Myopic crescent

A myopic crescent is a moon-shaped feature that can develop at the temporal (lateral) border of disc (it rarely occurs at the nasal border) of myopic eyes. It is primarily caused by atrophic changes that are genetically determined, with a minor contribution from stretching due to elongation of the eyeball. In myopia that is no longer progressing, the crescent may be asymptomatic except for its presence on ocular examination. However, in high-degree myopia, it may extend to the upper and lower borders, or form a complete ring around the optic disc and form a central scotoma.