The Effects of Pterygium Surgery on Refraction and Corneal Curvature

Effects of pterygium surgery on front and back corneal surfaces and anterior segment parameters

“…Even without involvement of the optical zone, pterygium can produce significant alterations in corneal shape and curvature. Thus, many studies have shown that pterygium is associated with regular and irregular astigmatism as well as changes in corneal curvature and refractive status, which improve at least in part after the surgery [1][2][3][4][5][6][7][8][9][10][11][12][13]. Corneal curvature in these studies has been investigated with corneal topography, which evaluates the front corneal surface.…”

Effects of Pterygium on Ocular Aberrations

“…The change is often characterized as with-the-rule astigmatism resulting from localized flattening of the cornea, but this type of astigmatism is usually irregular. 1 Several reports evaluated the effects of pterygium on refraction and corneal topography. These effects become quantified as sphere or astigmatism changes, but as readers know, irregular astigmatism could not express to sphere and cylinder.…”

“…These effects become quantified as sphere or astigmatism changes, but as readers know, irregular astigmatism could not express to sphere and cylinder. [1][2][3][4][5][6][7] Recently, ocular aberrometry enables us to evaluate irregular astigmatism more precisely. In addition, this method is able to discern refraction of the eye within 0.05 diopters (D), approximately 25-50 times greater than autorefraction or topographic analysis.…”

Gaze-Induced Desçemet’s Folds Secondary to a Primary Pterygium

“…9 Evidence that pterygia, including those located outside the optical zone, cause topographic changes and refractive error has been shown. 7 The pathophysiology of irregular astigmatism induced by pterygia was studied by Oldenburg et al 10 They concluded that the astigmatism could be the result of the combined effect on the corneal surface of pterygium-induced altered tear film in conjunction with the contracting fibrovascular fibers of the head of the pterygium. In addition, it has been shown that mechanical compression of the cornea by a pterygium may induce astigmatism on lateral gaze.…”

“…Pterygia have also been shown to cause decreased visual acuity. 3,7 The decrease in visual acuity may be the result of encroachment of the pterygium into the visual axis, additional induction of astigmatism induced by the pterygium, breakup of the precorneal tear film, or restricted ocular motility. 3 Desçemet's membrane, the basement membrane of the corneal endothelium, also known as the posterior limiting lamella, is a 7-m thick condensation of a collagenous substance that is composed primarily of collagen type IV and laminin and becomes thicker with age.…”