Variations in Globe Shape and Size

Staphylomas

A common finding in eyes with long axial lengths, as in high myopia, is posterior staphyloma. Although staphylomas can be detected ophthalmoscopically, they can be dramatically displayed by B-mode ultrasonography.

Staphylomas appear as a large, concave depression in the retina-choroid-sclera complex. If the staphyloma is present in the posterior pole, it can result in a significant increase in myopia.

For every 1-mm increase in axial length, there is a 3-diopter increase in myopia. If the staphyloma involves the macula, it is not surprising to find significant increases in visual acuity once the myopia induced by the staphyloma is corrected.