Gyrate atrophy of the choroid and retina is a disease characterized by progressive constriction of visual fields, a 10-fold to 20-fold elevation in plasma ornithine, and depressed activity of L-ornithine:2 oxoacid aminotransferase. Morphologically conspicuous but clinically unimportant atrophy of Type II muscle fibers progresses concomitantly with the eye disease. A pathogenic component of the disease may be deficient formation of creatine, caused by hyperornithinemia, which leads to a shortage of cellular phosphocreatine energy stores. To test the therapeutic value of replenishing the postulated deficiency of creatine, we supplemented the diet of seven patients with 1.5 g of creatine daily. During one year of this treatment the diameters of Type II muscle fibers increased from 34.1 +/- 7.1 to 49.9 +/- 7.0 micron (mean +/- S.D.) (P less than 0.001). There was no significant increase in the diameters of Type I fibers. The visual-field tests showed no further constriction during the therapy. Fundus photography revealed slow impairment at an age otherwise associated with rapid progression of the disease. These promising preliminary results need further evaluation with long-term follow-up studies.

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A biologically modified polymer can support migration and adhesion of corneal epithelial cells in vivo. The collagen I-modified surface exhibited the most promising performance, both clinically and histologically.

ABSTRACT.Purpose: To establish whether features of environmental lighting in far northern latitudes might be associated with prevalence of myopia. Methods: Using both questionnaires and military medical examinations, this cross-sectional survey of Finnish conscripts assessed both light exposure and conventional risk factors for myopia. Results: While myopia was not associated with the month of birth, there was a trend towards a higher prevalence of myopia among conscripts living above the Arctic Circle, consistent with the hypothesis that ambient lighting might influence refractive development. Other novel associations with myopia were decreased sunglasses use and brown iris colour. As indicated by other reports, myopia was found to be associated with family history, education and nearwork. Conclusion: Although constraints inherent in surveying this military population may have limited our ability to detect associations, the positive findings suggest that studying northern populations may prove useful in clarifying any potential role of the light/dark cycle in refractive development.