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R LeBlanc

Publications and source records attributed to R LeBlanc.

32 records · Page 2Linked to original sources
PubMed1990

Use of suprathreshold test data to predict the results of quantitative testing in the nasal periphery.

We compared the results of suprathreshold testing of the nasal periphery with those of quantitative assessment of the same area. One eye each from 81 patients in four categories (normal [21 subjects], low-risk ocular hypertensive [20 subjects], high-risk ocular hypertensive [20 subjects] and early glaucoma [20 subjects]) was tested with the nasal suprathreshold points of the Octopus G1 program and the Sargon peripheral field-nasal (PFN) program. Simple algorithms were developed to generate from the nasal suprathreshold points of the G1 program two "qualitative indices", mean defect-qualitative (MD-Q) and loss variance-qualitative (LV-Q); these are analogous to the indices mean defect and loss variance respectively, which were calculated from the PFN program data. MD-Q and LV-Q were found to be well correlated with their quantitative counterparts. They provide a uniform method for interpreting the nasal suprathreshold points of the G1 program and help identify patients in whom further quantitative testing is likely to yield useful information.

Adult↗
PubMed1988

The value of indices in the central and peripheral visual fields for the detection of glaucoma.

We assessed 81 patients in four groups (normal, low- and high-risk ocular hypertension, and early glaucoma) with the standard Octopus G1 central visual field program in addition to two quantitative programs, PFN (peripheral field-nasal) and PFT (peripheral field-temporal), designed for this study to test the nasal and temporal periphery, respectively. Indices were calculated for each program for each subject in all groups. We then examined the behavior of the indices across the separate visual field areas within each group as well as the behavior of the indices of each field area among the different groups. We found that quantitative testing of the peripheral nasal visual field provided valuable information in the detection of glaucomatous visual dysfunction additional to that provided by quantitative testing of the central visual field. Quantitative testing of the temporal periphery was less valuable.

Adult↗
PubMed1988

Efficacy of twice-daily levobunolol in the treatment of elevated intraocular pressure.

The efficacy of twice-daily treatment with 0.5% levobunolol hydrochloride was compared with that of 0.5% timolol maleate in 27 patients with open-angle glaucoma or ocular hypertension in a double-blind randomized trial. At all follow-up visits the patients in both groups had significantly decreased intraocular pressure (p less than 0.05); there was no significant difference between the groups. Levobunolol produced significant decreases in mean heart rate (p less than 0.05). One patient with an undisclosed history of childhood asthma experienced bronchospasm related to an acute upper respiratory tract infection while receiving levobunolol. Neither drug caused any significant ocular problems. The results show a clear ocular hypotensive effect with twice-daily 0.5% levobunolol.

Aged↗
PubMed1984

Visual field defects in ocular hypertension and glaucoma.

We measured visual fields using three unconventional test stimuli; sine-wave grating targets of 2 and 5 cycles/degree and a visual acuity target. Of 15 patients with ocular hypertension (OHT), eight had visual field defects for contrast sensitivity when tested with a sine-wave grating target of low spatial frequency; these patients had normal perimetric fields and normal fields for visual acuity. We hypothesize that the outer extremities of the largest dendritic trees of retinal ganglion cells become functionally ineffective in some patients with OHT and early glaucoma, possibly due to retinal ischemia, and as a result visual sensitivity to low spatial frequency gratings is reduced while visual acuity is spared. Since this hypothetical mechanism may be somewhat independent of the mechanism that causes ganglion cell loss, not all the contrast field defects in OHT would be expected to progress to glaucomatous field defects and be evident to clinical perimetry.

Aged↗
PubMed1979

Computerized tomography findings in arteriovenous malformations of the brain.

Computerized tomography (CT) scans of 54 patients with an arteriovenous malformation (AVM) of the brain were reviewed. The 31 males and 23 females (mean age: 33 years) were classified according to clinical presentation: 1) intracranial hemorrhage (30 patients); 2) seizure disorder (19 patients); and 3) other neurological disturbance (five patients). A brain hematoma was identified in all of the patients in the hemorrhage group have a CT scan within 1 week of the bleed. Extension of hemorrhage into the ventricular system as seen in eight cases was invariably accompanied by severe neurological dysfunction. A high-density lesion without associated mass effect was found in 48% of patients presenting with a seizure disorder. Dilatation of the ipsilateral lateral ventricle, a common finding in this group of patients, was thought to indicate an atrophic process. Evidence of discrete brain infarction was unusual. Intravenous infusion with Hypaque provided additional information in 31 of the 35 patients so studied. Demonstration of prominent or enlarged feeding arteries and/or draining veins occurred in 20% of patients with large malformations. Six cases of angiographically occult AVM's were found. A correlation of the CT scan with clinical, angiographic, and histological findings is presented.

Adolescent↗
PubMed1976

A 'black cornea' secondary to topical epinephrine.

We report a case of 'black cornea" secondary to topical epinephrine therapy and present the biochemical analysis of the lesion. The formed pigment is a melanin and not the intermediate substance, adrenochrome, as has been previously reported. The pathogenesis of melanin deposition is reviewed and a hypothesis of epinephrine-melanin binding is suggested.

Cornea↗
PubMedDate not supplied

Relationship between morphologic somatotypes and standing posture equilibrium.

Previous studies have identified height and weight as important factors affecting quiet standing stability but studies have not addressed body morphology as a global factor. Using anthropometric measurements, the morphologic somatotypes were defined in terms of body composition and structure. The aim of this study was to test the hypothesis that morphologic somatotypes were related to standing posture equilibrium in able-bodied girls. A total of 43 able-bodied girls having a mean age of 13.8 +/- 2.2 years participated in this study. Somatotype measurements were taken to determine their endomorphic, mesomorphic or ectomorphic components. Then, subjects were asked to stand still on a force platform for 64 s with their eyes opened, feet about 23 cm apart and arms aligned with the trunk. Afterwards, subjects were grouped based on the highest value of their somatotype component. There was no statistical difference in age, height and weight among the groups. The surface area of an ellipse delineated by the displacement of the centre of pressure (COP) was statistically larger (236.9 +/- 134.3 mm2) for the ectomorphs than for the endomorphs 137.7 +/- 71.4 mm2). The minor axis was longer (8.1 +/- 2.9 mm) for the ectomorphs than for the endomorphs (5.7 +/- 2.2 mm). The decrease in standing posture stability of the ectomorphic group was attributed to a relatively low muscle component, a high height weight ratio and an elevated position of the body centre of mass in this population of girls. Somatotypes should be considered when assessing standing posture in both able-bodied subjects and patients.

Adolescent↗
PubMedDate not supplied

Crutch walking.

This article provides nurses with information on crutch walking which is helpful for patient teaching in a variety of settings. Two nursing diagnoses are discussed: knowledge deficit and potential for injury related to crutch walking. Preparatory exercises and measurement of the patient for crutches are explained, as well as types of weight bearing and point and swing gaits for crutch walking. Crutch maneuvers in and out of a chair or bed, and on stairs are also included. A discharge instruction sheet with tips on crutch walking is provided for use with patients.

Crutches↗