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AAPOS Workshop

Pediatric refractive surgery: Corneal and intraoculartechniques and beyondEvelyn A. Paysse, MD,a Lawrence Tychsen, MD,b and Erin Stahl, MDc

SUMMARY Refractive surgery has now been used successfully to treat severe anisometropia andisoametropia associated with amblyopia in children who cannot wear standard spectaclesor contact lenses. Extraocular techniques include photorefractive keratectomy, laser-assisted subepithelial keratomileusis, and laser-assisted in situ keratomileusis. Intraoculartechniques include refractive lensectomy and phakic intraocular lenses and are still beinginvestigated in children for refractive errors outside the treatment dose capabilities ofthe excimer laser. This workshop discusses the various techniques, how and when to useeach, and their risks and benefits. Newer techniques currently being used in adults thatmay someday be used in children are also introduced. ( J AAPOS 2012;16:291-297)

Excimer laser surgery for high refractive error asso-ciated with amblyopia has been reported in thepublished literature with good visual acuity and

refractive results and minimal complications for over 15years.1-25 Intraocular refractive procedures have beenreported for up to 7 years in the published literature,albeit in smaller numbers for higher refractive errors,also with good visual and refractive outcomes and fewcomplications.26-32 Although refractive surgery has beenshown to be effective for improving vision and reducingrefractive error in children, it is important to rememberthat it is appropriate only in special circumstances for

a few pediatric subpopulations. This workshop discussesappropriate populations to consider for refractivesurgery, eligibility criteria, the nuts and bolts of settingup a pediatric refractive surgery center, extraocular andintraocular techniques for normalizing refractive error inchildren, and newer technology that may prove useful inchildren in the future.

Conventional amblyopia therapy consists of the follow-ing steps: (1) clearing the ocular media if there is a visualobstruction such as a leukoma, visually significant cataract,or vitreous hemorrhage; (2) correcting significant refrac-tive error with either spectacles or contact lenses; and(3) occlusion or pharmacologic and/or optical penalizationof the fellow eye.33-35 These conventional therapies aresuccessful in the majority of children with amblyopia.

There are, however, several subsets of the pediatricpopulation in which conventional therapies are oftenineffective, as follows: Children with high-magnitude isoametropia who are

spectacle noncompliant or intolerant. These childrentypically have neurobehavioral abnormalities related togenetic mutations, autism, cerebral palsy, or prematu-rity.

Children with severe anisometropia who are noncompli-ant or intolerant of spectacle and contact lens wear.

Children with high ametropia, either anisometropia orisoametropia, who have other special circumstances,

such as craniofacial anomalies, ear deformities, or neckhypotonia that preclude the use of refractive correction.In the past, no other treatment options existed for these

patients, resulting in varying levels of visual impairmentand, with continued lack of treatment, degradation offunctional vision (uncorrected visual acuity)up to 20/3400(ie, counting fingers) in the affected eye(s),30 tantamountto functional blindness in bilateral cases.

Children with high levels of uncorrected refractive errorunnecessarily exist within a cocoon of visual isolation

where visual stimuli are noxious and frightening. Thisoften leads to or compounds antisocial behavior, lack ofinterest, and behavioral difficulties. Refractive surgerycan normalize refractive error in these children. The re-sulting improvement in visual acuity in bilaterally affectedchildren improves their developmental quotient and socialskills16 (Paysse EA, Gonzalez-Diaz M, Wang D, Turcich

MR, Hager J, Coats DK. Developmental improvement inchildren with neurobehavioral disorders following photo-refractive keratectomy for bilateral high-refractive error.

J AAPOS 2011;15:e6 [Abstract 022]).Untreated severe refractive error in young children can

also result in severe amblyopia akin to deprivation ambly-opia occurring with dense congenital cataract or leukoma.

This form of amblyopia must be treated in the same way we

Author affiliations:aBaylor College of Medicine, Texas Childrens Hospital, Houston, Texas;bSt. Louis Childrens Hospital, Washington University Medical Center, St. Louis, Missouri;cChildrens Mercy Hospital, University of MissouriKansas City, Kansas City, Missouri

Submitted May 31, 2011.Revision accepted January 29, 2012.Correspondence:Evelyn A. Paysse, MD, TexasChildrens Hospital,6701 Fannin St, MC

640.00, Houston, TX (email:[email protected]).Copyright 2012 by the American Association for Pediatric Ophthalmology and

Strabismus.1091-8531/$36.00doi:10.1016/j.jaapos.2012.01.012

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mailto:[email protected]://dx.doi.org/10.1016/j.jaapos.2012.01.012http://dx.doi.org/10.1016/j.jaapos.2012.01.012mailto:[email protected]


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approach other causes of vision deprivation: by offeringa surgical procedure that treats the cause of the vision dep-rivation, namely, refractive surgery. Surgery can treat highrefractive error and it appears to be safe at medium-termfollow-up (10 years); it is thus an appropriate treatmentfor these conditions when standard therapy fails and thealternative will be certain functional blindness in the

affected eye(s). Refractive surgery in the future may evenbe used to prevent refractive amblyopia.

Types of Refractive Surgery Used in Children

To the lay public, refractive surgery is synonymous withLASIK (laser in situ keratomileusis) surgery. For the re-fractive surgeon, the surgical devices and techniques avail-able for improving uncorrected vision are many, and newtechnology is being developed and investigated at a rapidpace. The refractive surgeons current armamentariumincludes lasers, corneal inlays, microwave devices, bio-chemical manipulation, and intraocular lenses.

Refractive surgery has been evolving since 1950, whenJose Barraquer developed an instrument to create a cornealflap to correct refractive error. Radial keratotomy, epiker-atophakia, and hexagonal keratotomy followedtechniques that have been supplanted by the introductionof laser technology. Excimer laser was first proposed forthe treatment of corneal refractive errors by Stephen

Trokel in 1983. Laser technology evolved rapidly andphotorefractive keratectomy (PRK) was first performedon humans in the mid-1980s by Theo Seiler. As a meldingof PRK and Dr. Barraquers early thoughts on keratomi-leusis, LASIK was first performed in 1990 by Lucio

Burrato and Ioannis Pallikaris. Today, extraocular laserprocedures are performed by the excimer laser and includePRK and laser-assisted subepithelial keratectomy (LA-SEK), henceforth referred to as advanced surface ablation(ASA) and LASIK. ASA and LASIK have been approvedto treat up to 12 D of myopia, 5 D of hyperopia, and4 D of astigmatism.

Extraocular procedures change the corneal power byflattening or steepening the corneal curvature. Theintraocular procedures in use today are typically used totreat higher refractive errors that fall outside the treat-ment parameters for excimer laser or in cases where thecornea is too thin for the safe application of the excimerlaser.

Phakic intraocular lens (IOL) procedures add or reducelens power. In the United States, phakic IOLs have beenavailable since 2004 and are only FDA-approved for adultsfor myopia.36 An IOL is placed into either the anterior orthe posterior chamber, with preservation of the naturalcrystalline lens. The anterior chamber lens available inthe United States is the Verisyse lens (Abbott MedicalOptics, Santa Ana, CA), the same lens as the Artisan phakicIOL marketed in Europe and Asia. This phakic IOL can beused to treat severe high myopia if the anterior chamber isdeep enough to tolerate the lens (minimum 3.2 mm).

Hyperopic phakic IOLs are available by special requestand are distributed by Ophthtec (Boca Raton, FL, byspecial request); the same anterior chamber depth require-ments hold. The posterior chamber lens that is available inthe United States is the Visian ICL (Staar Surgical,

Monrovia, CA). No minimum anterior chamber depth isrequired for this lens. The other procedure in use today

that changes lens power is refractive lens exchange, alsoknown as clear lens extraction. In this procedure, the non-cataractous natural lens is removed with or without IOLplacement as a refractive procedure. Currently, bothexcimer and intraocular refractive procedures are utilizedoff-label in children.

Procedures

Photorefractive Keratectomy

We prefer ASA to LASIK because it has a lower risk profile(Table 1). The main risk of ASA is corneal haze, whichoccurs infrequently if the proper postoperative regimen is

followed. Our procedure for PRK from induction to anes-thesia recovery is as follows: general anesthesia can be in-duced either in a separate induction room or in the sameroom as the laser. An intravenous line is placed after thechild is asleep, and a laryngeal mask airway is insertedinto the posterior pharynx. If the childwas induced in a sep-arate induction room, then he is transported to the adjacentoperating room fully monitored. In the operating room,the laryngeal mask is connected to a standard semiclosedcircle system through which the patient receives inhala-tional anesthesia per the anesthesiologist. Propofol mayalso be used if desired. Once the child is anesthetized, an

examination under anesthesia is performed to reconfirmpachymetry, keratometry, axial length, and intraocularpressure. A slit-lamp examination and a nondilated fundusexamination are also performed.

The PRK is then performed as follows. The childs headis first fixated in the desired position with a pneumatic pil-low so that the orbital rim is orthogonal to the axis of thelaser. The surgeon fixates the eye with forceps to positionthe plane of the iris perpendicular to the laser beam, takingcare to avoid globe/corneal distortion. The laser aimingbeam is centered on the entrance pupil. The central corneais marked to 9 mm using a corneal marker, and the epithe-lium is removed manually or with an automated rotarybrush. The desired refractive correction is programmedinto the excimer laser machine. Autotracking is employedto negate minor head oscillations due to respiration, andthe laser procedure is performed. Topical nonsteroidalanti-inflammatory drug and fourth-generation fluoroqui-nolone and fluorometholone 0.1% are placed in the treatedeye and a disposable contact lens is placed on the cornea. Atransparent shield is then taped over the operated eye(s).Goggles can be used instead. Immediate postoperativemedications include topical moxifloxicin and fluorometho-lone (0.1%) four times daily in the treated eye(s). Topicalketorolac can be used up to four times a day as needed

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for discomfort for the first two postoperative days. Oralvitamin C (500 mg) once a day is also prescribed.37 Oralacetaminophen, ibuprofen, or narcotic can also be usedfor postoperative discomfort. After 1 week, the bandagecontact lens is removed and the child is maintained on flu-orometholone (0.1%) four times a day for 6 months and thesame dose of oral vitamin C for 1 year. The other medica-tions are discontinued. The postoperative follow-up sched-ule at our institutions is at a minimum at 5-7 days, 1 month,2-3 months, 6 months, 12 months, and then yearly thereaf-ter. If amblyopia therapy is continued, follow-up may bemore frequent as indicated.

Safety of ASA versus LASIKAlthough LASIK has been shown to be effective in childrento correct refractive error, ASA has several advantages. Themain advantage of ASA over LASIK is that no corneal flapis created; thus, there is no risk of flap loss, epithelialin-growth, or flap striae, which may occur with LASIK.

Also, because ASA is performed on the surface of the cor-nea, the posterior stromal bed remains thicker, with lessrisk of keratectasia, an important consideration becausemost children that need treatment with excimer laser pro-cedures require a large treatment dose. Fortunately, therehave been no reported cases to date of keratectasia follow-ing PRK in children. The main long-term risk of ASA iscorneal haze. In our experience, severe corneal haze occursrarely, typically only when the topical steroid (fluorome-tholone) was discontinued too early (usually before 5 monthspostoperatively); topical fluorometholone should be usedfor 6 months and occasionally longer. Topical mitomycinhas been shown to reduce the risk of haze in adults.38 Itis being considered in children. The risk of corneal hazecan be further controlled by limiting ablation treatmentsto within the FDA-approved treatment parameters. Theother important issue with excimer refractive proceduresin general is refractive regression. Regression of treatmenteffect will occur over the first 6 to 12 months and then

it usually stabilizes. There may be still some myopic shiftover the years, but that may well be due to eye growth.

Myopic regression also tends to be more severe with higherexcimer treatment doses.

Phakic IOL Procedure

The implant30we prefer and thatis used most in several re-ports from other investigators 39-41 is the anterior chamber

Artisan iris-enclaved IOL.42-44 As mentioned previously,the myopic Verisyse lens in the United States is the samelens as the Artisan lens marketed in Europe and Asia.Safe insertion and lower long-term risk for loss of cornealendothelial cells require an anterior chamber depth 3.2 mmor greater. A small iridotomy or iridectomy is performedduring the procedure to reduce the chance of pupillaryblock. In cases of high isoametropia, we recommend thatthe eyes are implanted sequentially, with approximately1 month elapsing before operation on the second eye.30

Because childrens eyes heal rapidly, a superior clear cor-neal incision can be employed that achieves the therapeuticeffect of a relaxing limbal incision, as most astigmatism inchildren is with the rule.Preoperative astigmatism may bereduced by about 50%.28,30,45 Absorbable sutures [9-0polyglactin 910 (Vicryl; Ethicon Inc., Cincinnati, OH)]are used to avoid reanesthetizing the child for suture re-moval. In some children, arm restraints may be needed

for the first postoperative week to prevent eye rubbing.Posterior chamber phakic IOLs have alsobeen implantedin children.26,46,47Tychsen and colleagues30 provide a de-tailed description of pediatric phakic IOL implantation.

Phakic Intraocular Lens Safety

Phakic IOL implantation is not subject to significant re-fractive regression and may be considered the currentlypreferred method for surgical correction of pediatric myo-pia and hyperopia beyond the range of ASA.30,31 Anothermajor advantage is reversibility. The anterior chamberdepth required for an iris-enclaved IOL precludes the use

Table 1. Refractive surgery techniques

Procedure FeaturesRefractive

correction range Risks

ASA Excimer surface ablation Myopia: up to 12 DHyperopia: up to 5 DAstigmatism: up to 4 D

Corneal haze, Regression of treatment effect,Keratectasia (extremely rare)

LASIK Excimer stromal ablation Same as ASA Regression of treatment effect, epithelial ingrowth,keratectasia (more common than with ASA), flap

problems (loss, striae, debris under flap, free flap,decentered flap), diffuse lamellar keratitis, dry eye

PhIOL Anterior chamber or posteriorchamber phakic intraocular lens

Unlimited Endophthalmitis, corneal endothelial cell loss, glaucoma,pigment dispersion, cataract

RLE Procedure is identical to cataract surgeryexcept the crystalline lens is notcataractous. The purpose is to inserta properly powered intraocular lens.

Unlimited Endophthalmitis, corneal endothelial cell loss, glaucoma,pigment dispersion, retinal detachment

ASA, advanced surface ablation; LASIK, laser-assisted in situ keratomileusis; PhIOL, phakic intraocular lens; RLE, refractive lens exchange.

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of this lens in some children. Children who have high len-ticular myopia after retinopathy of prematurity may also beunsuitable because they often haveshallow chambers (ar-rested anterior segment growth48). The major concern

with the use of any phakic IOL in a child is the long-term effect on the corneal endothelium. Experience todate indicates that endothelial cell loss is low, no greater

than that reported in adult implantation.

26,29,30,39-41,46,47,49

The data here, however, are meager and accurateendothelial cell counts are difficult to obtain in thechildren who may benefit most from implantation.30 It isimportant to note that any refractive surgical procedure,including ASA, phakic IOL, or refractive lens exchange,can be expected to cause some reduction of endothelialcell density. What we currentlydo not know and need toknow is the comparative loss.30 Success with implantationof posterior chamber phakic IOLs in children has alsobeen reported.46 Because these implants lie immediatelyadjacent to the iris pigment layer and lens, they posegreater risk for pigment dispersion and cataract formation

in a pediatric eye.

Refractive Lens Exchange Procedure

For children with ametropia exceeding approximately 20 D(the upper limit for phakic IOL power) or anterior chamberdepth less than 3.2 mm, a refractive lens exchange procedureis required.28,45 Standard pediatric lensectomy, posteriorcapsulectomy, and anterior vitrectomy techniques areemployed. If emmetropia is to be achieved, a foldable,acrylic IOL (monofocal or multifocal) is implanted,depending on axial length and lens power calculations. A

primary capsulectomy/anterior vitrectomy is advisabledue to the high rate posterior capsule fibrosis inchildrens eyes when the capsule is preserved, just as inpediatric cataract extraction.28We perform an examinationunder anesthesia a few months before the planned lensec-tomy. The peripheral retina is examined in detail by de-pression. Accurate, immersion axial lengthmeasurementsare obtained. Tychsen and colleagues28 and Ali andcolleagues45 may be consulted for detailed descriptions ofrefractive lens exchange.

Refractive Lens Exchange SafetyRefractive lens exchange is the only option for children withshallow anterior chambers who have refractive error beyondthe range of effective ASA treatment.28,45 Removing thenatural lens makes accommodation impossible. The majorlong-term risk of refractive lens exchange is retinal detach-ment, with an estimated prevalence in adults of 0.26% to2.2%.50,51 If the axial length exceeds approximately 29mm, a barrier diode laser therapy can be applied to reducethe risk.52,53This retinal detachment risk must be weighedagainst the certainty of blur-induced blindness in theaffected eyes if uncorrected.

Improvements in Visual Acuity and VisualFunction

Is refractive surgery in children effective? Yes, with a qualifi-cation. The relevant measure of effectiveness in children

who are completely noncompliant with spectacle or contactlens use is uncorrected visual acuity. Our work, and that ofother investigators, shows substantial gains in uncorrected

visual acuity using either ASA, LASIK, phakic IOLs, or re-fractive lens exchange. Impressive gains are also achievedin isoametropic children.1,3,18,28,30 More modest butconsistent gains are achieved in the amblyopic eyes ofanisometropic children.6,7,9,12-16,18,22,24,54,55 Improvementsin best-corrected visual acuity have also been reported.36

The qualification is that one seldom achieves in childrenthe precision commonplace in adult refractive surgery.

The goal in pediatric surgery is to prevent blinding levelsof refractive amblyopia.

In children with isoametropia averaging 7.1 D (andvisuomotor comorbidities), treated using ASA, theaverage

gain in uncorrected visual acuity was 13-fold,18

froma mean 20/810 to a mean 20/60. In the subset of thesechildren who would wear glasses during testing, the gainin best-corrected visual acuity was an average twofold. Inchildren with ametropia averaging 15 D (and visuomotorcomorbidities) treated by phakic IOL implantation, theaverage gain in uncorrected visual acuity was 60-fold,from a mean 20/3400 to a mean 20/57.30 The averagegain in best-corrected visual acuity was twofold. Similargains in uncorrected (100-fold) and best-corrected visualacuity have been reported in children with isoametropia,averaging 19 D, treated by refractive lens exchange.28

The majority of reports on pediatric refractive surgeryreflect use of ASA to treat anisometropic ambly-opia.3,7,8,11-19,22,56,57 There have also been quite a fewstudies using LASIK, and these also show reliable visualand refractive results.6,7,20,21,24,58 These case series showa reliable response: initial correction of large refractiveerror to 1.5 D of emmetropia in approximately 90% oftreated eyes. The gains in uncorrected or best-corrected

visual acuity range from modest to excellent (two to sevenlines of improvement), with no reported losses of visualacuity. One half or more of the children treated haveimproved binocular fusion and stereopsis.12-15,22

Beyond the gains measured in office testing of acuity or

binocularity, refractive surgery has also been shown to havepositive effects on childrens day-to-day visual function(Paysse EA, et al. Developmental improvement in children

with neurobehavioral disorders following photorefractivekeratectomy.).30 Enhanced visual awareness, attentiveness,and social interactions have been reported in approxi-mately 80% of children treated for high isoametropia.

When measured using Likert-scale visual function ques-tionnaires before and after refractive surgery, scores foreye contact, tracking, observing and reacting, judgingdepth and distance, and reading improved by an average73% in isoametropic children and 58% in anisometropic

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children (Ghasia FF, Wilson BS, Gordon MO, BrunstromJE, Tychsen L. Validating a pediatric cerebral palsy visuo-motor impairment questionnaire. IOVS 2007;48:ARVOE-Abstract 954).30,59 The developmental quotient,calculated as the mental age divided by the biological agemultiplied by 100, has also been shown to improvefollowing PRK in children with neurobehavioral disorders

and severe isoametropia (Paysse EA, et al. Developmentalimprovement in children with neurobehavioral disordersfollowing photorefractive keratectomy.).

Strategy for Pediatric Refractive Surgery

The general strategy for children eligible for refractivesurgery is as follows. Children with hyperopic isoametro-pia or anisometropia of 3-6 D or myopic isoametropia oranisometropia of 3-11 D are treated with ASA. Children

with refractive errors beyond this range can be treatedwith a phakic IOL if the anterior chamber depth is 3.2 mmor greater. The remainder of the children can undergo

refractive lens exchange. These procedures need to be per-formed in the majority of cases under general anesthesia.

Refractive Surgery Technologies on theHorizon

Since 1990, excimer laser technology has gone through20 years of maturation. Broad-beam lasers with abrupttransition zones have given way to variable and flying-spot lasers for precise tissue ablation with smooth blendzones. The speed of excimer lasers has increased fromseveral minutes per treatment to as fast as 5-10 seconds.

Eye tracking systems have been implemented that allowfor exact laser treatments as saccades and grosseye move-ments can be followed during laser ablation,60 includingpatients with mild to moderate nystagmus.

The original goal for refractive surgery was to move theadult patient with high refractive error being treated withthick glasses or contact lenses to a more functional opticalsystem and a reduced need for this powerful spectacle orcontact lens refractive correction. In modern laser refrac-tive surgery, the postoperative goal is vision better than20/20. To achieve this goal, there have been advances inthe laser ablation treatment patterns. Attention has turnedto reducing optical aberrations already present in thepatients optical system and to preventing the creation ofnew aberrations. To achieve this, new anterior segmentand wavefront diagnostic devices have beendeveloped tomap the cornea and the entire visual system.61A further ad-

vancement in laser refractive surgery is the transition frommanual microkeratomes to femtosecond lasers to make thecorneal flap in LASIK surgery. This technology reducesthe risks involved in LASIK surgery as flap creation ismade safer and more accurate.62

New excimer laser platforms have minor changes inergonomics, speed, and beam patterns but no significanttechnology differences. Diagnostic equipment development

continues to progress and will likely lead to the next ad-vances in laser refractive surgery. In the United States, laserstreatments are programmed to treat based on phoroptermeasurements or wavefront measurements. New diagnosticcapabilities are emerging that can accurately map corneal,epithelial, lens, and wholeeye contributions to the error ofthe optical system.63,64 With these new diagnostic

capabilities, future laser ablation patterns can be targetedto correct the specific defects contributing to an individualpatients refractive error.

New technologies are emerging that address corneal-and lens-based procedures to correct refractive error andpresbyopia. One of the most versatile tools for new refrac-tive procedures is the femtosecond laser. This laser, mostcommonly used to create LASIK flaps, can be used to cutcorneal and intraocular tissues precisely. Proposed cornealprocedures include the creation of intrastromal annularincisions to treat presbyopia,65 laser-assisted astigmatickeratotomy incisions for the treatment of astigmatism,66

penetrating cornea incisions for use in refractive lens sur-

gery,67 and the creation of intrastromal pockets for theplacement of corneal inlays.68 Lens-based femtosecondprocedures include the creation of an anterior or posteriorcapsulotomy and disassembling the lens nucleus for easyremoval by aspiration.69The femtosecond laser will likelybecome an essential tool for the comprehensive refractivesurgeon.

Advances are also being made in other aspects of cornealrefractive surgery. A novel technology is the use of micro-

waves in the peripheral cornea toflatten the central corneatemporarily to treat low myopia.70This noninvasive proce-dure could be a safe, office-based treatment for children

with low myopia. This treatment is currently being usedinternationally and will soon be investigated in the UnitedStates.

As a complement to such temporary treatments, cornealcollagen cross-linking may be indicated to lock-in theeffect. In corneal cross-linking the cornea is saturated

with a riboflavin solution and then exposed to ultravioletlight. Thistreatment increases the stiffness of the corneaby 300%71 and can also be used to stabilize ectaticcorneal conditions such as keratoconus, infectious cornealmelts, postrefractive ectasia, and pellucid marginaldegeneration.71-73

For many patients, corneal refractive surgery is not theideal procedure to correct their refractive error. In casesof thin corneas, previous surgery, overly steep or flatkeratometry, or for refractive errors outside of the rangeof corneal surgery, lens-based surgery may be a preferredoption. New advances in phakic IOLs include foldablelenses that could be inserted through a smaller incisionand modification of materials and footplates to make thelenses more tolerable for the angle and corneal endothe-lium.74 Refractive lens exchange patients may have futureoptions of using accommodative, light adjustable, orbag-filling lens models that allow for accommodation andeliminate the need for glasses to improve near vision.

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As knowledge and use for each of these new technologiesincrease for the adult population, potential applications forthe use in children will arise. Although it is often difficult tonavigate the additional challenges of applying adult tech-nology to children, these new technologies may have thepotential to address unique needs of young patients andshould not be ignored.

In conclusion, surgery for children with high refractiveerror unresponsive to standard therapy appears to be effec-tive at this medium-term follow-up. Interventional caseseries and case-control studies of excimer laser refractivesurgery, phakic IOLs, and refractive lens exchange in chil-dren have demonstrated improvements in uncorrected andbest-corrected visual acuity, and developmental and socialfunctioning, in addition to reduced refractive error withfew complications. The majority of children with eitherunilateral or bilateral refractive error do well with contactlenses or spectacles, but for the subset of children who donot, refractive surgery is a reasonable surgical alternativeand the last option to prevent a lifetime of severe visual im-

pairment. Randomized clinical trials would be helpful toconfirm or disprove efficacy.

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