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Wednesday 2 January 2013

[opto] MOHINDRA RETINOSCOPY TECHNIQUE

MOHINDRA RETINOSCOPY TECHNIQUE

Introduction
Mohindra retinoscopy has been introduced by Mohindra (1977, 1980). This is a technique of near retinoscopy that are very beneficial in determining the refractive errors of infants or children. Some studies have shown a good correlation between this technique and cycloplegic retinoscopy.

Equipment
Retinoscopy      and lens rack    

Procedure
1.    The examiner should be 50cm from patient. During this procedure, the examiner may use the same eye to examine both eyes of patient.
2.    The room illumination should be completely dark.
3.    Set the intensity of the retinoscopy to a level that allows for observation of the reflex without being aversive to patient.
4.    Sit in front of patient. Mother can hold the child if the child can not sit.
5.    Occlude the left eye and test the right eye. Patient is instructed to look at the light. For infant, usually they tend to look at the light automatically, but if it is not happen, stimulate the child’s attention by making sounds.
6.    Shine the light to the eye, and  observe the principal meridian. Then use lens rack to neutralizes each meridian and identify the power.
7.    Calculate the retinoscopy finding in minus cyl form.
8.    After that, add -1.25D sphere to the spherical component of the finding. The resultant sphero-cylinder represents the patients correction.
a.    -1.25D represents a constant number for lag of accommodation
9.    Repeat the procedure for the other eye.

Overview
Studies have shown that the more hyperopic an infant is the less accurate Mohindra becomes when compared to cycloplegic retinoscopy. If infants exhibit esophoria or esotropia it appears to also not show a good correlation with the actual amount of hyperopia present.

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