Corneal Topography

The cornea is the anterior transparent optical element of the eye. It plays a vital role in focusing the rays of light on the retina. It contributes to two-thirds of the total refractive power of the eye. In Greek, “topos” means “place” and “graphien” means “to write.” Topography relates to studying a surface. Corneal topography was developed as a technique to analyze the anterior surface of the cornea. Traditionally, topography refers to a two-dimensional representation of the corneal surface. In contrast, “tomos” means “section”; corneal tomography is a three-dimensional representation of the cornea derived from the anterior and the posterior surfaces of the cornea [1]. A good understanding of the principles of corneal topography and tomography and the ability to interpret these images accurately is crucial to diagnose corneal disorders such as keratoconus, pellucid marginal degeneration, keratoglobus, regular or irregular astigmatism, or corneal ectasia following refractive surgery. With the recent increase in the number of people opting for refractive surgery, corneal topography has become an indispensable tool for screening them for their eligibility and determining the procedure of choice.