|Year : 2013 | Volume
| Issue : 3 | Page : 151-154
Retro-pupillary iris fixated intraocular lens in pediatric subluxated lens
Vipul Bhandari, Jagdeesh K Reddy, Smita Karandikar, Indeevar Mishra
Sankara Eye Centre, Coimbatore, Tamil Nadu, India
|Date of Submission||14-Apr-2013|
|Date of Acceptance||11-Jun-2013|
|Date of Web Publication||23-Aug-2013|
Sankara Eye Centre, Sivanadapuram, Sathy Road, Coimbatore, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Aims: The aim of this study was to evaluate the post-operative visual acuity and complications in pediatric patients with ectopia lentis who underwent lens removal and retro-pupillary iris fixated intraocular lens (IOL) implantation. Settings and Design: Retrospective, single center, 5-year clinical audit. Materials and Methods: A retrospective analysis of all pediatric cases who presented with lens subluxation and who underwent lens extraction with posterior iris claw implantation was performed over a period of 5 years from March 2008 to February 2013. A detail record of visual acuity, slit lamp examination and fundus examination was carried out. The iris claw IOL used in this case series had a 5.5/4.5 mm optic and 8/9 mm overall length. After lens removal iris claw, IOL was enclaved to the posterior surface of the iris. The main indications for surgery were reduced visual acuity and monocular diplopia. The main outcome measure was pre-operative and post-operative best corrected visual acuity (BCVA) and secondarily post-operative complications. Results: The study involved 36 eyes of 20 patients who underwent iris claw implantation showed improvement in mean BCVA from 2/60 pre-operatively to 6/18 post-operative. The mean age of the presentation was 12 years. Post-operative outcome in all patients was good. Only one patient developed traumatic dis-enclavation with subluxation of the iris claw IOL at 6 months in which re-enclavation was performed with success. The mean follow-up period was 7 months. No eye had serious complication such as cystoid macula edema, infection, glaucoma and dislocation of IOL. Conclusions: Retro-pupillary iris fixation of IOL is a simple, safe and viable option for correction of ectopia lentis in pediatric group.
Keywords: Enclavation, iris claw, retro-pupillary, pediatric, subluxated lens, intraocular lens
|How to cite this article:|
Bhandari V, Reddy JK, Karandikar S, Mishra I. Retro-pupillary iris fixated intraocular lens in pediatric subluxated lens. J Clin Ophthalmol Res 2013;1:151-4
|How to cite this URL:|
Bhandari V, Reddy JK, Karandikar S, Mishra I. Retro-pupillary iris fixated intraocular lens in pediatric subluxated lens. J Clin Ophthalmol Res [serial online] 2013 [cited 2020 Jul 9];1:151-4. Available from: http://www.jcor.in/text.asp?2013/1/3/151/116846
Ectopia lentis in children commonly occurs as an idiopathic or hereditary condition. Rarely, it can be due to trauma and the more common non-traumatic conditions are Marfan's syndrome, homocystenuria, Weil-Marchesani syndrome and metabolic syndromes. Spherophakia is another condition with abnormal sphere shaped lens and weak zonules.
Subluxation of the crystalline lens produces varying degree of refractive errors. These have both regular and irregular components with significantly very high higher-order aberrations. These irregular astigmatism or higher order aberrations cannot be corrected with spectacles as the aberrations are lenticular and internal. These uncorrected refractive errors can result in amblyopia in children. Refractive correction with spectacles and contact lens is much easier in total dislocation of the crystalline lens.
Often ectopia lentis in children is associated with very weak zonules and marked subluxation. It is difficult to achieve the proper centration using the capsule supported intraocular lens (IOL). The efficacy of capsular tension ring (CTR) and scleral fixated IOLs has been evaluated with mixed results. The CTR do not provide accurate centration in cases with profound zonular dialysis of more than 180°. Either the CTR or the haptics of the IOL have to be sutured to the sclera with prolene suture. 
We selected retro-pupillary fixation to keep the IOL in the posterior chamber, a very safe place, which gives maximum protection to the corneal endothelium.  It eliminates the need for sutures and the complications associated with it and has been safely used even in phakic eyes. ,,,,,,,
The possible dreaded complications with iris claw lenses include decentration, IOL tilting, iris chaffing, de-enclavation, secondary glaucoma and endothelial decompensation. ,, We carried out this study to understand the long-term efficacy and safety of posterior iris claw lens and establish it as a viable option for management of ectopia lentis.
| Materials and Methods|| |
It was a retrospective analysis of patients with congenital and traumatic subluxated lens [Figure 1] with more than 180° of zonular dialysis over a period of 5 years from March 2008 to February 2013. All surgeries were performed by a single surgeon.
A detailed medical history was recorded from patient's parents and examination by a pediatrician, to find out congenital anomalies was performed.
A pre-operative clinical examination, which included detail record of visual acuity using the Snellens charts, best corrected visual acuity (BCVA), slit lamp examination, fundus examination with pupillary dilatation using 90 D and indirect ophthalmoscopy was performed. B scan was performed when the fundus details were not clearly visible. Automated kerato-refractometer was used to obtain keratometric values and axial length was measured with A scan. All children in the age group of 6 months to 15 years having lens subluxation of 180° or more were selected for surgery if they presented with any one of the following: monocular diplopia, distance BCVA worse than 6/12 and variable refraction or variable BCVA measurements caused by progressive subluxation of the lens and bisection of the pupil. Patients with no perception of light (PL), corneal or retinal pathologies that would affect the final visual outcome were excluded from the study.
The iris claw IOL implanted in this case series (Excel Optics, Chennai Model No: PIC 5590, SIC4280P) is a modified version of Dr. Worst and Dr. Daljit Singh model. The overall length of the IOL is 8/9 mm so that the pupillary dilatation was good enough for posterior segment evaluation in the post-operative period. The optic is biconvex and 4.5/5.5 mm in size. The IOL has no angulation so that it can be implanted in either way. The estimated A constant was 117. The surgeon chose a lens power close to the power needed for emmetropia. The following guidelines were followed for correction of IOL power in age less than 8 years [Table 1]. Above 8 years of age, the IOL power was calculated as for adults.
Informed consent and physician fitness for general anesthesia was obtained for all patients. Pre-operative pupillary dilatation was performed with tropicamide 1% and phenylephrine 5%. The surgery was performed through a superior 5.5 mm limbal 3 plane incision. Sodium hyaluronate 1.4% was used as an ocular viscoelastic device (OVD). Two paracentesis incisions were made on either side at 3 and 9 0 clock position. A small capsulorhexis was carried out. Soft cortical matter was aspirated using Simcoe cannula with low infusion. The anterior chamber was filled with OVD and the capsular bag was pulled out and removed with a fine non-toothed forceps. Intracameral pilocarpine or acetyl choline (Miochol 0.01% preservative free from appasamy ocular devices) was injected to constrict the pupil to a diameter of at least 5 mm. A small vitrector peripheral iridectomy was performed followed by anterior vitrectomy. Iris claw IOL was introduced into the anterior chamber. OVD was injected at each stage to deepen the anterior chamber and maintain space. Holding the optic with a lens forceps one haptic side was tilted down and pushed under the iris with gentle manipulation. Simultaneously, a fine 30 gauge rod was passed through the paracentesis on the same side. Once the haptic was behind the iris, the haptic of IOL was tilted up to produce an indent on the iris. The iris was enclaved into the haptic claw with the gentle push of the rod. Then with similar maneuver the other side haptic enclavation was performed. If vitreous disturbance occurred during any stage of surgery, automated vitrectomy was performed.
The wound was closed with 10-0 nylon interrupted sutures in all cases. Post-operatively [Figure 2] topical prednisolone acetate 1% eye drops and ofloxacin 0.3% eye drops were prescribed 4 to6 times daily with a tapering schedule over 2 months. Topical ketorolac eye drops were prescribed twice daily for 3 months.
The patients were followed-up on 1 st day, 15 th day, 2 nd month and every 3 months thereafter for 1 year. At each follow-up, detailed slit lamp examination, intraocular pressure by non-contact tonometer, Snellens visual acuity and best spectacle corrected visual acuity was recorded. At 3 month follow-up, a detailed fundus evaluation was performed [Figure 3].
| Results|| |
The mean age at the time of surgery was 12 years, youngest being 6 months old.
Male:female ratio was 3:2 [Table 2], 4 unilateral and 16 bilateral cases in our audit. No eye had dislocation of the subluxated lens into the anterior chamber or vitreous or a cataractous lens.
The mean BCVA pre-operatively was 2/60 (range from 1/60 to 6/60). Visual acuity could not be obtained in one patient because of very young age and poor co-operation. Subjective improvement in visual function was noted from parents. The mean post-operative BCVA at the end of 2 months was 6/18 [Table 3].
A total of 34 cases showed a well centered IOL and a mild decentration of 0.5 mm to 1 mm was seen in two cases. However, the visual axis was clear in all cases with a round to minimally oval pupil. One patient developed traumatic dis-enclavation with subluxation of the IOL at 6 months. Re-enclavation was done with success.
Minimal pigment dispersion was noted in 6 cases, which subsided completely over 1 week with the ongoing post-operative steroid therapy. One patient developed total retinal detachment, which was noted at the 2 nd month follow-up, was subsequently treated with trans pars plana vitrectomy and silicone oil injection. Reattachment could not be achieved and the vision remained PL + .
No IOL dislocated during the post-operative follow-up period. No patients had clinically significant cystoids macular edema. No eyes had posterior synechiae. Complications such as endophthalmitis, uveitis or glaucoma did not occur in any patient.
| Discussion|| |
Anterior and scleral-fixated posterior chamber IOLs have been the most popular type of IOLs used in implantation in the absence of adequate capsule support and they avoid the need for aphakic spectacles or contact lenses. However, there is much discussion on the best method for secondary IOL implantation that offers the lowest complication rate and best possible visual rehabilitation over several years. Retro-pupillary fixation of an iris claw IOL has the advantages of true posterior chamber implantation, which results in a deeper anterior chamber and greater distance to the corneal endothelium and has a lower intra-operative and post-operative risk profile than anterior fixation.
Conservative management of ectopia lentis using spectacles or contact lenses is associated with improper correction of refractive condition with significant visual disability and the development of amblyopia. , A pars plana lensectomy with vitrectomy is one treatment option. However, pars plana lensectomy needs 2 or 3 sclerotomies and must be performed by an experienced retina surgeon. It predisposes to peripheral retinal damage.
Lensectomy with scleral fixation of the IOL is another option with fewer incidences of posterior capsule opacification. Late dislocation of sclera fixated IOL has been reported after 7-14 years.  Price et al. reported prolene suture degradation and cracking.  Tilting of the sclera sutured IOL and erosion of the prolene suture are well-known complication of this technique.
Cionni rings, CTR with extra hooks have been used to stabilize the capsular bag of subluxated lens by way of suturing the hooks to the sclera with 10-0 prolene suture. In cases with gross degree of subluxation due to weak zonules, this technique may not stabilize the capsular bag for a long time. Significant number of cases develops decentration of IOL, posterior capsule opacification and is known to require secondary surgical intervention. Often the IOL dislocates in the post-operative period requiring secondary suturing to the sclera or iris. ,
Iris fixated IOL were there for a long time, nearly for 4 decades with mixed results. They attracted a lot of debates and controversies. Most of the problems and complications with iris fixated IOL were solved with improved design, manufacturing techniques and surgical technique, ,,,,,, thanks to the efforts of its inventors Dr. John Worst and Dr. Daljit Singh. They have stood the test of time and emerged as safe IOLs. Food and Drug Administration has approved retro-pupillary iris claw lenses for aphakic refractive IOL correction.
The visual recovery and induced astigmatism also does not differ much with intra-haptic fixation of foldable IOL and iris claw lens. There is added difficulty in IOL power calculation with intrascleral haptic fixation. Retro-pupillary iris fixation gives good results comparable with sclera fixated lenses without many complications. Intrascleral haptic fixation can be alternative if the iris is damaged. 
Nearly, 70% of our patients achieved a final visual acuity of 6/12, which is comparable to 60% reported by De Silva et al. in their study  and about 63.5% reported by Gonnermann et al. 
The most common complication reported in our series was mild ovalization of pupil in 10% cases and decentration of IOL in two cases. Gonnermann et al. reported pupil ovalization in 13.9% cases. Pupil ovalization may be due to fixation of the haptic very tightly or asymmetrically.  De Silva et al.  reported the most common complication to be wound leak about 6% and iris claw dislocation 6%. Our series had no wound leak and one dis-enclavation, which was traumatic.
The mean post-operative Spherical Equivalent at the last follow-up was 0.00-1.21 diopters (D) (range from 2.50 to 4.50 D) comparable to reported by Gonnermann et al. 
The posterior position of the iris claw IOL and the greater distance from the endothelium make this technique safer. Accordingly, we did not observe corneal decompensation in our patient. However, a limitation of our study is that corneal endothelial cell counts were not performed sequentially after surgery.
Retro-pupillary iris fixation of IOL is a simple, safe and viable option for correction of ectopia lentis in pediatric group.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3]