Development of an integrated automated retinal surgical laser system

Diabetes is a serious disease that affects millions of people world wide. One of the many complications that may result from this disease is an eye disorder called diabetic retinopathy. This side effect is characterized by the leaching of fluid, mainly blood, into the retinal tissue ultimately killing the rods and cones in the area. Scientists have discovered that by occulating and destroying some of the capillaries near the infected area, further damage may be limited and further vision loss prevented. This procedure is performed on the retina by using a Continuous Wave argon laser to place a pattern of lesions that kill the rods, cones, and underlying capillaries. The "Computer Aided Laser Optics System for Ophthalmic Surgery" or CALOSOS is a system that fully integrates the placement of therapeutic retinal lesions through computer control. To date, two different sub-systems have been used to achieve the desired accuracy needed including lesion placement and depth; an all-digital system and a hybrid analog/digital system. The current tracking system that precisely controls the laser uses a wide-angle lens camera to view the whole retina. The difficulty lies in the fact that the only way to control the depth of the lesion is to measure the central reflectance. The goal of this research is to establish that there is a linear relationship between the reflectance of the lesion and the depth of the lesion when this wide-angle lens is used.