Special Types of Retinoscopy

Dynamic Retinoscopy

In this type of Retinoscopy, accommodative target is present. Patient is instructed to look at the accommodative target and performing the Retinoscopy. There are different types of Dynamic Retinoscopy. Among them, one is Monocular Estimation Method or MEM Retinoscopy [1]. Monocular Estimation Method In this procedure, opaque aperture with central hole is attached to Streak Retinoscope. Some numbers of optotypes are written around the hole and patient is instructed to look at that letters/optotypes. While patient is looking at the optotypes, neutralization should be achieved. By this value, practioner is able to know the accommodative status of the patient [2].

To achieve Neutralization, plus power is used. If neutralization is achieved within the range of +0.50 Ds to +1.25 Ds, then Accommodative status is normal. If Neutralization is achieved by the use of +1.50 Ds , then it is considered as “Accommodative Insufficiency”. If Neutralization is achieved by the use of -0.25 Ds lens, then it is considered as “Accommodative Stimulus of over Accommodation”

Near Retinoscopy

It is also known as “Mohindra Technique.” Usually, in this method, cycloplegic drugs are used. This procedure is performed in complete dark room. Patient is instructed to look at the Retinoscopic light and like this room light will be enlighten by Retinoscopic light. “-1.25” will always be added to the Neutralization value. Eg. If Neutralization is achieved at +4.00 Ds then, Near Retinoscopy value will be [+4.00 + (-1.25)] = +2.75 D. This procedure is performed monocularly [3].

Chromo Retinoscopy

Chromo means colour. During distance Retinoscopy, i.e. patient is instructed to look 6/60 letter, on that time “red light” is used. When patient is instructed to look at the Accommodative target, on that time, green light is used in Retinoscopy. This method is not much popular like other Retinoscopy.

Radical Retinoscopy

This Retinoscopy is performed in case of media opacities like corneal opacity, cataract etc. Observers have to move closer to the patient and perform the Retinoscopy. Distance should be 20 cm or less.

String Retinosocopy

Here, string is attached to the Retinoscope and coloring beads are attached to the string. Here, patient is instructed to look at the distant target. If Retinoscopy is performed at 33cm and Neutralization is achieved with +3.00 Ds lens, it means patient is emmetropic. If Retinoscopy is performed at 50 cm and Neutralization is achieved, it means patient is Hypermetropic because +2.00 Ds lens is required for Neutralization.