부산대학교 도서관

PURPOSE:: Human photoreceptors are sensitive to infrared light (IR). This sensitivity can be used as a novel indicator of retinal function. We measured diabetic retinopathy patients using in-vivo two-photon excitation and compared their scotopic IR threshold with that of healthy patients. METHODS:: Sixty-two participants, 28 healthy and 34 with diabetic retinopathy; all underwent a comprehensive eye exam, where we assessed visual acuity and contrast sensitivity. IR thresholds were measured in the fovea and parafovea following 30-min dark-adaptation. We used a two-photon excitation device with integrated pulsed laser light (1045 nm) for sensitivity testing and scanning laser ophthalmoscopy for fundus imaging. RESULTS:: The mean Snellen visual acuity of diabetic patients (6/7.7) was worse than in the healthy group (6/5.5), which was significantly different (P<.001). Disease patients had decreased contrast sensitivity, especially at 6 and 18 cycles/degree. The mean retinal sensitivity to IR light in diabetic retinopathy (11.6 ±2.0 dB) was significantly (P<.001) lower than in normal eyes (15.5 ±1.3 dB). CONCLUSION:: Compared to healthy controls, the IR-light sensitivity of diabetic patients was significantly impaired. Two-photon measurements can be used in the assessment of retinal disease, but further studies are needed to validate IR-light stimulation in various stages of diabetic retinopathy.