Journal of Pediatric Ophthalmology and Strabismus

Short Subjects 

Spontaneous Subluxation of Iris-Claw Aphakic Intraocular Lens Causing Complications in Two Children

Hon Shing Ong, MBBS; Malavika Subash, BSc, BM, FRCOphth; G. G. W. Adams, MBChB, FRCS (Ed), FRCOphth

Abstract

Many surgeons consider implantation of iris-claw intraocular lenses a favorable option for pediatric aphakic eyes with poor capsular support. The authors present two children who had spontaneous subluxation of such lenses resulting in complications that required explantation. These cases highlight the potential sight-threatening complications of such intraocular lenses.

From the Department of Paediatric Ophthalmology, Moorfields Eye Hospital, London, United Kingdom.

Presentation in part as a poster at The European Paediatric Ophthalmological Society 37th Annual Conference, October 13–15, 2011, Thessaloniki, Greece.

The authors have no financial or proprietary interest in the materials presented herein.

Address correspondence to Hon Shing Ong, MBBS, Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, United Kingdom. E-mail: honshing@gmail.com

Received: March 17, 2012
Accepted: August 22, 2012
Posted Online: October 09, 2012

Abstract

Many surgeons consider implantation of iris-claw intraocular lenses a favorable option for pediatric aphakic eyes with poor capsular support. The authors present two children who had spontaneous subluxation of such lenses resulting in complications that required explantation. These cases highlight the potential sight-threatening complications of such intraocular lenses.

From the Department of Paediatric Ophthalmology, Moorfields Eye Hospital, London, United Kingdom.

Presentation in part as a poster at The European Paediatric Ophthalmological Society 37th Annual Conference, October 13–15, 2011, Thessaloniki, Greece.

The authors have no financial or proprietary interest in the materials presented herein.

Address correspondence to Hon Shing Ong, MBBS, Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, United Kingdom. E-mail: honshing@gmail.com

Received: March 17, 2012
Accepted: August 22, 2012
Posted Online: October 09, 2012

Spontaneous Subluxation of Iris-Claw Aphakic Intraocular Lens Causing Complications in Two Children

Introduction

It is not always easy to choose an ideal intraocular lens (IOL) in pediatric aphakic eyes with poor capsular support. Since its introduction, many surgeons consider iris-claw anterior chamber intraocular lenses (AC-IOLs) a favorable option for implantation in such children due to their predictable postoperative outcomes and safety profiles. This case report describes two children who had spontaneous subluxation of such IOLs resulting in complications that required explantation. It aims to highlight the potential sight-threatening complications of such IOLs.

Case Reports

Case 1

A 9-month-old female infant presented to the ophthalmology department with bilateral dense central cataracts. She subsequently underwent bilateral cataract extractions. She had an uncomplicated left cataract extraction with a primary posterior capsulorhexis and anterior vitrectomy. An in-the-bag +35.0 diopters (D) posterior chamber intraocular lens was implanted. In her right eye, due to the density of the cataract and its adherence to the posterior capsule, the integrity of the posterior capsule was not maintained during surgery. An anterior vitrectomy was performed and she was left aphakic.

In the postoperative period, her parents reported an improvement in her visual behavior. However, she was noted to have a preference for her left eye and developed a right convergent squint. Unaided visual acuities with Cardiff acuity cards at 50 cm were 6/500 in the right eye and 6/76 in the left eye. Cycloplegic refraction revealed +14.00 diopter sphere (DS) in the right eye and +2.00 DS in the left eye.

To correct her anisometropia and prevent worsening of her right amblyopia, an aphakic +30.0 D Artisan Iris-Claw AC-IOL (Ophtec BV, Groningen, The Netherlands) was implanted in her right eye at the age of 14 months at another institution. Postoperatively, her binocular visual acuity on Cardiff acuity cards at 50 cm was 6/48. Cycloplegic refraction was plano/−0.75 × 100 in her right eye and −0.75 DS in her left eye. At 2 years of age, her visual acuities with Kays Crowded logarithm of the minimum angle of resolution at 3 m were 4/60 in the right eye and 3/30 in the left eye. She had regular follow-up for visual rehabilitation and twice yearly monitoring.

At the age of 8 years, she presented to our ophthalmic emergency department with acute pain, redness, and increasing photophobia in her right eye. There was no history of trauma. Her visual acuities were 6/76 in the right eye and 6/38 in the left eye. On examination, her right conjunctiva was injected and her cornea was hazy with marked stromal edema. In addition, she had a fibrinous anterior uveitis. It was noted that the nasal iris claw of the AC-IOL was not clipped. Her right pupil was eccentric, likely caused by previous surgical trauma and chronic inflammation. Intraocular pressures were within normal limits. She began taking intensive steroid drops (dexamethasone 0.1%), mydriatic drops (cyclopentolate 1%), and antibiotic drops (ofloxacin 0.3%). The inflammation improved but her cornea remained hazy and the child remained photophobic with no improvement in her vision. Because her right corneal decompensation failed to improve, she underwent intraocular lens removal (Figure 1). Since explantation, her right cornea has remained edematous and her vision poor, but she reports less photophobia.

The right eye of case 1. (A) Pseudophakic corneal decompensation resulting from the dislocated Artisan Iris-Claw anterior chamber intraocular lens implant (AC-IOL) (Ophtec BV, Groningen, The Netherlands). The nasal iris claw of the lens was not clipped (arrow), resulting in the temporal displacement of the AC-IOL. The eccentric pupil is likely to be caused by previous surgical trauma and chronic in3 ammation. (B and C) Surgical explantation of the intraocular lens. Under viscoelastic, the temporal iris claw of the AC-IOL was dislodged; the AC-IOL was rotated and explanted through a superior corneal incision.

Figure 1. The right eye of case 1. (A) Pseudophakic corneal decompensation resulting from the dislocated Artisan Iris-Claw anterior chamber intraocular lens implant (AC-IOL) (Ophtec BV, Groningen, The Netherlands). The nasal iris claw of the lens was not clipped (arrow), resulting in the temporal displacement of the AC-IOL. The eccentric pupil is likely to be caused by previous surgical trauma and chronic in3 ammation. (B and C) Surgical explantation of the intraocular lens. Under viscoelastic, the temporal iris claw of the AC-IOL was dislodged; the AC-IOL was rotated and explanted through a superior corneal incision.

Case 2

A 2-year-old boy was diagnosed as having bilateral congenital cataracts in Ethiopia. He underwent bilateral cataract extractions and was prescribed glasses for his refractive error. At 5 years of age, a posterior chamber IOL was implanted in his right eye. In the left eye, he received an Artisan Iris-Claw AC-IOL due to insufficient capsular support. Old records revealed recorded visual acuities of 6/9 in both eyes postoperatively.

At 11 years of age, he presented to our ophthalmology department with redness, discomfort, and reduced vision in his left eye. There was no history of trauma. His visual acuities were 6/9 in his right eye and 6/60 in his left eye. He had a left acute anterior uveitis and the AC-IOL had dislocated inferotermporally into the iridocorneal angle (Figure 2). The IOL was not in contact with the corneal endothelium and, aside from endothelial pigmentary deposits, his cornea was clear. However, his intraocular pressure was raised at 34 mm Hg in the left eye and 16 mm Hg in the right eye. He commenced steroid drops (dexamethasone 0.1%) and intraocular pressure-lowering drops (betaxolol 0.25% and lantanoprost 0.005%). His ocular inflammation improved but intraocular pressure remained persistently high at 30 mm Hg. He has been advised to undergo AC-IOL removal.

The left eye of case 2 showing inferotemporal dislocation of the Artisan Iris-Claw anterior chamber intraocular lens implant (Ophtec BV, Groningen, The Netherlands). Both nasal and temporal iris claws were dislodged (arrows).

Figure 2. The left eye of case 2 showing inferotemporal dislocation of the Artisan Iris-Claw anterior chamber intraocular lens implant (Ophtec BV, Groningen, The Netherlands). Both nasal and temporal iris claws were dislodged (arrows).

Discussion

The Artisan Iris-Claw AC-IOL was first introduced by Fechner et al. in 1978.1 A modified biconcave phakic version was implanted in 1986 for correction of high myopia. The aphakic model was developed in 1996.

In patients with insufficient capsular support for intracapsular IOL, the choice of an ideal lens is a difficult one. The options include anterior chamber IOL (angle-supported or iris-fixated) and scleral-fixated posterior chamber IOL. Problems with angle-supported AC-IOL have been reported. These include endothelial cell loss, pseudophakic bullous keratopathy, uveitis, secondary glaucoma, and cystoid macular edema.2 Scleral-fixated posterior chamber IOLs are also not ideal. Reported complications include rhegmatogenous retinal detachment, IOL decentration, pigmentary dispersion, and transcleral suture erosion and infection.3 There are also concerns regarding suture breakage with scleral-fixated posterior chamber IOL.4

Many surgeons consider the iris-claw aphakic IOL a favorable choice for primary and secondary implantation where there is insufficient capsular support. More than 300,000 aphakic eyes have been implanted with this lens worldwide.5 Multi-center studies have shown that iris-claw IOLs are safe, stable, and predictable.6,7 Conversely, most studies on the safety of iris-claw lenses are on phakic patients receiving such lenses in the correction of refractive errors. A recently published retrospective study of 32 eyes with aphakic Artisan Iris-Claw AC-IOL implantation did demonstrate improvement in best-corrected visual acuities with few complications.8 However, the mean follow-up for this study was only 17.3 months. In 2011, De Silva et al. published a series of 116 aphakic patients receiving iris-claw lenses with a prevalence of lens subluxation of 6.0%.9 None of these subluxed lenses needed explantation.

Many studies have concluded that endothelial cell densities remain stable after implantation of such lenses. Budo et al. showed that corneal endothelial cell loss is stabilized to the physiologically normal level after 3 years.6 Again, these studies were on phakic eyes undergoing refractive surgery and may not be directly applicable to our patients.

In 2006, a case series of three children who underwent Artisan lens implantation following congenital cataract extraction reported no difference in the corneal endothelial cell density in the eyes receiving surgery and the control eyes after 9.5 years of follow-up.10 More recently, Sminia et al. published long-term follow-up data on 10 children who received bilateral aphakic Artisan Iris-Claw AC-IOL after bilateral congenital cataract extraction.11 They found that the mean corneal endothelial cell density after more than 10 years of follow-up was comparable to the mean normal endothelial cell density for the similar age group reported in the literature. These studies were retrospective and had relatively few numbers to make definitive conclusions. In our patients, the first case described had corneal decompensation, which was likely to be due to movement of the subluxed IOL within the anterior chamber.

Other reported complications following Artisan lens implantation include uveitis, glaucoma, and pupillary block.5,12 Once again, no large series have reported the incidence of these. Surgical factors such as surgeon experience and training on enclavation of these lenses may also affect the incidence of complications. In our two cases, it is difficult to establish surgical factors due to the lag time between implantation and subluxation and because the operations were performed in other institutions. A known technique to reduce the risk of corneal decompression is the use of the Artisan Iris-Claw IOL on the posterior iris.13 However, risks of pigment dispersion have been reported with this technique.14

There is a low rate of reported complications for the Artisan Iris-Claw AC-IOL and its use is considered generally safe. Subluxation of such lenses is rare and often the result of trauma.15 To our knowledge, this is the first case report of children with spontaneous subluxation of such aphakic IOLs requiring explantation in one case and advised explantation in the other due to corneal decompensation and ocular hypertension.

The authors believe it is important for surgeons to be made aware of these potential sight-threatening complications. Long-term review and examinations after implantation of these lenses is recommended. Larger, prospective studies on pediatric aphakic eyes receiving the Artisan Iris-Claw AC-IOL are required to determine its safety profile.

References

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  2. Hennig A, Johnson GJ, Evans JR, et al. Long term clinical outcome of a randomised controlled trial of anterior chamber lenses after high volume intracapsular cataract surgery. Br J Ophthalmol. 2001;85:11–17. doi:10.1136/bjo.85.1.11 [CrossRef]
  3. Asadi R, Kheirkhah A. Long-term results of sclera fixation of posterior chamber intraocular lenses in children. Ophthalmology. 2008;115:67–72. doi:10.1016/j.ophtha.2007.02.018 [CrossRef]
  4. Buckley EG. Hanging by a thread: the long-term efficacy and safety of transscleral sutured intraocular lenses in children (an American Ophthalmological Society thesis). Trans Am Ophthalmol Soc. 2007;105:294–311.
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  8. Lett KS, Chaudhuri PR. Visual outcomes following Artisan aphakia iris claw lens implantation. Eye. 2011;25:73–76. doi:10.1038/eye.2010.146 [CrossRef]
  9. De Silva SR, Arun K, Anandan M, Glover N, Patel CK, Rosen P. Iris-claw intraocular lenses to correct aphakia in the absence of capsule support. J Cataract Refract Surg. 2011;37:1667–1672. doi:10.1016/j.jcrs.2011.03.051 [CrossRef]
  10. Odenthal MTP, Sminia ML, Prick LJ, Gortzak-Moorstein N, Volker-Dieben HJ. Long-term follow-up of the corneal endothelium after artisan lens implantation for unilateral traumatic and unilateral congenital cataract in children: two case series. Cornea. 2006;25:1173–1177. doi:10.1097/01.ico.0000243961.52769.5f [CrossRef]
  11. Sminia ML, Odenthal MTP, Prick LJ, Mourits MP, Volker-Dieben HJ. Long-term follow-up of the corneal endothelium after aphakic iris-fixated IOL implantation for bilateral cataract in children. J Cataract Refract Surg. 2011;37:866–872. doi:10.1016/j.jcrs.2010.07.040 [CrossRef]
  12. Hogewind BF, Theelen T. Slit-lamp-adapted optical coherence tomography of pupillary block after Artisan lens implantation for aphakia. Int Ophthalmol. 2007;27:337–338. doi:10.1007/s10792-007-9075-4 [CrossRef]
  13. Baykara M, Ozcetin H, Yilmaz S, Timuçin OB. Posterior iris fixation of the iris-claw intraocular lens implantation through a scleral tunnel incision. Am J Ophthalmol. 2007;144:586–591. doi:10.1016/j.ajo.2007.06.009 [CrossRef]
  14. Rijneveld WJ, Beekhuis WH, Hassman EF, Dellaert MM, Geerards AJ. Iris claw lens: anterior and posterior iris surface fixation in the absence of capsular support during penetrating keratoplasty. J Refract Corneal Surg. 1994;10:14–19.
  15. Yoon H, Macaluso DC, Moshirfar M, Lundergan M. Traumatic dislocation of an Ophtec Artisan phakic intraocular lens. J Refract Surg. 2002;18:481–483.

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