Evaluation of the Clinical Efficacy of Full Femtosecond Laser Surgery in the Treatment of Myopia

Objective:To evaluate the clinical effect of full femtosecond laser surgery in the treatment of myopia patients.Methods:120 myopia patients admitted to our hospital from January 2022 to June 2023 were selected.According to the random number table method,60 patients in the observation group underwent full femtosecond laser surgery,and 60 patients in the control group underwent femtosecond laser-assisted in situ keratomileusis(FS-LASIK)surgery.The clinical effects of the two groups were compared.Results:10 days postoperatively and 6 months after operation,the visual acuity level of the observation group was higher than that of the control group,the postoperative corneal asphericity coefficient and corneal full-thickness were lower than those of the control group,and the total effective rate 6 months after operation was higher than that of the control group(P<0.05).Conclusion:Full femtosecond laser surgical treatment can improve the postoperative visual acuity of patients with myopia,enhance the corneal asphericity coefficient(Q)and corneal full-thickness,and exert significant clinical effects.

LIMITATIONS OF CANCER MARGIN DELINEATION BY MEANS OF AUTOFLUORESCENCE IMAGING UNDER CONDITIONS OF LASER SURGERY

Limitations of cancer margin delineation and surgical guidance by means of autofluorescence imaging under conditions of laser ablation were investigated and preliminary results are presented.PinPoint^(TM)(Novadaq Technologies Inc.,Canada)was used to capture digital images and Er:YAG laser(2.94μm,Glissando,WaveLight^(TM),Germany)was exploited to cause laser ablation on both normal and cancer sites of the specimen.It was shown that changes of the autofluorescence image after ablation extend beyond the actual sizes of the ablation loci.The tumor tissue after the laser ablation starts to emit fluorescent light within the green wavelength band(490-550nm)similar to normal tissue stating that the current technology of in-process tissue classification fails.However,when the autofluorescence was collected in the red range(600-750nm),then the abnormal/normal contrast was reduced,but still present even after the laser ablation.The present study highlights the importance of finding a proper technology for surgical navigation of cancer removal under conditions of high power effects in biological tissues.

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.

Oncologic outcome of CO_2 laser surgery for glottic carcinoma

The curative effect of CO2 laser in treatment of glottic carcinoma has been focused on for a long time. The oncologic results were based on the comparison with conventional methods, survival rate and laryngeal function outcome. Data in the past literature produced convincing evidence that endoscopic surgery with CO2 laser can be considered as a valid alternative to radiotherapy and open neck surgery （larynfissure cordectomy, vertical partial laryngectomy, etc）.

Neurodevelopmental Outcome After Fetoscopic Laser Surgery for Twin-twin Transfusion Syndrome:A Systematic Review of Follow-up Studies from the Last Decade

Objective:To review the literature on long-term neurodevelopmental outcome after fetoscopic laser surgery for twin-twin transfusion syndrome(TTTS).Methods:A literature search in PubMed,Embase,Emcare,Web of Science,Cochrane library,and Academic Search Premier was performed.Inclusion criteria were studies between 2009 and 2019 in TTTS-survivors treated with fetoscopic laser surgery and followed-up after the neonatal period with cognitive developmental tests and neurologic exams.Exclusion criteria were non-English articles and reviews,case reports,letters,and guidelines.Results:Nineteen articles were included.Long-term severe neurodevelopmental impairment(NDI)was reported by seven and ranged from 4.0%to 18.0%with a mean of 9.7%(95%confidence interval(CI):7.8-11.5).The prevalence of cerebral palsy ranged from 1.6%to 18.2%,with a mean of 5.1%(95%CI:4.1-6.2).The mean prevalence of minor impairment was 13.7%(95%CI:11.4-16.0).However,only 78.9%(15/19)studies used a validated neurodevelopmental test.As studies lack uniform definitions of primary outcome,timing of follow-up,inclusion criteria,and methods,adequate comparison is hampered.Conclusion:The prevalence of severe NDI and cerebral palsy after fetoscopic laser surgery for TTTS in the last decade remains stable around 9.7%and 5.1%,respectively.International agreements on primary outcomes,methods,and follow-up are necessary to improve the knowledge of NDI in TTTS-survivors.

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.

Profitability analysis of a femtosecond laser system for cataract surgery using a fuzzy logic approach

AIM：To define the financial and management conditions required to introduce a femtosecond laser system for cataract surgery in a clinic using a fuzzy logic approach.METHODS：In the simulation performed in the current study,the costs associated to the acquisition and use of a commercially available femtosecond laser platform for cataract surgery（VICTUS,TECHNOLAS Perfect Vision GmbH,Bausch ＆ Lomb,Munich,Germany） during a period of 5y were considered.A sensitivity analysis was performed considering such costs and the countable amortization of the system during this 5y period.Furthermore,a fuzzy logic analysis was used to obtain an estimation of the money income associated to each femtosecond laser-assisted cataract surgery（G）. RESULTS：According to the sensitivity analysis,the femtosecond laser system under evaluation can be profitable if 1400 cataract surgeries are performed per year and if each surgery can be invoiced more than $500.In contrast,the fuzzy logic analysis confirmed that the patient had to pay more per surgery,between $661.8 and $667.4 per surgery,without considering the cost of the intraocular lens（IOL）.CONCLUSION：A profitability of femtosecond laser systems for cataract surgery can be obtained after a detailed financial analysis,especially in those centers with large volumes of patients.The cost of the surgery for patients should be adapted to the real flow of patients with the ability of paying a reasonable range of cost.

Two-micron （thulium） laser resection of the prostate- tangerine technique： a new method for BPH treatment

Two-micron （thulium） laser resection of the prostate-tangerine technique （TmLRP-TT） is a transurethral procedure that uses a thulium laser fiber to dissect whole prostatic lobes off the surgical capsule, similar to peeling a tangerine. We recently reported the primary results. Here we introduce this procedure in detail. A 70-W, 2-um （thulium） laser was used in continuous-wave mode. We joined the incision by making a transverse cut from the level of the verumontanum to the bladder neck, making the resection sufficiently deep to reach the surgical capsule, and resected the prostate into small pieces, just like peeling a tangerine. As we resected the prostate, the pieces were vaporized, sufficiently small to be evacuated through the reseetoscope sheath, and the use of the mechanical tissue morcellator was not required. The excellent hemostasis of the thulium laser ensured the safety of TmLRP-TT. No patient required blood transfusion. Saline irrigation was used intraoperatively, and no case of transurethral resection syndrome was observed. The bladder outlet obstruction had clearly resolved after catheter removal in all cases. We designed the tangerine technique and proved it to be the most suitable procedure for the use of thulium laser in the treatment of benign prostatic hyperplasia （BPH）. This procedure, which takes less operative time than standard techniques, is safe and combines efficient cutting and rapid organic vaporization, thereby showing the great superiority of the thulium fiber laser in the treatment of BPH. It has been proven to be as safe and efficient as transurethral resection of the prostate （TURP） during the 1-year follow-up.

The influence on biotissue laser resection of a strongly absorbing layer at the optical fiber tip

In this paper,we consider a method of laser resection using the silica glass core from which the cladding layer has been removed as the cutting part of a laser scalpel.An absorbing layer coating the silica fiber tip markedly alters its biotissue cutting character istics.The results of histological studies of skin after exposure to a laser scalpel with and without a strongly absorbing coating(SAC)at a wavelength of 097μm show that resection using a coated scalpel is more sparing.When an uncoated scalpel was used,skin injury was more apparent in both its surface spread and the depth of structural damage,resulting in poorer tissue regeneration.

Feasibility of en bloc thulium laser enucleation of the prostate in a large case series. Are results enhanced by experience?

Objective:To provide the first large single-operator case series of patients who undergo“en bloc”thulium laser enucleation of the prostate(ThuLEP)and to demonstrate an improvement in enucleation efficacy with experience.Methods:We prospectively evaluated a cohort of patients with symptomatic benign prostatic hyperplasia(BPH)who underwent“en bloc”ThuLEP between May 2015 and November 2017.Association between dependent variables(delivered energy and operating time)and independent variables(adenoma volume and experience)were estimated with regression analysis.The experience was calculated as the time interval between the date of the first operation of the series and the date of the operation being considered.Results:A total of 100 patients were registered for the study.Median operative time was 56.5 min(interquartile range[IQR]:40-85 min).Median enucleation time was 17.4 min(IQR:15-21.5 min).Median enucleation index(enucleation time per adenoma gram)was 0.3 min/g(0.2-0.3 min/g).The overall operative time is not influenced by experience,but we registered a significant trend towards a reduction in the total amount of energy delivered energy normalized per adenoma gram(p=0.0148).Conclusion:We believe that further attention is needed for these new“en bloc”prostatic enucleation techniques,which can facilitate some surgical steps,leading to a widespread use of laser technology for BPH surgical treatment.

Refractive surgical corrective options after cataract surgery

Cataract surgery is one of the most commonly performed surgeries among the elderly today.The volume of cataract surgeries has dramatically increased in the past few decades due to technological advancements leading to decreased morbidity,better overall outcomes,and increased expectation for correction of refractive error and spectacle independence after cataract surgery.The number of cataract surgeries is expected to continue to rise with the increase of the elderly population.Thus,accurate predictions of intraocular lens(IOL)power and the ability to correct for any postoperative refractive errors are critical.Despite the improved ability of cataract surgeons to accurately calculate IOL power,postoperative refractive errors still do occur due to various reasons such as imperfect preoperative measurements,toric-lens misalignment,and existing or surgically-induced astigmatism.The aim of this article is to review the various surgical options,including intraocular and corneal refractive surgical approaches,to correct post-operative refractive errors after cataract surgery.

Evaluation of greenlight photoselective vaporization of the prostate for the treatment of high-risk patients with benign prostatic hyperplasia

Aim： To explore the feasibility and safety of greenlight photoselective vaporization of the prostate （PVP） on high-risk patients presenting with lower urinary tract symptoms suggestive of benign prostatic hyperplasia （BPH） and to evaluate their clinical and voiding outcome. Methods： A total of 85 high-risk patients with obstructive BPH underwent PVP with an 80 W potassium-titanyl-phosphate laser, which was delivered through a side-deflecting fiber with a 23 Fr continuous flow cystoscope. Operative time, blood loss, indwelling catheterzation, international prostate symptom score （IPSS）, quality of life score （QoL）, uroflowmetry, postvoid residual urine volume and short-term complication rates were evaluated for all patients. Results： All patients got through the perioperative period safely. The chief advantages of PVP were： short operative time （25.6 ± 7.6 min）, little bleeding loss （56.8 ± 14.3 mL） and short indwelling catheterization （1.6 ± 0.8 d）. The IPSS and QoL decreased from （29.6 ± 5.4） and （5.4 ± 0.6） to （9.5 ± 2.6） and （1.3 ± 0.6）, respectively. The vast majority of patients were satisfied with voiding outcome. The mean maximal urinary flow rate increased to 17.8 mL/s and postvoid residual urine volume decreased to 55.6 mL. These results are significantly different from preoperative data （P 〈 0.05）. No patient required blood transfusion or fluid absorption. There were few complications and very high patient satisfaction after operation. Conclusion： PVP has a short operative time and high tolerance, and is safe, effective and minimally invasive for high-risk patients, therefore it might be considered as a good alternative treatment for high-risk patients with obstructive urinary symptoms as a result of BPH.

Combined phacoemulsification and goniosynechialysis with or without endoscopic cyclophotocoagulation in the treatment of PACG with cataract

AIM:To investigate the efficacy and safety of combined phacoemulsification and goniosynechialysis with or without endoscopic cyclophotocoagulation(PGE group and PG group)for the treatment of patients with coexisting primary angle-closure glaucoma(PACG)and cataracts.METHODS:The clinical data of patients with PACG and cataract were retrospectively reviewed.There was a total of 88 eyes in the study and were divided into two groups,42 eyes in PGE group and 46 eyes in PG group.Surgery success cumulative survival,preoperative and postoperative intraocular pressure(IOP),number of IOPlowering medications,best corrected visual acuity(BCVA)in the two groups were observed for more than 12 mo and compared within each group and between two groups.RESULTS:The mean IOP in PGE group declined from24.9 mm Hg preoperatively to 14.1 mm Hg at the first month after operation(P<0.001)and at the last visit 16.2 mm Hg(P<0.001).Meanwhile PG group also showed significant decrease,from 24.1 mm Hg preoperatively to 13.0 mm Hg at Imo after operation(P<0.001)and 15.3 mm Hg at the last visit(P=0.004).The mean medications reliance reduced in both groups,in PGE group was reduced from 1.62 preoperatively to 0.13 at the last visit(P<0.001),in PG group from 0.87 to 0.10(P<0.001).At the last visit,BCVA increased from 0.21 to 0.60 in PGE group(P<0.001)and from 0.24 to 0.67 in PG group(P<0.001).The success rate of PGE group at 1 mo was95.2%,then decreased to 70.7%at the last visit,whereas in PG group,the success rate at 1 mo was 100%,at the last visit was 73.4%.CONCLUSION:PGE shows promise for PACG patients with cataracts to reduce IOP,lighten the medication burden and improve visual acuity,and PG still has its value in specific patients.

On the possible ultrasonic inspection of micro-bubbles generated by the optical fiber tip

We demonstrate the possibility of detection and monitoring of bubbles emerging near the tip of an optical fiber by means of ultrasonic method.The excitation of bubbles at their resonant frequencies is performed using short ultrasonic pulses having a wide frequency range simulta-neously with their modulation by means of a long pulse of a monochromatic frequency.This method allows detection of bubbles of various sizes.Used signal processing method,which allows increased bubble detection accuracy,is proposed for ressearch in envir onments of biological-like medium which show continuous variations in structure and properties when exposed to optical emission.The method has been demonstrated on model objects:in a liquid and in a biological tissue phantom using various methods of bubble generation(hydrolysis and optical enission).We studied bubble formation by the tip of a fiber of the surgical laser LSP-007/10 "IRE Polus"with a wavelength of 0.97μm coated with a highly absorbing graphite layer.

Comparison of diode laser continuous wave and in soft tissue surgery using pulsed modes in vitro

In this study, the interaction between diode laser radiation and chicken soft tissue was studied in vitro by a high-speed digital video camera. We used a diode laser with a wavelength of （980 ±10）nm and average power of 10 W. The diode laser was operated in continuous wave （CW） and pulsed modes. In CW mode, the average laser radiation power was 10 W; in pulsed mode, the average laser radiation power was I0 W and the peak power was 20 W. Diode laser radiation was delivered to soft tissue （chicken meat） using a quartz optical fiber with either a clear distal end （clear tip） or a distal end containing an optothermal converter （hot tip）. Application of the diode laser in pulsed mode resulted in crater depths and areas of collateral damage in soft tissue about 1.6 times greater than those observed in CW mode at treatment with the clear tip. Significant differences in the crater depth and collateral damage width of chicken meat were not found after hot-tip treatment with the diode laser in CW and pulsed modes. Soft tissue treated with the hot tip showed crater depths about 3.4 times greater than those observed after treatment with the clear tip. Hot tip treatment further resulted in collateral damage widths about 2.7 times lower than those obtained after treatment with the clear tip.

A recognition survey of granular corneal dystrophy type 2 genetic detection in China

AIM:To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2(GCD2)by a questionnaire conducted among citizens in five cities in China.METHODS:The data were collected by questionnaire,and analyzed by Chi-square test and one-tailed t test in IBM SPSS statistics.RESULTS:Based on the survey data on the awareness of GCD2 genetic detection in this study and the positive predictive analysis report of the citizens in five cities in China,the vast majority(84.2%)of respondents had never heard of it and did not know that GCD2 patients have been prohibited from performing excimer surgery that can deteriorate GCD2 patients’condition even leading to blindness.Though 3.4%of patients understood GCD2 very much,they have no idea that GCD2 could not be 100%accuracy diagnosed by the conventional inspection methods.CONCLUSION:It is feasible and necessary to use GCD2 genetic detection as an excimer preoperative examination project.In order to promote the development of detection project,a few improvements should be carried out in terms of the promoting efforts,costs,and research progress.

Evaluation of greenlight photoselective vaporization of the prostate for the treatment of high-risk patients with benign prostatic hyperplasia

Aim:To explore the feasibility and safely of greenlight photoselective vaporization of the prostate(PVP)on high-risk patients presenting with lower urinary tract symptoms suggestive of benign prostatic hyperplasia(BPH)and to evalu- ate their clinical and voiding outcome.Methods:A total of 85 high-risk patients with obstructive BPH underwent PVP with an 80W potassium-titanyl-phosphate laser,which was delivered through a side-deflecting fiber with a 23 Fr continuous flow cystoscope.Operative time,blood loss,indwelling catheterzation,international prostate symptom score(IPSS),quality of life score(QoL),uroflowmetry,postvoid residual urine volume and short-term complication rates were evaluated for all patients.Results:All patients got through the perioperative period safely.The chief advantages of PVP were:short operative time(25.6±7.6min),little bleeding loss(56.8±14.3mL)and short indwelling catheterization(1.6±0.8d).The IPSS and QoL decreased from(29.6±5.4)and(5.4±0.6)to(9.5±2.6)and(1.3± 0.6),respectively.The vast majority of patients were satisfied with voiding outcome.The mean maximal urinary flow rate increased to 17.8 roLls and postvoid residual urine volume decreased to 55.6mL.These results are signifi- cantly different from preoperative data(P<0.05).No patient required blood transfusion or fluid absorption.There were few complications and very high patient satisfaction after operation.Conclusion:PVP has a short operative time and high tolerance,and is safe,effective and minimally invasive for high-risk patients,therefore it might be considered as a good alternative treatment for high-risk patients with obstructive urinary symptoms as a result of BPH.

Standard manual capsulorhexis / Ultrasound phacoemulsification compared to femtosecond laser-assisted capsulorhexis and lens fragmentation in clear cornea small incision cataract surgery

Background:Femtosecond-laser assisted clear cornea cataract surgery may hold promise in safer and more effective procedures.We decided to perform a comparative study to standard manual incision phacoemulsification surgery.Methods:This is a single-center,single-intervention,and prospective comparative data evaluation of 133 consecutive cases subjected to cataract surgery.Group-A(Phaco),manual capsulorhexis&ultrasound phacoemulsification(n=66);Group-B femtosecond-laser assisted capsulorhexis and lens fragmentation(n=67),employing the LenSx laser(Alcon Surgical,Ft.Worth,TX).All cases were evaluated for refraction,visual acuity,keratometry,tomography,pachymetry,endothelial cell counts,intraocular pressure,and type of intraocular lens(IOL)implanted.The groups were matched for age,gender,pre-operative vision metrics,and cataract grade,and were followed up to 1 year.Results:In group-A post-operative uncorrected distance visual acuity(UDVA)was 20/20 or better in 61.5%and 20/25 or better in 78.5%of the eyes.The femtosecond laser group-B had improved outcomes(p=0.075 and p=0.042,respectively):post-operative UDVA was 20/20 or better in 62.7%of the eyes and 20/25 or better in 85.1%.Linear regression scatterplots of achieved versus attempted spherical equivalent had excellent regression coefficients(r^(2)=0.983 in group-A and 0.979 in group-B).There were 75.2%cases in group-A and 80.6%in group-B(p=0.8732)within±0.50 D of targeted refractive equivalent.Slight trend of under-correction was noted in group-A.Average residual manifest cylinder in the toric subgroup-A was-0.50 D(95%Limit-of-Agreement(LoA)=-0.78 D),and in toric subgroup-B-0.45 D(LoA=-0.45 D).Conclusions:Mean spherical equivalent refraction and visual acuity are comparable with laser cataract surgery compared with manual capsulorhexis&ultrasound phacoemulsification.Improved astigmatism correction may be among the benefits of femtosecond laser–assisted cataract surgery.Transient corneal edema may be a first day transient disadvantage in femtosecond laser–assisted cataract surgery.

Combined subfascial endoscopic perforator surgery and endovenous laser treatment without impact on the great saphenous vein for management of lower-extremity varicose veins

Background Conventional high ligation and stripping of the great saphenous vein （GSV） has a good curative effect but is highly traumatic with a considerable relapse rate. Subfascial endoscopic perforator surgery （SEPS） plus endovenous laser treatment （EVLT） could be applied as individual therapy. This study aimed to evaluate the feasibility of performing combined SEPS and EVLT without impacting GSV in the management of valvular insufficiency of the lower-limb venous perforators. Methods Placement of lower-limb venous perforator insufficiency was marked by ascending phlebography in 83 affected limbs from September 2010 to June 2011. After randomization, SEPS was performed on 41 limbs to address the insufficiency of the venous perforators under the deep fascia, in combination with EVLT to close the superficial varicose veins without impacting the GSV. The remaining 42 limbs were treated using traditional GSV phlebectomy as controls. Results Postoperatively, all varicose veins were resolved, with lightening of the pigmentation and healing of the ulcer. Within a follow-up period of 5-11 months, no symptoms had recurred. Compared with the control group, the operation time, the number of incisions sutured, and the in-hospital time decreased on average by 1.5 hours, 4.7, and 6.8 days, respectively （P 〈0.01 in all cases）. Conclusion Combined SEPS and EVLT for treatment of valvular insufficiency of the lower-limb venous perforators offer the advantages of microtrauma and rapid cure.

Intraocular lens power calculation following laser refractive surgery

Refractive outcomes following cataract surgery in patients that have previously undergone laser refractive surgery have traditionally been underwhelming.This is related to several key issues including the preoperative assessment(keratometry)and intraocular lens power calculations.Peer-reviewed literature is overwhelmed by the influx of methodology to manipulate the corneal or intraocular lens(IOL)powers following refractive surgery.This would suggest that the optimal derivative formula has yet been introduced.This review discusses the problems facing surgeons approaching IOL calculations in these post-refractive laser patients,the existing formulae and programs to address these concerns.Prior published outcomes will be reviewed.