CLINICAL INVESTIGATION OF AN INFRARED DIGITAL SCANNING LASER OPHTHALMOSCOPE

An infrared scanning laser ophthalmoscope (SLO) has been custom built in order to investigate the application of confocal and indirect mode SLO imaging to patients with fundus disease. Infrared light is reflect ed from the fundus to a greater extent than visible light permitting l ower illumination power and, as it penetrates the retinal pigment epit helium, choroidal structures can be readily imaged. Furthermore, as co nventional infrared illumination and detection systems are not well su ited to ophthalmoscopy, this area is underdeveloped as a potential sou rce of useful clinical data. Confocal, direct and indirect imaging mod es have been used to image fundi of normal volunteers and patients wit h fundus disease. In comparison with conventional fundus photography c onfocal infrared SLO imaging improves visualisation of choroidal vascu lature, retinal pigment epithelial abnormalities, laser photocoagulati on scars, and optic disc pores in the lamina cribrosa. Direct infrared SLO imaging enables fundus visualisation through nuclear lens opaciti es. Furthermore, indirect mode imaging enhances significantly the appe arance of macular drusen. The potential clinical benefit of these obse rvations is discussed.