Anterior chamber iris-fixated phakic intraocular lens for anisometropic amblyopia

Refractive Surgery in Myopic Children

In this paper, we summarize the current knowledge on refractive surgery performed in the myopic pediatric population. We describe the main concerns about refractive surgery in myopic children and the indications for refractive surgery in this age group. We present a range of surgical procedures that are being used for the management of unilateral/bilateral myopia in children: corneal refractive surgery (PRK, LASEK, LASIK, FS-LASIK and SMILE) and intraocular refractive surgery (phakic intraocular lens implantation, refractive lens exchange or clear lens extraction), with both their advantages and drawbacks. We also describe the various complications and measures to prevent them.

The Outcome of Artisan Intraocular Lens Implantation in Children: A Narrative Review

Aphakia is a condition in which the eye's crystalline lens is not in its proper position because of a perforating injury, surgical removal, dislocation of the lens, or congenital anomaly. The management of aphakia can be either conservative or surgical. Various surgical techniques could be used, including retro pupillary-fixated iris-claw intraocular lenses (IOLs) and anterior-fixated iris-claw IOLs. One of the challenges faced by ophthalmologists is the optical rehabilitation of pediatric aphakic patients because a child's eye is still growing, resulting in fundamental variations in their refractive elements, and the immature visual system faces the risks of amblyopia development in the case of defocus or inequality of visual input between both eyes. There is also the risk of the incidence of side effects that can be accepted in adults but not in children. Finally, accurate postoperative supervision and optical rehabilitation in pediatrics will be more complex than that in adults. This review showed that it is possible to place, replace, and exchange the Artisan IOL with minor surgical trauma. Hence, this procedure can be an acceptable therapeutic method for correcting the developmental refractive changes of the growing aphakic eye. However, some worries are still caused by probable long-term side effects, including endothelial cell loss. Finally, a significant attempt at visual rehabilitation is to treat pediatric aphakia with Artisan IOL.

Visual Autism

Autism spectrum disorder (ASD) is a lifelong neurodevelopmental disorder characterized by deficits in social communication and restricted, repetitive behaviors. It affects approximately 2.2% of children. Both genetic and environmental risk factors have been identified for ASD. Visual comorbidities are relatively common among children with ASD. Between 20 and 44% of ASD children have visually significant refractive error, on-third have strabismus, and one-fifth have amblyopia. In addition, ASD is 30 times more common in children with congenital blindness. It is unknown whether the association of ASD with visual morbidity is causal, comorbid, or contributing. Structural and functional abnormalities have been identified in MRIs of ASD children, and ASD children have been noted to have aberrant eye tracking. ASD children with visually significant refractive errors and poor spectacle compliance (present in 30% of ASD children) offer the opportunity for investigation into how improved visual acuity influences ASD behaviors. In this review, we focus on what is known of the visual system, refractive surgery, and ASD.

Impact of Ocular Conditions and Improvements After Refractive Surgery in Quality of Life for Children With Neurodevelopmental Disorders

PURPOSE

This study aims to characterize the eye-related quality of life of children with neurodevelopmental and ocular disorders at baseline and after refractive surgery.

DESIGN

Prospective interventional case series.

METHODS

We enrolled children and adolescents 5 to 18 of age with neurodevelopmental disorders undergoing refractive surgery (6 for pre-/postsurgical assessment and 14 for baseline analysis). Eye-related quality of life was measured using the Pediatric Eye Questionnaire (PedEyeQ). Baseline levels of adaptive functioning and social behaviors were measured using the Adaptive Behavioral Assessment System (ABAS-3) and Social Responsiveness Scale (SRS-2). We assessed the correlation between baseline PedEyeQ scores, number of ocular comorbidities, magnitude of refractive error, and ABAS-3 and SRS-2 scores.

RESULTS

At baseline, 14 patients demonstrated decreased median eye-related quality of life (<60/100) in 5 of 9 PedEyeQ domains, moderate deficiencies in social behaviors (SRS-2 median 71, range 49-90), and low adaptive functioning (ABAS-3 median percentile for age of 0.100). Baseline PedEyeQ scores did not correlate with magnitude of refractive error or adaptive functioning scores but did correlate with number of ocular comorbidities and social behavior scores. Six patients have undergone refractive surgery without complication. Postoperatively, 11 of 11 eyes were within ±1.5 diopters spherical equivalent. Four of 6 patients exhibited clinically significant improvements in PedEyeQ scores after surgery.

CONCLUSIONS

Even in the presence of significant social and adaptive impairments, quality of life in children with neurodevelopmental disorders is decreased by ocular disorders. Refractive surgery is associated with clinically significant improvements in eye-related quality of life.

Anterior Chamber Iris-Fixated Phakic Intraocular Lens Implantation for Treatment of High Anisometropia in Children: Long-term Results

PURPOSE

To evaluate the long-term efficacy of anterior chamber iris-fixated phakic intraocular lens (PIOL) implantation in the treatment of high myopic (> -9.00 diopters [D]) or hyperopic (> +6.00 D) anisometropia in children with intolerance to spectacles or contact lenses.

METHODS

A total of 58 children with anisometropic myopia (range: -9.25 to -18.50 diopters [D]) and 13 children with anisometropic hyperopia (range: +6.00 to +8.50 D) underwent unilateral iris-claw PIOL implantation from 2008 to 2018. The mean age was 6.7 years. The mean follow-up was 38.5 months. Target refraction was emmetropia.

RESULTS

The cycloplegic refraction (mean spherical equivalent) improved from -12.47 D (range: -9.25 to -18.50 D) to -0.73 D (range: +0.75 to -1.50 D) in myopic eyes and reduced from +7.15 D (range: +6.00 to +8.50 D) to +0.94 D (range: -0.50 to + 1.75 D) in hyperopic eyes. Eighty-four percent of eyes were corrected to within ±1.00 D of emmetropia. The mean uncorrected distance visual acuity (UDVA) improved from 1.74 ± 0.36 to 0.45 ± 0.28 logarithm of the minimum angle of resolution (logMAR) (P = .0014). The mean corrected distance visual acuity (CDVA) changed from 0.68 ± 0.32 to 0.27 ± 0.15 logMAR (P = .02179). The safety index was 2.18 and the efficacy index was 1.51. The mean pre-operative endothelial cell count of 2,874.7 cells/mm² changed to 2,685.3 cells/mm² at 2 to 6 years postoperatively. Binocular vision quality was improved in 55 patients. No patient had serious complications or lost any Snellen lines of CDVA.

CONCLUSIONS

Iris-fixated PIOL implantation is an effective and safe method in the treatment of high anisome-tropic myopia and hyperopia and amblyopia in pediatric patients who are noncompliant with spectacles or contact lenses. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XX-XX.].

Evaluation of the efficacy, safety, and stability of posterior chamber phakic intraocular lenses for correcting intractable myopic anisometropic amblyopia in a pediatric cohort

BACKGROUND

Myopic anisometropic amblyopia in pediatrics is one of the most challenging clinical situations that can face an ophthalmologist. Conventional correction modalities for myopic anisometropia, using spectacles, contact lenses, and/or occlusion therapy, may not be suitable for some pediatric patients or for some ocular conditions. This may lead to the development of anisometropic amblyopia. The aim of the present study was to evaluate the visual and the refractive efficacy, safety, and stability of Posterior Chamber Phakic Intraocular Lenses (PC-pIOLs) for correcting myopic anisometropic amblyopia in a pediatric cohort.

METHODS

This case series, prospective, interventional study was conducted at Watany Eye Hospital, Cairo, Egypt. It comprised children and teenagers with myopic anisometropic amblyopia and unsuccessful conventional therapy. After implantation of Intraocular Collamer Lenses "ICLs" (Visian ICL, Model V4c, STAAR Surgical, Monrovia, California, USA), postoperative follow-up visits were scheduled, with automated refraction and Pentacam imaging performed.

RESULTS

The study enrolled 42 eyes of 42 patients. The age range was 3 to 18 years (mean ± SD = 10.74 years ±4.16). The mean preoperative spherical equivalent (SE) was - 12.85 D ± 2.74. The results declared a significant improvement in the postoperative Corrected Distance Visual Acuity "CDVA" (P value < 0.01) and SE (P value < 0.01). The efficacy index had a value of 1.18 ± 0.3 and the safety index was 1.09 ± 0.24. The follow-up visits had a mean ± SD of 14.67 months ±16.56 (range of 1 to 54 months). The results showed a refractive stability, with statistically insignificant improvements in the patients' visual acuity and refractive status on evaluating the enrolled pediatrics during the follow-up visits compared to the first postoperative visits. No postoperative complications were encountered. Worthy of mention is that there was a significant (80%) non-compliance with the prescribed postoperative occlusion therapy.

CONCLUSIONS

The present study, with the longest reported follow-up range, declared the long-term efficacy, safety, and stability of Visian ICLs for correcting myopic anisometropic amblyopia in pediatrics. The reported non-compliance with occlusion therapy validates the early implantation of Visian ICLs in cases with failed conventional therapy to guard against anisometropic amblyopia.

Visual outcomes after refractive laser corneal surgery and phakic IOL in amblyopic eyes

PURPOSE

To evaluate the outcomes of laser corneal surgery and phakic IOL surgery in adult amblyopic eyes.

METHODS

Retrospective assessment was done in 688 amblyopic eyes 640 patients who underwent LASIK or phakic IOLs. Ophthalmological evaluation included measurement of uncorrected (UDVA) and corrected (CDVA) distance visual acuities. Analysis of modulation transfer function (MTF) was also done post-operatively as a measure of contrast sensitivity. Patients completed follow-up examinations at 1 day, 3 day, 3 months and 12 months after surgery.

RESULTS

The mean patient age was 24.30 ± 3.04 years with 59% females. The CDVA of amblyopic eyes improved significantly from the mean preoperative level of 0.48 ± 0.18 to 0.59 ± 0.18 at 12 months. There was improvement in the contrast sensitivity at all spatial frequencies. Refractive errors were corrected in both LASIK and phakic IOL group, but there was no clinically significant difference in visual outcomes between each group.

CONCLUSION

Laser vision correction and phakic IOL surgery for amblyopic eyes are promising alternative methods for improving visual outcomes in adult refractive amblyopia patients who have failed with conventional approaches.

New advances in amblyopia therapy II:

The treatment of anisometropic or ametropic amblyopia has traditionally enjoyed a high treatment success rate. Early initiation and consistent use of spectacle correction can completely resolve amblyopia in a majority of patients. For those with anisometropic amblyopia that fail to improve with glasses wear alone, patching or atropine penalisation can lead to equalisation of visual acuity. However, successful treatment requires full-time compliance with refractive correction and this can be a challenge for a patient population that often has one eye with good acuity without correction. Other barriers for a select population with high anisometropic  or ametropic amblyopia include rejection of glasses for various reasons including discomfort, behavioural or sensory problems, postural issues and visually significant aniseikonia. When consistent wear of optical correction proves difficult and patching/atropine remains a major obstacle, surgical correction of refractive error has proven success in achieving vision improvement. Acting as a means to achieve spectacle independence or reducing the overall needed refractive correction, refractive surgery can offer a unique treatment option for this patient population. Laser surgery, phakic intraocular lenses and clear lens exchange are three approaches to altering the refractive state of the eye. Each has documented success in improving vision, particularly in populations where glasses wear has not been possible. Surgical correction of refractive error has a risk profile greater than that of more traditional therapies. However, its use in a specific population offers the opportunity for improving visual acuity in children who otherwise have poor outcomes with glasses and patching/atropine alone.

Phakic Intraocular Collamer Lens (Visian ICL) Implantation for Correction of Myopia in Spectacle-Aversive Special Needs Children

PURPOSE

A subset of children with high anisometropia or isoametropia and neurobehavioral disorders have chronic difficulties with spectacle or contact lens wear. We report the results of refractive surgery in a series of these children treated using bilateral or unilateral intraocular collamer lens (Visian ICL) implantation for moderate to high myopia.

DESIGN

Prospective nonrandomized cohort study.

METHODS

Clinical course and outcome data were collated prospectively for 40 implanted eyes in 23 children (mean age 10.2 ± 5.3 years, range, 1.8-17 years). Myopia ranged from -3.0 to -14.5 diopters (D), mean -9.2 ± 3.5 D. Goal refraction was plano to +1 D. Correction was achieved by sulcus implantation of a Visian ICL (STAAR Surgical, Monrovia, California, USA) under general anesthesia. Mean follow-up was 15.1 months (range, 6-22 months).

RESULTS

Thirty-five eyes (88%) were corrected to within ±1.0 D of goal refraction; the other 5 (12%) were corrected to within 1.5 D. Uncorrected distance visual acuity improved substantially in all eyes (from mean 20/1050 [logMAR 1.72] to mean 20/42 [logMAR 0.48]). Spherical regression at last follow-up was an average of +0.59 D. Visuomotor comorbidities (eg, amblyopia, nystagmus, foveopathy, optic neuropathy) accounted for residual postoperative subnormal visual acuity. Thirteen of the 23 children (57%) had a neurobehavioral disorder (eg, developmental delay/intellectual disability/mental retardation, Down syndrome, cerebral palsy, autism spectrum disorder). Eighty-five percent (11/13) of those children were reported to have enhanced visual awareness, attentiveness, or social interactions. Endothelial cell density was measureable in 6 cooperative children (10 eyes), showing an average 1% decline. Central corneal thickness, measured in all children, increased an average of 8 μm. Two children (8%) required unplanned return to the operating room on the first postoperative day to alleviate pupillary block caused by a nonpatent iridotomy. No other complications were encounterd.

CONCLUSION

Visian ICL implantation improves visual function in special needs children who have moderate to high myopia and difficulties wearing glasses or contact lenses.

Phakic posterior chamber intraocular lens for unilateral high myopic amblyopia in Chinese pediatric patients

AIM

To assess the outcomes of posterior chamber implantable collamer lens (ICL) implantation in Chinese pediatric patients with unilateral high myopic amblyopia.

METHODS

Eleven eyes of 11 amblyopic patients aged 11.02±3.34y underwent ICL (model V4, Staar Surgical Inc.) implantation to treat unilateral anisometropia were studied. Visual acuity, cycloplegic refraction, contrast sensitivity, stereopsis, intraocular pressure (IOP), vaulting, corneal endothelial cell count and complications were evaluated. Patients completed follow-up at 3d, 1, 3mo and the last follow-up time (mean 8.18±2.82mo) after surgery.

RESULTS

The mean myopic anisometropia was -13.70±3.25 D preoperatively and +0.69±2.63 D at 8mo postoperatively. The logMAR corrected distance visual acuity (CDVA) of the amblyopic eye was 1.51±0.72 preoperatively and 0.75±0.40 at 8mo postoperatively. The logMAR CDVA at 3d, 1, 3 and 8mo postoperatively improved by a mean of 0.64, 1.55, 1.82 and 2.64 lines and gained more than 2 lines accounted for 18%, 45%, 45%, 64%, respectively. The contrast sensitivity of 0.5, 1 and 2 cpd in amblyopic eyes was significantly increased after surgery. No patient had near stereopsis recovery. The vaulting at 3 and 8mo was significantly lower than that at 1mo postoperatively. No other intraoperative or postoperative complications were observed, except an acute pupillary block glaucoma happened in a patient at two weeks postoperatively.

CONCLUSION

This short-term results indicate that ICL implantation can be a promising alternative therapy for high myopic anisometropic amblyopia in pediatric patients who have failed with conventional treatments and not suitable to corneal refraction surgery.

Visual acuity improvement in adult amblyopic eyes with an iris-fixated phakic intraocular lens: long-term results

PURPOSE

To evaluate the effect of implantation of iris-fixated phakic intraocular lenses (pIOLs) (Artisan) in adult amblyopic eyes.

SETTING

Optical Express, London, United Kingdom.

DESIGN

Retrospective case series.

METHODS

The study analyzed data from 5 years of follow-up of amblyopic eyes that were implanted with iris-fixated pIOLs and had a preoperative corrected distance visual acuity (CDVA) of 6/15 or worse. Visual acuity, refraction, endothelial cell count, and complications were assessed.

RESULTS

Data for 103 eyes were analyzed as 2 groups. Group 1 comprised 82 eyes with myopia or myopic astigmatism, and Group 2 contained 21 eyes with hyperopia or hyperopic astigmatism. The mean preoperative sphere in Group 1 was -13.42 diopters (D) ± 5.62 (SD) with a mean cylinder of -2.35 ± 1.75 D. In Group 2, the mean sphere and cylinder were +6.77 ± 1.91 D and -2.63 ± 2.43 D, respectively. The mean CDVA improved from 0.51 ± 0.15 logMAR to 0.34 ± 0.16 logMAR (P<.001) in Group 1 and from 0.54 ± 0.17 logMAR to 0.46 ± 0.14 logMAR in Group 2 (P<.005). The safety index was 1.48 in Group 1 and 1.19 in Group 2. The efficacy index was 1.21 in Group 1 and 1.00 in Group 2. The mean gain in CDVA was statistically significantly greater in Group 1 (0.17 ± 0.14 logMAR) than in Group 2 (0.08 ± 0.11 logMAR). Two or more lines of CDVA were gained by 48.8% of eyes in Group 1 and by 19.0% of eyes in Group 2.

CONCLUSION

The iris-fixated pIOL was a safe and effective option for improving visual acuity in adult amblyopic eyes.

FINANCIAL DISCLOSURE

Dr. Schallhorn is a consultant to Abbott Medical Optics, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

The role of phakic intraocular lens implants in treatment of high-refractive errors and amblyopia in children

Introduction

This article aims to evaluate the role of phakic intraocular lens (pIOL) implants in the treatment of high-refractive errors and amblyopia in the pediatric setting.

Methods

A literature search of the PubMed database was conducted in December 2012 using the keywords: pIOL implants, amblyopia, pediatric refractive surgery and ametropia, and articles of high or medium clinical relevance were selected for review. Inclusion criteria were children aged 0–17 years who had undergone pIOL implantation for the treatment of refractive errors and/or amblyopia.

Results

Multiple studies have shown the relevancy and effectiveness of pIOL implantation as an alternative surgical management for highly significant pediatric ametropia in selective patients who are noncompliant with medical treatment.

Conclusions

In the management of clinically significant severe pediatric ametropic and/or anisometropic myopia or hyperopia and in the event of nonadherence to traditional medical treatment, phakic anterior chamber IOL implantation is currently considered an effective modality of treatment. Long-term follow-up of pediatric patients following pIOL implantation is necessary. Future clinical trials are needed to address the safety and efficacy of the type of and the best time for pIOL implantation in treatment and/or prevention of amblyopia in children.

Foldable iris-fixated intraocular lens implantation in children

PURPOSE

  To describe the results of foldable iris-fixated intraocular lens (IOL) implantation in children.

METHODS

  Children with high bilateral or unilateral myopia who were intolerant of spectacle or contact lens correction were implanted with an iris-fixated foldable IOL and prospectively followed. We measured pre- and postoperative visual acuity, refraction, endothelial cell density (ECD) and National Eye Institute Visual Functioning Questionnaire-25.

RESULTS

  Eleven eyes of six children were implanted. Indications were high bilateral myopia in children with comorbid neurobehavioural disorders, high anisometropia and high myopic astigmatism. Mean preoperative spherical equivalent (SE) refraction was -14.6 dioptres (D)±4.2 SD. Mean follow-up was 15 months. Postoperative SE refraction was -2.40 D±2.40 SD. Corrected distance visual acuity (CDVA) improved from mean logMAR 0.84±0.4 SD to postoperative 0.67±0.34 SD (p=0.005). CDVA was reduced because of coexistent ocular disorders and amblyopia. Vision-related quality of life (QOL) measures improved significantly. There were no intraoperative or postoperative serious complications.

CONCLUSION

  Foldable iris-fixated IOL insertion can give a significant improvement in vision and in vision-related QOL in a subset of paediatric patients with special refractive needs who are intolerant to conventional treatment. Long-term follow-up is required for monitoring of ECD.

Pediatric refractive surgery: corneal and intraocular techniques and beyond

Refractive surgery has now been used successfully to treat severe anisometropia and isoametropia associated with amblyopia in children who cannot wear standard spectacles or contact lenses. Extraocular techniques include photorefractive keratectomy, laser-assisted subepithelial keratomileusis, and laser-assisted in situ keratomileusis. Intraocular techniques include refractive lensectomy and phakic intraocular lenses and are still being investigated in children for refractive errors outside the treatment dose capabilities of the excimer laser. This workshop discusses the various techniques, how and when to use each, and their risks and benefits. Newer techniques currently being used in adults that may someday be used in children are also introduced.

Pediatric phakic intraocular lens surgery: review of clinical studies

PURPOSE OF REVIEW

To report on the accumulating peer-reviewed data of phakic intraocular lens (pIOL) implantation in the pediatric population. I evaluate and compare the published peer-reviewed articles for the reported efficacy and complications of phakic intraocular lens implantations in children for correction of clinically significant high refractive errors.

RECENT FINDINGS

Multiple studies have shown the relevancy and effectiveness of pIOL implantation as an alternative surgical management for highly significant pediatric ametropia in selective patients who are noncompliant with medical treatment.

SUMMARY

In the management of clinically significant severe pediatric ametropic and/or anisometropic myopia or hyperopia and in the event of nonadherence to traditional medical treatment, phakic anterior chamber IOL implantation is currently considered an effective modality of treatment. Long-term follow-up of pediatric patients following pIOL implantation is necessary. Future clinical trials should focus on children of various age groups to assess the variables of visual acuity gain or loss, stereopsis, contrast sensitivity, high-order aberrations, corneal physiology, and long-term complications to accurately and properly address the safety and efficacy of the type of and the best time for pIOL implantation in treatment and/or prevention of amblyopia in children.

LASIK correction of vision in adults with unilateral amblyopia

PURPOSE

to evaluate the effects of laser refractive surgery in adult patients with mild to moderate amblyopia due to anisometropic myopia.

METHODS

a retrospective review of 30 patients (60 eyes) with unilateral amblyopia (corrected distance visual acuity [CDVA] 0.6 or worse) who underwent simultaneous bilateral laser vision correction using the Technolas 217z excimer laser (Bausch & Lomb) was performed. Mean patient age was 31.03 ± 10.05 years (range: 18 to 53 years). Visual outcomes in the amblyopic eye were compared with those in the fellow nonamblyopic control eye of the same patient.

RESULTS

mean preoperative CDVA improved in amblyopic eyes from 0.50 ± 0.13 to 0.57 ± 0.20 postoperatively (average gain of 0.075 ± 0.14; P=.007) and improved from 0.92 ± 0.12 preoperatively to 0.93±0.15 after surgery (mean gain of 0.013 ± 0.14; P=.603) in the fellow nonamblyopic eyes. The safety index was significantly greater in the amblyopic eyes compared with the nonamblyopic fellow eyes (1.15 ± 0.30 vs 1.02 ± 0.15, P=.035), therefore, no difference was noted in efficacy (P=.913). Five of 30 eyes with mild to moderate amblyopia gained 2 to 4 lines of CDVA.

CONCLUSIONS

laser refractive surgery for myopic correction was found to be safe and effective in eyes with mild to moderate amblyopia.

Phakic anterior chamber intraocular lens (Verisyse) implantation in children for treatment of severe ansiometropia myopia and amblyopia: Six-month pilot clincial trial and review of literature

Purpose:

The current study aims to evaluate both safety and efficacy of Verisyse^™ (AMO, Irvine, CA) phakic anterior chamber intraocular lens (IOL) in the reduction of clinically significant (>−8 D) myopic anisometropia in children who are noncompliant to traditional medical treatment including spectacle correction or contact lenses.

Design:

Retrospective interventional case series.

Methods:

Six anisometropic myopic pediatric patients in one practice were identified through chart-review. None of the patients were compliant with specatacle correction or contact lens wear and as a result had dense amblyopia of less than 20/400 by Snellen or Allen visual acuity (mean <20/400). All patients underwent Verisyse^™ phakic IOL implantation in the more myopic eye by one surgeon (AP). Pre- and post-operative visual acuity, anterior/posterior segment examination, stereoacuity, axial biometry measurements, cycloplegic refraction, and endothelial cell counts were performed in all patients whenever feasible.

Results:

The age of patients ranged from 5–11 years. The mean post-operative follow-up time was six months from the time of IOL insertion. Improvement in visual acuity >6 lines was achieved in four patients (mean visual acuity of 20/70 at six months). Improvement in stereoacuity was noted in all six patients (from total mean zero seconds-arc to six-months post-operative mean of 500 seconds-arc by randot stereoacuity testing). Improvement of >2 lines of visual acuity lines was achieved in the other two patients. No patient lost any lines of visual acuity. Enhanced physical activity, coordination, and improved social interaction were noted in patients and were reported by the parents. No intra/post-operative complications were noted.

Discussion:

Irreversible or intractable amblyopia secondary to severe anisometropic myopia is a serious medical concern in the pediatric population. Failure of compliance with contact lens therapy consistently leads to visual loss. Anterior chamber phakic IOLs may provide a safe alternative in treatment of noncompliant anisometropic myopic patients who do not accept spectacle wear or contact lens therapy.

Conclusion:

To reduce or eliminate highly significant anisometropic myopia in children who are noncompliant with traditional medical treatment, phakic anterior chamber IOL implantation may be considered as an alternative modality of treatment.

Phakic intraocular lens correction of high ametropia in children with neurobehavioral disorders

PURPOSE

A subset of children with high ametropia and neurobehavioral disorders have chronic difficulties with spectacle or contact lens wear. We report the results of refractive surgery in a series of these children treated using bilateral or unilateral phakic intraocular lenses (IOLs) for ametropia >10 D.

METHODS

Clinical course and outcome data were collated prospectively in a group of 12 children (mean age, 10.1 years; range, 4-17 years) with neurobehavioral disorders exacerbated by poor compliance with spectacles. Myopia in 18 eyes ranged from -10.0 to -22.75 D (mean, -15.2 D) and in 2 hyperopic eyes from +10.25 to +10.75 (mean, +10.5 D). Goal refraction was approximately 0 to +1 D. Correction was achieved by implantation of an iris-enclaved phakic IOL under general anesthesia. Mean follow-up was 9.1 months (range, 3-15 months).

RESULTS

Myopia correction averaged 14.5 D and hyperopia correction 9.4 D. Eighty-six percent of eyes (17/20 eyes) were corrected to within +/- 1 D of emmetropia and the remaining 14% (3 eyes) to within +/- 2 D. Uncorrected visual acuity improved substantially in all 20 eyes (60-fold; from a mean of 20/3400 to a mean of 20/57). Ocular comorbidities in each child accounted for residual postoperative, subnormal visual acuity (eg, amblyopia, nystagmus, albinism, regressed retinopathy of prematurity). Visual functions (measured using a 23-item validated survey) improved. One eye required IOL exchange; no other clinically significant complications have been encountered.

CONCLUSIONS

Phakic IOL implantation improves visual function substantially in neurobehaviorally impaired children who have high ametropia and difficulties wearing glasses.

Traumatic pediatric cataract: a decade of follow-up after Artisan aphakia intraocular lens implantation

PURPOSE

To describe the long-term clinical outcome of Artisan((R)) aphakia intraocular lens (IOL; Ophtec, Groningen, The Netherlands) implantation in five aphakic eyes of five children, without capsular support, after cataract extraction following penetrating ocular trauma.

METHODS

The charts of the five children were retrospectively reviewed. The data collected included follow-up time, nature of injury, age at cataract extraction and IOL implantation, visual outcome, endothelial cell counts, complications, and subsequent surgical interventions.

RESULTS

Average follow-up was 11.0 years (range, 8.0-14.6 years). All eyes had a corneal perforation with various degrees of anterior segment injury. Mean patient age at lens extraction was 7.8 years (range, 5.6-10.2 years). Mean age at Artisan aphakia IOL implantation was 7.9 years (range, 5.7-10.2 years). The best spectacle-corrected visual acuity at last follow-up was 20/40 or better in four eyes. Mean endothelial cell loss compared with the healthy fellow eye was 40%. No patients experienced IOL dislocation, corneal decompensation, chronic anterior uveitis, cystoid macular edema, or iris atrophy. One eye had a retinal detachment 19 months after primary injury and needed vitreoretinal surgery.

CONCLUSIONS

The Artisan aphakia IOL offers a useful alternative for correction of traumatic childhood aphakia. Although we only have results of a small number of patients, taking into account our long follow-up period, we feel that implantation of the Artisan aphakia IOL can be considered a treatment option in aphakic eyes of children that lack capsular support due to trauma.

Diagnosis and treatment of refractive errors in the pediatric population

PURPOSE OF REVIEW

The diagnosis and successful treatment of visually significant refractive errors in children are a subject of continued study and debate.

RECENT FINDINGS

Treatment of significant refractive errors is widely accepted to reduce lifelong vision loss from amblyopia. Children aged 3-5 years may be screened for unexplained vision loss, refractive errors and amblyogenic factors using traditional eye charts as well as newer modalities such as autorefractors and photoscreeners. The accuracy of various screening methods is variable throughout the literature. Debate remains as to who is best suited to administer vision screening tests. Compliance with follow-up with an eye-care professional once a child is identified with an amblyogenic factor remains suboptimal. Treatment of significant refractive errors in certain populations of pediatric patients with refractive surgery shows promise but requires further study.

SUMMARY

The timely diagnosis of significant refractive errors in children remains a significant challenge, especially for ages 3-5 years, but treatment may provide significant improvement of visual acuity and quality of life.

Unilateral lens extraction for high anisometropic myopia in children and adolescents

INTRODUCTION

A subpopulation of children with anisometropic myopia, amblyopia, and neurobehavioral disorders is noncompliant with spectacle wear and ill-suited to correction using contact lenses. We report the results of refractive surgery in a series of these children treated using lensectomy alone (clear lens extraction) or lensectomy with simultaneous implantation of an intraocular lens (refractive lens exchange).

METHODS

Clinical course and outcome data were collated retrospectively in a group of 7 children and adolescents (mean age, 9.1 years; range, 4-20 years) with neurobehavioral disorders and noncompliance with spectacle wear for anisometropic myopia. Myopia in the 7 eyes ranged -11.9 to -24.5 D (mean, -16.7 D). Goal refraction was 0 to + 4 D. Correction was achieved by lensectomy in 5 eyes and lensectomy with intraocular lens implantation in 2 eyes. Primary posterior capsulectomy/subtotal vitrectomy was performed during the primary procedure in 5 eyes (71%). Mean follow-up was 3.8 years (range, 0.5-5.4 years).

RESULTS

Myopia correction averaged 17.3 D. A total of 86% (6 eyes) were corrected within +/- 3 D of the goal refraction and the remaining 14% to within +/- 4 D. Uncorrected visual acuity improved postoperatively in all 7 eyes, albeit modestly (average gain 0.14 Snellen fraction; gain from a mean 20/2550 to a mean 20/130). Myopic regression averaged approximately 0.43 D/year. Capsular opacification necessitated YAG-laser membranectomy in the 2 eyes that had preservation of the posterior capsule at the primary procedure. Retinal detachment has not occurred in any of the eyes during the follow-up period.

CONCLUSIONS

Refractive myopic lensectomy reduced high anisometropia and improved functional vision in children who have high myopia beyond the range of excimer laser correction and who will not wear glasses. Further study is indicated to determine the long-term safety of this procedure in similar pediatric populations.

Optical Analysis of Visual Improvement after Correction of Anisometropic Amblyopia with a Phakic Intraocular Lens in Adult Patients

PURPOSE

To analyze possible reasons for an increase in visual acuity observed in myopic patients with anisometropic amblyopia after implantation of a phakic intraocular lens (PIOL) using a theoretical eye model.

DESIGN

Retrospective case series.

PARTICIPANTS

Fifty-nine eyes of 48 patients with anisometropic amblyopia implanted with an angle-supported PIOL.

METHODS

Inclusion criteria were anisometropia of at least 3 diopters (D) and a best spectacle-corrected visual acuity (BSCVA) of 0.7 or less in the best eye. Follow-up was performed at 1, 3, 6, and 12 months and then annually for up to 10 years. The theoretical analysis of mechanisms to explain the visual improvement was performed using a theoretical eye, based on the Kooijman model, in which the measured values of radii and thickness of the different surfaces were substituted. The magnification and spot size were calculated by a ray tracing process.

MAIN OUTCOME MEASURES

Uncorrected visual acuity, improvement in best spectacle-corrected visual acuity, and spherical equivalent.

RESULTS

Mean gain in visual acuity was 3 lines (range, 0-7 lines). Fifty-four eyes (91.5%) gained at least 1 line of visual acuity, whereas no eyes lost lines of vision. The change in BSCVA did not correlate with preoperative BSCVA (Pearson coefficient, r = 0.19) or with the degree of anisometropia (Pearson coefficient, r = 0.23). The calculations using a Kooijman eye model corrected with spectacles and with a PIOL accounted for the full increase in visual acuity in terms of the magnification (increased by a factor of 1.2) and the spot size (reduced by a factor of 2).

CONCLUSIONS

After implantation of a PIOL, the visual acuity of myopic patients with anisometropic amblyopia showed a significant increase. This increase was explained using a theoretical eye model not only in terms of magnification but also including changes in aberrations. An evident role of neuroprocessing in this visual improvement was not identified.

Long-Term Follow-Up of the Corneal Endothelium After Artisan Lens Implantation for Unilateral Traumatic and Unilateral Congenital Cataract in Children

PURPOSE

To retrospectively estimate the long-term corneal endothelial cell loss in children after perforating corneal trauma and implantation of an iris-fixated anterior-chamber intraocular lens (IOL), either the Artisan aphakia lens or the Artificial Iris Implant, and to compare this corneal endothelial cell loss to that in children who received an Artisan aphakia lens to correct aphakia after cataract extraction for unilateral congenital cataract.

METHODS

A retrospective study was performed, evaluating the charts and endothelial photographs of 6 patients with unilateral traumatic cataract, with a mean age at IOL implantation of 9.5 years (range: 5.8-12.8 years) and a mean follow-up after IOL implantation of 10.5 years (range: 8.0-14.7 years), and of 3 children who were operated on for unilateral congenital cataract at a mean age of 2.7 years and who received an Artisan aphakia IOL, with a mean follow-up after IOL implantation of 9.5 years (range: 4.7-14.5 years). Parameters that were studied were central endothelial cell density (CECD) in both the operated and the normal eye at the last follow-up visit, percentage of cell loss in the operated eye compared with the normal eye, and length and location of the corneal scar in the injured eye.

RESULTS

: In the traumatic cataract group, CECD was, on average, 41% (range: 22%-58%) lower in the operated eye (1.647 +/- 322 [SD] cells/mm) than the normal eye (2.799 +/- 133 cells/mm). A significant negative linear correlation was found between the length of the corneal perforation scar and CECD. In the congenital cataract group, no statistical difference in CECD was found between the operated (3.323 +/- 410 cells/mm) and the unoperated (3.165 +/- 205 cells/mm) eye.

CONCLUSION

Endothelial cell loss 10.5 years after iris-fixated IOL implantation for traumatic cataract was substantial and related to the length of the corneal scar of the original trauma. In children operated on for congenital cataract, no difference was found in CECD in the operated and unoperated eyes 9.5 years after Artisan aphakia IOL implantation.

Pediatric refractive surgery

Refractive surgery in children is controversial; it is mainly performed when conventional treatment has failed. The primary indications are anisometropic amblyopia and bilateral high myopia. The major areas of concern are unstable refraction due to ongoing growth of the eye, and long-term implications. The most popular procedures are photorefractive keratectomy or laser-assisted subepithelial keratomileusis followed by laser-assisted in situ keratomileusis. There are technical difficulties involved in performing these procedures because of smaller palpebral apertures and the need for general anesthesia in younger children. Reports of minimal haze and regression in children who have undergone photorefractive keratectomy for high myopia are of interest, as this is contrary to what occurs in adults. Additional study may result in better long-term data and further indications for refractive surgery in children.

Refractive surgery for high bilateral myopia in children with neurobehavioral disorders: 2. Laser-assisted subepithelial keratectomy (LASEK)

INTRODUCTION

A subpopulation of children with high myopia and neurobehavioral disorders is noncompliant with spectacle wear and ill-suited to correction using contact lenses. We report the results of refractive surgery in a series of these children treated bilaterally using excimer laser technology.

METHODS

Clinical course and outcome data were collated prospectively in a group of 9 children (mean age, 10.2 years; range, 3-16 years) with neurobehavioral disorders exacerbated by chronic noncompliance with spectacle wear, causing profoundly low functional vision. Myopia in the 18 eyes ranged from -3.75 to -11.5 D (mean -16.6 D) and the desired refraction was approximately +1D. Correction was achieved by bilateral laser-assisted subepithelial keratectomy (ie, LASEK) performed under brief general anesthesia. Mean follow-up was 17 months (range, 6-36 months).

RESULTS

Myopia correction averaged 7.9 D. Eighty-nine percent (16/18 eyes) were corrected to within +/-1 D of goal refraction. Uncorrected acuity improved postoperatively in all 18 eyes, with commensurate gains in behavior and environmental visual interaction in 88% (15/17 children). Myopic regression averaged approximately 0.8 d/year. the only complication encountered was mild (1+) corneal haze in 35% of treated eyes.

DISCUSSION/CONCLUSIONS

Bilateral excimer laser surgery is effective for improving functional vision substantially in highly myopic, neurobehaviorally impaired children who have difficulties wearing glasses. Myopic regression is common. Further study is indicated to determine the long-term safety of these and alternative refractive procedures in similar pediatric populations.

Refractive surgery for high bilateral myopia in children with neurobehavioral disorders: 1. Clear lens extraction and refractive lens exchange

INTRODUCTION

A subpopulation of children with high myopia and neurobehavioral disorders is noncompliant with spectacle wear and ill-suited to correction using contact lenses. We report the results of refractive surgery in a series of these children treated using lensectomy alone (clear lens extraction), or lensectomy with simultaneous implantation of an intraocular lens (refractive lens exchange).

METHODS

Clinical course and outcome data were collated prospectively in a group of 13 children (mean age 10.4 years, range 1 to 18 years) with neurobehavioral disorders exacerbated by chronic noncompliance with spectacle wear, causing profoundly low functional vision. Myopia in the 26 eyes ranged from -14.25 to -26.00 D (mean -19.1 D). Goal refraction was approximately +1 D. Correction was achieved by lensectomy alone in 10 eyes, and lensectomy with intraocular lens implantation in 16 eyes. Primary posterior capsulectomy/subtotal vitrectomy was performed during the primary procedure in 11 eyes (42%). Mean follow-up was 4.5 years (range 1.3 to 7.5 years).

RESULTS

Myopia correction averaged 19.9 D. Eighty-one percent (21 eyes) were corrected to within +/-2 D of goal refraction and the remaining 19% (5 eyes) to within +/-4 D. Uncorrected acuity improved substantially (ie, an average 2 log units) in all 26 eyes, with commensurate gains in behavior and environmental visual interaction in 85% [corrected] of children (11/13) [corrected] Myopic regression averaged -0.16 D/year. Capsular regrowth and/or opacification necessitated vitrector or YAG-laser membranectomy in 13 [corrected] eyes (50%) [corrected] Focal retinal detachment (successfully repaired) occurred after eye contusion in one eye (4%) with cicatricial retinopathy of prematurity.

CONCLUSIONS

Bilateral refractive lensectomy is effective for improving functional vision in neurobehaviorally impaired children who have high myopia (beyond the range of excimer laser correction: see companion publication) and difficulties wearing glasses. Posterior capsule regrowth/opacification is common, necessitating secondary membranectomy. Further study is indicated to determine the long-term safety of this procedure in similar pediatric populations.

Phakic Intraocular Lenses

An analytical review of the data available in the field of phakic intraocular lens implantation was conducted. Particular attention was paid to the more critical issues of intraocular lens sizing and safety guidelines. A comprehensive, competitive analysis of different implantation sites, intraocular lens model designs, and safety guidelines has been included. Specialized biometry techniques, such as very high frequency ultrasound and Scheimpflug imaging, have been reviewed, and a critical review of commercial claims regarding intraocular lens technologies has been included. Clinical studies of phakic intraocular lenses demonstrate increasing promise for the correction of refractive errors not amenable to mainstream excimer laser refractive surgery. The main issues currently revolve around adequate lens design (VHF ultrasound study suggests that custom-design and sizing may be the most effective and safest approach for every phakic IOL model), because these devices will be required to remain physiologically inert and anatomically compatible with internal ocular structures and relations for several decades. The possibility of safe removing or exchanging the IOL should remain a feasible option over time. It is of utmost importance that we continue to critically evaluate current encouraging short-term outcomes, which are being extrapolated to the longer term by ongoing high resolution imaging and monitoring of the anatomical and functional relations of implanted phakic IOLs.

Secondary artisan phakic intraocular lens for correction of progressive high myopia in a pseudophakic child

An 8-week-old infant underwent unilateral cataract extraction and posterior chamber intraocular lens implantation for total cataract in the left eye. After surgery, a residual progressive myopic error was observed, ranging from -4.5 diopters (D) 6 months after the operation to -14.0 D at the age of 3 years. Because of parental noncompliance for contact lens and spectacles use, secondary implantation of Artisan phakic IOL of -14.0 D power was performed. No intra- or postoperative complications were observed. Nine months after this second operation, myopia diminished to -3.25 D.

Experience with the Artisan phakic intraocular lens in Asian eyes

PURPOSE

To investigate the efficacy and safety of implantation of an iris-claw phakic intraocular lens (PIOL), Artisan Myopia, in Asian eyes.

SETTING

Minamiaoyama Eye Clinic, Tokyo, Japan.

METHODS

Forty-four eyes of 32 Japanese patients and 1 Korean patient with high myopia had Artisan Myopia lens implantation to correct their refractive errors. Lens models, 5/8.5 or 6/8.5 (optic diameter/overall diameter), were chosen as standard lens model. A smaller lens model (5/7.5-Artisan Myopia Small) was implanted in eyes with corneal diameter less than 11.0 mm. Postoperative examinations were performed on 1 day, 1 week, 1 month, 3 months, 6 months, 1 year, and 2 years after surgery. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, corneal endothelial cell counts, intraocular pressure, and complications were evaluated.

RESULTS

Artisan Myopia Small lenses were implanted in 4 eyes (9.1%) and 8.5 mm diameter lenses were implanted in 40 eyes. Preoperative UCVA (logMAR) improved from 1.57 to 0.09 at 1 month after surgery and no regression was observed thereafter. Postoperative manifest refraction was -1.02 +/- 0.87 D (-3.25 to -0.00 D), and within 1.0 D in 20 eyes (55.6%), within 2.0 D in 32 eyes (88.9%) at 1 month after surgery, and stable during the follow-up period. The final BCVA decreased 2 lines in 2 eyes (4.5%) due to progression of age-related cataract. No serious complications such as angle closure or progressive endothelial cell loss were observed.

CONCLUSION

Implantation of an Artisan iris-claw PIOL implantation may be a safe and effective procedure for Asian eyes.

Correction of Myopia of 7 to 24 Diopters With the Artisan Phakic Intraocular Lens: Two-year Follow-up

PURPOSE

To evaluate the safety and efficacy of the iris claw phakic intraocular lens (Artisan; Ophtec BV, Groningen, The Netherlands) in patients with high myopia.

METHODS

Between May 1999 and July 2001, 93 Artisan phakic intraocular lenses (IOLs) were implanted in 60 patients affected by high myopia. All patients underwent 24-month follow-up. The power of the lenses ranged from -7.5 to -22.0 diopters (D). Patients were divided into two groups: group 1 (68 eyes), myopia -6.75 to -15.50 D (SE), and group 2 (25 eyes), myopia -16.0 to -23.0 D (SE). Pre- and postoperative patient evaluation included manifest and cycloplegic refractions, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), endothelial cell count, intraocular pressure, complication rate, safety, and efficacy.

RESULTS

At 4 months, 83.8% (57/68) (group 1, myopia -6.75 to -15.50 D) and 68% (17/25) (group 2, myopia -16.0 to -23.0 D) of eyes achieved UCVA of > or =20/40. The BSCVA remained the same or improved in 100% of eyes. After 4 months, 69.1% (47/68) of eyes in group 1 and 52% (13/25) of eyes in group 2 were within +/-1.00 D of the desired refraction; the mean refraction was stable between 4 and 24 months. Of the intraoperative complications, 69.2% were observed in the first 25 lenses implanted; postoperative complications included iris atrophy in 11.8% (11/93), lens decentration in 5.4% (5/93), and night glare in 6.4% (6/93) of eyes. No IOLs were removed. Mean endothelial cell loss was 2.8% at 4 months, 3.9% at 12 months, and 5.4% at 24 months.

CONCLUSIONS

Our results regarding implantation of the Artisan phakic IOL confirm that these lenses are safe and effective for the correction of high myopia, with a stable refractive outcome but with a higher than normal rate of endothelial cell loss during 2-year follow-up.

Artisan aphakic intraocular lens in children with subluxated crystalline lenses

PURPOSE

To evaluate the results of Artisan (Ophtec) aphakic intraocular lens (IOL) implantation in children with idiopathic subluxated lenses.

SETTING

Department of Ophthalmology, Soroka University Medical Center, Beer-Sheva, Israel.

METHODS

This retrospective small case series comprised 4 eyes (3 children) with idiopathic essential subluxated lenses that had lens washout, lens capsule removal, Artisan IOL implantation, and peripheral iridectomy. The indications for surgery were reduced visual acuity and monocular diplopia. The main outcome measures were postoperative refraction and change in best corrected visual acuity (BCVA).

RESULTS

The postoperative follow-up ranged from 8 to 10 months. After surgery, the BCVA was 6/12 or better in the 3 cases that could be recorded. Visual acuity improved by 2 or more Snellen lines in all 4 eyes. The postoperative spherical equivalent was within +/-1.00 diopter in all cases. No significant postoperative complications were observed.

CONCLUSIONS

In 4 eyes with a subluxated crystalline lens, implantation of an Artisan aphakic IOL improved visual acuity. Studies with a larger number of patients and longer follow-up are necessary to confirm these results.

Advances in phakic intraocular lenses: indications, efficacy, safety, and new designs

PURPOSE OF REVIEW

The recent evolution of phakic intraocular lenses (PIOLs) has made this refractive surgical technique safer, very predictable, and effective. Due to these reasons, PIOLs have been expanding the horizon of their indications. The aim of this review is to update the reader in the recent advances reported on the topic during the year 2003.

RECENT FINDINGS

The most recent progress has been made towards decreasing the incision size down to 3 mm or less for all PIOLs models to avoid pupil ovalling in angle-supported designs with new biomaterials or exchangeable haptics, and to decrease the incidence of cataract induction in posterior chamber models with modified designs and better sizing. High-order aberrations and the quality of vision are improved with PIOLs. The main limitation for the further development of PIOLs is the lack of adequate diagnostic imaging techniques to perform a precise preoperative study of the anterior segment anatomy. Emerging diagnostic technologies based on the use of very high frequency (100 MHz) ultrasound and optical coherence tomography seem to have a most important role in the future development of PIOLs defining preoperatively the most adequate anatomic conditions for each design. PIOLs offer today an excellent alternative for the correction of high and moderate myopia, hyperopia, and astigmatism. Emerging indications, still under investigation, include presbyopia and pediatric anisometropic amblyopia.

SUMMARY

Due to their advantages for quality of vision and the increased knowledge on their safety, as well as the evidence of their predictability, PIOLs are expected to largely increase their clinical use as a refractive surgical technique in the coming years.