Clinical Validation of a Smartphone-Based Adapter for Optic Disc Imaging in Kenya

Abstract

Importance Visualization and interpretation of the optic nerve and retina is an essential part of most physical examinations. Objectives To design and validate a smartphone-based retinal adapter enabling image capture and remote grading of the retina Design, setting and participants Validation study comparing the grading of optic nerves from smartphones images with those of a Digital Fundus Camera. Both image sets were independently graded at Moorfields Eye Hospital Reading Centre. Nested within the six-year follow-up of the Nakuru Eye Disease Cohort in Kenya: 1,460adults (2,920eyes) aged 55years and above were recruited consecutively from the Study. A sub-set of 100 optic disc images from both methods were further used to validate a grading app for the optic nerves. Main outcome(s) and measure(s) Vertical cup-to-disc-ratio (VCDR) for each test was compared, in terms of agreement (Bland-Altman & weighted Kappa) and test-retest variability (TRV). Results 2,152 optic nerve images were available from both methods (additionally 371 from reference but not Peek, 170 from Peek but not the reference and 227 from neither the reference camera or Peek). Bland-Altman analysis demonstrated a difference of the average of 0.02 with 95% limits of agreement between -0.21 and 0.17 and a weighted Kappa coefficient of 0.69 (excellent agreement). An experienced retinal photographer was compared to a lay photographer (no health care experience prior to the study) with no observable difference in image acquisition quality between them. Conclusions and relevance Non-clinical photographers using the low-cost Peek Retina adapter and smartphone were able to acquire optic nerve images at a standard that enabled comparable independent remote grading of the images to those acquired using a desktop retinal camera operated by an ophthalmic assistant. The potential for task-shifting and the detection of avoidable causes of blindness in the most at risk communities makes this an attractive public health intervention.

Prevalence and severity of ocular surface Neoplasia in African nations and need for early interventions

“…These applications have been shown to safely and effectively diagnose various ophthalmic conditions ranging from the anterior segment to the posterior segment, including visualization of the optic nerve and even detailed measurements of toric intraocular lens alignment. [272829] Use of smart phone technology would provide a user-friendly and accessible way for health professionals in remote settings to transmit images for second opinions and to more rapidly and accurately diagnose OSSN. These strategies can hopefully lead to earlier diagnosis and earlier, less invasive interventions for OSSN, particularly in places such as East Africa where there is limited access to specialists.…”

Raised intracranial pressure in those presenting with headache

“…Instruments that might be easier to use than the standard direct ophthalmoscope include the PanOptic ophthalmoscope (Welch Allyn),9 and the Arclight, a pocket ophthalmoscope 10. Another option is fundus photography, using (for example) the Peek Retina, a smart phone attachment,11 or a non-mydriatic camera 12. If there is doubt regarding the examination or imaging findings seek review from an experienced ophthalmologist or optometrist, specifically asking for comment on the presence or absence of papilloedema,13 as ophthalmoscopy is a common diagnostic error in patients with headache12 and those with idiopathic intracranial hypertension 14…”

Clinical Application of a Smartphone-Based Ophthalmic Camera Adapter in Under-Resourced Settings in Nepal

“…14 Teleophthalmology has been shown to be an effective tool for diagnosing diabetic retinopathy and macular edema 15 well before the advent of high resolution smartphone cameras, and these above studies suggest an emerging role for smartphones for this purpose. In addition, Kanagasingam et al (1999) and Bastawrous et al (2016) evaluated the potential for teleophthalmologic diagnosis and screening of glaucoma using a portable fundus camera and smartphone-based retinal adapter, respectively, and found the camera and smartphone adapter provided similar reliable diagnostic results. 16,17 Thus, there is a growing consensus about the potential for smartphone-based imaging to enhance teleophthalmology.…”

“…In addition, Kanagasingam et al (1999) and Bastawrous et al (2016) evaluated the potential for teleophthalmologic diagnosis and screening of glaucoma using a portable fundus camera and smartphone-based retinal adapter, respectively, and found the camera and smartphone adapter provided similar reliable diagnostic results. 16,17 Thus, there is a growing consensus about the potential for smartphone-based imaging to enhance teleophthalmology.…”