Scanning Digital Ophthalmoscope (SDO) Compared to Conventional Fundus Photography

Abstract

Abstract: : Purpose: To compare fundus image quality obtained by a new scanning laser digital ophthalmoscope (SDO) to standard slide photography with a Zeiss 450 FF camera. Methods:Fundus images of 23 patients were obtained digitally by SDO and on slide by a Zeiss 450 FF camera system. All digital SDO pictures were then printed on 35 mm transparency slides and finally the slides of both machines were evaluated side–by–side by three graders blinded to the image source. On visual analogue scales, a total of eight image characteristics were graded: overall quality, contrast, colour brilliance, sharpness, resolution and details, noise, artefacts and validity of clinical assessment. The results of grading were compared and correlated to lens densitometry with the Interzeag Lens Opacity Meter 701. Results: No significant differences in overall image quality and for most of the subscales were found between the SDO and Zeiss system. For two of the subscales, noise (p=0.001) and artefacts (p=0.01), direct Zeiss slide photography performed better than the image taken digitally by SDO and secondarily transferred to slides. Lens opacities did not influence most subscales for image quality significantly, but "resolution" and "details" deteriorated similarly with increasing media opacities for both imaging modalities (both p=0.03). Conclusions: SDO digital imaging gives results well comparable to expert photography on 35 mm slides using a Zeiss 450 FF camera system.

Keywords: retina • optic disc