Abstract
Purpose: :
To evaluate the use of a navigating laser photocoagulator to treat diabetic macular edema in an open use multicentered clinical testing environment. The Navilas device tracks retinal movement in patients and allows precise visualization of targeted laser treatment positions identified by angiography or fundus photography in a patient, allowing laser targeting and laser stabilization to the retina in a moving eye and was used to focally treat microaneurysms in diabetic macular edema.
Methods: :
76 consecutive eyes with diabetic macular edema at three sites were imaged and treated with the Navilas device. This device is a scanning slit digital ophthalmoscope, which provides continuous high-resolution digital imaging in color using white light illumination, infrared imaging and fluorescein angiography. A photocoagulation laser is integrated into the device emitting at 532 nm. Utilizing eye tracking from real-time imaging the position of the treatment laser can be adjusted to compensate for eye motion.
Results: :
Laser photocoagulation of targeted microaneurysms was possible in all eyes. The retina surgeon manually marked each aneurysm after the angiogram was performed on the device. The pre-positioning mode was used to automatically advance the targeting aiming beam from targeted retinal position to position after the aiming beam and pre-planned target was stabilized on the living fundus. The surgeon actuated the laser manually after the target lock was verified by the surgeon. The duration of planning for two eyes of a given was under 7 minutes and was verified by the surgeon. An alternating infrared to color video fundus visualization mode allowed post-treatment observation of the retinal burn for 2-3 seconds after each application to allow adjustment of burn intensity without patient discomfort. Treatment comfort as assessed by the patients was very high. In no cases was the fovea or optic nerve treated accidentally. Preliminary work with wide angle mid-peripheral imaging and treatment will be presented.
Conclusions: :
In all 3 study sites, treatment and results analyses show that Navilas allows angiography, treatment planning, and laser treatment of focal lesions with high confidence. Retinal lesions were precisely located and burn intensity could be titrated in a predictable manner. The system is an improvement over manual laser coagulation in accuracy, speed, and patient comfort.
Keywords: diabetic retinopathy • imaging/image analysis: clinical • laser