Laser-induced retinal injury following a recreational laser show: two case reports and a clinicopathological study.

BACKGROUND: Two patients who attended a dance festival with an audience-scanning laser show presented in our department with a decrease in visual acuity from a direct laser hit in one eye. Ophthalmoscopy showed a similarly sized retinochoroidal coagulation spot, which had led to a retinal hemorrhage in both patients. Because the organizers of the show concluded that the retinal injury was caused by powerful, handheld laser pointers in the crowd, we were interested in determining if these laser pointers could cause this kind of acute retinopathy. METHODS: A 44-year-old man with an extrafoveal, temporal choroidal melanoma was scheduled for enucleation. The eye (visual acuity 20/20) had a healthy-appearing macula. Prior to enucleation, the retina was exposed to eight different durations (0.5-64 seconds) of laser beam from a commercially available, handheld, class 3B green laser pointer (500 mW). RESULTS: Histologic analysis was unable to identify any abnormalities in the choriocapillaris, the photoreceptors or the retinal pigment epithelium (RPE). CONCLUSION: The use of powerful laser appliances (class 4 lasers) directed into the audience (audience-scanning laser show) can cause significant retinal injuries with lifelong visual consequences. It is unlikely that laser pointers, even those of class 3B, can cause these ocular injuries.

Cyclical etidronate increases bone density in the spine and hip of postmenopausal women receiving long term corticosteroid treatment. A double blind, randomised placebo controlled study.

OBJECTIVE: To study the effect of cyclic etidronate in secondary prevention of corticosteroid induced osteoporosis. METHODS: A double blind, randomised placebo controlled study comparing cyclic etidronate and placebo during two years in 37 postmenopausal women receiving long term corticosteroid treatment, mainly for polymyalgia rheumatica (40% of the patients) and rheumatoid arthritis (30%). Bone density was measured in the lumbar spine, femoral neck, and femoral trochanter. RESULTS: After two years of treatment there was a significant difference between the groups in mean per cent change from baseline in bone density in the spine in favour of etidronate (p = 0.003). The estimated treatment difference (mean (SD)) was 9.3 (2.1)%. Etidronate increased bone density in the spine (4.9 (2.1)%, p < 0.05) whereas the placebo group lost bone (-2.4 (1.6)%). At the femoral neck there was an estimated difference of 5.3 (2.6)% between the groups (etidronate: 3.6% (1.4)%, p < 0.05, placebo: -2.4 (2.1)%). The estimated difference at the trochanter was 8.2 (3.0) (etidronate: 9.0 (1.5)%, p < 0.0001, placebo: 0.5 (2.3)%). No significant bone loss occurred in the hip in placebo treated patients. CONCLUSIONS: Cyclic etidronate is an effective treatment for postmenopausal women receiving corticosteroid treatment and is well tolerated.