The overall prevalence of pterygium was found to be higher in Ta’if than in Al-Khobar (2.4% and 0.074%, respectively), which may be attributed to the high prevalence rate of pterygium in the populations living at higher altitudes who are exposed to high levels of UVB sunlight [7], as UV radiation can cause mutations in genes such as the P53 tumor-suppressor gene, resulting in its abnormal expression in the pterygial epithelium in a manner suggesting uncontrolled cell proliferation [13-15]. Here, TP53 is linked to pterygium.