RED: Retinoscopy using endoscopy device

Dear Editor, Retinoscopy is a technique to acquire subjective refraction in daily clinical practice. The accuracy is directly proportionate to the skill of the retinoscopist, and teaching this skill is challenging. “Gimbalscope” is a frugal technique which enables simultaneous viewing and recording of retinoscopy reflexes by multiple observers.[1] It uses a smartphone camera to image the reflexes created by the retinoscope. However, the attachment is not sturdy and is difficult to align. Here, we describe a novel three-dimensional (3D) printed adapter called RED, which attempts to solve the problem. Innovation “Gimbalscope” described the attachment of a smartphone device to a retinoscope using a do-it-yourself stand, made by gluing together two commercially available smartphone holder clamps reinforced with rubber bands. The retinoscope is passed through one stand and the smartphone through the other. The camera is aligned with the retinoscope eyepiece and retinoscopy is performed, to allow simultaneous viewing by the performer and the observer. This stand is unstable and requires adjustments to allow accurate alignment. 3D printing is utilized to design and produce a small adaptor that can be attached onto the retinoscope. An aperture is provided for the fixation of an endoscopic camera, which aligns to the eyepiece of the retinoscope, such that the camera would act like the eye of the performing examiner. The camera would then capture the reflexes as would be seen by the examiner and would relay the visualized reflex onto a monitor. [Figs. 1 and 2]Figure 1: (a) RED – the 3D printed adaptor in various colors. (b) Retinoscope, RED, endoscopic camera with wire. (c) Preparation of the retinoscope. (d) Creation of the groove for attachment. (e) Attachment of RED onto the retinoscope. (f) Insertion of the endoscopic cameraFigure 2: (a) Retinoscopy performed with RED on a dummy eye, being telecasted via video call. (b) Neutralization of reflex using a convex lens. (c) Retinoscopy reflex as visualized through RED. (d) Neutralized reflex as visualized through REDDiscussion Retinoscopy has a steep learning curve. Teaching this skill is difficult, as the reflexes can only be observed by the person performing retinoscopy. The use of a camera can make teaching easier and more reliable. Attempts at digital retinoscopy with smartphones were attempted by Langue and Soni,[2] Chan et al.,[3] and others. Common problems faced were the complexity of adjustments, suboptimal image quality, and dependence on the camera and processing quality of the smartphone. The Gimbalscope sought to make digital recording of retinoscopy possible, but the weight of the apparatus was increased and was unstable. RED serves to solve this problem by creating a small, portable adaptor. The 3D printed device needs to be hooked on to the retinoscope, and multiple people can observe the reflexes on a screen. This makes sharing of these images easy and can facilitate creation of video-based remote learning, to serve to improve the quality of refraction in remote hospitals and point-of-contact care. The use of 3D printing made it possible to customize an adaptor that would fit our requirements. 3D printing constructs 3D objects from a model under computer control, using plastics, polymers, ceramics, or metal alloys.[4] The use of RED can extend beyond educating ophthalmic personnel. With the advent of Artificial Intelligence and complex mathematical processing, data of reflexes and refractive errors can be complied into a database. System learning can analyze the data and provide automation of the process. An attempt to automate retinoscopy has been made by Aggarwal et al.[5] Though we are far from considering this as a gold standard, it is a big step in the right direction. It makes the learning curve easier to master the skill of skiascopy.