Laser photocoagulation of an avulsed persistent pupillary membrane vessel causing recurrent hyphaema.

摘要

The tunica vasculosa lentis is an extensive embryonic capillary network supplied by the hyaloid artery to nourish the crystalline lens in utero.1 This mesoderm-derived network typically begins to involute at the eighth month of gestation and completely disappears by birth or within a few weeks thereafter.1-2 Incomplete involution results in a persistent pupillary membrane (PPM) which may range from a few non-pigmented threads to a thick membrane covering the entire pupil. These remnants typically originate at the iris collarette and may extend to other locations on the iris, lens or cornea.