Lin A, Stern G
Department of Ophthalmology, University of Florida College of Medicine, Gainesville 32610-0284, USA.
Cornea. 1998 Jan;17(1):28-30. doi: 10.1097/00003226-199801000-00005.
Before 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.
Thirty-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.
Pterygia 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.
Once 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.
在翼状胬肉侵入视轴之前，通常会引起顺规散光，这在视觉上可能具有重要意义。在本研究中，我们试图使用角膜地形图和数字成像来评估翼状胬肉大小与诱导性角膜散光之间的定量关系。
对25例原发性翼状胬肉患者的33只眼进行角膜地形图（TMS）、裂隙灯摄影和数字成像评估，以关联翼状胬肉大小参数与3毫米和6毫米光学区的诱导性角膜散光。
翼状胬肉引起不对称的顺规散光。病变延伸超过角膜半径的45%或在视轴3.2毫米范围内会产生逐渐增加的诱导性散光。
一旦翼状胬肉达到临界大小，它们就会引起在视觉上具有重要意义的中央顺规散光变化，而主观验光可能无法发现这些变化。这一发现有助于识别那些可能从手术干预中受益的患者。
