All-digital Binocular Indirect Virtual Video Ophthalmoscope | OPTH - Dove Medical Press

Introduction

Since the instauration of the modern self-luminous binocular indirect ophthalmoscope (BIO) successful the mid-20th century, enhancements person been directed chiefly to amended illumination without overmuch alteration successful the halfway optical system.^1,2 The optical rule of BIO depends connected the simplification of the interpupillary region (IPD) of the examiner by means of mirrors and/or prisms to let the examiner’s ocular axes of some eyes to simultaneously person airy rays bouncing backmost done the patient’s pupil. Light rays coming backmost from the ocular fundus are collimated by indirect ophthalmoscopy lens to signifier a real, inverted and laterally reversed representation betwixt the diligent and the examiner. Performing and anatomically interpreting a BIO introspection is simply a accomplishment which ophthalmology trainees make during their residency grooming programs.³ Conventional BIOs are not susceptible of capturing videos and images of the examination. Video enabled BIO devices are commercially disposable astatine a higher cost, are bulkier and let 2D capturing of videos and inactive images of the ophthalmoscopy introspection by means of an integrated integer camera^4–6 The limitations of presently disposable video enabled BIO devices see imaginable decentration of the captured representation from the presumption of the examiner that requires predominant adjustments⁴ and the deficiency of stereovision of the recordings arsenic they supply 2 dimensional (2D) alternatively than stereoscopic 3D images. Herein, we picture a caller plan of an all-digital video signaling enabled BIO prototype that provides stereoscopic 3 dimensional (3D) signaling of the ocular fundoscopy representation with the imaginable of real-time anatomical correction.

Methods

This prospective observational aviator survey was approved by the quality probe morals committee of the Research Institute of Ophthalmology, Giza, Egypt, and was performed successful accordance with each section laws and successful compliance with the principles of the Declaration of Helsinki. A written informed consent was obtained from each survey participants. The prototype utilized successful this survey consists of a generic LED airy root and 2 synchronized 15 mm isolated side-by-side minicameras. The minicameras are connected to a processor, retention media (a Samsung note-9 android smartphone successful the existent prototype), and a virtual world acceptable (VISIONHMD Bigeyes H1 3D Video Glasses, successful the existent prototype) (Figure 1). The synchronized dual cameras were configured to export their captured video to the Samsung note-9 telephone by means of a connecting console (Samsung Dex Dock Station). A custom-made android exertion was designed to seizure the introspection media from the dual camera truthful that the close camera projects to the close fractional of the surface and the near camera projects to the near fractional of the surface to make a side-by-side stereogram. The bundle besides allows optional real-time anatomic correction of the introspection presumption by touching a surface fastener oregon via a wired distant shutter. Examination media are past projected to the virtual world acceptable truthful that the representation of the close camera is projected to the close broadside of the virtual world glasses and is seen by the examiner’s close oculus and the near representation from the near camera is projected to the near broadside of the virtual world glasses and is seen by the examiner’s near eye.

Figure 1 (A) A schematic diagram and (B) existent prototype of the all-digital binocular indirect virtual video ophthalmoscope prototype featuring its creation from 2 minicameras, a airy source, virtual world set, a connecting console, and a smartphone.

The prototype was archetypal tested and adjusted connected 3 antithetic schematic eyes including Ocular Imaging Eye Model (Ocular Instruments inc. Bellevue, WA, USA), RetCam Digital Retinal Camera Practice Kit (Massie Research Laboratories Inc., Pleasanton, CA, USA), and Reti Eye Model (Gulden Ophthalmics, Elkins Park, PA, USA). The LED airy was tested for its information to the quality oculus successful presumption of airy strength and spectrum. Light strength was 3.8 mW/cm² (safe limits are astatine slightest 1 bid of magnitude beneath the information bounds acceptable by the ISO15004-2.2 which is 706 mW/cm²)^7,8 and airy spectrum fell wholly successful the harmless disposable spectrum with nary ultraviolet oregon infrared composition.

Binocular, stereoscopic indirect ophthalmoscopy was past attempted connected 15 eyes of 15 patients successful a dim airy information aft dilation of the pupils with Tropicamide 1% eyedrops without and with integer real-time anatomic correction of the introspection view. Collateral video output was attempted to different virtual world acceptable for observers to presumption successful 10 patients and to an extracurricular show successful 5 patients.

Results

Binocular, virtual, stereoscopic indirect ophthalmoscopic introspection could beryllium successfully tested connected the 3 schematic exemplary eyes utilizing this prototype successful conjunction with a +20 diopter indirect ophthalmoscopy lens.

Binocular video stereo ophthalmoscopic media could beryllium obtained successful each patients (n = 15). Anatomic correction of the introspection presumption was achieved successful each patients (n = 15) (Figure 2 and Supplementary Video). A collateral acquisition presumption could beryllium simultaneously streamed successful each patients either to different acceptable of virtual world glasses (10 patients retired of 10) and to a show surface (5 patients retired of 5).

Figure 2 Indirect retinal photography showing (A) optic disc, (B) macular, and (C) peripheral retinal pathologies.

Discussion

The purpose of this enactment was to analyse the feasibility of indirect binocular ophthalmoscopy utilizing a recently designed all-digital, binocular indirect ophthalmoscope that replaces the accepted optical strategy of BIO by 2 side-by-side minicameras. This achieves the extremity of decreasing the examiner’s IPD and allowing virtual binocular indirect simultaneous visualization done the pupil of the taxable and projects 2 images of the ocular fundus presumption to the corresponding surface of a virtual world set. This allows the examiner to spot the ocular fundus virtually and binocularly successful real-time.

Conventional BIOs are not susceptible of signaling the introspection successful pictures oregon videos. Video enabled BIOs are disposable astatine markedly higher cost, are bulkier successful size, supply 2D recordings and whitethorn beryllium constricted by the decentration of the presumption of the camera comparative to the examiner’s presumption that requires predominant adjustments.⁴ In our design, the video introspection of the ocular fundus seen by the examiner is simultaneously recorded successful stereoscopic 3D side-by-side format.

The representation of the ocular fundus seen by the examiner is inverted and laterally reversed comparative to the existent anatomic predisposition successful accepted BIO examination.¹ Using our described design, anatomic correction of the presumption of the introspection is achievable during the real-time introspection by digitally horizontally reversing and vertically inversing each of the 2 side-by-side images of the ocular fundus examination. Although the accomplishment of anatomical mentation of the BIO representation is usually mastered during the residency grooming years,³ providing the enactment of an anatomically corrected presumption whitethorn marque this portion of a BIO introspection much convenient.

Ophthalmology trainees tin observe the ophthalmoscopy introspection findings done an accessory teaching reflector attached to the beforehand of the accepted BIO devices. These teaching mirrors supply a 2D representation of the examiners view⁹ that tin beryllium seen by the trainee successful a constrictive model betwixt the examiner and the diligent which whitethorn beryllium inconvenient to the patient. In video enabled BIOs, trainees tin ticker the introspection findings successful 2D successful real-time oregon aft the introspection connected a connected monitor.⁵ Kong et al, described utilizing 2 accessory cameras with the accepted BIO to supply the trainees with a 3D view.¹⁰ This makes the BIO bulkier, heavier to enactment connected and does not forestall decentration of the trainees’ presumption from the presumption seen by the examiner. Our plan provides the ophthalmology trainees with a real-time stereoscopic 3D presumption of the ophthalmoscopy identical to the presumption seen by the examiner. The introspection tin besides beryllium captured successful 2D oregon successful 3D for documentation and for objective education. Limitations of our existent provisional prototype see the usage of commercially disposable affordable minicameras and virtual-reality headset since our purpose astatine this constituent was conscionable to beryllium the concept. We deliberation that the presumption tin beryllium made superior to this and the instrumentality tin beryllium much compact if the minicameras tin beryllium upgraded and custom-designed.

Conclusion

We picture a caller plan of a video signaling enabled BIO instrumentality that replaces the analyzable optical strategy of accepted BIO with 2 intimately placed side-by-side minicameras. Advantages of this caller plan see optional real-time anatomic correction of the examiner’s presumption of the ocular fundus and optional identical signaling of the examiner’s BIO presumption successful stereoscopic 3D arsenic good arsenic successful 2D which tin heighten objective documentation and education.

Data Sharing Statement

Data utilized successful this survey is disposable from the corresponding writer upon tenable request.

Ethics Approval and Consent to Participate

This study was approved by the Research Institute of Ophthalmology Research Ethics Committee and followed the tenets of the Declaration of Helsinki. A written informed consent was obtained from each participating patients.

Acknowledgments

The plan described successful this nonfiction is related to a pending planetary patent for Dr Omar Solyman (PCT # PCT/US2021/071604).

Funding

There is nary backing to report.

Disclosure

Dr Omar Solyman initiated a commencement up of ophthalmology related hardware and bundle solutions for Wadjet: the Eye Gadget. The plan of the prototype described successful this nonfiction is related to a pending planetary patent for Dr Omar Solyman (PCT # PCT/US2021/071604). The authors study nary different conflicts of involvement successful this work.

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