Biomechanical considerations of high myopia: Part I--Physiological characteristics.

Prior to a discussion of biomechanical considerations in high myopia, a review of anatomical and physiological patterns in high myopia is presented. A scleral pathogenesis or mesodermal hypothesis of the anomaly is presented with the inclusion of supporting evidence. Retinal, choroidal, and vitreous malformations in high myopia also are highlighted. Notable is a pattern consistent with the concept of gradual stretching of the vitreous chamber. The association of high myopia with other diseases is shown, with special attention being given to the concomitant features of high myopia and glaucoma. A discussion of animal deprivation studies examines their relevance to cases of clinical myopia. The dopamine deficit found in the retinas of visually deprived animals appears to be an area that will attract considerable future research. However, there may be no connection of these experimental findings in deprived animals to most cases of high myopia.