Singapore Optometric Association

IMI – Report on Experimental Models of Emmetropization and Myopia

The results of many studies in a variety of species have significantly advanced our
understanding of the role of visual experience and the mechanisms of postnatal eye growth,
and the development of myopia. This paper surveys and reviews the major contributions
that experimental studies using animal models have made to our thinking about
emmetropization and development of myopia. These studies established important
concepts informing our knowledge of the visual regulation of eye growth and refractive
development and have transformed treatment strategies for myopia. Several major findings
have come from studies of experimental animal models. These include the eye’s ability to
detect the sign of retinal defocus and undergo compensatory growth, the local retinal
control of eye growth, regulatory changes in choroidal thickness, and the identification of
components in the biochemistry of eye growth leading to the characterization of signal
cascades regulating eye growth and refractive state. Several of these findings provided the
proofs of concepts that form the scientific basis of new and effective clinical treatments for
controlling myopia progression in humans. Experimental animal models continue to
provide new insights into the cellular and molecular mechanisms of eye growth control,
including the identification of potential new targets for drug development and future
treatments needed to stem the increasing prevalence of myopia and the vision-threatening
conditions associated with this disease.