[Erbium laser phacoemulsification--a clinical pilot study]

Abstract

Introduction: From August 1997 to March 1998, we performed a prospective pilot study to examine erbium laser phacoemulsification in cataract surgery under clinical conditions and to determine the side effects of this method.

Patients and method: 34 patients (40 eyes) with senile cataract were recruited. Slit lamp findings, keratometry, best corrected visual acuity, refraction, pachymetry, endothelial cell count and intraocular pressure were determined preoperatively and on 1st, 4th, 14th and 60th postop day according to a standardised protocol (single pulse energy between 10 and 20 mJ, frequency of application 60 Hz, average phaco time 3 min, total energy 38.5 mJ). The operations were done with the erbium laser system MCL 29, Aesculap-Meditec Co., Jena, Germany.

Results: A total emulsification of the nucleus was possible in 36 of 40 eyes (90%) (nucleus hardness between 0 and 3). A partial emulsification of the nucleus in nucleus hardness 3 was possible in 2 eyes, in nucleus hardness 4 in 1 eye and in nucleus hardness 2 in 1 eye (4 eyes--10%). Visual acuity increased from 0.3 preop to 0.8 two months postop (median). Intraocular pressure decreased from 16 mm Hg preoperatively to 13 mm Hg two months postoperatively (median). The increase of corneal thickness was not statistically significant compared to baseline. The decrease of endothelial cell count was 0.96%. Postoperative complications which are not known in ultrasonic phacoemulsification did not appear in erbium laser phacoemulsification.

Conclusion: Erbium laser phacoemulsification is a surgical method that makes the emulsification of softer nuclei under clinical conditions possible with a low rate of complications also in the beginning of the learning curve. For higher nucleus hardnesses, technical and surgical parameters have to be optimised. Advantages of erbium laser phacoemulsification compared to ultrasonic phacoemulsification are less energy transmission into the eye, no heating of anterior chamber, impossibility of corneal burns and easier access in eyes that are deep into the orbit. Especially advantageous is the high protection of endothelium by erbium laser phacoemulsification. A prospective controlled comparative study to ultrasonic emulsification is desirable.