ABSTRACT
Requirements for cataract surgery have gradually increased from the original rehabilitation procedure to personalized refraction surgery.Femtosecond laser-assisted cataract surgery is being widely used because of its precision of incision,accuracy of capsule cutting and high efficiency of nuclear fracturing in recent year.Currently some operating systems of femtosecond laser-assisted cataract surgery include LenSx,Catalys,LenSAR and Victus,and they are different in the design of contact interfaces,video and operating bed and therefore present different working methods.Ophthalmologists should be aware of the differences of these operating systems and accurate assess the clinical findings of patients in order to consider the preciseness,accuracy,efficiency of incision,capsulorhexis and nucleus fragmentation to avoid the intraoperative and postoperative complications.
ABSTRACT
Background The innovation of pre-chop technique lies in shortening surgery duration,reducing ultrasound power,and deseasing the loss of corneal endothelial cells (CECs).Objective This study was to compare the efficacy and safety of pre-chop technique using a reverse-chopper and phaco-and-chop phaco technique to super high myopia associated with hard nucleus cataract.Methods A prospective randomized-controlled-clinical interventional study was performed.Fourty eyes of 40 high myopia associated with cataract patients with Ⅲ-ⅣV degree of nucleus were enrolled in Beijing Tongren Hospital from March to September 2016.The patients were randomized into the pre-chop group and matched phaco-and-chop group according to random number table,and the self-made reverse chopper-assisted pre-chop phacoemulsification (phaco) surgery and phaco-and-chop phaco surgery were performed on the eyes of different groups,respectively.The phaco power,effective phaco duration and best corrected visual acuity (BCVA) were recorded and compared between the two groups to evaluate the efficacy,and the loss rate of corneal endothelial cells and eyes in different grades of cornea edema after operation were compared between the two groups to assess the safety of surgery procedure.Written informed consent from each patient was obtained prior to relevant examination and surgery.Results The surgery was finished smoothly in the eyes.The mean effective phaco duration was (47.30±11.29) seconds and (57.70± 14.51) seconds in the pre-chop group and phaco-andchop group,respectively,with a significant difference between them (t =-2.530,P =0.016).The BCVA was better at the seventh day after surgery in the pre-ehop group than that in the phaco-and-chop group (4.75t0.11 vs.4.67± 0.14),showing a significant difference between the two groups (t=2.147,P=0.038).In 1 month after surgery,the CECs loss rate was (10.82±3.77)％ in the pre-chop group,which was lower than (16.11±6.47)％ in the phacoand-chop group (t=-3.758,P=0.001).The number of the eyes with grade 2-3 of corneal edema in the pre-chop group was significantly decreased in comparison with the phaco-and-chop group 7 days after surgery (Z =11.822,P=0.008).Conclusions Compared with the conventional phaco-and-chop technique,reverse-chopper prechop technique appears to have a better efficacy and safety in phaco surgery for high-myopia associated with hard nuclear cataractous eyes.
ABSTRACT
Background Pseudoexfoliation syndrome (PEX) has a high incidence in Uygur population and usually leads to secondary glaucoma and complicated cataract.The abnormal change of lens tissue and degeneration of zonular fibers bring a lot of difficulties for phacoemulsification (phaco) with intraocular lens implantation,especially stop-and-chop phaco technique.Prechop technique is a new choping technology,but its application in PEX with cataract is less.Objective This study was to compare the efficacy and safety of pre chop phaco technique and stop-and-chop phaco technique for PEX combined cataract.Methods A randomized controlled Clinical trial was designed.Forty-one eyes of 41 patients with PEX combined cataract of Ⅲ degree of nucleus were enrolled in People's Hospital of Hetian District from March 2015 to January 2016.The patients were randomized into the prechop group and stop-and-chop group according to random nubmer table,and cystotome-assisted prechop phaco surgery and stop-and-chop phaco surgery were performed in different groups,respectively.The effective phaco duration,corneal endothelium loss rate,cornea edema eye number after operation,vision outcomes and complications were compared between the two groups.Results The mean effective phaco duration was 14.0 (13.0,16.5) minutes and 18.5 (16.5,24.0) minutes in the prechop group and stop-and-chop group,with a significant difference between them (Z =17.354,P ＜ 0.01).The corneal endothelial cells were (2 101.90 ± 209.08)/mm in the prechop group,and the number was similar to (2 002.30 ± 207.04)/mm of the stop-and-chop group (t =-1.530,P =0.134).Corneal endothelial cell lossing rate was (8.27±2.23)％ in the prechop group,which was lower than (13.09±4.26)％ in the stop-and-chop group (t =3.810,P =0.001).The BCVA was better in the prechop group than that in the stop-and-chop group in postoperative day 3 (P =0.044),and the corneal edema degree was not signigicantly different in postoperative day 1 and day 3 between the two groups (P=0.221,0.446).Intraoperative complication was rapture of zonule and occurred in 1 eye and 2 eyes in the prechop group and stop-and-chop group,respectively.Conclusions Compared with the stop-and-chop phaco technique,the prechop phaco tequnique can decrease intraoperative complication,lighten the postoperative damage of corneal endothelial cells and accelerate visual rehabilitation in PEX combined with cataract patients.