Evaluation of the Performance of a 3D-Printed Smartphone-Based Retinal Imaging Device as a Screening Tool for Retinal Pathology in Mozambique.

Low-income countries carry approximately 90% of the global burden of visual impairment, and up to 80% of this could be prevented or cured. However, there are only a few studies on the prevalence of retinal disease in these countries. Easier access to retinal information would allow differential diagnosis and promote strategies to improve eye health, which are currently scarce. This pilot study aims to evaluate the functionality and usability of a tele-retinography system for the detection of retinal pathology, based on a low-cost portable retinal scanner, manufactured with 3D printing and controlled by a mobile phone with an application designed ad hoc. The study was conducted at the Manhiça Rural Hospital in Mozambique. General practitioners, with no specific knowledge of ophthalmology or previous use of retinography, performed digital retinographies on 104 hospitalized patients. The retinographies were acquired in video format, uploaded to a web platform, and reviewed centrally by two ophthalmologists, analyzing the image quality and the presence of retinal lesions. In our sample there was a high proportion of exudates and hemorrhages-8% and 4%, respectively. In addition, the presence of lesions was studied in patients with known underlying risk factors for retinal disease, such as HIV, diabetes, and/or hypertension. Our tele-retinography system based on a smartphone coupled with a simple and low-cost 3D printed device is easy to use by healthcare personnel without specialized ophthalmological knowledge and could be applied for the screening and initial diagnosis of retinal pathology.

Possible Intraluminal Obstruction of the XEN45 Gel Stent Observed With Anterior Segment Optical Coherence Tomography.

PURPOSE: We herein describe possible intraluminal obstruction because of a hyperreflective material found in anterior segment optical coherence tomography (AS-OCT) in 16 of 46 cases with XEN45 gel stent. MATERIALS AND METHODS: This is a retrospective case series of 46 eyes of 39 patients with noncomplicated XEN45 gel stent surgery, analyzed with AS-OCT and slit-lamp photography after at least 6 postoperative months. RESULTS: Possible luminal obstruction in the subconjunctival segment of the implant was observed in 16 eyes of 15 patients, characterized by hyperreflective material on AS-OCT, which was not visible in slit-lamp photography. This was found in 15 eyes following combined procedures and in 1 eye following XEN45 alone. None showed signs of filtering bleb on AS-OCT or slit-lamp photography. In 1 case, the discontinuity between the hyperreflective material and subconjunctival opening of the implant tube was evidenced, and in another case, a focal deposit in the intracameral end of the implant was seen. CONCLUSIONS: We have successfully described the lumen implant deposit of material as a possible cause of late failure of the implant. AS-OCT allows the identification of such cases and may be useful to plan further postoperative interventions for better patient outcomes.