Laser hazards and safety.

Lasers are a key component of the vision practitioner's arsenal of care, and provide a wonderful new frontier of diagnostic and therapeutic options. In light of their expanded utilization, it is crucial that eye care practitioners have a thorough understanding of potential laser hazards and the regulations that establish guidelines for their safe application. This review describes the American National Standards Institute (ANSI) standards applicable to the safe use of lasers (Z 136.1) and the safe use of lasers in health care facilities (Z 136.3). Laser hazard classification, the organization of a laser safety program, and administrative and procedural controls are included.

The rhesus monkey as an animal model for age-related maculopathy.

In a survey of 100 rhesus monkeys, the prevalence of macular changes was similar to that in age-related macular degeneration in humans. Ophthalmoscopically visible drusen were observed in 31% of the monkeys. A statistically significant correlation existed between the age of the animals and the degree of drusen. Considering equivalent ages, monkeys appear to develop drusen earlier than humans. Pigment mottling occurred in 10% and hypopigmented spots in 8% of the sample. A dull foveal reflex was seen in 8% and no reflex in 27%. There was a statistically significant correlation between the absence of a reflex and the presence of pigment mottling or hypopigmentation in the macula.

Ultrastructural evaluation of the retina in retinopathy of prematurity and correlations with vitamin E therapy.

Histological evidence of retinal damage associated with the clinical observation of Retinopathy of Prematurity (ROP) grade III was documented in preterm infants receiving the minimum dosage of vitamin E recommended by the American Academy of Pediatrics (5 mg/kg/day), and exposed to high concentration/duration of oxygen at birth. Matched infants that were provided a higher oral dosage of vitamin E (100 mg/kg/day) did not develop the serious grade of retinopathy (grade III) (1,2). In this paper cytological correlates are described which substantiate pre-existing theories concerning the pathological changes associated with the development of the disease at a light microscopic level. Moreover, observations made at the electronmicroscopic level permit distinctions to be made concerning the newly formed retinal vessels, in treated versus non-treated infants, that have not been noted in the history of this disease. These retinal distinctions suggest that vitamin E may be efficacious in reducing the severity of ROP. Lastly, a mechanism is suggested for the action of vitamin E in reducing the severity of ROP.

Retrolental fibroplasia: efficacy of vitamin E in a double-blind clinical study of preterm infants.

We performed a double-blind study in 101 preterm infants who weighed less than or equal to 1500 g at birth, who had respiratory distress, and who survived for at least four weeks, to evaluate the efficacy of oral vitamin E in preventing the development of retrolental fibroplasia. Weekly indirect ophthalmologic examinations begun when the infants were three weeks old revealed a significant decrease in the incidence of retrolental fibroplasia greater than or equal to Grade III (P less than 0.03) and greater than or equal to Grade II (P less than 0.05) (McCormick classification) in the 50 infants given 100 mg of vitamin E per kilogram of body weight per day as compared with 51 given 5 mg per kilogram per day (controls). When multivariate analysis was applied to the controls, five risk factors were identified: gestational age, level and duration of administration oxygen, intraventricular hemorrhage, sepsis, and birth weight. When multivariate analysis was applied to both control and treatment groups, the severity of retrolental fibroplasia was found to be significantly reduced in infants given 100 mg of vitamin E (P = 0.012).