Effective low-cost pediatric vision screening by naive nonophthalmic examiners using the 'Arclight' device.

PURPOSE: To explore whether a low-cost ophthalmoscope (Arclight) can be used by naive nonophthalmic examiners to effectively screen for pediatric eye disease. METHODS: Fifty-four children (108 eyes) were examined by five medical students using an Arclight. Gold standard examination was performed by an ophthalmologist using a slit lamp and indirect ophthalmoscope. Examinations performed included ophthalmoscopy of the optic disc, estimation of the cup-to-disc ratio (CDR), corneal light reflex test (CRT), Bruckner's reflex test (BRT), and evaluation of refractive error. We determined the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the nonophthalmologist's Arclight exam compared to the gold standard findings of comprehensive evaluation by pediatric ophthalmologists. RESULTS: Using the Arclight, the optic nerve exam was successfully completed in 65% of patients. CDRs above and below 0.5 could be determined with 66.7% sensitivity and 84.4% specificity. Arclight CRT measurements were significant (P < .00001) predictors of strabismus, with 80% sensitivity, 95.1%, specificity, 80% PPV, and 95.1% NPV. BRT was not a significant predictor of amblyopia, with a 34.6% sensitivity, 85.7% specificity, 69.2% PPV, and 58.5% NPV. Refractive error was estimated with a success rate of 81% for emmetropia, 38% for myopia, and 21% for hyperopia. The Arclight ease-of-use was rated on average as 4.4 (SD = 0.9) on a scale of 1 to 5, with 1 being the hardest and 5 being the easiest. CONCLUSIONS: Our study shows the Arclight as an affordable and effective alternative to the traditional ophthalmoscope for assessing eye disease in children. This device can improve eye health services in under-resourced regions.

Optimization of a Novel Automated, Low Cost, Three-Dimensional Photogrammetry System (PHACE).

Introduction: Clinical tools are neither standardized nor ubiquitous to monitor volumetric or morphological changes in the periorbital region and ocular adnexa due to pathology such as oculofacial trauma, thyroid eye disease, and the natural aging process. We have developed a low-cost, three dimensionally printed PHotogrammetry for Automated CarE (PHACE) system to evaluate three-dimensional (3D) measurements of periocular and adnexal tissue. Methods: The PHACE system uses two Google Pixel 3 smartphones attached to automatic rotating platforms to image a subject's face through a cutout board patterned with registration marks. Photographs of faces were taken from many perspectives by the cameras placed on the rotating platform. Faces were imaged with and without 3D printed hemispheric phantom lesions (black domes) affixed on the forehead above the brow. Images were rendered into 3D models in Metashape (Agisoft, St. Petersburg, Russia) and then processed and analyzed in CloudCompare (CC) and Autodesk's Meshmixer. The 3D printed hemispheres affixed to the face were then quantified within Meshmixer and compared to their known volumes. Finally, we compared digital exophthalmometry measurements with results from a standard Hertel exophthalmometer in a subject with and without an orbital prosthesis. Results: Quantification of 3D printed phantom volumes using optimized stereophotogrammetry demonstrated a 2.5% error for a 244µL phantom, and 7.6% error for a 27.5µL phantom. Digital exophthalmometry measurements differed by 0.72mm from a standard exophthalmometer. Conclusion: We demonstrated an optimized workflow using our custom apparatus to analyze and quantify oculofacial volumetric and dimensions changes with a resolution of 244µL. This apparatus is a low-cost tool that can be used in clinical settings to objectively monitor volumetric and morphological changes in periorbital anatomy.