Biomedical subjects
Publications and source records attributed to M A Terry.
Multiple-choice test questions are the most widely used and highly regarded of the presently available objective or selective test items. They can be used to test all levels of learning and are applicable to the measurement of most important educational outcomes. Although it is difficult to construct these questions well, they are versatile and can be used in settings involving large numbers of students.
We used standard 2,450-MHz microwave irradiation to achieve sterilization of hydrophilic contact lenses contaminated with a variety of bacterial, fungal, and viral corneal pathogens. A three-dimensional rotisserie was used to overcome the problem of "cold spots" within the microwave oven. The contact lenses became dehydrated in approximately two minutes. Rehydration with normal saline restored their shape and appearance. The time necessary to prohibit all growth of the bacterial and fungal organisms studied ranged from 45 seconds to eight minutes. All viral contaminants were completely inactivated after four minutes of microwave exposure. Refractive properties were unaffected after 101 exposures to microwaves for ten minutes. Slit-lamp examination and scanning electron microscopy disclosed minute particles on the surface of these contact lenses but no damage to the lens matrix from irradiation.
We utilized ten eye bank eyes to evaluate and quantitate the immediate corneal topographic shifts that occur after each stage of a modified Ruiz procedure for astigmatism. Computer digitization of photokeratoscope (Corneascope) photographs revealed that the initial two central paired tangential incisions induced an average of 5.10 diopters (D) of central astigmatism by flattening the meridian perpendicular to the incisions and by steepening the meridian 90 degrees away. Additional tangential incisions did not significantly alter the topography after placement of the first two central incisions. Addition of corridor incisions produced an additional 5.25 D of induced astigmatism by further extensive flattening of the incised meridian. The completed procedure produced an average of 11.03 D of astigmatic shift, but with a wide range of effect (7.15 to 12.96 D). With modification, the Ruiz procedure is a powerful keratorefractive surgical technique.
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Care management must be marketed by home healthcare agencies as a formalized, separate entity for which reimbursement is received. The authors explore this new venture from the perspectives of the care management process and resulting service delivery issues.
Selective suture removal following corneal transplant surgery can facilitate the reduction of astigmatism. We present concepts concerning astigmatism analysis after keratoplasty related to suture compression by reviewing keratoscopy, slit-lamp biomicroscopy, and retinoscopy findings. Keratoscopy observations indicating tight sutures include peripheral indentation of the keratoscope rings, individual keratoscope ring images between tight sutures, and decentration of the corneal apex away from a tight suture. The utilization of the Van Loenen keratoscope at the slit-lamp in "dynamic keratoscopy" allows the surgeon to readily recognize these findings and also proves useful intraoperatively. Slit-lamp biomicroscope observations indicative of tight sutures include a doughnut of tissue compression, Kaye's epithelial white dots, and epithelial or endothelial stress lines. Retinoscopy observations demonstrate that tight sutures induce astigmatism with the narrowest side of the retinoscopy beam pointing directly toward the tightest suture. Astigmatism management plays a major role in the future success of ophthalmology and needs to be increasingly integrated into the practice of the general ophthalmologist.