Biomedical subjects

Gregory Kosmorsky

Publications and source records attributed to Gregory Kosmorsky.

5 recordsLinked to original sources

PubMed2006

Development and validation of a computerized expert system for evaluation of automated visual fields from the Ischemic Optic Neuropathy Decompression Trial.

BACKGROUND: The objective of this report is to describe the methods used to develop and validate a computerized system to analyze Humphrey visual fields obtained from patients with non-arteritic anterior ischemic optic neuropathy (NAION) and enrolled in the Ischemic Optic Neuropathy Decompression Trial (IONDT). The IONDT was a multicenter study that included randomized and non-randomized patients with newly diagnosed NAION in the study eye. At baseline, randomized eyes had visual acuity of 20/64 or worse and non-randomized eyes had visual acuity of better than 20/64 or were associated with patients refusing randomization. Visual fields were measured before treatment using the Humphrey Field Analyzer with the 24-2 program, foveal threshold, and size III stimulus. METHODS: We used visual fields from 189 non-IONDT eyes with NAION to develop the computerized classification system. Six neuro-ophthalmologists ("expert panel") described definitions for visual field patterns defects using 19 visual fields representing a range of pattern defect types. The expert panel then used 120 visual fields, classified using these definitions, to refine the rules, generating revised definitions for 13 visual field pattern defects and 3 levels of severity. These definitions were incorporated into a rule-based computerized classification system run on Excel(R) software. The computerized classification system was used to categorize visual field defects for an additional 95 NAION visual fields, and the expert panel was asked to independently classify the new fields and subsequently whether they agreed with the computer classification. To account for test variability over time, we derived an adjustment factor from the pooled short term fluctuation. We examined change in defects with and without adjustment in visual fields of study participants who demonstrated a visual acuity decrease within 30 days of NAION onset (progressive NAION). RESULTS: Despite an agreed upon set of rules, there was not good agreement among the expert panel when their independent visual classifications were compared. A majority did concur with the computer classification for 91 of 95 visual fields. Remaining classification discrepancies could not be resolved without modifying existing definitions. Without using the adjustment factor, visual fields of 63.6% (14/22) patients with progressive NAION and no central defect, and all (7/7) patients with a paracentral defect, worsened within 30 days of NAION onset. After applying the adjustment factor, the visual fields of the same patients with no initial central defect and 5/7 of the patients with a paracentral defect were seen to worsen. CONCLUSION: The IONDT developed a rule-based computerized system that consistently defines pattern and severity of visual fields of NAION patients for use in a research setting.

Automation↗

PubMed2006

Wilbrand's knee: does it exist?

OBJECTIVE: In 1904, Hermann Wilbrand reported that nasal ON fibers form a loop into the contralateral ON, subsequently referred to as Wilbrand's knee. He had further theorized that a lesion affecting Wilbrand's knee would develop a distinct visual field defect characterized by an ipsilateral central scotoma with a contralateral superotemporal visual field defect. We present clinical evidence that disputes the existence of Wilbrand's knee. METHODS: A retrospective analysis of 3 patients whose ONs were divided at the ON-chiasm junction is presented. Two patients had an ONS meningioma and the other patient had sarcoidosis of the ON. Resection of the lesion and the ON up to the nerve-chiasm junction was done to prevent the disease from extending into the OC and the contralateral ON. The patients had detailed neuro-ophthalmologic evaluations preoperatively and postoperatively. RESULTS: After the resection of the ON at the ON-chiasm junction in the 3 patients, junctional scotoma could not be detected by visual perimetry. CONCLUSION: No clinical perimetric evidence was found to support the existence of Wilbrand's knee in the anterior visual pathway.

Adult↗

PubMed2005

Optic atrophy and sensorineural hearing loss in a family caused by an R445H OPA1 mutation.

Autosomal dominant optic atrophy (ADOA) is the most common form of inherited optic atrophy. Four genetic loci have been associated with ADOA: OPA1, OPA2, OPA3, and OPA4. Out of these four loci, only one gene has been identified, OPA1. We previously described a unique syndrome of optic atrophy, sensorineural hearing loss, ptosis, and ophthalmoplegia in two unrelated families associated with an R445H mutation in OPA1. The R445H mutation is the only OPA1 mutation that has been associated with this syndrome. In this manuscript, we clinically characterize an unrelated family with four members affected by optic atrophy and hearing loss without extraocular motility abnormalities or ptosis. This family also harbors the R445H mutation. These cases help illustrate the intra- and inter-family variability in phenotype associated with this mutation. As we continue to learn more about OPA1 and the function of its protein product, we will begin to understand the pathophysiology of optic atrophy. This understanding will ultimately lead to novel treatments directed toward preventing the visual loss and disability associated with this inherited disease.

Adult↗

PubMed2003

Management of surgical clinoidal meningiomas.

OBJECT: Clinoidal meningiomas remain a major neurosurgical challenge. Surgery-related outcome has been less than desirable in the past, and little attention has been directed toward improving visual deficits. The authors advocate a skull base technique for the removal of these difficult tumors and describe its advantages in terms of improving extent of resection and enhancing overall outcome, particularly visual function. METHODS: A retrospective analysis was performed on data obtained in 26 consecutive patients with clinoidal meningiomas (including one patient with hemangiopericytoma) who underwent resection between June 1995 and January 2003. In 24 cases the skull base procedure involved extradural anterior clinoidectomy, optic canal unroofing, and optic sheath opening; in two cases a standard pterional craniotomy was performed. Fourteen of the 26 patients suffered significant preoperative visual deficits. All patients underwent thorough pre- and postoperative ophthalmological evaluations. The follow-up period ranged from 3 to 91 months (mean 42.3 months). Total resection was achieved in 20 patients (77%), and the majority (76.9%) of patients with preoperative visual impairment experienced significant improvement. CONCLUSIONS: With the use of the skull base technique, total resection and excellent visual outcome may be achieved with minimal morbidity in most patients with clinoidal meningiomas.

Adolescent↗

PubMed2002

A multicenter, randomized, double-blind, placebo-controlled trial of adjuvant methotrexate treatment for giant cell arteritis.

OBJECTIVE: To evaluate treatment with methotrexate (MTX) in patients with newly diagnosed giant cell arteritis (GCA) to determine if MTX reduces GCA relapses and cumulative corticosteroid (CS) requirements and diminishes disease- and treatment-related morbidity. METHODS: This was a multicenter, randomized, double-blind study. Over 4 years, 16 centers from the International Network for the Study of Systemic Vasculitides enrolled patients with unequivocal GCA. The initial treatment was 1 mg/kg/day (<or=60 mg every day) prednisone, plus either 0.15 mg/kg/week MTX (increased to 0.25 mg/kg/week, for a maximum weekly dosage of 15 mg) or placebo. Two physicians, both blinded to treatment allocation, evaluated each patient at every trial visit. One physician was responsible for providing global medical care. The other assessed GCA status according to a standard protocol. Treatment failure was defined as 2 distinct relapses or persistence of disease activity after the first relapse, in spite of increased CS therapy. RESULTS: Ninety-eight patients were enrolled. No significant differences between treatment groups were noted with regard to age, frequency of positive findings on temporal artery biopsy (placebo 87%, MTX 79%), or comorbidities at the time of enrollment. The median dosage of MTX was 15 mg/week. The incidence of treatment failure was comparable between groups after 12 months: 57.5% in the MTX group failed treatment (95% confidence interval [95% CI] 41.6-73.4%) compared with 77.3% in the placebo group (95% CI 61.9-92.8%) (P = 0.26). In a Cox regression analysis, MTX was not associated with a reduced risk of treatment failure (relative risk 0.72; 95% CI 0.41-1.28). There were no significant differences between groups with regard to abnormal elevations of the erythrocyte sedimentation rate following initial remissions, serious morbidity due to GCA, cumulative CS dose, or treatment toxicity. In the MTX group, there were fewer cases of GCA relapse heralded by symptoms of isolated polymyalgia rheumatica (1 case versus 5 in the placebo group; P = 0.05). CONCLUSION: The results of this randomized, multicenter trial do not support the adjunctive use of MTX to control disease activity or to decrease the cumulative dose and toxicity of CS in patients with GCA.

Aged↗