Laser corneal refractive surgery is based on the use of a laser (typically an excimer one) to change the corneal curvature to compensate for refractive errors of the eye1. It has become the most successful technique, mainly due to the submicron precision and the high repeatability of the ablation of the cornea accompanied by minimal side effects. One of the most significant side-effects in myop...

O ver the years, refractive surgeons have devised strategies for coping with some of the more common complications that can occur after LASIK. Nonetheless, ectasia, a condition characterized by a progressive increase in corneal curvature, remains somewhat of a mystery. Its most likely causes appear to be undetected preoperative keratoconus and excessively deep keratectomies. This article presen...

PURPOSE To present the authors' long-term experience of radial keratotomy (RK) for the optical rehabilitation of patients with mild to moderate keratoconus--central corneal thickness of greater than 400 microm and without apical scarring. METHODS In this observational, noncomparative series of cases, all consecutive patients with mild or moderate keratoconus, treated by RK between 1990 and 20...

PURPOSE To describe the corneal and anterior segment determinants of posterior corneal arc length (PCAL) and posterior corneal curvature (PCC). METHODS Cross-sectional, population-based study of 1069 subjects (1069 eyes) aged 40-80 years, from three major Asian ethnic groups. All underwent anterior segment optical coherence tomography imaging and analysis with Zhongshan Angle Assessment Progr...

Methodological aspects of multivariate statistical models to describe and to assess data from computer-analyzed corneal topographers (CACT) are considered. The data generated by repeated curvature mappings of calibrated steel balls are discussed in detail with the objective of formulating the basic questions and suggesting directions to assess data from clinical applications of CACT. The interp...