Case report:simultaneous femtosecond laser astigmatic keratotomy and toric intraocular lens implantation in femtosecond laser-assisted cataract surgery in a patient with surgically induced high corneal astigmatism

Background:Femtosecond laser astigmatic keratotomy(FSAK)and toric intraocular lens(IOL)implantation have been studied individually for comparison to treat astigmatism at cataract surgery.We report a case of surgically induced high corneal astigmatism by laser thermal keratoplasty(LTK)in a patient with cataract who was successfully treated with simultaneous combination of FSAK and toric IOL implantation with femtosecond laser-assisted cataract surgery(FLACS).This is the first report of both procedures combined simultaneously,with or without history of LTK.Case Description:A 68-year-old male presented with a history of LTK with two enhancements each eye in 2004,with subsequent surgically induced high corneal astigmatism,and with age-related nuclear cataract of both eyes.IOL master demonstrated+7.71 diopters of astigmatism at 163 degree right eye and+3.29 diopters of astigmatism at 4 degree left eye.After extensive discussion of the risks and benefits,the patient agreed to undergo FLACS with FSAK with two 61 degrees of relaxation incisions(RIs)and toric IOL(Alcon SN6AT9)right eye;FLACS with toric IOL(Alcon SN6AT7)alone left eye.At 2-year follow-up,uncorrected visual acuity was 20/30 right eye,20/25 left eye.His best corrected visual acuity was 20/25(+0.25+1.00 axis 21)right eye and 20/20(plano+0.25 axis 90)left eye;his best corrected near visual acuity was J1+with add+2.50 diopters right eye and left eye.Conclusions:Patients with age-related cataract and LTK induced high corneal astigmatism can hardly be sufficiently treated with FSAK or toric IOL alone at the time of cataract surgery.An effective way is to combine large FSAK and toric IOL of the highest cylindrical power of T9,in our case,simultaneously,which can achieve an excellent long term visual outcome.

Comparison between toric and spherical phakic intraocular lenses combined with astigmatic keratotomy for high myopic astigmatism

Background:To compare the outcomes of a toric phakic intraocular lens(PIOL)and a spherical PIOL combined with astigmatic keratotomy(AK)for the correction of high myopic astigmatism.Methods:This study enrolled patients with high myopic astigmatism,including 30 eyes(22 patients)that received a toric PIOL implantation(TICL group),and 32 eyes(24 patients)that received combined AK and a spherical PIOL implantation(AK+ICL group).The outcomes were compared between the two groups before surgery,and at the following time points after surgery:1 week,1,3,6 months,and 1,2 years.Results:Preoperatively,the mean manifest spherical equivalent(SE)was−14.14±2.12 D in the TICL group and−14.83±2.79 D in the AK+ICL group(P=0.28),and the mean manifest refractive cylinder,−2.87±1.09 D and−2.58±0.85 D,respectively(P=0.28).Two years postoperatively,the mean safety index was 1.53±0.55 in the TICL group and 1.60±0.70 in the AK+ICL group(P=1.00),and the mean efficacy index,1.18±0.45 and 1.38±0.52,respectively(P=0.86).The mean manifest refractive cylinder correction was 1.94±1.07 D in the TICL group and 1.39±0.71 D in the AK+ICL group(P=0.02).The mean changes in SE and refractive cylinder from 1 week to 2 years were less than 0.50 D in both groups.Conclusions:Both TICL implantation and AK+ICL implantation are a good alternative for correction of astigmatism in addition to high myopia.TICL implantation has better predictability in correction of high myopic astigmatism.

Femtosecond laser-assisted astigmatic keratotomy: a review

Background:Astigmatic keratotomy(AK)remains an accessible means to correct surgically induced or naturally occurring astigmatism.The advantages of femtosecond laser-assisted astigmatic keratotomy(FSAK)over conventional methods have been recognized recently.Main text:This review evaluates the efficacy,complications,and different methods of FSAK for correction of astigmatism in native eyes and those that underwent previous penetrating keratoplasty(PKP).The penetrating and intrastromal FSAK(IFSAK)techniques can reduce post-keratoplasty astigmatism by 35.4%to 84.77%and 23.53%to 89.42%,respectively.In native eyes,the penetrating and IFSAK techniques reduce astigmatism by 26.8%to 58.62%and 36.3%to 58%respectively,implying that the magnitude of the astigmatic reduction is comparable between the two FSAK procedures.Nonetheless,IFSAK offers the additional advantages of almost no risk of infection,wound gape,and epithelial ingrowth.The use of nomograms,anterior-segment optical coherence tomography,and consideration of posterior cornea and corneal biomechanics are helpful to enhance the efficacy and safety of FSAK.The complications of FSAK in eyes that underwent PKP include overcorrection,visual loss,microperforations,infectious keratitis,allograft rejection,and endophthalmitis.The reported difficulties in native eyes include overcorrection,anterior gas breakthrough,and suction loss.Conclusions:In eyes that underwent PKP,FSAK effectively reduces high regular or irregular astigmatism,with rare and manageable complications.Nevertheless,the drawbacks of the procedure include the potential loss of visual acuity and low predictability.For native eyes undergoing femtosecond laser-assisted cataract surgery,IFSAK is a good choice to correct low astigmatism(<1.5 diopters).The refractive effect of astigmatism from the posterior cornea needs to be considered in the nomograms for native eyes undergoing refractive cataract surgery.To further improve the efficacy of FSAK,more large-scale randomized studies with longer follow-up are needed.

Corneal astigmatic outcomes after femtosecond laser-assisted cataract surgery combined with surface penetrating arcuate keratotomies

AIM:To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies(FAKs)combined with femtosecond-laser assisted cataract surgery(FLACS)over 12mo follow-up.METHODS:Totally 145 patients with bilateral cataracts and no ocular co-morbidities were recruited to a singlecentre,single-masked,prospective randomized controlled trial(RCT)comparing two monofocal hydrophobic acrylic intraocular lenses.Eyes with corneal astigmatism(CA)of>0.8 dioptres(D)received unpaired,unopened,surface penetrating FAKs at the time of FLACS.Visual acuity,subjective refraction and Scheimpflug tomography were recorded at 1,6,and 12mo.Alpins vectoral analyses were performed.RESULTS:Fifty-one patients(61 eyes),mean age 68.2±9.6y[standard deviation(SD)],received FAKs.Sixty eyes were available for analysis,except at 12mo when 59 attended.There were no complications due to FAKs.Mean pre-operative CA was 1.13±0.20 D.There was a reduction of astigmatism at all post-operative visits(residual CA 1mo:0.85±0.42 D,P=0.0001;6mo:0.86±0.35 D,P=0001;and 12mo:0.90±0.39,P=0.0001).Alpins indices remained stable over 12mo.Overall,the cohort was under-corrected at all time points.At 12mo,61%of eyes were within±15 degrees of pre-operative astigmatic meridian.CONCLUSION:Unpaired unopened penetrating FAKs combined with on-axis phacoemulsification are safe but minimally effective.CA is largely under-corrected in this cohort using an existing unmodified nomogram.The effect of arcuate keratotomies on CA remained stable over 12mo.

Post-keratoplasty astigmatism management by relaxing incisions:a systematic review

Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,photorefractive procedures,wedge resection,intra-ocular lens implantation,intracorneal ring segments,relaxing incisions with or without compression sutures and repeated keratoplasty.Relaxing incisions can be made in the graft,graft-host interface or host cornea.Despite the unpredictability of the method because the flat and steep meridians are usually not orthogonal after penetrating keratoplasty,with asymmetric power distribution,all the studies showed an overall reduction of refractive,keratometric or topographic astigmatism,ranging from 30%to 72%with manual or femtosecond-assisted techniques.Most patients with astigmatism higher than 6 diopters had residual cylinder less than or equal to 3 diopters,which can be treated by laser excimer ablation or secondary intraocular lens implantation.