الفهرس 
Basic optics for IOL power calculationsOnly 14 pages are availabe for public view
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Abstract
Since intraocular lenses were first introduced, science has never stopped developing IOL power calculations and biometric methods. The formulas for IOL calculations passed through consecutive stages of modification and optimization, according to increasing patients’ needs and desired emmetropic refraction outcome. This was always limited by available biometric techniques at each time.
As all modern formulas include constants varying between axial length, anterior chamber depth, estimated lens position, K-readings, etc., the need for highly developed instruments and recent precisive appliances has emerged into concern.
A-scan biometers were the first to be used either contact, non-contact or B-mode guided, depending on ultrasonic waves. In 1999, a new era of optical biometry and imaging began through the IOLMaster using the partial coherence interferometry.
The most recent biometric technology is the Pentacam, using light and rotating Scheimpflug camera to capture 3-D images of the whole anterior segment with modern software to calculate anterior chamber depth, corneal thickness, anterior corneal curvature, posterior corneal curvature and lenticular thickness.
A huge number of studies were done to evaluate and compare different formulas, biometric methods and instruments.
Recent technologies together with increasing surgical skills gave rise to the ability to accurately calculate IOL power in patients whom underwent corneal refractive surgeries and developed cataracts afterwards.
It is research that keeps us always rise with science and improve patients’ surgical refractive outcome.