__Abstract__
Myopia (nearsightedness) is a highly common eye condition that is
predominantly caused by an axial elongation of the eye. Myopia can
usually be corrected with negative glasses, contact lenses, and/or laser
refractive surgery. Unfortunately, however, high myopia (-6 diopters or
more) can lead to structural changes in the retina and optic disc,
resulting in sight-threat ening complications. Myopia results from an
interplay between genetic and environmental risk factors (eg. nearwork,
. higher educational level, playing outdoors).
In this thesis, we studied 130.000 patients from myopia studies from all
over the world. We discovered that one third of the European population
is myopic. 1 in 3 persons with high myopia becomes blind or visually
impaired over time. Furthermore, we identified 26 genetic factors for
myopia and 9 for axial length. These genetic factors play a role in
neurotransmission, ion transport, retinoic acid metabolism, extracellular
matrix remodeling, and eye development. Additionally, we described the
role of education (an environmental risk factor) in the development of
myopia, and we provide compelling evidence of a gene-by-environment
interaction; persons with a high genetic susceptibility and a high
educational level are more likely to develop myopia than persons with
only one of these two factors.
The studies described in this thesis have provided considerable insight
into the complex genetic and environmental factors that give rise to
myopia and refractive error, and they have given us new directions for
treating and/or preventing this rising health issue
