Ability of MultiColor scanning laser ophthalmoscope to detect non-glaucomatous retinal nerve fiber layer defects in eyes with retinal diseases

Abstract Purpose To compare the ability of ocular fundus images obtained by Spectralis MultiColor scanning laser ophthalmoscope (MC-SLO) to that obtained by conventional color fundus images (CF) in detecting non-glaucomatous nerve fiber layer defects (NFLDs). Methods A cross-sectional, retrospective study. Patients with retinal diseases who had ocular examination with both the MC-SLO and CF instruments at the Kagoshima University from December 2016 to February 2017 were studied. Eyes that had NFLDs with non-glaucomatous optic discs were analyzed. The visibility of the NFLDs was classified into three grades: grade 0, not visible; grade 1, barely visible; and grade 2, clearly visible. The NFLD grade for blue, green, and red scanning lights of the MC-SLO, merged images with three wavelengths and the color and red-free images were determined by two ophthalmologists. These scores were compared by Steel-Dwass tests. Results Thirty-one eyes of 26 patients with a mean age of 63.1 ± 11.2 years were studied. There were 14 eyes with diabetic retinopathy, 11 eyes with age-related macular degeneration, 3 eyes with a branch retinal vein occlusion, and 3 eyes with an epiretinal membrane/macular hole. Both the intra-rater (0.631–0.790) and inter-rater (0.637–0.733) agreements were good. NFLDs were detected by the blue wavelength in all cases and by green wavelength and merged wavelengths in 90.3% of the images. The mean NFLD grade was 1.58 ± 0.49 for blue light images, 1.13 ± 0.54 for green light images, 0.07 ± 0.24 for red light images, and 1.16 ± 0.56 for merged images. The NFLD score for blue wavelength was significantly higher than that for green and red wavelength images (P < 0.05 and P < 0.01) but not significantly higher than that for the merged images. NFLDs were detected in 12 eyes (38.7%) in the color images and 16 eyes (51.6%) in the red-free images. The NFLD score for the CF and the red-free image was 0.41 ± 0.55 and 0.70 ± 0.67 which is significantly lower than that of blue MC-SLO images. Conclusion The images obtained by MC-SLO are superior to that obtained by CF in detecting NFLDs in eyes with retinal diseases. We recommend MC-SLO imaging to screen for NFLDs in eyes with retinal diseases