Presumed Ocular Histoplasmosis Syndrome
(POHS) is an eye condition associated with changes and scarring in the retina and choroid, the layer of blood vessels beneath the retina. These changes may include small scars known as histo spots and areas of atrophy around the optic nerve.
Most people with histo spots do not experience symptoms. In some cases, however, abnormal blood vessel growth can develop near a scar and affect the macula, the part of the retina responsible for sharp central vision. When this occurs, vision may become blurred or distorted.
POHS often causes no noticeable symptoms, particularly in its early stages. When abnormal blood vessel growth affects the macula, symptoms may include:
- Blurred or decreased central vision
- Straight lines appearing wavy or distorted
- A gradual or sudden change in vision
- A blind or blurry spot in the center of vision
Treatment is generally only necessary when abnormal blood vessel growth develops. In these cases, medications called anti-VEGF treatments may be used to control the abnormal blood vessels and help protect central vision.
When treated early, particularly before significant scarring develops in the macula, the outlook for maintaining vision is generally favorable.
