The aim of this study is to survey the astigmatism type in patient with pterygium.Pterygium is a most known illness in ophthalmology diseases and occur in triangle shape prominent mass from a thick bulbar conjunctiva with expansion on the cornea

All patients with pterygium assigned for study (non-randomize) and their astigmatism type and it's degree determined. Patients' information aggregated into the standard checklists including their demographic data ,rural and urban habitancy ,occupation ,determined astigmatism type and value with refractometer (with/against-the-rule). Collected data analyzed by SPSS v.16 software and also descriptive statistics (frequency percentage ,mean and variance indices). For determining the correlation between pterygium and astigmatism type ,chi-square test was applied.

100 patients including 55 males (55%) and 45 females (45%). 32 (32%) patients with right eye,38 (38%) left eye and 30 (30%)patients with both eyes pterygium is seen. Comparing astigmatism type in the normal eye and eyes involved with pterygium show that; from the 130 eyes with pterygium ,83 (63/8%) eyes with withthe- rule astigmatism , 13(10%) eyes with against-the-rule astigmatism and 34 (26/2%) eyes with oblique astigmatism are seen. From the 67 normal eyes ,30 (44/8%) eyes with with-the-rule astigmatism ,12 (17/9%) eyes with against-the-rule · astigmatism ,and 25 (3 7/3%) eyes with oblique astigmatism are seen. Regarding to the chi-square analyze , astigmatism type in normal eye and eye with pterygium differ significantly (P=0.01). The mean astigmatism value in 130 eyes with pterygium is -1/52+/-1/32 and in 67 normal eyes is -1104+/-1/41 diopter. Regarding to the t-test results astigmatism mean value in normal eye and eye with pterygium differ significantly (P=O.Ol). Pterygium cause the with-the-rule astigmatism and seriously affect the astigmatism value.

Pterygium is one of the popular eye disease that cause Astigmatism, vision imitations and cosmetic problems. Among the general symtoms and signs of Pterygium are red eye, photophobia, tearing and decreased vision due to improvements to visual axis, Astigmatism and visual field restriction. In our study, 83% of Astigmatisms were with the rule Astigmatism and there was significant statistical difference between Astigmatisms in control and Pterygium eyes.