A loose fold of iris tissue is grasped by resilient claw-shaped haptic tips. Iris-claw IOLs were designed by. Worst, who began implanting them in aphakic eyes in.
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cases of anterior vitrectomy in this cohort had concomitant risk factors for glaucoma and steroid response; thus, triamcinolone was used sparingly in this cohort.dMichael E. Snyder, MD, Ivey L. Thornton, MD, Brian McMains, MS REFERENCES
1. Eller AW, Barad RF. Miyake analysis of anterior vitrectomy techniques. J Cataract Refract Surg 1996; 22:213–217 2. Burk SE, Da Mata AP, Snyder ME, Schneider S, Osher RH, Cionni RJ. Visualizing vitreous using kenelog suspension. J Cataract Refract Surg 2003; 29:645–651
Iris-clip versus iris-claw intraocular lenses We read with interest the case series on anterior megalophthalmos by Messina et al.1 They indicated that in 4 eyes, an iris-clip anterior chamber intraocular lens (IOL) was implanted. There is a difference between the terms iris-clip IOL and iris-claw IOL, which appears to have been overlooked by Messina et al. The term iris-clip refers to a model of IOLs that is no longer in use. On the other hand, iris-claw IOLs (Artisan, Ophtec BV, and Verisyse, Abbott Medical Optics, Inc.) have a totally different design and are available today. Designed by Binkhorst in 1957 and called the iris-clip IOL since the first publication on this topic in 1959 to the last reports of its use in the 1970s, the iris-clip IOL had 2 wire loops, bent at right angles and attached to its posterior surface close to the equator. This allowed it to be fixated at the pupil margin with one wire loop located anteriorly to the iris and the other one located posteriorly, in a fashion similar to how a paper clip works.2,3 On the other hand, the iris-claw IOLs have a different principle based on fixation to the anterior peripheral iris stroma. A loose fold of iris tissue is grasped by resilient claw-shaped haptic tips. Iris-claw IOLs were designed by Worst, who began implanting them in aphakic eyes in 1979.4 These iris-claw IOLs have been used in some countries in Europe since at least 1980 and today are available almost globally. However, some ophthalmologists in many countries have limited knowledge of the properties and indications of this IOL for aphakia and this IOL has not been used to its full potential. A surgeon in our group (V.G.) was the first to implant these types of IOLs in Colombia in 1998. Still, some surgeons in our country perform complex procedures (eg, suturing IOLs to sclera in eyes with a normal iris) even though fixation of an iris-claw IOL on the anterior surface or posterior surface of the iris is much safer and easier and has yielded excellent results.5 We noted that in Case 2, the authors performed a pars plana vitrectomy with lensectomy. Ten months later, an aphakia iris-claw IOL was implanted in the anterior chamber. Undoubtedly, to perform the 2 procedures in the same surgical setting would have been preferable. Six years later, loss of enclavation of the iris-claw IOL at the 9 o’clock
position was observed. As the authors suggested, enclavation of a generous fold of iris tissue is recommended to prevent this complication. We had a positive experience, as cited by Messina et al., of fixating an iris-claw Artisan aphakic IOL to the posterior surface of the iris in an eye with anterior megalophthalmos; the results and long-term stability were very good.6 This approach has the advantage of placing the IOL in the posterior chamber, farther from the endothelium. On the other hand, it can be technically more challenging for the surgeon. Virgilio Galvis, MD Alejandro Tello, MD Carlos M. Rangel, MD Nestor I. Carre~ no, MD Ruben D. Berrospi, MD Camilo A. Ni~ no, MD Floridablanca and Bucaramanga, Colombia
REFERENCES
1. Messina M, Ross AR, Pocobelli G, Said DG, Dua HS. Cataract surgery with intraocular lens implantation in 3 brothers with megalocornea: long-term follow-up. J Cataract Refract Surg 2018; 44:399–402 2. Binkhorst CD. Iris-supported artificial pseudophakia. A new development in intraocular artificial lens surgery (iris-clip lens). Trans Ophthalmol Soc U K 1959; 79:569–581; discussion 581–584 3. Binkhorst CD. Results of implantation of intraocular lenses in unilateral aphakia. With special reference to the pupillary or iris clip lensda new method of fixation. Am J Ophthalmol 1960; 49:703–710 4. Worst JGF. Iris claw lens [letter]. Am Intra-Ocular Implant Soc J 1980; 6:166– 167 ~o NI, Revelo ML. Retropupillary iris-claw intraocular 5. Galvis V, Tello A, Carren lens in aphakic eyes [letter]. J Cataract Refract Surg 2013; 39:970–971 6. Galvis V, Tello A, Miotto G, Rangel CM. Artisan aphakic lens for cataract surgery in anterior megalophthalmos. Case Rep Ophthalmol 2012; 3:428–433. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3551436/pdf/ cop-0003-0428.pdf. Accessed August 22, 2018
Reply: We agree with Galvis et al. that iris-clip IOL was first used to refer to a certain type of anterior chamber IOL designed by Binkhorst and the claw IOL by Worst. The terms iris-clip and iris-claw are, however, used interchangeably in recent publications.1 Worst frequently referred to his IOL as the lobster-claw IOL, iris-bridge IOL, or “Worst lobster-claw IOL.”2 We preferred to use the term iris-clip for reasons below. The term iris-clip IOL is used to describe the Artisan IOL in a patient information manual published by the Royal College of Ophthalmologists in April 2017.3 Likewise, the term iris-clip is also used by the manufacturer in the patient information brochure for the Artisan phakic IOL.A Both avoided the term claw because the term might seem “unfriendly” to patients. Terminology has an effect on patient perception. The original Worst IOL did not gain popularity in English-speaking countries because patients were hesitant to have the “Worst” IOL implanted in their eyes,4 hence the tendency to drop the term claw as well. Interestingly, the Binkhorst iris clip IOLs did not have clips but, more precisely, had loops.5 On the other hand,
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the haptics of iris-claw Artisan IOLs are referred to as clips or claws. Moreover, the mechanism of fixation of the irisclaw IOL is referred to as enclavation or clipping1 to the iris; in other words the claw IOL is clipped to the iris, not clawed to it. Despite the semantics, Galvis et al. make a valid point that the literature should be more consistent to avoid confusion. The preference seems to be veering toward irisclip IOLs clipped to the iris. Although Galvis et al. had access to the claw IOL in the 1990s, it was not available to us in the United Kingdom. We agree that retropupillary fixation of the Artisan IOL is in vogue; however, the IOL was not designed for that purpose and hence would constitute off-label use. Also, biometry adjustments have to be made if the IOL is to be so implanted. The principle of generous clipping or enclavation to the iris applies regardless of whether the lens is fixed anterior or posterior to the iris. Inadequate enclavation can result in dislocation.dHarminder S. Dua, MD,
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PhD, Andrew R. Ross, MD, MSc, Marco Messina, MD, Giulio Pocobelli, MD, Dalia G. Said, MD, FRCS REFERENCES
1. Lee GA, Hann JV, Braga-Mele R. Phacoemulsification in anterior megalophthalmos. J Cataract Refract Surg 2006; 32:1081–1084 2. Figueras MJ, Jongebloed WL, Worst JGF. Scanning electron microscopy study of experimental intraocular lens implantation in the rabbit eye. J Cataract Refract Surg 1986; 12:523–528 3. Royal College of Ophthalmologists. Patient Information. Phakic Intraocular Lens Implantation. London, UK, The Royal College of Ophthalmologists, 2017; 2–9 4. Trivedi RH, Wilson ME. Historical overview. In: Wilson ME, Trivedi RH, eds, Pediatric Cataract Surgery; Techniques, Complications, and Management, 2nd ed. Philadelphia, PA, Williams & Wilkins, 2014; chapter 11 5. Yeh O, Werner L, Letocha CE, Mamalis N. Long-term follow-up of obsolete design: Iris-clip glass intraocular lens. J Cataract Refract Surg 2008; 34:520–522
OTHER CITED MATERIAL A. Ophtec USA, Inc. ArtisanÒ Phakic IOL. Facts you need to know about implantation of the ArtisanÒ phakic IOL ( 5 to 20 D) for the correction of myopia (nearsightedness). Patient information brochure, September 2004. Available at: https://www.accessdata.fda.gov/cdrh_docs/pdf3 /P030028d.pdf. Accessed August 22, 2018
