Photolysis using the dodick–ARC laser system for cataract surgery

Abstract

Purpose To report the intraoperative and postoperative results of cataract surgery using a pulsed Q-switched neodymium:YAG (Nd:YAG) laser. Setting Eye Clinic, Kreiskrankenhaus Bad Hersfeld, Germany. Methods This prospective study involved 100 consecutive patients who had cataract surgery between October 1998 and May 1999. The patients were allocated to 3 groups based on the hardness of the nucleus using the LOCS III system: Group 1 (NO ≤ 2.9), 48 patients; Group 2 (NO 3.0 to 3.9), 46 patients; Group 3 (NO ≥ 4.0), 6 patients. Plasma was generated with a pulsed Q-switched Nd:YAG laser (ARC GmbH). A clear corneal incision of 1.25 mm provided access for the laser tip. An intraocular lens (CeeOn® Edge [Pharmacia & Upjohn] or AcrySof® [Alcon]) was implanted via a separate clear corneal incision. Intraoperative laser pulse rate and total energy were recorded. Preoperative and postoperative (2 days and 6 months) central cornea thickness was compared. Results In all cases, the cataract was removed within an acceptable time without converting to the conventional phacoemulsification technique. Mean total energy was 1.97 J ± 1.43 (SD) in Group 1, 3.37 ± 1.59 J in Group 2, and 7.70 ± 2.09 J in Group 3. No significant postoperative changes between preoperative and postoperative central pachymetry were seen in Groups 1 and 2; there was a 1.9% postoperative increase in central pachymetry in Group 3. This could be a consequence of the higher volume of intraoperative balanced salt solution and the prolonged procedure in this group. Six months postoperatively, there were no significant changes from the preoperative values. Conclusion Photolysis of the lens nucleus can be used safely and efficiently for nuclei with a hardness up to NO 3.9. The energy required for lens removal was 83% less than that required by phacoemulsification.