Pterygium is one of the common ocular surface disorders , it's is an elastotic triangular fibro-vascular tissue covered by conjunctival epithelium that spreads over the cornea. Pterygium causes differences in curvature & power across the cornea .~The prevalence of pterygium varies from 1.1% to 53% globally in different environmental conditions. Risk factors include;UV radiation, geographical latitude near to the equator, outdoor activity , aging, male, and dusty environment.~Pterygium excision is important in patients suffering from blurred vision due to astigmatism . Surgical techniques include ; bare sclera excision, conjunctival autograft, conjunctival transpositional flap, and amniotic membrane grafting. Pterygium excision increases in the mean central corneal curvature & reduces astigmatism that leads to improvement in visual acuity.~Corneal topography is a gold standard in corneal pathology follow-up. Corneal topography is a computer assisted diagnostic tool that creates a three-dimensional map of the surface curvature of the cornea. Corneal topography produces a detailed, visual description of the shape and power of the cornea.~In this study , corneal topography is used to detect how does corneal curvature change after excision of pterygium .
Aim of the work:~To study the corneal topographic pattern changes in patients who have pterygium excision by two surgical techniques (bare sclera, conjunctival autograft).