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Journal of Current Ophthalmology logoLink to Journal of Current Ophthalmology
. 2023 Aug 11;35(1):1–10. doi: 10.4103/joco.joco_249_22

Efficacy and Safety of Iris-Claw Intraocular Lens in Pediatric Ectopia Lentis: A Literature Review

Dian Estu Yulia 1,✉, Diajeng Ayesha Soeharto 1
PMCID: PMC10481981  PMID: 37680281

Abstract

Purpose:

To review current evidence regarding the use of iris-claw intraocular lens (IOL) in terms of its efficacy and safety in the population of pediatric ectopia lentis.

Methods:

A comprehensive literature search of six electronic databases (PubMed-NCBI, Medline-OVID, Embase, Cochrane, Scopus, and Wiley) and secondary search through reference lists was conducted using keywords selected a priori. All primary studies on the use of iris-claw in pediatric ectopia lentis that evaluated visual acuity (VA), complications, and endothelial cell density (ECD) were included and critically appraised using the Newcastle–Ottawa Scale.

Results:

Ten studies were eligible for inclusion with an overall sample size of 168 eyes of children with ectopia lentis, and the majority of studies evaluated anterior iris-claw IOL. All studies reported improvement in postoperative VA. The most commonly reported complication across studies was IOL decentration. All studies reported decreasing ECD, and this was observed in both anterior and retropupillary iris-claw IOL.

Conclusion:

Current evidence shows that iris-claw IOL is effective in terms of improving VA in pediatric ectopia lentis. Due to the lack of long-term evidence of its safety in children, one must remain cautious regarding potential endothelial cell loss. Further high-quality, interventional, long-term studies are needed.

Keywords: Children, Ectopia lentis, Intraocular lens, Iris-claw

INTRODUCTION

Ectopia lentis is defined as the displacement of the crystalline lens resulting from weakened or damaged zonules. A relatively rare finding, pediatric ectopia lentis is typically found in patients with systemic diseases. Surgery is indicated when patients present with poor best-corrected visual acuity (BCVA) and progressive severity of subluxation and generally involves removal of the crystalline lens, followed by visual rehabilitation with glasses, contact lens, or intraocular lens (IOL) implantation. Choice of visual rehabilitation is dependent on the patient condition, and IOLs are typically indicated in cases of patient intolerance toward contact lenses or glasses. To date, the literature regarding absolute indications for surgery and insertion of IOLs in the pediatric population is very limited.1,2

As ectopia lentis involves impaired zonules or capsular support, the most viable options for IOLs include anterior chamber IOLs, scleral-fixated (SF) IOL, and iris-claw IOLs. Iris-claw IOLs have promising features due to its ease of technique and comparable outcomes to other options in adult studies. Safety and efficacy of iris-claw IOL implants in adults are thoroughly studied,3,4,5,6 however, such studies in the pediatric population are limited. This review aimed to elucidate current evidence regarding the use of iris-claw IOL in terms of its efficacy and safety in the population of pediatric ectopia lentis.

METHODS

A comprehensive literature search of electronic databases (PubMed-NCBI, Medline-OVID, Embase, Cochrane, Scopus, and Wiley) and secondary search through reference lists was conducted. Search strategy involved the following search terms and synonyms of the search words were incorporated with Boolean operators as well as wildcards and truncation: iris-claw, artisan, Verisyse, intraocular lens, and pediatric or children. Detailed search strategy used is enlisted in Appendix 1. Search results were managed using Endnote (X9.3.3.).

Search results were screened by evaluating the title and abstract as well as examining full studies with regard to the eligibility criteria of this review: (1) English language full-text publications, (2) primary studies published before June 2022, (3) population of pediatric patients with ectopia lentis who underwent iris-claw IOL implantation, and (4) included outcomes of this review. Studies that included traumatic ectopia lentis and did not separate analysis of primary outcome were excluded from the study.

Primary outcomes extracted from this study were visual acuity (VA), with secondary outcomes including complications and endothelial cell density (ECD). The reviewer independently assessed the methodological quality of the included studies, which was scored according to the Newcastle–Ottawa Scale (NOS) for observational studies.7

RESULTS

Search of electronic databases yielded 192 potentially relevant studies, from which 78 duplicate studies were removed. The remaining 114 records were screened based on title and abstract, in which 82 were excluded as they did not fit this review’s eligibility criteria. The remaining 32 records had the full-text articles assessed for eligibility, from which 22 were excluded. Thus, this left a total of ten studies that were considered eligible for inclusion [Figure 1].

Figure 1.

Figure 1

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Summary of search strategy illustrated with Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowcharts

As this review attempted to include all current literature regarding iris-claw IOL use in pediatric ectopia lentis, we did not limit the type of primary studies included. There were a variety of types of studies included: one randomized comparative study,8 three prospective observational studies,9,10,11 three retrospective observational studies,12,13,14 one prospective intervention noncontrolled case series,15 one case series,16 and one case study.17 Critical assessment according to the NOS is summarized in Table 1, with nearly all studies lacking in the comparability criteria as the majority of studies did not include a comparison group.

Table 1.

Quality assessment of observational studies according to Newcastle Ottawa Scale

Study Selection Comparability Outcome Total score
Representativeness of the exposed cohort Selection of the nonexposed cohort Ascertainment of exposure Demonstration that outcome of interest was not present at start of study Comparability of cohorts on the basis of the design or analysis Assessment of outcome Was follow-up long enough for outcomes to occur Adequacy of follow-up of cohorts
Barbara et al. (2016)17 * * * * * * 6
Catala Mora et al. (2017)10 * * * * * * 6
Cevik et al. (2017)14 * * * * * * 6
Cleary et al. (2012)12 * * * * * * 6
Gawdat et al. (2015)15 * * * * * * 6
Lifshitz et al. (2004)16 * * * * * * 6
Manning et al. (2016)13 * * * * * * 6
Rastogi et al. (2022)8 * * * * * * * * 8
Rastogi et al. (2018)11 * * * * * 5
Siddiqui et al. (2013)9 * * * * * * 6
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The review included a total of ten studies with an overall sample size of 168 eyes of children with ectopia lentis that received iris-claw IOL [Table 2]. In terms of IOL placement, the majority of studies used anterior iris-claw, with only three studies used retropupil or posterior iris-claw IOLs. Indication for surgery was not identical among the studies, with surgery indications as follows: increase in degree of myopia or VA17 (VA <20/63;10 BCVA <20/60 or <20/409), intolerance toward contact lenses or spectacles,13,17 severe bilateral ectopia lentis affecting pupillary axis or anterior chamber or vitreous subluxation,10 subluxation >7 clock hours,8,11 and monodiplopia.16 Average age at surgery ranged across the studies from 4 to 16 years of age. Most studies evaluated primary IOL implantation, where implantation of the iris-claw was conducted in the same procedure as lensectomy, whereas three studies evaluated secondary iris-claw IOL implantation.13,15,17

Table 2.

Summary of included studies

Study Type of study Etiology of ectopia lentis Sample size Age at surgery Anterior or posterior Comparison Follow-up
Barbara et al. (2016)17 Case study Marfan’s syndrome 2 eyes (1 patient) 5 years Anterior N/A 12 months
Catala Mora et al. (2017)10 Prospective cohort Marfan’s syndrome, idiopathic, megalopthalmos-glaucoma, ectopia lentis et pupillae 21 eyes (12 patients) 8.0±5.3 (range, 3–17) years Anterior N/A 39.3±13.0 (23–78) months
Cevik et al. (2017)14 Retrospective study Marfan’s syndrome, homocystinuira, no hereditary disease 30 eyes (17 patients) 103±53 (range, 30–196) months Posterior N/A 38 (8–72) months
Cleary et al. (2012)12 Retrospective study Marfan’s syndrome, idiopathic 8 eyes (5 patients) 7–16 years Anterior N/A 28 (4–58) months
Gawdat et al. (2015)15 Prospective, intervention noncontrolled case series Marfan’s syndrome, homocystinuria, idiopathic, trauma* 25 eyes (18 patients) 7.86±3.08 years Anterior N/A 12 months
Lifshitz et al. (2004)16 Case series Idiopathic 4 eyes (3 patients) 4–11 years Anterior N/A 8–10 months
Manning et al. (2016)13 Retrospective study Marfan’s syndrome 16 eyes (8 patients) 12.7±2.7 years Anterior Lensectomy without IOL 4.1±2.8 years
Rastogi et al. (2022)8 Randomized comparative interventional study Marfan’s syndrome 60 eyes; 30 eyes in each group 9.57±4.13 (6–18) Posterior SFIOL 1.5 years
Rastogi et al. (2018)11 Prospective study Marfan’s syndrome 14 eyes 11.92 (8–17) Posterior N/A 6 months
Siddiqui et al. (2013)9 Prospective study Idiopathic, Marfan’s syndrome 18 eyes (11 children) 11.58±2.9 (8–16) Anterior N/A 9.12±4.30 (5–14) months
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*Trauma patients were separated for analysis of visual acuity. IOL: Intraocular lens, SFIOL: Scleral-fixated IOL, N/A: Not available

All studies reported an increase in postoperative BCVA to preoperative BCVA, with the majority of studies with statistically significant results [Table 3]. Lifshitz et al. reported 88% of eyes had BCVA improvement of 2 or more Snellen lines,16 and Manning et al. reported 28/30 eyes achieved BCVA of 0.18 or better, although they reported no difference between postoperative BCVA of the iris-claw IOL group in comparison to the aphakic groups who received spectacles or contact lenses.13 In Rastogi et al.’s comparative study, they reported both iris-claw and SFIOL groups experienced statistically significant improvements in VA; the mean improvement in BCVA at 1.5 years was 0.44 ± 0.45 logMAR in the SFIOL group and 0.28 ± 0.41 logMAR in the iris-claw group, although the difference between groups was not statistically significant (P = 0.322).8

Table 3.

Average preoperative and postoperative visual acuity

Study Preoperative BCVA (logMAR) Postoperative BCVA (logMAR) P
Catala Mora et al. (2017)10 0.91±0.29 0.18±0.23 <0.0001*
Cevik et al. (2017)14 1.08±0.26 (1.3–0.5) 0.39±0.46 (0.0–2) 0.011*
Cleary et al. (2012)12 0.21±0.2 0.04±0.09† 0.041*
Gawdat et al. (2015)15 0.7±0.26 0.3±0.2 0.00011*
Manning et al. (2016)13 0.15±0.16 (0.08–0.48) 0.12±0.19 (0.00–0.60) 0.521
Rastogi et al. (2022)8 0.91±0.42 0.63±0.28 0.025*
Rastogi et al. (2018)11 0.771±0.132 (1.0–0.6) 0.351±0.154 0.003*
Siddiqui et al. (2013)9 0.88±0.55 0.26±0.13 0.001*
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*Statistically significant P value, †Only postoperative uncorrected visual acuity was reported in this study. BCVA: Best-corrected visual acuity

Reported complications varied among the studies [Table 4], with two studies on anterior iris-claw IOL stated no complications having occurred.12,16

Table 4.

Postoperative complications

Study Iris-claw IOL position Complications, number of eyes (%)
Barbara et al. (2016)17 Anterior Unclipped nasal haptic: 1/2 (50)
Catala Mora et al. (2017)10 Anterior IOL dislocation and retinal detachment after severe ocular contusion requiring
vitrectomy: 1/21 (4.8)
Cystoid macular edema: 1/21 (4.8)
Iridododenesis: 1/21 (4.8)
Vitreous hemorrhage: 6/21 (28.6)
Cevik et al. (2017)14 Posterior Lens dislocation: 11/30 (36); hypotonia: 3/30 (10); retinal detachment: 3/30 (10)
Cleary et al. (2012)12 Anterior None
Gawdat et al. (2015)15 Anterior Traumatic lens dislocation with de-enclavation: 2/25 (8)
Iritis with incipient pupillary membrane and fine keratic precipitates: 2/25 (8) Pupillary block: 1/25 (4)
Lifshitz et al. (2004)16 Anterior None
Manning et al. (2016)13 Anterior Pseudophakic pupil block: 1/16 (6.3)
IOL de-enclavation: 1/16 (6.3)
Rastogi et al. (2022)8* Posterior Transient raised IOP: 3/30 (10) versus 1/30 (7)
Hypotony: 1/30 (7) versus 3/30 (10)
Anterior uveitis: 3/30 (10) versus 4/30 (13.3)
Corneal edema: 4/30 (13.3) versus 4/30 (13.3)
IOL tilt: 1/30 (7) versus 3/30 (10)
IOL decentration: 1/30 (7) versus 3/30 (10)
Pupil ovalization: 18/30 (60) versus 0/30
Choroidal detachment: 1/30 (7) versus 0/30
Vitreous hemorrhage: 0/30 versus 2/30 (6.66)
Cystoid macular edema: 4/30 (13.33) versus 3/30 (10)
Rastogi et al. (2018)11 Posterior Pupil ovalization: 3/14 (21.42); IOL disenclavation: 1/14 (7.14)
Raised IOP: 1/14 (7.14)
Siddiqui et al. (2013)9 Anterior Raised IOP: 1/18 (5.9)
Transient horizontally oval pupil: 4/18 (23.5)
Iris depigmentation: 18/18 (100)
Endophtalmitis: 1/18 (5.9)
Traumatic IOL de-enclavation: 1/18 (5.9)
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*Reported as iris-claw IOL group versus scleral-fixation IOL group. IOL: Intraocular lens, IOP: Intraocular pressure

A common concern is IOL dislocation or unclipped haptics, which was reported in several studies and occurred in both anterior and posterior placements. Among the studies on anterior iris-claw, rates varied from 1 to 2 eyes in each respective cohort,9,13,15,17 whereas among the studies on posterior iris-claw, rates varied from 1 to 11 eyes in each respective cohort.10,11,14 In addition, in Rastogi et al.’s randomized comparative study, they reported 1/30 (7%) had IOL tilt and 1 (7%) had IOL decentration in their iris-claw cohort, which was less than the SFIOL group which had 3/30 (10%) that had IOL tilt and decentration.8 IOL de-enclavation was reported as a result of posttraumatic injury in most studies.8,11,13,15,17 IOL dislocation occurred at various times postoperatively, ranging from 2 months to 7 years after surgery. All IOLs were successfully reenclavated with no further complications.

Pseudophakic pupil block was reported in several studies, with 1/16 (6.3%) in Manning et al.’s study which occurred 5 months after surgery,13 and 1/25 (4%) in Gawdat et al.’s study which occurred 3 days after surgery,15 both cases which were treated with peripheral iridectomy and recovered without further complications. In addition, transient increase of intraocular pressure (IOP) was reported in several studies as well, with Rastogi et al. reporting 3/30 (10%) which normalized after 2 weeks. Moreover, Siddiqui and Khan and Rastogi et al. reported 1/14 (7.14%)9 and 1/18 (5.9%)11 of their cohorts with acutely raised IOP, respectively, both studies reported complete resolution with antiglaucoma treatment. Hypotonia was also reported in 1/30 (3.3%) of Rastogi et al.’s cohort, this was explained as a result of choroidal detachment and was normalized with resolution of the choroidal detachment.8 Similarly, hypotonia was found in Çevik et al.’s study with 3/30 (10%) of their cohort, two underwent scleral tunnel suturing while one recovered in 1 month without any treatment.14

Severe infection was also rarely reported, with 1/18 (5.9%) of Siddiqui and Khan cohort with endophthalmitis 2 weeks after surgery. Catala Mora et al. reported 1/21 (4.8%) with sterile anterior uveitis resolved with topical corticosteroids, which developed into cystoid macular edema 3.5 years after surgery and resolved with dexamethasone implant.10 Rastogi et al. reported 4/30 (13.3%) with cystoid macular edema in their iris-claw cohort, with comparative numbers in their SFIOL cohort (3/30, 10%), all cases resolved by 2-week follow-up.8 They also reported corneal edema in 4/30 (13.3%) in both iris-claw and SFIOL cohorts, all cases resolved in 2 weeks on topical drugs. Retinal detachment was rarely reported and was only found in Çevik et al. in 3/30 (10%) of their cohort, and in Catala Mora et al. in 1/21 (4.8%) which was reported to be as a result of traumatic contusion of the eye.10,14

Other complications which were rarely reported include iritis (Gawdat et al. with 1/25, 4%), pupil ovalization (Rastogi et al. with 18/30, 60%), iris depigmentation (Siddiqui and Khan, in all 18 eyes), and iridiodenesis (Catala mora et al. with 1/21, 4.8%).8,9,10,15 The latter study also reported + 1 vitreous hemorrhage in 6/21 (28.6%) eyes, all of which resolved spontaneously.

One of the major concerns of iris-claw IOL is ECD, with all studies observing a noticeable trend of decreasing ECD [Table 5]. Notably, the range of follow-up varied with the shortest being 6 months and the longest being 78 months. Although mean cell loss was not reported in all studies, it ranges from 1.5% to 59.1%. Annual cell loss rate was reported in two studies, with the average being at 3.16% and 3.6%, respectively. Only one study by Çevik et al. had no data on ECD.

Table 5.

Preoperative and postoperative endothelial cell density

Study Average follow-up Anterior or posterior Preoperative (cells/m2) Postoperative (cells/m2) P Mean cell loss (%) Annual cell loss rate (%)
Barbara et al. (2016)17 12 months Anterior OD: 3325 OS: 3274 OD: 3053 OS: 2411 N/A N/A N/A
Catala Mora et al. (2017)10 39.3±13.0 (23–78) months Anterior 3257 (2577–3508) 2655 (2193–3215) N/A 5.04±9.58 3.16±4.46
Cleary et al. (2012)12 28 (4–58) months Anterior 3312±277 2913±268 <0.001 14.2 N/A
Gawdat et al. (2015)15 12 months Anterior 3573±468 2892±441 <0.001 6.1 N/A
Manning et al. (2016)13 4.1±2.8 years Anterior 3109±458 2632±592 0.003 477±606 (32–2260) 15.4 (1.5–59.1) 3.6
Rastogi et al. (2022)8 1.5 years Posterior 2782.5±494.86 2429.57±496.34 <0.001 N/A N/A
Rastogi et al. (2018)11 6 months Posterior 2838.42±474.76 2810±461.24 0.117 0.99 N/A
Siddiqui et al. (2013)9 9.12±4.30 (5–14) months Anterior 3450±308 2860±435 0.000 17.1 N/A
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N/A: Not available, OD: Ocula dextra, OS: Ocula sinistra

DISCUSSION

Ectopia lentis presents as a particularly difficult case to manage due to inadequate capsular support and weak zonules. Loss of significant zonular support makes the lens unstable, potentially complicating lens extraction with IOL implantation in children. Various IOL methods are available, with one of the most conventional being anterior chamber IOLs, however, this is notably related to the risk of damage to the corneal endothelium and severe complications such as secondary pseudophakic bullous keratopathy, glaucoma, and retinal detachment.18 Capsular tension ring (CTR) could be used to manage localized zonular weakness. However, CTR cannot provide adequate support in the presence of extensive zonular dehiscence, which is often the case in pediatric ectopia lentis. Furthermore, previous studies have reported significant complications following this procedure.19,20 With this, surgeons tend to prefer SFIOL or iris-claw IOLs as potential appropriate choices in pediatric ectopia lentis. Although both are effective, each IOL is associated with their own set of complications. SFIOL is commonly associated with inflammation, retinal tears, choroidal hematoma, and cystoid macular edema, which may be due to its invasive and complex technique. Some studies have also reported scleral fixated CTR for ectopia lentis as a viable option; one study with a median follow-up of 23.4 months showed good visual results, but almost 60% developed posterior capsular opacity (PCO) that required treatment.21 Another study with a mean follow-up of 35.3 months also showed similar results, with 52% of eyes developing PCO, one eye with uveitis-glaucoma, and three requiring IOL repositioning.22 A meta-analysis comparing three different IOLs (transscleral, intrascleral, and iris-claw) in aphakic adult patients with insufficient capsular support showed that in terms of visual outcomes, no statistically significant difference was found between the IOLs.23 Currently, there is no consensus regarding the singular best IOL that one should use, and thus, surgeon preference based on experience and the patient’s condition serves as the major determining factor.3

Iris-claw IOLs are uniquely designed lenses that are either placed anterior to the iris and secured by enclavation of small sections of the mid-peripheral iris. Alternatively, they can also been fixated posteriorly.24 Iris-claw IOLs have been proven to be effective in adult cases with weak capsular support in previous studies.3,6,23,25 This is in line with the findings of our review on pediatric ectopia lentis, in which the included studies exemplify overall improved VA, most being statistically significant. Furthermore, one of the studies included in our review that compared SFIOL showed that they had similar visual outcomes among the iris-claw and SFIOL groups.8 In addition, Manning et al. found no significant differences between the final best VA between their group that underwent secondary iris-claw implant following lensectomy and their group that only underwent lensectomy and used conventional correction such as spectacles or contact lenses.13 This shows that iris-claw IOLs have comparable efficacy to other IOLs, and even to conventional vision correction in cases, where it is tolerated by the child, and is thus effective in achieving appropriate VA in pediatric ectopia lentis.

A major benefit of iris-claw IOL is its simple technique that involves shorter surgical time, particularly in comparison to other IOLs which involve more complex techniques. In addition, a previous meta-analysis on adult aphakic populations suggested iris-claw IOLs had less hemorrhagic events than transscleral or intrascleral IOLs. Moreover, iris-claw IOLs were found to have lower risk of elevated IOP and glaucoma, and this was suggested to be due to SFIOLs involving more invasive and complex manipulation around the ciliary choroidal body leading to more time consumption and more risk of hemorrhage.23 Similarly, in our review, such severe complications are rarely reported, with only one study observing vitreous hemorrhage that resolved spontaneously.10

The most common complication mentioned among the studies was IOL dislocation, and the majority of this occurred secondary to trauma. Other complications such as pseudophakic pupil block were reported in only two eyes in two separate studies, while other occurrences of increased IOP were also transient and found in a minority of cases. Moreover, pigment dispersion and pupil ovalization were mentioned to occur in a majority of patients in two separate studies.8,9

With iris-claw IOL, decreased corneal ECD is a big concern. All included studies in this review exemplified decrease in ECD after surgery. It is worth noting that the studies in this review have a follow-up of no longer than 78 months. A case series on four eyes of two patients by Sminia et al. had the only long-term follow-up of 12 years after iris-claw IOL implantation for pediatric ectopia lentis, however, they did not evaluate baseline ECD and compared the numbers to a historical control; they found that the ECD at adulthood was comparable to their historical control group (eyes without lens surgery).26 While long-term studies on ECD of children with iris-claw IOLs are limited, several studies have done this on adults. A 12-year study on adults by Tang et al. highlighted a 29.1% ECD loss in aphakic eyes that received iris-claw IOLs, and they recommended annual monitoring of ECD.4 A long-term study by Galvis et al.5 on adults with phakic iris-claw IOLs with average follow-up of 9.6 years showed that mean total ECD loss was 10.5%–18.5% at last follow-up, and two eyes had a final density of <1200 cells/mm2. Similar findings were reported in a prospective 10-year study by Jonker et al. that showed annual ECD loss of 48-61 cells/mm2, with total ECD loss of 16.6%–21.5% from 6 to 10 years postoperatively.27 Galvis et al. recommended periodical ECD evaluations to monitor for critical ECD loss, and to be cautious in determining selection criteria for phakic iris-claw IOL candidates, stating a minimum of 3.0 mm anterior chamber depth and ECD of 3000 cells/mm2 in patients under 25 years of age.5 Notably, no recommendations specifically for aphakic pediatric patients based on long-term studies are currently available.

While endothelial cell loss is mostly highlighted as a concern of anterior chamber implantation, retropupil placement of iris-claw in the studies included in this review also showed decrease ECD.8,11 A study on iris-claw IOLs in aphakic adults showed comparable rates of ECD loss over a period of 8–9 months in anterior and retropupil iris-claw IOLs, with 6.7% and 7.2% mean ECD loss, respectively.28 Although some may argue that retropupillary fixation of the iris-claw IOL may preserve corneal endothelium and offer a more physiological optical position of the lens, it remains debatable whether or not retropupillary implantation is truly superior than anterior chamber implantation due to the lack of long-term follow-up data on children with pediatric ectopia lentis. Anterior implantation is arguably easier and provides for greater control of centration and orientation of the lens, and such view is also supported in previous studies.29

Several adult studies comparing anterior and posterior iris-claw have exemplified that both methods are safe and effective in cases of weak capsular support. However, in a recent retrospective study on 171 adult eyes, in which most were complicated cataract surgery, it was noted that most complications developed in the anterior location. Iris-claw IOL decentration occurred more in the anterior location (20.6% for anterior vs. 6.6% for retropupillary, P = 0.011), although there was no difference between anterior and posterior placement in terms of spontaneous deenclavation (8.4% vs. 6.6%, P > 0.05). Furthermore, high IOP readings or the prolonged use of postoperative antiglaucoma agents were associated much more in the anterior location (28% vs. 13.1%, P = 0.019).6 This was not quite in line with our study, although it is worth pointing out that included studies were mostly of anterior placement rather than posterior in the pediatric population in this review. With this, there is not enough evidence regarding the differences between the placement of iris-claw in children to draw a conclusion, and both seem to offer similar efficacy and safety profiles.

This review provides the most updated and comprehensive review of existing literature on the use of iris-claw IOL in pediatric ectopia lentis. Limitations of this review include the varying type and quality of the included studies. From our comprehensive literature search, no randomized controlled trials were found to be available on this topic. Most studies eligible for inclusion were observational in nature and lacked control groups in their design, and only six out of ten included studies had a follow-up of more than 1 year. This may be explained by the rarity of ectopia lentis in the general population, thus, designing large-scale intervention studies on this disease is considerably challenging. Currently, there is an ongoing phase 3 clinical trial on the use of Artisan lens for the correction of aphakia in children and is estimated to be complete in the year 2025.30 Heterogeneity of the included studies in this review serves as a reflection of the existing literature on this topic and highlights the need for further high quality, interventional, long-term studies to be conducted.

In conclusion, current evidence shows that iris-claw IOL is effective in terms of improving VA in pediatric ectopia lentis. The most common reported complication among studies in this review was IOL decentration. There is reason to remain cautious regarding potential endothelial cell loss as there is a lack of long-term evidence of its safety in children.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

APPENDIX

Appendix 1: Search strategy

Ovid MEDLINE (R):

  1. Lenses, Intraocular/and iris claw.mp.

  2. Lens Implantation, Intraocular/and iris claw.mp.

  3. Lens Implantation, Intraocular/and iris fixated.mp.

  4. Iris fixated.mp. and Lenses, Intraocular

  5. artisan.mp. and Lenses, Intraocular

  6. Lens Implantation, Intraocular/and artisan.mp.

  7. Lens Implantation, Intraocular/and verisyse.mp.

  8. verisyse.mp. and Lenses, Intraocular

  9. Artisan aphakia.mp.

  10. verisyse aphakia.mp.

  11. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10

  12. Ectopia lentis.mp. or exp Ectopia Lentis

  13. Lens subluxation.mp. or exp Lens Subluxation

  14. Ectopic lens.mp.

  15. 12 or 13 or 14

  16. 11 and 15

PubMed:

  1. (((“iris claw”[All Fields]) OR (iris fixated) OR (“artisan”[All Fields]) OR (“artisan aphakia”[All Fields]) OR (“verisyse”[All Fields]) OR (“verisyse aphakia”[All Fields])) 2104

  2. ectopia lentis[MeSH Terms]

  3. “lens subluxation”[MeSH Terms]

  4. ((“lens subluxation”[All Fields]) OR (“ectopic lens”[All Fields]) OR (“ectopia lentis”[All Fields]))

  5. #2 OR #3 OR #4

  6. #1 AND #5

  7. ((“paediatric”[All Fields]) OR (“pediatric”[All Fields]) OR (“children”[All Fields]) OR (“child”[All Fields]))

  8. #1 AND #5 AND #7

Cochrane:

”iris claw” OR “iris fixated” OR “Artisan aphakia”

“ectopia lentis” OR “ectopic lens” OR “subluxated lens”

Embase:

  1. Lenses, Intraocular/and iris claw.mp.

  2. Lens Implantation, Intraocular/and iris claw.mp.

  3. Lens Implantation, Intraocular/and iris fixated.mp.

  4. Iris fixated.mp. and Lenses, Intraocular

  5. Artisan.mp. and Lenses, Intraocular/

  6. Lens Implantation, Intraocular/and artisan.mp.

  7. Lens Implantation, Intraocular/and verisyse.mp.

  8. Verisyse.mp. and Lenses, Intraocular/

  9. Artisan aphakia.mp.

  10. Verisyse aphakia.mp.

  11. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10

  12. Ectopia lentis.mp. or exp Ectopia Lentis

  13. Lens subluxation.mp. or exp Lens Subluxation

  14. Ectopic lens.mp.

  15. 12 or 13 or 14

  16. 11 and 15

Scopus:

  1. Lenses, Intraocular/and iris claw.mp.

  2. Lens Implantation, Intraocular/and iris claw.mp.

  3. Lens Implantation, Intraocular/and iris fixated.mp.

  4. Iris fixated.mp. and Lenses, Intraocular/

  5. Artisan.mp. and Lenses, Intraocular/

  6. Lens Implantation, Intraocular/and artisan.mp.

  7. Lens Implantation, Intraocular/and verisyse.mp.

  8. verisyse.mp. and Lenses, Intraocular/

  9. Artisan aphakia.mp.

  10. Verisyse aphakia.mp.

  11. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10

  12. Ectopia lentis.mp. or exp Ectopia Lentis/

  13. Lens subluxation.mp. or exp Lens Subluxation/

  14. Ectopic lens.mp.

  15. 12 or 13 or 14

  16. 11 and 15

Wiley:

  1. Lenses, Intraocular/and iris claw.mp.

  2. Lens Implantation, Intraocular/and iris claw.mp.

  3. Lens Implantation, Intraocular/and iris fixated.mp.

  4. Iris fixated.mp. and Lenses, Intraocular/

  5. Artisan.mp. and Lenses, Intraocular/

  6. Lens Implantation, Intraocular/and artisan.mp.

  7. Lens Implantation, Intraocular/and verisyse.mp.

  8. Verisyse.mp. and Lenses, Intraocular/

  9. Artisan aphakia.mp.

  10. Verisyse aphakia.mp.

  11. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10

  12. Ectopia lentis.mp. or exp Ectopia Lentis/

  13. Lens subluxation.mp. or exp Lens Subluxation/

  14. Ectopic lens.mp.

  15. 12 or 13 or 14

  16. 11 and 15

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