Telemedicine screening for eye disease.

Abstract

Telemedicine is increasinglyused fordiseasemonitoringandmanagement of chronic medical and mental disorders, but also has screening and diagnostic applications such as teleradiology and teledermatology. Indeed, “therapy at a distance” will complement office-based care in the 21st century. Another screening application is teleophthalmology, in which digital photography with telemedicine links has proven cost-effective for retinal disorders, including diabetic retinopathy and retinopathy of prematurity.1,2 Ina recent study in JAMAOphthalmology, Chasanetal3 complementedpriorcost-effectivenessanalysesof teleretinal screeningprogramsbyexaminingboth theaccuracyofdiabetic teleretinal screening as well as the subsequent eye care use and resources required in such a program. Regarding accuracy, screening tests that have good sensitivity and specificity are likely to bemore cost-effective. Regarding resource use, implementation of screening generates more referrals, testing, and procedures. The cost-effectiveness of any screening program is therefore contingent on reasonable test accuracy coupledwith a sufficient supply of resources tomeet the increased demand. Chasan et al3 conducted the study in community-based clinics ofasingleVeteransAffairs (VA)medical center.Of 1935patientswho underwent diabetic retinal screening, 465 (24%) had an abnormal finding on the retinal photograph and were referred to the VA eye clinic, of whom 326 were seen by an eye specialist and had a confirmatorydiagnosis.Themostcommonreasonsfor referralwerenonmacular diabetic retinopathy (43.2%), nerve-related disease (30.8%), lensormediaopacity (19.1%), age-relatedmacular degeneration (12.9%), and diabetic macular edema (5.6%). The percentageof agreementbetween retinal screeningand theophthalmicexamination for all diagnoseswas 90.4%,with a sensitivity of 73.6%. Sensitivity may have been somewhat inflated for 2 reasons. First, onlypatientswithabnormal retinalphotographswere referred, thus greatly increasing the number of cases with disease and minimizing thenumberof caseswithoutdisease. This verificationbias (also known as “workup bias” or “referral bias”) is a type of measurementbias inwhich the resultsof adiagnostic test affectwhether the gold standard procedure is used to verify the test result. Second, it is not clear that the clinician performing the ophthalmic examinaJAMAOPHTHALMOLOGY