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To explore the possibility of extracting cataracts percutaneously, we have carried out in-vitro studies on ablation of cataractous human eye lenses using a TE-C02 laser of pulse duration 135 nsec FWHM. The threshold flue2ce of ablation is found to be about 5 J/cm and the ablation yield about 0.5 mg/Jcm which slowly tends to decreasewith the laser fluence. Temporal evolution of the ablation shows a sharp spike of about1 psec FWHM followed by a long ejection pulse of about 30 jjsec FWHM. Comparedto the commonly used XeCl excimer laser for phaco-ablation a TE-C02 laser resultsin a more efficient ablation on an energy basis and does not invol ye the risk of carcino- genesis or cataracts. Thermal damage in the remainder tissue can be comparable at shorter pulse durations of the TE-C02 laser to that of the XeCl excimer laser. 1. INTRODUCTION Conventional surgical cure of cataracts involves an incision of about 10-15 mm inlength. To reduce the chances of post—operative complications, infection, scarring and |
