A novel smartphone ophthalmic imaging adapter: User feasibility studies in Hyderabad, India

Abstract

Aim of Study:To evaluate the ability of ancillary health staff to use a novel smartphone imaging adapter system (EyeGo, now known as Paxos Scope) to capture images of sufficient quality to exclude emergent eye findings. Secondary aims were to assess user and patient experiences during image acquisition, interuser reproducibility, and subjective image quality.Materials and Methods:The system captures images using a macro lens and an indirect ophthalmoscopy lens coupled with an iPhone 5S. We conducted a prospective cohort study of 229 consecutive patients presenting to L. V. Prasad Eye Institute, Hyderabad, India. Primary outcome measure was mean photographic quality (FOTO-ED study 1–5 scale, 5 best). 210 patients and eight users completed surveys assessing comfort and ease of use. For 46 patients, two users imaged the same patient's eyes sequentially. For 182 patients, photos taken with the EyeGo system were compared to images taken by existing clinic cameras: a BX 900 slit-lamp with a Canon EOS 40D Digital Camera and an FF 450 plus Fundus Camera with VISUPAC™ Digital Imaging System. Images were graded post hoc by a reviewer blinded to diagnosis.Results:Nine users acquired 719 useable images and 253 videos of 229 patients. Mean image quality was ≥ 4.0/5.0 (able to exclude subtle findings) for all users. 8/8 users and 189/210 patients surveyed were comfortable with the EyeGo device on a 5-point Likert scale. For 21 patients imaged with the anterior adapter by two users, a weighted κ of 0.597 (95% confidence interval: 0.389–0.806) indicated moderate reproducibility. High level of agreement between EyeGo and existing clinic cameras (92.6% anterior, 84.4% posterior) was found.Conclusion:The novel, ophthalmic imaging system is easily learned by ancillary eye care providers, well tolerated by patients, and captures high-quality images of eye findings.

A Novel Device for Smartphone-Based Fundus Imaging and Documentation in Clinical Practice: Comparative Image Analysis Study

“…Although initially the lens needed to be held in the optical path manually [ 1 - 3 ], different proprietary adapters are available now [ 4 - 7 ]. Smartphone-based fundus imaging can be performed based on both direct [ 4 , 5 ] and indirect ophthalmoscopy [ 6 , 8 - 10 ]. Given the low costs and great mobility, smartphone-based fundus imaging has the potential to revolutionize eye care, especially in lower-resource settings [ 11 , 12 ].…”

Agreement between retinal images obtained via smartphones and images obtained with retinal cameras or fundoscopic exams – systematic review and meta-analysis

“…Ludwig et al29 assessed the posterior segment of 128 eyes of cases of different diseases in India. They obtained 84.4% high quality images when the examiner was an ophthalmologist, greatly exceeding students or optometrists.…”

A Smartphone-Based Tool for Rapid, Portable, and Automated Wide-Field Retinal Imaging

“…Variability in image quality that could arise from nonideal settings and nonexpert operators is a critical consideration when screening in the community. 37 , 38 In order to assess this potential limitation with the CellScope Retina, we performed a feasibility study wherein image acquisition for grading of DR was performed by a medical student and medicine intern rather than ophthalmologists or ophthalmic photographers. We found that even when image acquisition was performed by nonexpert operators, grading of CellScope Retina images demonstrated good agreement for DR and CSDME compared with clinical examination by slit-lamp biomicroscopy, consistent with other photographic-based methods, 49 and met British Diabetic Association guidelines for sensitivity in screening tools used in DR. 40 This was achieved, in part, by leveraging the processing power of the phone to simplify operational steps in image acquisition.…”

“…Subsequent studies have demonstrated that three-field, 45° nonmydriatic fundus photography was effective in grading DR to determine referral-warranted disease, whereas a single 45° photograph was insufficient to accurately grade DR. 34 – 36 Importantly, imaging by nonexpert operators may affect image quality and is an important consideration for community-based screening efforts. 37 , 38 Several studies have investigated smartphone-based screening of DR 4 , 16 , 39 and reported sensitivities of 80% or more with high specificities, as recommended by the British Diabetic Association for new imaging devices in population-based screening. 40 However, other investigators have found insufficient sensitivities of below 60% for detecting DR 37 suggesting smartphone imaging is not universally reliable.…”