Conjunctival examination for trachomatous inflammation-follicular (TF) guides public health decisions for trachoma. Smartphone cameras may allow remote conjunctival grading, but previous studies have found low sensitivity. A random sample of 412 children aged 1-9 years received an in-person conjunctival examination and then had conjunctival photographs taken with 1) a single-lens reflex (SLR) camera and 2) a smartphone coupled to a 3D-printed magnifying attachment. Three masked graders assessed the conjunctival photographs for TF. Latent class analysis was used to determine the sensitivity and specificity of each grading method for TF. Single-lens reflex photo-grading was 95.0% sensitive and 93.6% specific, and smartphone photo-grading was 84.1% sensitive and 97.6% specific. The sensitivity of the smartphone-CellScope device was considerably higher than that of a previous study using the native smartphone camera, without attachment. Magnification of smartphone images with a simple attachment improved the grading sensitivity while maintaining high specificity in a region with hyperendemic trachoma.

Background Improvements in technology could facilitate task-shifting and ocular disease screening in rural areas. Methods Visual acuity (VA) was tested using a Ministry of Health 3-m VA card. Anterior segment photographs were taken using a three-dimensional printed cellphone attachment and remotely graded. Results Of 326 photographed eyes, 1 was ungradable. Of 123 eyes with non-refractive visual impairment, cataract was identified in 35.8%, pterygium in 41.5%, corneal opacity in 5.7% and phthisis in 2.4%. Conclusions While the cause of visual impairment cannot be determined without a posterior segment examination, the smartphone attachment proved to be easy to use by non-specialist workers and identified anterior segment pathology in most cases.