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Biomedical subjects

A R Berrospi

Publications and source records attributed to A R Berrospi.

10 recordsLinked to original sources

Betaxolol. A new beta-adrenergic blocking agent for treatment of glaucoma.

The intraocular pressure response to topically instilled 0.25% betaxolol hydrochloride was evaluated in 12 patients with chronic open angle glaucoma or ocular hypertension. The drug produced a significant lowering of IOP in all 12 of the patients under study. A 30% to 35% decrease below baseline IOP was observed and was maintained during the one-year observation period. Visual acuity was stable in all subjects throughout the study and corneal anesthesia was not encountered. Tear secretion was not adversely effected by betaxolol, nor did topical administration of the drug produce any systemic cardiovascular response of consequence. Blood pressure and pulse rate remained stable throughout the year. These data suggest that an ophthalmic formulation of betaxolol may have substantial clinical potential for the treatment of glaucoma.

Adrenergic beta-Antagonists

The human corneal endothelium in keratoconus: A specular microscopic study.

The corneal endothelium in 12 cases of keratoconus was examined with the clinical specular microscope. There appeared to be an increase in cellular pleomorphism with many cells considerably smaller than normal distributed throughout the endothelial cell population. There were also many large, elongated cells whose long axis showed a definite tendency to assume a similar directional orientation. The long axis of these cells seemed oriented toward the apex of the cone, and the cells appeared to have been stretched by the ectatic process. Many endothelial cells contained dark intracellular structures. Their significance is unknown. The single cornea in this series with a history of acute hydrops contained a localized area in which the endothelial cells were seven to ten times larger than normal. This suggests that rupture of the endothelium and Descemet's membrane, responsible for the acute edematous process, occurs at this site, and that the adjacent cells enlarged to fill the defect.

Cornea

Epithelialization of the anterior chamber: clinical investigation with the specular microscope.

Four patients, each of whom had had an uncomplicated cataract extraction, were examined because of an apparent epithelialization of the anterior chamber. In each instance, the diagnosis was later verified histopathologically. The involved eye was photographed with the clinical specular microscope and the endothelial photomicrographs were analyzed. It was noted that considerable endothelial cell loss had occurred, as evidence by the larger size of the remaining cells. Endothelial cells were present but they were grossly abnormal well below the demarcation line visible with the slit-lamp biomicroscope. These in vivo observations support the thesis that damage to the corneal endothelium is a necessary factor for epithelial invasion of the anterior chamber.

Aged

Penetration of topically administered prednisolone acetate into the human aqueous humor.

A single standardized drop of 1.0% prednisolone acetate labeled with tritiated thymidine was administered topically to one eye of 58 patients shortly before elective cataract extraction. An aqueous humor sample was aspirated at varying intervals and its corticosteroid content was determined. Peak drug concentration in aqueous humor was 1.13 mug/ml, which occurred 30 to 45 minutes after instillation of the medication. Substantial quantitites of corticosteroid were found in the aqueous humor five minutes after drug administration. The area under the drug concentration in aqueous humor-vs-time curve (a measure of the drug's bioavailability in aqueous humor) was 88 mug min/ml, and its half-life in human aqueous humor was 28 minutes. None of these values were significantly different from the comparable values in rabbit eyes.

Adult

Human conjunctivitis. I. Diagnostic evaluation.

One hundred forty-three patients (207 eyes) with conjunctivitis or blepharoconjunctivitis were studied. Attempts were made to establish an etiologic diagnosis by clinical and laboratory methods. The etiologic diagnosis that was made on the basis of the initial clinical examination correlated poorly with the results of standard laboratory tests. Conversely, the standard laboratory evaluation failed to establish a definitive diagnosis in the majority of cases. These findings suggest that the diagnostic dogmatism prevalent in conjunctivitis is unwarranted. Morphologic signs and routine laboratory tests leave us without a verified etiologic diagnosis in a substantial number of cases.¿

Acute Disease

Human conjunctivitis. II. Treatment.

One hundred forty-three patients (207 eyes) with conjunctivitis or blepharoconjunctivitis were investigated to determine (1) the safety of topical corticosteroid therapy and the relative efficacy of formulations of increasing potency and (2) the effectiveness of a steroid-antibiotic preparation compared to each of its components alone and to a placebo. The corticosteroids were equally effective in suppressing conjunctival inflammation; all were more effective than the placebo. Active conjunctivitis was controlled more readily by those preparations containing a steroid, both alone and in combination. The corticosteroid alone (dexamethasone) was more effective in producing inactivation of conjunctivitis than the antibiotic alone ( a mixture of neomycin sulfate and polymyxin B sulfate). This observation remained unchanged when cases of Staphylococcus aureus conjunctivitis were analyzed separately. No serious complications resulted from any treatment regimen.

Administration, Topical

Morphological changes in corneal endothelial cells after penetrating keratoplasty.

Fifteen patients who had had a successful penetrating keratoplasty were photographed with the clinical specular microscope and the resulting endothelial photomicrographs were analyzed. The average endothelial cell area was one to six times larger and the average endothelial cell perimeter was one to 2 1/2 times larger than that of a normal cornea of a subject the same age as the donor. In each corneal graft, endothelial cell areas and perimeters clustered tightly around a mean value, although the mean value for different corneas varied significantly. The thickness and transparency of each graft was normal, indicating that within the observed limits the success of the transplantation procedure did not depend on final endothelial cell size or perimeter.

Cornea

Initial treatment of descemetocele with hydrophilic contact lenses.

A hydrophilic contact lens was used as the initial mode of therapy in 5 cases of descemetocele. The lens was left in place over the descemetocele continuously for periods ranging from 2 to 15 months. Corneal perforation did not occur, and the anterior chamber remained formed in all cases. The device seemingly provides sufficient structural reinforcement to Descemet's membrane to prevent its distension by the intraocular pressure. It also maintains Descemet's membrane in a moist state and protects the descemetocele from the trauma of the lid margins during blinking. This series of cases indicates that a hydrophilic contact lens can be a very effective temporizing measure for the treatment of descemetocele, enabling the surgeon initially to cope with an ocular emergency in a very simple manner, and to convert the ultimate surgical repair to a scheduled, carefully planned procedure with a much greater potential for success.

Adult