Correlation Between Pterygium Size and Induced Corneal Astigmatism

    loading  Checking for direct PDF access through Ovid


PurposeBefore invasion of the visual axis, pterygia typically induce with-the-rule astigmatism, which can be visually significant. In this study, we attempted to assess the quantitative relation between pterygium size and induced corneal astigmatism using corneal topography and digital imaging.MethodsThirty-three eyes of 25 patients with primary pterygia were evaluated using corneal topography (TMS), slit-lamp photography, and digital imaging to correlate parameters of pterygium size with induced corneal astigmatism at the 3- and 6-mm optical zones.ResultsPterygia induce asymmetric with-the-rule astigmatism. Lesions extending >45% of the corneal radius or within 3.2 mm of the visual axis produce increasing degrees of induced astigmatism.ConclusionOnce pterygia reach a critical size, they induce visually significant central with-the-rule astigmatic changes that may not be apparent by subjective refraction. This finding helps to identify those patients who may benefit from surgical intervention.

    loading  Loading Related Articles