The Muranga Teleophthalmology Study: A Comparison of Virtual (Teleretina) Assessment with in-person Clinical Examination to Diagnose Diabetic Retinopathy and Age-related Macular Degeneration in Kenya

Abstract

Purpose: This study compares a web-based teleophthalmology assessment with a clinical slit lamp examination to screen for diabetic retinopathy (DR) and age-related macular degeneration (AMD) among diabetic patients in a rural East African district.

Methods: Six hundred and twelve eyes from 306 diabetic patients underwent both a clinical slit lamp examination and a teleretina (TR) assessment by an experienced ophthalmologist. Both assessments were compared for any DR and AMD using the early treatment diabetic retinopathy study and age-related eye disease study grading scales, respectively.

Results: Of the 612 TR assessment photos, 74 (12%) were deemed ungradable due to media opacities, poor patient cooperation, or unsatisfactory photographs. The ability to detect DR and AMD showed a fair agreement (kappa statistic 0.27 and 0.23, respectively) between the TR and clinical slit lamp examination. Relative to a clinical slit lamp evaluation, a positive TR diagnosis carried a 75.0% positive predictive value when diagnosing DR and a 27.3% positive predictive value when diagnosing AMD. A negative TR diagnosis carried a 97.2% negative predictive value for the diagnosis of DR and a 98.1% negative predictive value for the diagnosis of AMD.

Conclusion: When comparing TR assessments to clinical slit lamp examinations to diagnose DR and AMD, there was a fair agreement. Although further validation is needed, the TR approach provides a promising method to diagnose DR and AMD, two major causes of ocular impairment worldwide.

Keywords: Age-related macular degeneration; diabetic retinopathy; slit lamp examination; teleophthalmology; teleretina.

Figure 1

(a) Dr. Dan Kiage seen grading teleophthalmology images wearing LCD shutter goggles. The fundus image appears on one screen while the grading form appears on a separate screen. (b) Nurse Florence taking a fundus photograph in Muranga

Figure 2

Fundus photographs demonstrating a variety of retinal pathologies. (a) Microaneurysms (ETDRS level 20) (b) CSME (ETDRS level 35D). (c) Moderate NPDR (ETDRS level 35F) (d) Moderate NPDR (ETDRS level 43B) e) PDR (ETDRS level 65C) f) PDR (ETDRS level 65B) ETDRS: Early treatment diabetic retinopathy study, CSME: Clinically significant macular edema, NPRDR: Non-proliferative diabetic retinopathy, PDR: Proliferative diabetic retinopathy