Myopia Pharmacology: Etiologic Clues, Therapeutic Potential

Parameters Associated with the Different Astigmatism Axis Orientations

“…The balancing of corneal and internal sources of astigmatism to reduce the toricity in individual eyes 31 also suggests a role for nonmechanical biological processes in generating astigmatism, as now seemingly underlies refractive errors in general. 12 Although they were not as pronounced as in other studies reporting the ethnic differences in the prevalence of astigmatism, 6 -8,31 we did detect modest differences in the proportion of WTR, ATR, or OBL axes among astigmatic conscripts whose families originated from different geographic regions. Israeli and Eastern ethnic origin were associated with more WTR axis compared with Western origin.…”

“…12 Most of these reports have isolated the spherical component of refractive error, not astigmatism. Recent studies also have suggested that childhood refractive development might be modulated by perinatal or even prenatal influences, including lighting, season of birth, diet, or chemical exposures (Fotedar R, et al IOVS 2008;49: ARVO E-Abstract 3142).…”

Form-Deprivation Myopia in Chick Induces Limited Changes in Retinal Gene Expression

“…Disturbances of visual input also cause myopia in children. 2,4 Although form deprivation induces a robust myopic response in newly hatched chicks, as evaluated in the current study, its effects persist to a more limited extent in chickens at ages that correspond developmentally to human adolescence. 5 As further validations for the use of this model in the study of signaling pathways potentially pertinent to the clinical disorder, an antimyopia drug first identified in form-deprivation myopia in the chick 6 has been shown to be active against human myopia in two multicenter clinical trials, 7,8 and risk factors suggested by the pharmacology of this model have been corroborated indirectly through cross-sectional clinical surveys.…”

“…Persuasive evidence in animals and humans has localized the controlling mechanism(s) for refractive development in large part to the retina. [1][2][3][4] Although evidence implicates various specific neurotransmitters or other intercellular signaling molecules, a cohesive understanding of the retinal cells and signaling pathways that account either for normal refractive development or for refractive errors has remained elusive. 4 Form deprivation has been a useful biological model for assessing mechanisms potentially pertinent to clinical myopia.…”

“…[1][2][3][4] Although evidence implicates various specific neurotransmitters or other intercellular signaling molecules, a cohesive understanding of the retinal cells and signaling pathways that account either for normal refractive development or for refractive errors has remained elusive. 4 Form deprivation has been a useful biological model for assessing mechanisms potentially pertinent to clinical myopia. 1,2 Disturbances of visual input cause myopia in chicks, as well as in tree shrews, primates, and other mammals.…”