Improved diagnosis of retinal laser injuries using near-infrared autofluorescence.
De Silva SR., Neffendorf JE., Birtel J., Herrmann P., Downes SM., Patel CK., Hildebrand GD., Gliem M., Issa PC.
PURPOSE: To assess whether near infrared autofluorescence (NIR-AF) imaging is a useful imaging modality in the diagnosis of handheld laser retinal injuries. DESIGN: Retrospective observational case series. METHODS: 12 patients identified to have handheld laser retinal injuries were included at two academic centers. Patients underwent ophthalmic assessment and retinal imaging including fundus photography, optical coherence tomography (OCT), conventional blue autofluorescence (B-AF) and NIR-AF imaging. RESULTS: In all cases, lesions consistent with retinal laser injury were detected by NIR-AF imaging. The lesions showed a characteristic appearance with central hyperfluorescence and surrounding hypofluorescence although the number and extent of lesions varied between patients. Findings using other imaging modalities were variable: on color fundus photography these included localized pigmentary changes and on OCT imaging an ellipsoid zone interruption or outer nuclear layer changes. Only subtle changes were evident on B-AF imaging. Other macular conditions, such as poppers retinopathy or solar maculopathy, which may have similar findings on OCT imaging as laser damage, can be differentiated using NIR-AF imaging. CONCLUSION: An increased incidence of retinal injuries secondary to handheld lasers has been reported in recent years. We show that the diagnosis and full extent of retinal laser injuries is best demonstrated by NIR-AF, as other modalities give variable results. We propose that NIR-AF should be included when investigating patients suspected of macular injury secondary to exposure to handheld lasers.