EC Ophthalmology

Background/Aim: To evaluate corneal tissue trauma and effectiveness of cataract surgery using the nanolaser (NL) photofragmentation technique compared to phacoemulsification (US).

Methods: This prospective, randomized, double-masked, clinical interventional study was approved by the regional ethics committee (Aktenzeichen: F - 2013 - 094) and was conducted at the Department of Ophthalmology, Charlottenklinik, Stuttgart, Germany. Sixty-eight consecutive eyes were enrolled and randomized into two groups that underwent cataract surgery using NL or US. The main outcome measure was corneal endothelial cell loss (ECL) at 84 days. Secondary intraoperative (fluidics, effective phacoemulsification/photofragmentation time (EPT), and energy used) and post-operative (central corneal thickness, uncorrected visual acuity, and distance corrected visual acuity) outcome measurements were also evaluated.

Results: Between-group differences in uncorrected and corrected distance visual acuity were not significantly significant. Postoperatively, there were no between-group differences in the endothelial cell count. The largest decrement of endothelial cell count compared to preoperative values was observed in the US group after seven days and after 30 days in the NL group. Statistically significant differences in the central corneal thickness were not observed. The mean EPT was significantly lower in US (59.7 ± 57.0 sec) than in NL (138.7 ± 68.8 sec) (p < 0.001). There was a significant difference in the mean energy consumption between the two groups (38.5 ± 29.9J and 1.2 ± 0.7J, respectively) (p < 0.001). The difference in fluidics (33.1 ± 37.2 ml and 54.9 ± 30.6 ml, respectively) was statistically significant (p = 0.015).

Conclusion: The NL procedures, although requiring a longer EPT and more fluidics, were effective in cataract removal releasing less energy in the eye. It also resulted in an ECL of 3.5% compared to 7.3% with US.

 Keywords: Cataract Surgery; Phaco Energy; Phacoemulsification; Nanosecond Laser; Corneal Endothelial Cell Loss

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