The relation between pterygium size and refractive astigmatism among a group of patients in Erbil city
DOI:
https://doi.org/10.15218/zjms.2018.019Keywords:
Pterygium, Size, Refractive astigmatism, ErbilAbstract
Background and objective: A pterygium is a triangular fibrovascular subepithelial ingrowth of degenerative bulbar conjunctival tissue over the limbus onto the cornea. Excision is indicated if the pterygium approaches the visual axis, causing loss of vision from irregular astigmatism or in cases of considerable irritation. This study aimed to determine the percentage of astigmatism in patients presented with pterygium and measure the effect of size (width and height) of pterygium on a degree of astigmatism and indication of early surgery.
Methods: A hospital based cross-sectional study using non-probability convenience sampling was conducted in the ophthalmology department of Rizgary and Erbil teaching hospital in Erbil city from June 2015 to February 2016. Ninety-six eyes of eighty patients with pterygium were included in this study.
Results: The mean age ± SD of the 80 patients included in the study was 37.5 ± 9.62 years ranging from 22-58 years. There were 45 male and 35 female patients. Two-thirds of eyes (72.6%) had with-the-rule astigmatism while 12.6 % of eyes had against-the-rule astigmatism. A highly significant strong correlation was seen between a fraction of corneal area encroached by pterygium with induced astigmatism (r = 0.727, P <0.001). A highly significant strong correlation was found between the area of pterygium and corneal astigmatism in a case of severe pterygium (pterygium encroaching > 4 mm area on the cornea) (r = 0.802, P <0.001).
Conclusion: Pterygium size has a significant correlation to the amount of induced astigmatism. The correlation is stronger in the pterygia of severe degree (>4 mm) as in this group they are encroaching on the visual axis.
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