Abstract
PURPOSE: Pterygium is a chronic, degenerative condition of unknown cause, and its development can lead to significant refractive errors due to localized flattening of the cornea near the central area of the leading edge. However, to date, the impact of pterygium and its surgical removal on refractive errors has not been thoroughly compiled in a comprehensive study. This systematic review aims to evaluate the effect of pterygium surgery on refractive errors and to examine the relationship between the size of the pterygium and its effect on refractive errors both before and after pterygium surgery. METHODS: The Cochrane methodology was used to design and conduct the present systematic review. Relevant articles published up to December 2024 were searched and collected from four electronic databases: PubMed, Scopus, MEDLINE, and Web of Science. Additionally, a manual search was conducted to locate relevant studies. The keywords used in the search included "pterygium" combined with terms such as "refractive errors," "myopia," "hyperopia," "astigmatism," and "presbyopia." RESULTS: In total, 23 studies including 1,663 eyes were included in this review. In the majority of studies, more than one technique was used, with conjunctival autograft being the most common technique for pterygium treatment. In most reviewed studies, a significant improvement in visual acuity, keratometry values-both horizontal keratometry (K1) and vertical keratometry (K2)-corneal astigmatism, corneal spherical power, surface regularity index, and surface asymmetry index, as well as a decrease in corneal astigmatism, spherical error, and wavefront aberration, were reported after pterygium excision. CONCLUSIONS: Pterygium surgery can be effective in reducing refractive errors, including astigmatism, wavefront aberration, and spherical aberration, in various ways. However, this also depends on the size of the pterygium. The findings of this study suggest that early removal of pterygia reduces the likelihood of significant residual aberrations. Pterygia between 3 and 4 mm in size pose a notable risk for residual aberrations.