A Portable, Inexpensive, Nonmydriatic Fundus Camera Based on the Raspberry Pi® Computer

Abstract

Purpose. Nonmydriatic fundus cameras allow retinal photography without pharmacologic dilation of the pupil. However, currently available nonmydriatic fundus cameras are bulky, not portable, and expensive. Taking advantage of recent advances in mobile technology, we sought to create a nonmydriatic fundus camera that was affordable and could be carried in a white coat pocket. Methods. We built a point-and-shoot prototype camera using a Raspberry Pi computer, an infrared-sensitive camera board, a dual infrared and white light light-emitting diode, a battery, a 5-inch touchscreen liquid crystal display, and a disposable 20-diopter condensing lens. Our prototype camera was based on indirect ophthalmoscopy with both infrared and white lights. Results. The prototype camera measured 133mm × 91mm × 45mm and weighed 386 grams. The total cost of the components, including the disposable lens, was $185.20. The camera was able to obtain good-quality fundus images without pharmacologic dilation of the pupils. Conclusion. A fully functional, inexpensive, handheld, nonmydriatic fundus camera can be easily assembled from a relatively small number of components. With modest improvements, such a camera could be useful for a variety of healthcare professionals, particularly those who work in settings where a traditional table-mounted nonmydriatic fundus camera would be inconvenient.

A Purkinje image-based system for an assessment of the density and transmittance spectra of the human crystalline lens in vivo

“…In contrast to OCT or conventional techniques (e.g., Scheimpflug imaging 58 or double-pass aberrometry 59,60 ), a compact and low-cost device can be achieved using the Purkinje image-based technique. This is because the optical system in the Purkinje image-based technique consists of only a light source and a camera, and it could be easily miniaturized by various computing platforms such as Raspberry Pi-based system 61,62 . Although the Purkinje image-based technique cannot provide information on the detailed structure in the ocular lens unlike evaluation by OCT, the compact and low-cost device based on our technique allows for the computation of the lens transmittance over the entire visible spectrum and offers a simple investigation tool for visual and non-visual photoreception research.…”

Nonmydriatic Photographic Screening for Diabetic Retinopathy in Pregnant Patients with Pre-Existing Diabetes in a Safety Net Population: 1 Year Results from the Diabetic Retinopathy in Pregnant Patients Study

“…Alternatively, there are several new cost-effective options for portable nonmydriatic cameras (ranging from $5,000 to $10,000); however, there is still the unknown financial burden Veerappan Pasricha, et al; Women's Health Reports 2020, 1.1 http://online.liebertpub.com/doi/10.1089/whr.2020.0082 related to image and data handling. [42][43][44] Second, there is lack of uniform reimbursement policies and most do not provide competitive advantages for the providers involved. Reimbursement from commercial insurance companies, Medicare, and Medicaid for image-based evaluations of DR has been limited in the United States.…”

Measuring ocular torsion and its variations using different nonmydriatic fundus photographic methods

“…Also, pharmacological dilation tends to be inconvenient for both the medical practitioner and the patient, with the dilating drops taking about 30 minutes to take effect and the patient experiencing blurred vision and light sensitivity for up to several hours after inducing dilation. Furthermore, pharmacological dilation prevents subsequent ophthalmological and neurological examinations (e.g., of the pupils and accommodation tests) for several hours, which can be undesirable when monitoring inpatients with critical neurological diseases [ 19 ].…”

“…Wide-field imaging provides valuable information about the peripheral vasculature and other retinal lesions that might otherwise be missed when using traditional imaging systems. WFP has been used successfully in pediatric ophthalmology for evaluating various retinal disorders, such as Coat’s disease and premature retinopathy [ 19 ].…”