Qualitative and quantitative endothelium changes after cataract surgery: ultrasound phacoemulsification vs. nanolaser technique

PURPOSE: The aim of this study was to evaluate corneal endothelial cell density and morphology, central corneal thickness, and best visual acuity using ultrasound (US) phacoemulsification or nanosecond laser technique. SETTING: Department of ophthalmology, Nabeul, Tunisia. DESIGN: Prospective cohort study. METHODS: This study included eyes with nuclear cataracts with a density grade of 1, 2, 3, or 4 according to LOCS III, divided into two groups; group 1 had conventional US, and group 2 had nanosecond laser. The endothelial cell density (ECD), coefficient of variation (CoV) in cell size, percentage of hexagonal cells, central corneal thickness (CCT) and best visual acuity (VA) were evaluated during 24 months. RESULTS: Seventy-four eyes had uneventful surgery, 40 in group 1, 34 in group 2. Three procedures in group 2 required conversion to standard phacoemulsification. The mean ECD decreased from 2616.4 ± 194.6 cells/mm(2) in group 1 preoperatively to 2088.4 ± 229.9 after 2 years. In group 2, it decreased from 2611.8 ± 186.5 cells/mm(2) to 2276.4 ± 163.8 after 2 years. The change was statistically significant in both groups. The decline of the mean ECD in group 2 was significantly less important than in group 1 (p = <10(−2)). The mean percentage of hexagonal cells was 45.18 ± 4.9 preoperatively and 43.5% ± 6.6 after 2 years in group 1. In group 2, it remained almost stable with 45.6 ± 5.1 and 45.4% ± 6.6 preoperatively and after 2 years, respectively. Preoperatively, the mean CoV was 0.39 ± 0.037 in group 1 and 0.38 ± 0.04 in group 2. After 2 years, it was 0.38 ± 0.04 and 0.37 ± 0.038 in group 1 and group 2, respectively. The changes of the mean CoV and the mean percentage of hexagonal cells were significant in both groups, but the difference between the groups was significant only during the six first months postoperatively. In preoperative, the mean corneal central thickness was 509.7 ± 19.5 in group 1 and 510.3 ± 20.4 in group 2. In both groups, the mean corneal thickness increased on D1 postoperatively to 550.9 in group 1, and 528.2 in group 2. The mean corneal thickness decreased more rapidly after 1 week in group 2, to find the initial values. Visual acuity improved from 0.76 Log Mar ± 0.5 at enrolment to 0.45 Log Mar ± 0.2, and 0.033 Log Mar ± 0.086 in group 1 at 1 day post-operative and after 24 months, respectively and from 0.58 Log Mar ± 0.28 to 0.2 Log Mar ± 0.09 and 0.035 Log Mar ± 0.083, respectively in group 2. There was no significant difference in VA at each follow-up between groups except for day 1. CONCLUSION: Our study showed lower corneal tissue trauma, and lower endothelial cell loss in the laser cataract surgery compared to phacoemulsification. Clinical trial registration: (https://classic.clinicaltrials.gov/ct2/show/NCT05886283), identifier NCT05886283.