Human lens epithelial cell apoptosis and epithelial to mesenchymal transition in femtosecond laser-assisted cataract surgery

AIM： To evaluate human lens epithelium cell apoptosis and epithelial to mesenchymal transition （EMT） induced by femtosecond laser in femtosecond laser assisted cataract surgery （FLACS）. METHODS： Sixty cataract patients with N2 to N3 stage according to the LOCS III were enrolled in this study and divided into three groups randomly： FLACSl group （cataract surgery by FLACS with LenSx）, FLACS2 group （cataract surgery by FLACS with LensAR） and manual group （cataract surgery by phacoemulsification）. Patients in two FLACS groups performed anterior capsulotomy by LenSx or LensAR laser system. Patients in the manual group were performed continuous curvilinear capsulorrhexis （CCC） manually. The anterior capsules were fixed right after moved out of eye. Hematoxylin-eosine staining, immunofluorescence staining and real-time PCR were performed in order to observe human lens epithelium cells changes after cataract surgery. RESULTS： The capsule cutting edge was shown irregularity and roughness in two FLACS groups and smooth edge in manual capsulotomy by pathologic staining. Irregularities of the cell configuration with partly swollen and destroyed nuclei were observed in two FLACS groups. Femtosecond laser could induce a significantly higher cell apoptosis in human lens epithelium cell than manually performed CCC （P〈0.05）. Lens epithelium cells apoptosis were correlated with femtosecond laser duration according to Pearson correlation analysis. Decreased N-cadherin expression, alpha-SMA and FSP-1 level in two FLACS groups showed the inhibition of cell EMT. CONCLUSION： Femtosecond laser may affect the apoptosis and EMT of lens epithelium cells which are under the peeled central lens capsule.

Optimal incision sites to reduce corneal aberration variations after small incision phacoemulsification cataract surgery

AIM： To analyze the effect of steep meridian small incision phacoemulsification cataract surgery on anterior,posterior and total corneal wavefront aberration.· METHODS： Steep meridian small incision phacoemulsification cataract surgery was performed in age-related cataract patients which were divided into three groups according to the incision site： 12 o＇clock, 9o＇clock and between 9 and 12 o＇clock（BENT） incision groups. The preoperative and 3-month postoperative root mean square（RMS） values of anterior, posterior and total corneal wavefront aberration including coma,spherical aberration, and total higher-order aberrations（HOAs）, were measured by Pentacam scheimpflug imaging. The mean preoperative and postoperative corneal wavefront aberrations were documented.·RESULTS： Total corneal aberration and total lower-order aberrations decreased significantly in three groups after operation. RMS value of total HOAs decreased significantly postoperatively in the 12 o＇clock incision group（P 〈0.001）. Corneal spherical aberration was statistically significantly lower after steep meridian small incision phacoemulsification cataract surgery in BENT incision group（P 〈0.05） and Pearson correlation analysisindicated that spherical aberration changes had no significant relationship with total astigmatism changes in all three corneal incision location.·CONCLUSION： Corneal incision of phacoemulsification cataract surgery can affect corneal wavefront aberration.The 12 o＇clock corneal incision eliminated more HOAs and the spherical aberrations decreased in BENT incision group obviously when we selected steep meridian small incision. Cataract lens replacement using wavefront-corrected intraocular lens combined with optimized corneal incision site would improve ocular aberration results.