Effects Of Femtosecond Laser-assisted Phacoemulsification On Blood Flow Density And Nerve Fiber Layer Thickness In Optic Disc

Objective:Optical coherence tomography angiography(OCTA)was used to investigate the effects of femtosecond laser cataract surgery(FLACS)and conventional cataract phacoemulsification(CPCS)on the short-term blood flow density and nerve fiber layer thickness(RNFL)in the optic disc.Methods:A retrospective case-control study was conducted to collect 77 eyes of 69 patients diagnosed with age-related cataract from December 2020 to December 2021,including 37 eyes of 33 patients who underwent FLACS.40 eyes of 36 patients underwent CPCS.The changes of best corrected visual acuity(BCVA),intraocular pressure(IOP),blood flow density in the optic disc area and RNFL thickness around the optic disc were compared between the two groups before surgery,1 day after surgery,7 days after surgery,1 month and 3 months after surgery.Effective phacoemulsification time(EPT),corneal edema on 1 day after surgery and intraoperative IOP of FLACS group were recorded.To evaluate the effect of elevated intraocular pressure on blood flow density and RNFL thickness around optic disc during femtosecond laser pretreatment.Results:The visual acuity of the two groups was significantly improved on postoperative day 1,which was(0.140±0.087)Log MAR in the FLACS group and(0.1547±0.077)Log MAR in the CPCS group.There was no significant difference in visual acuity between the two groups on postoperativeon day 1,day 7,1 month and 3 month(P >0.05).The corneal edema in FLACS group was lighter than that in CPCS group on postoperative day 1.There was no significant difference in intraocular pressure between the two groups on the day 1,day 7,1 month and 3 months after surgery(P >0.05).In FLACS group,IOP still increased about 2.44 mm Hg after the vacuum device was withdrawn(P < 0.05).The superemulsification time of FLACS group was(1.05± 0.54)s,and that of CPCS group was(2.37 ± 0.82)s.The effective phacoemulsification time of FLACS group was significantly lower than that of CPCS group(P < 0.05).The preoperative blood flow density in FLACS group and CPCS group were(50.05 ± 2.28)% and(49.48 ± 2.34)%,respectively;the blood flow density in optic disc was(48.93 ± 2.79)% and(48.88 ± 3.10)%,respectively.Preoperative RNFL thickness around optic disc in FLACS group and CPCS group was(104.11±12.16)um and(103.80±11.89)um,respectively.Blood flow density in optic disc area decreased in both groups on postoperative day 1(P < 0.05),and RNFL thickness around optic disc increased slightly(P < 0.05).However,there were no significant differences in blood flow density in optic disc area and RNFL thickness around optic disc between the two groups on day 1,day 7,month 1 and month 3 after surgery(P > 0.05).Conclusions:Femtosecond laser cataract surgery has many advantages,but the main disadvantage of femtosecond laser cataract surgery is that the negative pressure suction device can cause the temporary increase of intraocular pressure,which has no effect on the changes of optic disc blood flow density and nerve fiber layer thickness,and the operation is safe.