Comparative Study Between Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty Regarding Anterior and Posterior Surface Apposition by Using Anterior Segment OCT

Abstract

Keratoconus is a vision disorder that occurs when the normally round cornea (the front part of the eye) becomes thin and irregular (cone) shaped. This abnormal shape prevents the light entering the eye from being focused correctly on the retina and causes distortion of vision. Keratoconus causes blurring and distortion of vision and increased sensitivity to glare and light. These symptoms usually appear in the late teens or late 20s. In patients with advanced keratoconus treatment options such as contact lenses or ICRS may fail to improve the CDVA often requiring keratoplasty, either lamellar or full thickness, depending on the extent of the stromal scar. PKP has traditionally been the surgery of choice for keratoconus, but nowadays lamellar techniques are the gold standard for patients with moderate to severe disease. Currently, an elective PKP is reserved for those advanced cases with hydrops or deep corneal scar involving DM. The precise apposition between the graft and host is an important goal of keratoplasty and is also a prognostic factor affecting the surgical outcome. Many studies found correlation between size of mal apposition and IOP, final refraction, keratometric cylinder,