Biomicroscopic wide-angle imaging of fundus with digital imaging system

초록

Purpose: To report a new method of biomicroscopic wide-angle imaging of ocular fundus by combining a conventional wide-angle contact lens with a slit lamp equipped with digital photographic system Method: Wide-angle imaging of fundus was performed in 200 eyes of 160 patients with wide-spread changes of fundus such as extensive diabetic retinopathy, retinal breaks with or without detachment, intermediate uveitis, posterior uveitis, peripheral abnormalities, and intraocular tumors using a wide-angle contact lens and a slit-lamp with a high resolution 3CCD color video camera and a personal computer(PC) for capture and archiving of the images. The patients are aged from 11 years to 78 years. The slit beam intensity, slit beam width, and illumination-observation angles were adjusted for efficient observation. The images were obtained instantly in one session of usual biomicroscopy and reviewed immediately. Results: This method provides the wide-angle images of high resolution covering nearly the entire postequatorial fundus, and by adjusting the angle, any quadrant of fundus from the optic disc to the vitreous base area. This also makes it possible to image through the small pupil, mild cataract, pseudophakia and intraocular tamponade with air, gas and silicon oil. Either vertical or horizontal wide-open slit beam with moderate-intensity is more appropriate to illuminate the wider area of fundus, which necessitates the slightly off-axis illumination with tilted contact lens for minimizing the reflection. Each image stored in the PC was reviewed immediately and later on for the purpose of photodocumentation, presentation, education, and explanation to patients. Conclusions: The main advantage of this method is to obtain a number of wide-angle images of fundus instantly when performing fundus biomicroscopy as usual. Simultaneously, it is possible to obtain the small-angle images for the details by simply adjusting magnification of the slit lamp. Furthermore, it is more convenient and affordable than the commercial wide-angle imaging Systems, and it might play a supplemental role in the current field of the fundus photography.