The Artisan® (Ophtec, Groningen, Netherlands) aphakia (iris claw) lens has been used since 1978 for the correction of aphakia following cataract surgery. Since the introduction of iris-fixated intraocular lenses (IOLs) in the early 1980s,1,2 there has been progressive improvement in IOL design. Implantation of IOLs has become the standard of care for patients with aphakia. Ideally, the lens is placed in the capsular bag, which affords stable fixation in a position closest to the nodal point of the eye; however, there will always be instances in which this will not be possible, such as congenital weakness of the lens zones, surgical complications of cataract surgery, trauma, etc. The options for the surgical correction of aphakia without capsular support include implantation of an angle-supported anterior chamber intraocular lens (ACIOL).
Trans-scleral fixation of a posterior chamber intraocular lens (PCIOL) and iris fixation of a PCIOL is carried out either by suturing the IOL to the overlying iris or by fixation with a lens claw. Trans-scleral fixation of a PCIOL is technically challenging, requiring more surgical time and being associated with the possibility of complications including ciliary and choroidal haemorrhage, retinal detachment, giant retinal tears, vitreous haemorrhage, cystoid macular oedema, lens tilting, decentration, vitreous prolapse into the anterior chamber and conjunctival erosion by trans-scleral sutures with associated risk of endophthalmitis.3,4 Angle-supported ACIOLs can be associated with short- and long-term complications such as corneal oedema, hyphaema, cystoid macular oedema, glaucoma, IOL instability, decentration, pupil distortion and retinal detachment, some of which are a direct consequence of the presence of haptics in the iridocorneal angle.5,6 In this prospective case study, retropupillary iris fixation of the IOL was carried out for the management of aphakia secondary to various causes by a single surgeon. This study includes a combination of multiple procedures with retropupillary IOL fixation. The visual rehabilitation, stability of the IOL and complications associated with the procedure were the main outcome measures.
Materials and methods
This prospective interventional case series consisted of seven eyes of seven patients who underwent retropupillary insertion of the Artisan iris claw lens from January 2012 to December 2012 in the Cataract and Refractive Surgery Department at Dubai Hospital. The sample consisted of three men and four women aged 11–82 years. The risks and benefits of treatment were explained to the patients and informed consent was obtained in accordance with the Helsinki Declaration before the procedures. As six of these patients required multiple procedures of the eye during Artisan insertion and two patients were amblyopic, the guarded visual prognosis due to a pre-existing ocular pathology was explained to the patient and his/her relatives.
The demographic details, the indications, associated eye conditions, and details of the surgery and its complications of all seven cases are given in Table 1. All the patients underwent best corrected visual acuity (BCVA) recording by Snellen chart, detailed slit-lamp eye examination, intraocular pressure measurement by Goldmann applanation tonometry, indirect ophthalmoscopy, B-scan ultrasonography (in cases of hazy media) and optical coherence tomography (OCT) for posterior pole assessment. The Artisan aphakia IOL is a polymethylmethacrylate IOL of 8.5 mm length and with a maximum height of 1.04 mm and a 5.4 mm optical zone. The IOL power was calculated by IOL Master® (Carl Zeiss Meditec AG, Jena, Germany) using the Sanders–Retzlaff–Kraff II formula. The manufacturer’s recommendation for a constant is 115.0 and our refraction goal was within –0.75 D in all cases. The inclusion criteria were unilateral aphakia or conditions for which IOL replacement was required, and the exclusion criteria were intractable glaucoma, active anterior uveitis, rubeosis with neovascular glaucoma, severe iris tissue loss or iris atrophy and silicon oil-filled eye.
CF, counting finger; CTF, close to face; HM, hand movements; LE, left eye; PKP, penetrating keratoplasty; PI, peripheral iridectomy; RE, right eye; RPE, retinal pigment epithelium.
The basic surgical technique in four patients was to make a biplanar 5.5 mm posterior vascular corneal incision at the 12 o’clock position. In non-vitrectomized eyes, automated anterior vitrectomy was performed. Peripheral iridectomy was performed with automated vitrector in cases for which the iridectomy hole was not present. Miochol®-E (acetylcholine chloride 1%) (Bausch & Lomb, NY, USA) was used to constrict the pupils. The desired pupil diameter was 4–5 mm at the time of Artisan insertion. This was followed by injection of Viscoelastics (Viscoat; Alcon Laboratories Inc., Fort Worth, TX, USA) in the anterior chamber. Two side ports were made diagonally opposite, at the 3 and 9 o’clock positions, and the Artisan was inserted in the reverse side and rotated in the anterior chamber such that the haptics were in line with the side ports. Holding the optic aspect of the lens with a lens forceps, one haptic was gently manipulated and pushed under the iris. Simultaneously, the air cannula (blunt enclavation) was passed through the paracentesis on the same side and the enclaving was carried out. Approximately 1 mm of iris tissue located in the mid-periphery was trapped by applying gentle pressure. The end point was noted by the dimple at the site of enclavation and ensured an adequate amount of iris tissue enclavation to enable pupil movement. Similarly, haptic encalvation was carried out on the other side of the eye. Care was taken to achieve ideal centration of the IOL and avoid ovalization of the pupils. At the end of the procedure, viscoelastic material from the anterior chamber was carefully removed using an automated bimanual irrigation and aspiration system and the corneal section was sutured with 4–5 interrupted 10–0 nylon sutures. Penetrating keratoplasty combined with retropupillary fixation of the Artisan IOL was carried out in the following way: all three patients underwent corneal trephination with Barron suction trephine (Jedmed, St Louis, MO, USA). The recipient’s corneal button was then cut out with scissors and a graft of 8 mm diameter was chosen for a 7.5 mm recipient bed.
In cases 1 and 7, the pre-existing ACIOL was removed. In case 1, intracameral injection of acetylcholine was used to constrict the pupils after pupilloplasty to facilitate centring of the lens. The Artisan IOL was inserted with implantation forceps and slid through the pupillary area. The IOL was maintained behind the iris plane with the haptics positioned in horizontal 3 o’clock and 9 o’clock positions. The air cannula was used for blunt enclavation of the mid-peripheral iris tissue at both ends, while the IOL was firmly with the Artisan implantation forceps. The donor’s corneal button was then sutured to the recipient bed with 10–0 nylon sutures. In case 6, the PCIOL was removed, along with the capsular bag, and automated anterior vitrectomy and peripheral iridectomy were performed before Artisan insertion. Subconjunctival antibiotic (cefazolin) and dexamethasone were injected at the end of the surgery. Topical Pred Forte® (Allergan, Irvine, CA, USA) eye drops (prednisolone acetate 1%) were given eight times daily for 1 week and then this dose was tapered appropriately and Nevanac® (Alcon, Hünenberg, Switzerland) eye drops (nepafenac ophthalmic suspension 0.1%) were given three times daily for 2 months. Postoperatively, complete ocular examinations and an intraocular pressure (IOP) measurement were performed on the first day, at weekly intervals for a fortnight and then at monthly intervals. The minimum follow-up period was 6 months and maximum was 1 year. Anterior segment OCT (Visante anterior segment OCT system, Carl Zeiss Meditec, Dublin, CA, USA) and posterior segment OCT (Carl Zeiss Meditec AG, Jena, Germany) evaluation were performed after 1 month and whenever required thereafter. The corneal sutures were removed after 6–8 weeks and final refractive correction was given once the refractive error had stabilized. The main outcome measure was extent of visual rehabilitation because three eyes required combined keratoplasty at the time of Artisan insertion. One case was a child with a penetrating injury and a central corneal scar and amblyopia, and three patients required PCIOL removal at the time of Artisan insertion. We also assessed the stability of the Artisan lens after surgery by anterior segment OCT. We looked for complications mainly related to iris claw IOL insertions, such as uncontrolled uveitis, IOL haptic dislocation, decentration, ovalization of pupils, IOP rise and cystoid macular oedema.
The patient in case 1 underwent open sky ACIOL explantation, anterior vitrectomy and pupilloplasty with Artisan insertion followed by keratoplasty, as shown in Table 1. The patient in case 2 underwent the basic technique of Artisan insertion without vitrectomy, as the eye was already vitrectomized (see Table 1). The patients in cases 3 and 4 underwent explantation of complicated PCIOL with the basic technique of Artisan insertion (see Table 1) and Figure 1 displays an anterior segment image of case 3 showing opacified hydrogel PCIOL. The patient in case 5 underwent the basic technique of Artisan insertion with pupilloplasty and vitrectomy was not conducted as the eye was already vitrectomized (see Table 1). The patients from cases 6 and 7 underwent open sky explantation of PCIOL and ACIOL, respectively, alongside automated anterior vitrectomy peripheral iridectomy and Artisan insertion with keratoplasty (see Table 1). Figure 2 presents a slit lamp image of case 7 showing pseudophakic bullous keratopathy with a PCIOL.
The study comprised seven eyes of seven patients with various indications for retropupillary fixation of Artisan. The minimum period of follow-up was 6 months and all the patients showed improvement of vision. Cases 4 and 5 were amblyopic and, therefore, significant improvement of vision was not expected. The various indications for Artisan implantation, the pre-existing eye conditions and the outcomes are shown in Table 1. There was one case of disenclavation of the haptic, which occurred 6 months after surgery owing to progressive iris atrophy at the site of enclavation (Figure 3). The patient underwent explanation of the IOL and four cases developed pigment dispersion in the anterior chamber and pigment deposits on the lens with anterior uveitis for more than 2 weeks. These cases were managed with prolonged and increased frequency of topical steroids and Nevanac eye drops. There was no significant increase in intraocular pressure postoperatively at any time and, in one case, there was ovalization of the pupils. Figure 4 shows the postoperative anterior segment image of the patient in case 3 who underwent explantation of opacified hydrogel posterior chamber lens, anterior vitrectomy and peripheral iridectomy, and who experienced ovalization of the pupils. The patients from cases 1 and 5 had irregular pupils and both patients had previously experienced iridectomy and underwent pupilloplasty during Artisan insertions. Figure 5 shows the postoperative anterior segment image of the patient in case 1, who underwent keratoplasty, explantation of ACIOL and pupilloplasty with retropupillary fixation of the Artisan. Figure 6 shows the postoperative anterior segment image of the patient in case 7, who underwent keratoplasty, explantation of PCIOL and retropupillary fixation of the Artisan. There was no decentring of the optics in any of the cases during the follow-up period.
Figure 7 shows the well-centred IOL of case 4 after dilatation of pupils. None of the patients experienced diplopia following the procedure and the anterior segment OCT carried out in all cases after 1 month showed a well-centred Artisan with the lens plane parallel to the iris diaphragm (Figure 8, of case 3). Posterior segment OCT was routinely performed in all cases and one patient developed cystoid macular oedema within 3 months of follow-up. None of the patients developed posterior segment complications such as vitreous haemorrhage or retinal detachment.
Posterior chamber intraocular implantation of the lens is the standard method of correction of aphakia, as this position is closer to the nodal point of the eye. Over the years, owing to improved surgical techniques and equipment, surgical aphakia has become less common. However, aphakia is still encountered as a complication of cataract surgery, complicated cataracts, lens anomalies and trauma, etc. The options for the surgical corrections of aphakia without capsular support include implantation of ACIOL, trans-scleral fixation of a PCIOL and iris fixated IOL; however, these procedures are associated with short- and long-term complications. In our study, there were various indications for retropupillary fixation of IOL, including removal of opacified hydrogel PCIOL, removal of ACIOL with complications and surgical aphakia secondary to complicated cataract surgery and trauma. One of the main advantages of this procedure is that it can be easily combined with other procedures, such as penetrating keratoplasty, pupilloplasty, IOL explantation and automated anterior vitrectomy, at the same time. Other benefits of retrofixation of iris claw lens include the low risk of complications, it is more cosmetically acceptable as it hides the haptic and parts of the lens behind the iris and there is less chance of lens tilt and glare phenomenon. This technique is a simple and less traumatic method of correction of aphakia, especially in eyes that have already undergone multiple surgeries. The technique is associated with fewer intra- and postoperative complications and the angulation of the haptics and retrofixation of IOLs in the reverse side prevents the possibility of pupillary block. In addition, as the lens is situated away from the cornea, there is less chance of endothelial decompensation. In one of our patients, an 82-year-old man, disenclavation of the haptics occurred 6 months after surgery. The patient had progressive atrophy of iris at the site of iris enclavation and he underwent explantation of IOL. Therefore, very elderly patients with severe loss of iris tissue and iris atrophy may not suitable for retrofixation with the Artisan.
This study highlights the technique and frequently favourable outcome of a combination of procedures with retropupillary fixation of IOL for various indications. Although this study involved a small number of cases, it was our first learning experience with retrofixation of IOLs in complicated cases at our institute.