[Effect of phacoemulsification on the Berger space].

Objective: To investigate the effect of phacoemulsification on the Berger space (BS). Methods: A prospective cohort study. Patients with cataract who underwent phacoemulsification and intraocular lens implantation in the Department of Ophthalmology, Affiliated Hospital of Nantong University from May 2021 to October 2021 were enrolled. The BS was observed by slit-lamp microscopy and anterior segment optical coherence tomography (AS-OCT) before and 1 month after operation. Intraoperative optical coherence tomography with a 25G optical fiber was performed to observe the BS. The number of eyes with the BS and materials in the BS (MIB) detected perioperatively was counted, and the width of the BS was measured. Statistical analysis was carried out by the Chi-square test, generalized estimating equations, Mann-Whitney U test and binary logistic regression analysis. Results: A total of 119 patients (119 eyes) were included [44 males, 75 females; mean age, (65±12) years]. Preoperatively, the BS was identified in only 4 eyes (3.4%), and no MIB was found. Intraoperatively, the BS was identified in 47 eyes (39.5%), and the MIB was observed in 20 eyes (16.8%). At one month postoperatively, the BS was identified in 33 eyes (27.7%), of which 16 eyes (13.4%) still had MIB. There were significant differences in the detection rates of the BS and MIB between intraoperative and preoperative groups (both P<0.001). The difference in the detection rate of the BS postoperatively compared to intraoperatively was statistically significant (P=0.001), while the difference in the detection rate of MIB was not statistically significant (P>0.05). The intraoperative and postoperative width of the BS [M (Q1, Q3)] was 160.3 (61.6, 273.1) µm and 106.8 (0, 259.4) µm, respectively, and the difference was statistically significant (Z=-2.28, P=0.023). In addition, the detection rate of the BS and MIB in patients with a high risk of zonular fiber weakness [60.7% (17/28) and 42.9% (12/28)] was significantly higher than that in patients without this risk factor [33.0% (30/91) and 8.8% (8/91)] (χ²=6.90, P=0.009; P<0.001). In the multivariable model, weakness of zonular fibers (OR=0.214, 95%CI: 0.081 to 0.561) and higher cumulative dissipated energy (OR=1.255, 95%CI: 1.047 to 1.504) were the main risk factors for structural changes of the BS intraoperatively. Conclusion: Phacoemulsification can damage the normal anatomical structure of the BS, resulting in intraoperative entrance of fluid and particulates to the BS.