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R. Pini, L. Menabuoni, I. Lenzetti, F. Rossi, J.–M. Parel; Experimental Diode Laser–Induced Closure of Capsulorhexis . Invest. Ophthalmol. Vis. Sci. 2006;47(13):665.
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© ARVO (1962-2015); The Authors (2016-present)
To determine ex–vivo the feasibility of diode–laser lens capsule welding for closing capsulorhexes in lens refilling procedures (Phaco–Ersatz).
40 freshly enucleated porcine eyes were used to determine the optimal laser parameters. Closure tests of capsulorhexes were performed by applying flaps of anterior capsular tissue, harvested from donor eyes, on the recipient capsule and inducing tissue welding by means of diode laser irradiation at 810 nm. In 30 eyes, donor capsular flaps were first stained with a solution of Indocyanine Green (ICG) in sterile water as ICG exhibits a strong optical absorption at the diode laser emission wavelength. Laser pulses were delivered with a 200–micron–core–fiber, whose tip was gently applied to the capsule patch surface (contact welding technique) to produce tissue welding spots while the tissue was immersed underwater. In another 10 eyes lens refilling tests were performed; the laser–welding procedure was modified as follows: instead of completing the weld around the full circumference of the flap, one quadrant of the flap was initially left free. The partially welded flap thus served as a flap–valve through which the capsule could subsequently be filled with a polymeric fluid (polydimethylsiloxane, 1 Kcst silicone oil, Biosil, Omnia srl, Italy). After fully refilling the bag, the flap–valve was laser welded and physical tests were performed to assess polymer leakage.
Laser–welded capsular flaps showed a good adhesion to the recipient capsular surface, as they exhibited a resistance to mechanical load comparable to that of healthy tissue. The weld provided a very effective sealing of the rhexis as no leakage occurred even when strongly pushing onto the anterior capsule. The welding effect was found to be highly reproducible for laser pulses with fluences of 60–160 J/cm2 and pulse durations of 20–70 ms. With these energy doses, no clinically visible side–effects such as shrinkage or heat–induced alteration of the capsule occurred. This was confirmed by histology.
Ex vivo diode laser–induced closure of the capsule after Phaco–Ersatz procedure is feasible. The technique may be useful in repairing capsular breaks or tears caused by accidental traumas or produced intraoperatively during standard IOL implantation.
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