ABSTRACT
Purpose: To suggest a low cost, non-contact smartphone-based screening system in retinopathy of prematurity (ROP), and to illustrate its potential clinical application as a potential future tool for teleophthalmology. Methods: Neonatal intensive care unit (NICU)-based bedside ROP screening done between January 2018 and May 2018. Documentation of ROP was done by using a smartphone and +40D, +28D, or +20D indirect non-contact condensing lenses. By using the coaxial light source of the phone, this system works as an indirect ophthalmoscope that creates a digital image of the fundus. With smartphone-based camera we extracted high-quality still images extracted from the video clip. Results: Total of 228 eyes of 114 infants screened for ROP between January 2018 and May 2018. Incidence of total ROP was 23.68%, out of which incidence of type 1 ROP was 8.77%. After initial screening with indirect ophthalmoscope, we uesd smartphone imaging to document ROP in 28 eyes out of 55 eyes having ROP. Image quality was good in 89.28% eyes. Field of view vary from 46°, 53°, and 90° with +20D, +28D, and +40D indirect condensing lenses, respectively, which gives excellent images for bedside ROP documentation. Conclusion: The described technique of smartphone fundus photography is a light weight, cost-effective, user friendly, high-quality wide-field fundus photographs for bedside documentation of ROP in NICUs using readily available instruments that are handy and portable with simple power sources. Smartphones has the potential to be operated with only one hand. It can also be used as a future telescreening device.
ABSTRACT
Purpose: The purpose of this study is to describe in detail the procedure of performing indirect ophthalmoscopy using any smartphone along with instruments that are readily available in ophthalmic practice. Materials and Methods: The procedure was performed with a smartphone and a 20D or 28D lens. Using the flashlight of the phone as a coaxial light source, the system works as an indirect ophthalmoscope where the camera creates a digital image of the ocular fundus on the phone screen through the condensing lens. High definition videos of the fundus were recorded using the inbuilt video recorder of the phone, and subsequently good quality fundus images were extracted from the video clips. Results: With the described technique of smartphone indirect ophthalmoscopy, we were able to carry out basic screening of the ocular fundus without using a direct ophthalmoscope, slit lamp biomicroscopy or indirect ophthalmoscope. It also proved to be an excellent tool for documentation of fundus pathologies through good quality images. Conclusion: The described technique is an easy and inexpensive way to photograph the fundus in patients using readily available portable instruments. Commercially available fundus cameras are outside the reach of many practitioners and institutes. Hence, the method seems to be a good tool for basic screening and documentation of fundus pathologies. With a small learning curve, it is relatively simple to master and takes advantage of the expanding mobile-telephone networks for telemedicine.