Production of small-incision intraocular lenses (IOLs) for cataract replacement surgery has been optimized at Mentor ORC (Azusa, CA), where a 5-W diode laser system from Opto Power (City of Industry, CA). is used in a workstation to attach two monofilament loops, or haptics, to IOLs by thermally "staking" them to the lens at two opposite contact points (see photo). The small forces generated by the haptic filaments serve to center the lens within the pupil after insertion by the surgeon.
The bench-top laser system replaces a large floor-mounted xenon arc-lamp console and uses less than 120 W of power compared to the nearly 6 kW consumed by the xenon lamp, cutting operating costs. The near-infrared, 830-nm laser output is delivered via an optical fiber and has a linewidth of less than 2.5 nm. High-power arc-lamp output is less efficient, extending from 700 nm to 1.2 µm.
Single-shot, multi-shot, and CW operation of the diode laser are all possible. The operator can preset operation parameters such as power (0.1-5 W CW), pulsewidth (200 µs to CW), and repetition rate (up to 1 kHz). The user can also monitor an LCD front-panel display for pulse count as the system operates. A foot pedal permits hands-free operation and a 670-nm visible diode laser (collinear with the infrared beam) produces an aiming spot to give consistent results in attaching the haptics to the IOLs. The delivery fiber features a collimator-lens assembly that focuses the infrared laser beam into a spot less than 400 mm across, minimizing stray radiation damage to the IOL.
In addition to the laser components, the microprocessor-controlled system uses a video camera microscope for 100X magnification of the target area onto the operator’s TV monitor.