Telemedicine screening for cytomegalovirus retinitis using digital fundus photography.

BACKGROUND

Screening for cytomegalovirus retinitis (CMVR) is important in patients with acquired immune deficiency syndrome and low CD4(+) counts. However, many human immunodeficiency virus (HIV) patients lack access to specialist ophthalmological care. Telemedicine screening is a cost-effective method for screening these patients. We aimed to report the use of composite nine-field digital fundus photography (DFP) images for CMVR screening. We report its sensitivity and specificity in detecting CMVR and the level of agreement with gold-standard binocular indirect ophthalmoscopy.

MATERIALS AND METHODS

An audit was performed on our national CMVR screening program that screened all HIV patients referred to the Ophthalmology Department at Tan Tock Seng Hospital, Singapore. All patients underwent retinal screening with DFP. Images were categorized as CMVR-positive, CMVR-negative, suspicious, or unreadable by blinded retinal specialists. Patients subsequently underwent dilated gold-standard indirect ophthalmoscopy by a different retinal specialist. Diagnoses were categorized as CMVR-positive, CMVR-negative, or unreadable. Sensitivity and specificity of retinal findings on DFP and kappa values for level of agreement between the two screening methods were calculated.

RESULTS

Three hundred seventy screenings on 188 patients were performed. Twenty-three eyes diagnosed with CMVR on indirect ophthalmoscopy were also identified on DFP (100% sensitivity). A 99.9% specificity was achieved. The fundus photograph of one eye without CMVR was read as CMVR-positive because of an artifact, accounting for a false-positive. Kappa values ranged from 0.739 to 0.987.

CONCLUSIONS

DFP is a sensitive and specific method of screening HIV patients for CMVR and has a high level of agreement with indirect ophthalmoscopy.