The Orbscan II allows us to pick up cases of posterior keratoconus and other subtle corneal irregularities that may preclude a good refractive outcome. It can also help us to better understand some of the visual aberrations that our patients experience. In addition to screening refractive surgery patients, the devices are becoming the standard of care, from fitting contact lenses in difficult cases to diagnosing corneal pathology to assessing central corneal power for intraocular lens calculations. In refractive surgery, for example, the scanning slit system, if accurate, is important because it measures corneal thickness. Pachymetry has always been a critical point for refractive surgeons in avoiding inadvertent penetration into the anterior chamber.
Clinical Tips Make corneal topography the first measurement.
Use a standard, fixed scale. Quality control mire tracking. Repeat the exam if mistracking occurs. Confirm good focus and adequate patient fixation. Be sure you personally evaluate the exam and understand it to make the appropriate medical recommendation.