Pterygium‐induced corneal astigmatism

Abstract

A significant degree of corneal astigmatism can be induced by the encroachment of a pterygium onto a cornea. The pterygium generally causes with‐the‐rule corneal astigmatism that is hemimeridional on the side of the pterygium. There is a significant correlation between the extension of the pterygium onto the cornea and the amount of induced astigmatism. However, there is a poor correlation between pterygium‐induced astigmatism measured topographically and that measured by manifest refraction. Successful pterygium surgery will reduce pterygium‐induced refractive astigmatism and improve visual acuity. This paper outlines the management of a patient with an advanced pterygium, in whom a large degree of corneal astigmatism was induced by the encroachment of a pterygium onto the cornea. Subsequent excision of the pterygium brought about a reversal of the pterygium‐induced corneal astigmatism.

Key words:

• astigmatism
• corneal topography
• pterygium