions during two independent visits. In each session, five circular scans centered on the optic nerve head were performed. The first two sessions were performed by two experienced technicians. Followed by a 30-minute break, a third and a fourth session was completed by the same technicians. This sequence was duplicated on a second visit. Intrasession, intersession, intervisit, and interoperator reproducibility of quadrant and global RNFL measurements were calculated by use of a components of variance model. MAIN OUTCOME MEASURES: RNFL thickness. RESULTS: The coefficient of variation for the mean RNFL thickness was significantly smaller (P = 0.02) in normal eyes (6.9%) than in glaucoma eyes (11.8%). The estimated root mean squared error based on the statistical model using three scans per patient was 5.8 and 8.0 micrometer for normal and glaucoma eyes, respectively. A components of variance model showed most of the variance (79%) to be due to differences between patients. Only a modest contribution to variability was found for session (1%), visit (5%), and operator (2%). CONCLUSION: With the commercially available OCT, our results indicate that the RNFL measurements are reproducible for both normal and glaucomatous eyes.

Adult↗
PubMed2000

Laser photocoagulation spot-size errors stemming from the refractive state of the surgeon's eye.

PURPOSE: Meaningful errors in photocoagulation spot size may result from several factors. In this article we discuss one major factor, namely, fluctuations in the surgeon's accommodative state, coupled with an inaccurate setting of the slit-lamp oculars. DESIGN: Experimental study. METHODS: We analyzed and tested the optics of slit-lamp mounted lasers. Varying the ocular setting is correlated with measurements of the actual spot size obtained with each system. MAIN OUTCOME MEASURE: The spot size obtained. RESULTS: Three distinct, but related, phenomena that may lead to spot size errors are defined: (1) focusing the laser spot as opposed to focusing the retinal image; (2) instrument misalignment; (3) inadvertent accommodation. CONCLUSION: The ocular setting must be meticulously calibrated to produce a true spot-sized burn. At the 50 microm setting, each diopter of induced accommodation, or erroneous ocular setting, almost doubles the actual spot size obtained. With large (500 microm) spot size settings, the defocused delivery system is more prone to spot-size errors in contrast with parfocal lasers.

Accommodation, Ocular↗
PubMed2000

Visual function-specific perimetry for indirect comparison of different ganglion cell populations in glaucoma.

PURPOSE: To compare short-wavelength automated perimetry, frequency-doubling technology perimetry, and motion-automated perimetry, each of which assesses different aspects of visual function, in eyes with glaucomatous optic neuropathy and ocular hypertension. METHODS: One hundred thirty-six eyes from 136 subjects were evaluated with all three tests as well as with standard automated perimetry. Fields were not used in the classification of study groups to prevent bias, because the major purpose of the study was to evaluate each field type relative to the others. Seventy-one of the 136 eyes had glaucomatous optic neuropathy, 37 had ocular hypertension, and 28 served as age-matched normal control eyes. Glaucomatous optic neuropathy was defined by assessment of stereophotographs. Criteria were asymmetrical cupping, the presence of rim thinning, notching, excavation, or nerve fiber layer defect. Ocular hypertensive eyes had intraocular pressure of 23 mm Hg or more on at least two occasions and normal-appearing optic disc stereophotographs. Criteria for abnormality on each visual field test were selected to approximate a specificity of 90% in the normal eyes. Thresholds for each of the four tests were compared, to determine the percentage that were abnormal within each patient group and to assess the agreement among test results for abnormality, location, and extent of visual field deficit. RESULTS: Each test identified a subset of the eyes with glaucomatous optic neuropathy as abnormal: 46% with standard perimetry, 61% with short-wavelength automated perimetry, 70% with frequency-doubling perimetry, and 52% with motion-automated perimetry. In the ocular hypertensive eyes, standard perimetry was abnormal in 5%, short wavelength in 22%, frequency doubling in 46%, and motion in 30%. Fifty-four percent (38/71) of eyes with glaucomatous optic neuropathy were normal on standard fields. However, 90% were identified by at least one of the specific visual function tests. Combining tests improved sensitivity with slight reductions in specificity. The agreement in at least one quadrant, when a defect was present with more than one test, was very high at 92% to 97%. More extensive deficits were shown by frequency-doubling perimetry followed by short-wavelength automated perimetry, then motion-automated perimetry, and last, standard perimetry. However, there were significant individual differences in which test of any given pairing was more extensively affected. Only 30% (11/37) of the ocular hypertensive eyes showed no deficits at all compared with 71% (20/28) of the control eyes (P < 0.001). CONCLUSIONS: For detection of functional loss standard visual field testing is not optimum; a combination of two or more tests may improve detection of functional loss in these eyes; in an individual, the same retinal location is damaged, regardless of visual function under test; glaucomatous optic neuropathy identified on stereophotographs may precede currently measurable function loss in some eyes; conversely, function loss with specific tests may precede detection of abnormality by stereophotograph review; and short-wavelength automated perimetry, frequency-doubling perimetry, and motion-automated perimetry continue to show promise as early indicators of function loss in glaucoma.

Glaucoma↗
PubMed1999

Multifocal choroidal malignant melanoma: at least 3 melanomas in one eye.

OBJECTIVES: To describe a case of an enucleated eye harboring multiple choroidal malignant melanomas. METHODS: Clinical, ultrasonographic, and histopathological evaluations. RESULTS: Meticulous sectioning of the globe did not disclose any structural continuity between the 3 choroidal melanomas. Fourth and fifth masses were connected to one of the tumors by fibrous tissue and therefore were not considered as additional distinct lesions. CONCLUSION: Although very rare, a single eye can harbor multiple distinct choroidal melanomas.

Aged↗
PubMed1999

Corticosteroid-induced glaucoma attributable to an adrenocorticotropin-secreting malignant carcinoid tumor of the thymus.

PURPOSE: To describe the clinical and histopathologic findings in a patient with corticosteroid-induced open-angle glaucoma attributable to an adrenocorticotropin-secreting malignant carcinoid of the thymus. METHODS: Case report. In a 33-year-old man, the clinical course, laboratory findings, and imaging results as well as the histopathologic findings are described. RESULTS: Increased intraocular pressure in this patient represented a manifestation of severe hypercortisolism attributable to a malignant adrenocorticotropin-secreting carcinoid tumor. Surgical removal resulted in return of the intraocular pressure values to normal levels. CONCLUSION: Thymic carcinoid is a rare cause of Cushing syndrome, which can lead to increased intraocular pressure.

Adrenocortical Hyperfunction↗
PubMed1998

The role of preoperative ultrasonography for patients with dense cataract: a retrospective study of 509 cases.

BACKGROUND AND OBJECTIVE: Ocular ultrasonography is widely used for the evaluation of eyes with opaque ocular media. Although preoperative ultrasonography of the globe has been recommended for patients with dense cataracts, the value of such an examination is currently unknown. The purpose of this study was to evaluate the prevalence and nature of intraocular pathologies detected by preoperative ultrasound examination in patients with dense cataract. PATIENTS AND METHODS: The authors retrospectively studied 509 patients referred for routine ultrasound examination of the globe due to dense cataract. Exclusion criteria included known posterior segment pathology, previous ocular surgery or penetrating trauma, and age of younger than 18 years. All the patients underwent ultrasound examination by B-scan and standardized A-scan. RESULTS: In 19.6% of the patients, a posterior segment pathology was revealed by the ultrasound examination. The most frequently disclosed abnormalities were posterior staphyloma (7.2%), retinal detachment (4.5%), and vitreous hemorrhage (2.5%). One patient with a large choroidal malignant melanoma was identified. The prevalence of posterior segment pathologies was slightly higher in patients with a history of ocular trauma, compared with the nontraumatic cataract group (29.6% versus 19.0%, respectively; P = .1). The prevalence of retinal detachment was increased in the traumatic cataract subgroup (14.8% compared with 3.9%), but this difference did not reach statistical significance. CONCLUSION: Preoperative ultrasound examination for patients with dense cataract can be used to detect pathologies that may influence the surgical strategy and the postoperative visual prognosis.

Adult↗
PubMed1997

Recurrent abducens nerve palsy caused by dolichoectasia of the cavernous internal carotid artery.

PURPOSE: To describe a 59-year-old patient who had seven recurrent, self-limited episodes of isolated ipsilateral abducens nerve palsy in the previous 4 years. Each episode lasted between 2 and 5 weeks. METHODS: Systemic examination and neuroimaging studies were performed. RESULT: Repeated comprehensive examination failed to demonstrate any ocular or systemic condition apart from a lateral protrusion by dolichoectasia of the posterior portion of the cavernous left internal carotid artery, compressing the posterior left cavernous sinus. CONCLUSION: Numerous self-limited episodes of sixth nerve palsy may be associated with structural abnormalities of the intracranial carotid vasculature.

Abducens Nerve↗
PubMed1997

Multiple conjunctival metastases as the initial sign of metastatic uveal melanoma.

PURPOSE: To describe a 31-year-old patient who was initially examined with a uveal malignant melanoma metastatic to the ipsilateral conjunctiva. METHOD: Thirteen months after ruthenium 106 plaque therapy for a ciliochoroidal malignant melanoma, numerous pigmented conjunctival lesions first appeared. RESULTS: These lesions were excised and found to be metastases of melanoma to the superficial subepithelial conjunctival tissue, composed of epithelioid cells. CONCLUSION: The appearance of darkly pigmented conjunctival lesions in a patient known to harbor a uveal malignant melanoma, even though lacking any evidence of extrascleral extension or metastatic involvement, may indicate metastatic disease.

Adult↗
PubMed1996

On the origin of cancer.

In this paper, I present a highly unorthodox and provocative hypothesis, namely that cancer is an evolutionarily derived phenomenon, dormant in every human cell and actively triggered in certain individuals. Cancer is shown to help maintain the integrity of the common gene pool through active elimination of individuals, thus serving a definite advantage for the survival of the species. Those individuals who are less capable of maintaining the integrity of their genome are stopped from inheriting defective genes, and even more important, from bequeathing defective deoxyribonucleic acid conservation traits to their offspring. Genome stability is a primary prerequisite for survival. The spread of deteriorated, imperfect genes should have a disastrous effect on a species' chances for survival. Although we tend to focus our attention on mutations as evolution's driving force, the stability of the deoxyribonucleic acid molecule is what really maintains life on our planet. When observing evolution's end product, we tend to forget that the extreme stability of the genetic material is a genetic quality by itself, a product of a long evolutionary process. The hypothesis presented here is that the selection pressure imposed by cancer is one of the mechanisms leading to this stability.

Biological Evolution↗