Clinical Refraction Guide Ajay Kumar Bhootra
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81RETINOSCOPY GUIDE
  • Introduction
  • Retinoscopy and Autorefractometer
  • Parts of Retinoscope
  • Optical Principle of Retinoscope
  • Heine Beta 200 Retinoscope
  • Choosing the Working Distance
  • Patient and Practitioner Posture
  • Projecting the Light Beam
  • The Reflex
  • Spherical and Astigmatic Reflex
  • Movement of the Reflex
  • Correcting Lens
  • Neutralization
  • Estimating Cylinder Axis
  • Straddling the Axis
  • Retinoscopy Results
  • Step by Step Procedure
  • Case Studies
  • Tips for Difficult Retinoscopy
  • Additional Application of Retinoscopy
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IntroductionChapter 24

Retinoscopy is an objective method to determine the refractive status of the eye with respect to the point of fixation. If the point of fixation is at a close distance, it is called “Near Retinoscopy” or “Dynamic Retinoscopy” and if it is at a long distance, it is called “Static Retinoscopy”. In order to determine the refractive status of the eye, it projects the light beam onto the retina through the pupil. When the light beam focuses onto the retina, the direction of light travel is reversed. The observer sees the light reflex coming from the pupil through peephole in the scope and determines the refractive error by observing the behavior of the reflex under certain condition. Thus the results of the retinoscopy are not dependent upon the patient's response. The basic principles of retinoscopy for both static retinoscopy and dynamic retinoscopy are common.
 
IMPORTANCE OF RETINOSCOPY
Since the introduction of retinoscopy as a clinical procedure for eye examination, it has been performed as one of the very first procedures during the eye examination. It is a great tool to establish a strong basis for the refractive status of the eye on which subjective refraction can be followed. In addition retinoscopy helps to detect the aberrations of the cornea and the crystalline lens. It also provides some clues in respect of opacities of ocular media. Retinoscopy is particularly very helpful tool 84with uncooperative or malingering patients, infants, deafs and in all such cases where language or communication creates difficulties during the process of refraction.