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Excellent visual outcomes for ICL, but cataract formation still a problem Dermot McGrath in Lisbon LONGTERM clinical experience with the Implantable Contact Lens (Visian ICL, Staar Surgical) demonstrates consistently high rates of refractive success and patient satisfaction, but these benefits must be balanced with the possibility of eventual surgery for ICL-induced cataract, according to a number of researchers at the XXIII Congress of the ESCRS. “This foldable, posterior chamber, phakic IOL performs well in terms of safety, efficacy and predictability for moderate to high myopia, but there remains a concern in the long term due to the relatively high incidence of anterior subcapsular cataract found with this type of lens,” said Philippe Othenin-Girard MD. Dr Othenin-Girard, University Eye Hospital, Lausanne, “This foldable, posterior chamber, phakic IOL performs well in terms of safety, efficacy and predictability for moderate to high myopia, but there remains a concern in the long-term.” Switzerland, noted that the ICL can be implanted through a small incision, offers an excellent range of correction, and typically results in very good uncorrected acuity. Along with his co-researchers Drs Nguyen, Titzé, Bornet and Gonvers, Dr Othenin-Girard implanted 149 ICLs in 87 patients between April 1998 and August 2005. The final study data included 136 eyes of 82 patients with a mean age of 38 years, ranging from 16 to 65 years. Mean follow-up was 50 months with a range of 12 to 86 months. The mean preoperative spherical equivalent was –13.1 D, and the mean lens power was –16.3 D. Of 73 patients who were targeted for emmetropia, the mean preoperative spherical equivalent was –11.7 D (range –7.3 D to –17.8 D). Three generations of the Staar ICL were implanted over the course of the study, the majority of which were the latest model, the V4.The V4 is said to have improved vaulting to reduce the possibility of contact with the crystalline lens. Good predictability and safety Predictability was excellent, noted Dr Nguyen, who presented the visual acuity data. For the 73 eyes targeted for emmetropia, the mean final SE was –0.69 D (range +1.25D to –4.88 D). Some 78% of eyes were within 1.0 D of intended refraction, with 44% within 0.5 D. The data for safety were similarly encouraging. Some 72% of eyes gained one or more lines of best-corrected visual acuity, 22.5% remained stable and 5.6% lost one or two lines. Of the group that was targeted for emmetropia, uncorrected visual acuity was 0.5 or better in 77% of the eyes and 1.0 or better in 26%. The results for intraocular pressure showed that 52 eyes had a higher postoperative IOP, 21 eyes remained stable and 63 eyes recorded a lower IOP, although the differences were not statistically significant. Dr Nguyen also noted that there was no demonstrable correlation between an increase in IOP and the degree of vaulting. Complications associated with the procedure included two acute symptomatic vitreous detachments that occurred in the first week after Nd:Yag laser iridotomy. One of these led to rhegmatogenous retinal detachment three weeks after ICL implantation.The other patient complained of acute floaters and underwent a vitrectomy before ICL implantation. Intraoperative complications included two ICLs that had to be second, a clear lens three months after the surgery in order to exclude the possibility of a peroperative iatrogenic cataract. He said that between 2003 and 2005, the rate of ICL-induced subcapsular opacities progressed from 26% to 30%, necessitating six new phacoemulsifications. No subcapsular opacities were observed before the one-year follow-up point. Dr Othenin-Girard stressed that age played a role in the incidence of subcapsular opacities. “It is clear that the number of cataracts increases with age, “It is clear that the number of cataracts increases with age, 17.4% of the patients aged between 31 and 40 years developed a cataract, more than 44% between 41 and 50 years and 42% between 51 and 64 years.” removed and replaced during surgery – one because of a 180degree rotation of the ICL, and the other because a plate of the ICL had completely folded on itself. Postoperative complications included six cases of peripheral bulging of the plates, six cases of late ocular hypertension, four cases of asymptomatic late retinal tears, and four cases of excessive vaulting, one which required a surgical reposition eight months after surgery. Subcapsular opacities Focusing on the persistent problems of cataract formation associated with the ICL, Dr Othenin-Girard said that two main conditions needed to be satisfied for the development of an ICL-induced cataract: first, the presence of characteristic anterior subscapsular opacity and 17.4% of the patients aged between 31 and 40 years developed a cataract, more than 44% between 41 and 50 years and 42% between 51 and 64 years. There was also a correlation between the incidence of cataract and higher lens power.” Examination of peripheral vaulting by Scheimpflug photography confirmed the research team’s previous finding that total vaulting completely prevents cataract formation. Dr Othenin-Girard said that no ICL-induced cataracts had been observed before a follow-up of one year and that the number of cataracts had slowly increased thereafter, with a progressive density of opacities. He said that the typical subcapsular cataract is related to the age of the patient, the central vaulting and the ICL power value. “Total vaulting protects the lens against cataract, however only a minority of eyes have this complete vaulting. No matter what technology is used to measure the sulcus diameter, a precise total vaulting predictability cannot be actually achieved. We have therefore restricted our ICL indication to myopia over –9.0 D and for patients older than 40 years of age to reduce the risk of ICLinduced cataract in young patients, even if the risk is agerelated,” he said. Philippe Othenin–Girard MD [email protected] Good vaulting essential Exploring further the relationship between IOL vaulting and cataract development, Dr Othenin-Girard noted that all examinations were performed with Scheimpflug photography and a mean central vaulting had been calculated based on 10 values per eye. Analysis showed a significant difference between the clear lens group and the cataract group in terms of central vaulting, with a higher mean vault value in the clear lens group. EuroTimes March 2006