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PHAKIC EXPLANTS

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Posted: Tuesday, July 16, 2013

Endothelial cell loss and cataract were the two most common reasons for the removal of phakic IOLs cited in a long-term French study presented at the annual meeting of the French Implant and Refractive Surgery Association (SAFIR). In a retrospective review of 10 years of phakic IOL explantations carried out at the University Hospital, Toulouse, Pierre Fournié MD reported that 129 phakic implants in total were explanted between 2003 and 2012. The study looked at three broad categories of phakic implants: anglesupported anterior chamber IOLs, irisfixated anterior chamber lenses and posterior chamber IOLs. The average patient age at the time of explantation was 48.95 years.
Looking at the breakdown of the overall explantation data, the removals included 33 iris-fixated lenses, 46 angle-supported IOLs and 50 posterior chamber IOLs. The cause for removal of all lens categories combined was cataract in 52 per cent (Figure 1), endothelial cell loss in 35 per cent, endothelial decompensation in seven per cent (Figure 2) and various other reasons in six per cent. Focusing specifically on the anglesupported lenses, 63 per cent of these IOLs were removed because of endothelial cell loss, 20 per cent for endothelial decompensation, 13 per cent for cataract and four per cent for other reasons, including pupil ovalisation, retinal detachment and decentration. The average delay before explantation was 10.20 years. For the iris-fixated IOLs, endothelial loss was responsible for explantation in 64 per cent and cataract in the remaining 36 per cent, with an average time of 7.73 years before explantation.

Turning to the posterior chamber IOLs, cataract was implicated in the vast majority of cases (92 per cent), with the remainder removed for various reasons such as vaulting and retinal detachment. The mean time before explantation was 5.72 years. Dr Fournié noted that while the Toulouse study accorded with the scientific literature in terms of known complications associated with specific types of phakic IOL, there were some limitations to be borne in mind. “We need to be aware of the limitations of this type of study. This was a retrospective study that took account of different broad categories of implants. However, there are noticeable differences between different implants of the same class in terms of their design and material. Nor did the study take account of possible changes in IOL design and material from one generation of implant to the next,” he said.
Similar findings were also reported in a series of 32 phakic implants explanted at the University Hospital of Bordeaux between 2007 and 2011, according to Emilie Bardet MD. “Phakic implants remain a therapeutic alternative in refractive surgery for severe ametropias in patients where LASIK surgery is not a viable option. However, frequent postoperative visits are mandatory in order to monitor the possibility of postoperative complications, of which endothelial cell loss and cataract remain the most common,” she said.

Looking at the explants in greater detail, the list included: one AcrySof (Alcon) angle-supported lens (three per cent) removed after nine years for endothelial decompensation; six irisfixated Artisan (Ophthec/AMO) IOLs (18 per cent) removed after a mean of nine years for endothelial decompensation, eight angle-supported I-CARE (Corneal/ Allergan) lenses (25 per cent), removed after a mean of four years for endothelial decompensation; 14 angle-supported GBR (IOLTECH, Zeiss) lenses removed after a mean of 8.5 years for endothelial decompensation; one Sticklens (IOLTech/ Zeiss) sulcus fixated IOL (three per cent), removed after three years for cataract; and two ICL sulcus-fixated (Staar Surgical Company) lenses (six per cent), removed after a mean of three years for cataract.

Dr Bardet noted that concerns about the angle-supported lenses in particular led to their withdrawal from the French market between 2007 and 2008. The Alcon Cachet lens was also withdrawn from sale in 2012 because of concerns relating to sudden reduction in endothelial cell counts in implanted patients.