ABSTRACT
Corneal astigmatism in patients with cataract is very common,but it could not be accurately corrected during previous cataract surgery,which usually affects the visual quality seriously.The accurate measurement of corneal astigmatism power and meridian before surgery is key to the effective correction of astigmatism during the cataract surgery by either the determination of astigmatic keratotomies or the selection and implantation of toric intraocular lenses (IOL).The combination of IOL Master for sphere,the Pentacam for the total corneal refractive power and VERION Digital Marker for surgical orientation can provide promising refractive examination,treatment and good postoperative outcomes.Preexsisting astigmatism can be corrected during cataract surgery by modifying incision,performing arcuate keratotomy,or implanting a toric IOL.Femtosecond laser arcuate keratotomy combined with phacoemulsification is an effective,safe and precise method for the correction of low to moderate corneal astigmatism power,and it can improve visual acuity in cataract surgery candidates.Further work is required to establish corneal biomechanics numerical simulation and nomography protocol for cataract refractive surgery so as to improve the predictability and accuracy of femtosecond laser-assisted astigmatic keratotomy during refractive cataract surgery.
ABSTRACT
@# Objective To explore the effect of correcting astigmatism with corneal incision guided by the corneal topography preoperatively.Methods 97 patients(102 eyes) having undergone phacoemulsification and foldable introcular lens implanation,were divided into two groups according to the incision.Superior temple sclera tunnel incision was made on 51 eyes of the group A,and the clear cornea incision was made on the steepest meridian for the group B(51 eyes).The preexisting cornea astigmatism of all patients reneged from 0.25 D to 5.75 D.Corneal topography examination was made before the operation and one day,1 week,1 month and 3 months after surgery except for visual acuity,slit lamp and fundus examination.The value of surgical induced cornea astigmatism was observed.Results In the group A,the differences were not statistically significant between pre-operation and 1 day,1 week,1 and 3 months after surgery for the value of corneal astigmatism(P>0.05).In the group B,the value of corneal astigmatism in 1 day and 1 week after surgery were a little greater than that of pre-operation,but 1 month later,that was significant better than that pre-operation.The value of corneal astigmatism was reduced from 1.5 D before surgery to 0.52±0.14 D after surgery,from 1.5～2.5 D to 0.88±0.53 D and from over 2.5 D to 1.5±0.72 D respectively.Conclusion The incision guided by corneal topography can correct cornea astigmatism existed pre-operation and get the best visual outcome.