ABSTRACT

PURPOSE: To evaluate corneal tissue trauma and effectiveness of cataract surgery using ultrasound (US) phacoemulsification compared to nanosecond laser technique.

SETTING: Department of Ophthalmology, Charlottenklinik, Stuttgart, Germany.

DESIGN: Prospective, randomized, double masked, clinical interventional study.

METHODS: Patients were randomized in two groups. Group 1 received cataract surgery using ultrasound phacoemulsification and in group 2 the nanoslaser-assisted cataract surgery was applied. Main outcome measures included uncorrected visual acuity and distance corrected visual acuity, corneal endothelial cell count, corneal thickness at the center of the cornea and operational parameters like mean power consumption, mean amount/volume of irrigating fluid/balanced salt solution and effective phaco- or photofragmentation time (EPT).

RESULTS: Phacoemulsification was performed in 29 eyes and 32 eyes had the nanosecond laser procedure. Uncorrected and corrected distance visual acuity was not significantly different between the two groups. Postoperatively, there were no significant between-group differences (p > 0.05) in the endothelial cell count. The mean endothelial cell density was 2360 cells/mm ± 54 (SD) preoperatively and 2182 ± 76 cells/mm at 3 months in the US group and 2486 ± 45 cells/mm and 2386 ± 45 cells/mm, respectively, in the laser group. The largest decrement of endothelial cell count was observed in group 1 compared with preoperative values after 7 days and after 30 days in group 2. The central corneal thickness showed also no statistically significant difference (p > 0.05) between group 1 and 2.  Both groups reached a maximum thickness at the 1st day and then returned to presurgery levels after 90 days. The mean EPT was significantly lower in the phacoemulsification group (59,7 seconds ± 57,0 [SD]) than in the nanolaser group (138,7 ± 68,8 seconds) (p < 0,0001). There was a significant difference in the mean energy consumption between the 2 groups (38,5 Joule ± 29,9 (SD) in phacoemulsification group; 1,2 Joule ± 0,7(SD)) in nanolaser group) (p < 0.0001). At least there also was a significant between-group difference in the balanced salt solution volume between group 1 and 2 (33,1 Milliliter ± 37,2 (SD) in phacoemulsification group; 54,9 Milliliter ± 30,6 (SD)in nanolaser group).

CONCLUSION: The nanosecond laser procedure was effective in cataract surgery, reducing the mean energy consumption, while it showed a longer EPT and a higher volume of balanced salt solution consumption than cataract surgery using phacoemulsification. The Nanosecond laser also did not have disadvantages over US phacoemulsification in terms of corneal tissue trauma and central corneal thickness.