Date of Award

January 2020

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Ron A. Adelman


The purpose of this study was to determine and compare the sensitivity and specificity of three different handheld fundus cameras in detecting diabetic retinopathy (DR), age-related macular degeneration (AMD), and glaucoma in a resource-limited setting.

The design of the study was a cross-sectional, observational, single-site instrument validation study. Participants included patients who presented to the Ophthalmology Clinic at Maharaj Nakorn Hospital in Chiang Mai, Thailand between September 2018 and May 2019. All participants underwent fundus photography with each of three different handheld fundus cameras (Volk InView, Peek Retina, Volk Pictor Plus) as well as a dilated clinical examination performed by an ophthalmologist. Fundus photographs captured by each camera were graded for retinal disease by four teams of two masked ophthalmologists based on pre-defined, standardized grading criteria. Gradings were compared to diagnoses determined from the gold standard clinical examination. Measures of diagnostic accuracy (bootstrapped 95% confidence intervals of sensitivity (SN), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) of the three fundus cameras in detecting DR, AMD, and glaucoma compared to clinical examination.

Fundus photographs of 357 eyes from 187 participants were captured with each of the three retinal cameras. The prevalence of diabetic retinopathy, age-related macular degeneration, and glaucoma in the study population was 30.6%, 8.8%, and 5.0%, respectively. Compared with the clinical examination as a reference, the tested cameras achieved the following diagnostic accuracies in detecting DR: 70.5% (95% confidence interval [CI] = 63.7-75.2) SN and 85.6% (95% CI = 82.7-90.2) SP for the Volk Inview, 18.0% (95% CI = 14.0-24.1) SN and 9.6% (95% CI 9.4-9.7) SP for the Peek Retina, and 76.2% (95% CI = 73.3-82.6) SN and 91.0% (95% CI 88.6-94.1) SP for the Volk Pictor Plus.

All three handheld fundus cameras achieved high specificity but variable sensitivities in detecting DR, AMD, and glaucoma. The Volk Pictor Plus provided the highest overall diagnostic accuracy in screening for diabetic retinopathy and age-related macular degeneration, though the lower-cost, smartphone-based Volk Inview attained only slightly inferior results. The Peek Retina largely yielded images with insufficient fundus coverage or clarity for retinal screening. The handheld fundus cameras were not effective in screening for possible glaucoma.


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