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Biomedical subjects

R Z Levene

Publications and source records attributed to R Z Levene.

At least 19 recordsLinked to original sources
PubMed1993

Argon laser trabeculoplasty in pigmentary glaucoma.

PURPOSE: To evaluate the long-term effect of argon laser trabeculoplasty (ALT) in pigmentary glaucoma. METHODS: The authors retrospectively analyzed results of ALT in 32 eyes of 32 patients with medically uncontrolled pigmentary glaucoma. Data were longitudinally adjusted to normalize the disparity in time of follow-up and evaluated by life-table analysis. RESULTS: Mean age (+/- standard deviation) was 45.1 +/- 13.1 years (range, 23-72 years) (males, 46.3 +/- 13.7 years; females, 42.9 +/- 12.2 years). Mean baseline intraocular pressure (IOP) was 27.8 +/- 5.3 mmHg. Mean follow-up time was 33.0 +/- 5.0 months (range, 1 week [immediate failures] to 96 months). Three eyes were lost to follow-up at 3 months. Eleven eyes required trabeculectomy between 1 week (2 eyes) and 37 months after laser treatment. Life-table analysis indicated a cumulative success for all eyes of 80% at 1 year, 62% at 2 years, and 45% at 6 years. Mean IOP was significantly reduced (P < 0.001; paired Student's t test) for male and female eyes at all intervals calculated. Age was a significant factor in determining time to failure. CONCLUSION: Argon laser trabeculoplasty is effective in pigmentary glaucoma. Younger patients had a greater chance of success than older patients at all intervals. This became highly significant (P < 0.001) after 3 years.

Adult↗
PubMed1992

Central visual field, visual acuity, and sudden visual loss after glaucoma surgery.

The relationship between Snellen visual acuity and central visual field loss as determined by the Humphrey 10-degree test was examined in 96 glaucomatous eyes of 79 patients. The severity of the field defect was determined by the number of affected quadrants, defined as a sensitivity loss of at least 10 decibels from normal at the most central point of 1.4-degree eccentricity. The decrease in median acuity was gradual, one-half line per quadrant for one and two affected quadrants, and an additional one and one-half line to two lines for three and four quadrants. Loss of acuity was disproportionate when both temporal quadrants were affected. The major source of error was difficulty with fixation. One type, a prolonged fixation shift, was not related to short-term fixation losses. There was a significant correlation between acuity and foveal threshold over a wide range of both variables. Sudden visual loss from additional optic nerve damage was studied retrospectively in 96 eyes with advanced glaucoma and a central field defect. A frequency of 3% for any loss of visual acuity and a frequency of 1% for a loss to 20/200 or worse were noted. There were no apparent predictive factors.

Adult↗
PubMed1984

Glaucoma filtering surgery: factors that determine pressure control.

Factors that determine pressure control after filtering surgery were studied in 194 eyes of 158 patients in a retrospective study. Emphasis was placed on the cumulative probability method of Kaplan and Meier and multiple regression analysis. Aphakia and the presence of a surgical bleb were the most important factors. Age and type of surgical procedure were next. Race and race-sex interaction were the least important. The above factors accounted for only 6% to 16% of the total variance. The difference between eyes of the same patient was less than that between paired eyes of different patients but the former was surprisingly high. In the selected group of successful cases without medication the postoperative pressure was independent of the baseline pressure and choice of surgical procedure.

Adolescent↗
PubMed1984

Glaucoma filtering surgery factors that determine pressure control.

Factors that determine pressure control after filtering surgery were studied in 194 eyes of 158 patients in a retrospective study. Emphasis was placed on the cumulative probability method of Kaplan and Meier and multiple regression analysis. Aphakic and the presence of a surgical bleb were the most important factors. Age and type of surgical procedure were next. Race and race-sex interaction were the least important factors. The above factors accounted for only 6% to 16% of the total variance. The difference between eyes of the same patient was less than that between paired eyes of different patients but the former was surprisingly high. In the selected group of successful cases without medication the postoperative pressure was independent of the baseline pressure and choice of surgical procedure.

Cornea↗
PubMed1980

Biostatistical analysis of the collaborative glaucoma study. I. Summary report of the risk factors for glaucomatous visual-field defects.

A prospective collaborative study was conducted in five centers during a 13-year period to identify factors that influence the development of visual-field defects (GVFDs) of open angle glaucoma. In 5,000 subjects, GVFDs developed in only 1.7% of eyes. Statistical analysis of 26 factors at first examination identified five that were significantly related to the development of GVFDs--outflow facility, age, applanation pressure, cup-disc ratio, and pressure change after water drinking. Their absolute initial value, and not its change with time, was the important predictor. Multivariate analysis showed their collective predictive power to be undesirably poor, indicating that other factors must play an important role in the development of GVFDs. Mortality-table analysis indicated that during a period of five years, 98.54% of eyes with initial pressure less than 20 mm Hg continued to be free from GVFDs as compared with 93.34% of those with pressure of 20 mm Hg or greater.

Aged↗
PubMed1978

The incidence of HLA antigens in black primary open-angle glaucoma patients.

We compared the HLA antigen frequencies in black primary open-angle glaucoma patients to those in black non-glaucomatous patients; normal, nondiseased black persons; and nondiseased North American blacks. We found no statistically significant alteration in HLA antigen frequencies in black open-angle glaucoma patients as compared to a control population.

Adult↗
PubMed1977

Primary open-angle glaucoma and sensitivity to corticosteroids in vitro.

Corticosteroid inhibition of mitogen induced lymphocyte transformation was studied in patients with definite or suspected primary open-angle plaucoma (POAG). Patients without glaucoma served as normal controls. From a dose response curve with prednisolone-21-PO4 or prednisolone the value of 50% inhibition (I50) was determined for each patient. In Series I it was necessary to disqualify 70% of the data whereas in Series II less than 5% were excluded. In Series I the median I50 (M X 10(-8) prednisolone-21-PO4) was 12 for 11 controls and 8 for 18 total POAG'S (p less than .01). In Series II the opposite result was obtained. The median I50 was 8 for 49 controls and 12 for 79 total POAG'S (p less than .01). In series II similar results were obtained with prednisolone. There was no difference between definite and suspected glaucoma patients. The cause of the discrepancy between the present two series and among the other published studies is not clear. The source of normal controls, from either an eye clinic or volunteer groups, may be a factor.

Adrenal Cortex Hormones↗
PubMed1976

Fluorophotometry and the rate of aqueous flow in man. I. Instrumentation and normal values.

A new objective fluorophotometer, based on a previous model but with changes in electronic circuitry, was designed and built. The fluorometric method was applied to 38 normal eyes to obtain the aqueous outflow rate and fluorescein decay constant. Aqueous outflow rate has a direct correlation with the anterior chamber depth and an inverse correlation with age. The aqueous flow rate is higher in whites than in blacks, but in our sample, mean pressure was lower in whites. Acetazolamide decreases the aqueous flow rate and the fluorescein constant; the mean decrease in 10 eyes of 5 patients was approximately 38% and 22%, respectively. Fluorophotometry gives a higher value for the aqueous outflow rate than that calculated by tonography.

Acetazolamide↗
PubMed1976

Fluorophotometry and the rate of aqueous flow in man. II. Primary open angle glaucoma.

By fluorophotometry, the aqueous outflow rates of 38 eyes of 22 patients with definite or suspected primary open angle glaucoma, who were not receiving therapy, were determined. Although the values obtained do not differ from normal, the factors that modify or control the flow rate are different in normal and glaucomatous eyes. The flow rate decreases as the pressure increases in the glaucomatous group but not in the normal group. The flow rate increases with anterior chamber depth and decreases with age in the normal group but not in the glaucomatous group. The fluorescein decay constant is a measure of the movement of fluorescein from the cornea to the aqueous. This constant increases as the pressure increases in the glaucomatous group but not in the normal group.

Black or African American↗
PubMed1975

Gonioscopic differences between primary open-angle glaucoma and normal subjects over 40 years of age.

Gonioscopy was performed on 110 patients with primary open-angle glaucoma over 40 years of age and an equal number of normal sugjects, matched by race and age. The frequency distribution of various angle features differed in the two groups: in the glaucoma group, there were more iris processes at all levels of insertion, a higher insertion of the iris root and more trabecular pigmentation. A congenital angle anomaly is one important factor in the pathogenesis of the elevated pressure.

Adult↗
PubMed1975

Gonioscopic differences between eyes with primary open-angle glaucoma and normal eyes in subjects over the age of forty.

Gonioscopy was performed on 110 patients with primary open-angle glaucoma over the age of 40 and an equal number of normal subjects matched by race and age. The frequency distribution of various angle features differed in two groups. In the glaucoma group there were more iris processes at all levels of insertion, a higher insertion of the iris root, and more trabecular pigmentation. We believe that a congenital angle anomaly is an important factor in the pathogenesis of the elevated intraocular pressure.

Adult↗