Ординатура / Офтальмология / Английские материалы / Phakic Intraocular Lenses_Hardten, Lindstrom, Davis_2004

49.Baïkoff G, Maia N, Poulhalec D, et al. Diurnal variations in keratometry and refraction with intracorneal ring segments.

J Cataract Refract Surg. 1999;25:1056-1061.

50.Colin J, Cochener B, Savary G, Malet F. Correcting keratoconus with intracorneal rings. J Cataract Refract Surg. 2000;26:1117-1122.

51.Siganos CS, Kymionis GD, Kartakis N, et al. Management of keratoconus with Intacs. Am J Ophthalmol. 2003;135:6470.

52.Lovisolo CF, Fleming JF. Intracorneal ring segments for iatrogenic keratectasia after laser in situ keratomileusis or photorefractive keratectomy. J Refract Surg. 2002;18:535541.

53.Alio J, Salem T, Artola A, Osman A. Intracorneal rings to

54.Jimenez-Alfaro I, Miguelez S, Bueno JL, Puy P. Clear lens extraction and implantation of negative-power posterior

chamber intraocular lenses to correct extreme myopia.

J Cataract Refract Surg. 1998;24:1310-1316.

55.Wang J, Shi Y. Clear lens extraction with phacoemulsification and posterior chamber intraocular lens implantation for treatment of high myopia. Chung Hua Yen Ko Tsa Chih. 2001;37:350-354.

56.Pucci V, Morselli S, Romanelli F, et al. Clear lens phacoemulsification for correction of high myopia. J Cataract Refract Surg. 2001;27:896-900.

57.Barraquer C, Cavalier C, Majia LF. Incidence of retinal detachment following clear-lens extraction in myopic patients; retrospective analysis. Arch Ophthalmol. 1994;112:336-339.

58.Colin J, Robinet A, Cochener B. Retinal detachment after clear lens extraction for high myopia: seven-year follow-up. Ophthalmology. 1999;106:2281-2284.

59.Fan DS, Lam DS, Li KK. Retinal complications after cataract extraction in patients with high myopia. Ophthalmology. 1999;106:688-691.

60.Ripandelli G, Billi B, Fedeli R, Stirpe M. Retinal detachment after clear lens extraction in 41 eyes with high axial myopia. Retina. 1997;17:78-79.

61.Fine IH, Hoffman RS, Packer M. Clear-lens extraction with multifocal lens implantation. Int Ophthalmol Clin. 2001;41:113-121.

62.Dick HB, Gross S, Tehrani M, et al. Refractive lens exchange with an array multifocal intraocular lens. J Refract Surg. 2002;18:509-518.

63.Duffey RJ, Leaming D. US trends in refractive surgery: 2001 International Society of Refractive Surgery Survey. J Refract Surg. 2002;18:185-188.

64.Reviglio VE, Bossana EL, Luna JD, et al. Laser in situ keratomileusis for myopia and hyperopia using the Lasersight 200 laser in 300 consecutive eyes. J Refract Surg. 2000;16:716-723.

65.Salz JJ, Stevens CA. LASIK correction of spherical hyperopia, hyperopic astigmatism, and mixed astigmatism with the LADARVision excimer laser system. Ophthalmology. 2002;109:1647-1656.

66.Cobo-Soriano R, Llovet F, Gonzalez-Lopez F, et al. Factors that influence outcomes of hyperopic laser in situ keratomileusis. J Cataract Refract Surg. 2002;28:1530-1538.

67.Dausch DG, Klein RJ, Schroder E, et al. Photorefractive keratectomy for hyperopic and mixed astigmatism. J Refract Surg. 1996;12:684-692.

68.Pietila J, Makinen P, Pajari S, et al. Excimer laser photorefractive keratectomy for hyperopia. J Refract Surg. 1997;13: 504-510.

69.Vinciguerra P, Epstein D, Radice P, et al. Long-term results of photorefractive keratectomy for hyperopia and hyperopic astigmatism. J Refract Surg. 1998;14:S183-S185.

70.Jackson WB, Casson E, Hodge WG, et al. Laser vision correction for low hyperopia. An 18-month assessment of safety and efficacy. Ophthalmology. 1998;105:1727-1738.

71.Nagy ZZ, Krueger RR, Hamberg-Nystrom H, et al. Photorefractive keratectomy for hyperopia in 800 eyes with the Meditec MEL 60 laser. J Refract Surg. 2001;17:525-533.

72.Nagy ZZ, Munkacsy G, Popper M. Photorefractive keratectomy using the meditec MEL 70 G-scan laser for hyperopia and hyperopic astigmatism. J Refract Surg. 2002;18:542550.

73.Nagy ZZ, Palagyi-Deak I, Kovacs A, et al. First results with wavefront-guided photorefractive keratectomy for hyperopia. J Refract Surg. 2002;18:S620-S623.

74.Mendez A, Mendez Noble A. Conductive keratoplasty for the correction of hyperopia. In: Sher N, ed. Surgery for Hyperopia and Presbyopia. Philadelphia, Pa: Williams and Wilkins; 1997:163-171.

75.McDonald MB, Hersh PS, Manche EE, et al. Conductive keratoplasty for the correction of low to moderate hyperopia: U.S. clinical trial 1-year results on 355 eyes. Ophthalmology. 2002;109:1978-1989.

76.Siganos DS, Pallikaris IG. Clear lensectomy and intraocular lens implantation for hyperopia from +7 and +14 diopters. J Refract Surg. 1998;14:105-113.

77.Kolahdouz-Isfahani AH, Rostamian K, Wallace D, Salz JJ. Clear lens extraction with intraocular lens implantation for hyperopia. J Refract Surg. 1999;15:316-323.

78.Holladay JT, Gills JP, Leidlein J, Cherchio M. Achieving emmetropia in extremely short eyes with two piggy-back posterior chamber lenses. Ophthalmology. 1996;103:11181124.

79.Donoso R, Rodriguez A. Piggyback implantation using the AMO array multifocal intraocular lens. J Cataract Refract Surg. 2001;27:1506-1510.

80.Fenzl RE, Gills JP, Cherchio M. Refractive and visual outcome of hyperopic cataract cases operated on before and after implementation of the Holladay II formula. Ophthalmology. 1998;105:1759-1764.

81.Zaldivar R, Davidorf JM, Oscherow S, et al. Combined posterior chamber phakic intraocular lens and laser in situ keratomileusis: bioptics for extreme myopia. J Refract Surg. 1999;15:299-308.

82.Velarde JI, Anton PG, de Valentin-Gamazo L. Intraocular lens implantation and laser in situ keratomileusis (bioptics) to correct high myopia and hyperopia with astigmatism. J Refract Surg. 2001;17(2 Suppl):S234-S237.

83.Zaldivar R, Oscherow S, Piezzi V. Bioptics in phakic and pseudophakic intraocular lens with the Nidek EC-5000 excimer laser. J Refract Surg. 2002;18(3 Suppl):S336-S339.

84.Dick HB, Alio J, Bianchetti M, et al. Toric phakic intraocular lens: European multicenter study. Ophthalmology. 2003;110:150-162.

Since the end of the 19th century, various methods to correct high myopia have been developed. In 1890, Fukala proposed and performed the extraction of the clear crystalline lens for the correction of high myopia.1 However, toward the end of the century, increasing evidence that retinal detachment was a complication of this operation lead to rigid indications and decreased acceptance by surgeons.

In the 1950s, surgeons developed intraocular lenses (IOLs) to correct aphakia. Credit for the invention and first implantation of an IOL is given to Sir Harold Ridley of London (Figure 2-1A).2 His first implant was a biconvex disc designed for implantation in the posterior chamber (PC) after an extracapsular cataract extraction (ECCE) procedure (Figures 2-1B and 2-1C). The first permanent implantation was performed on February 8, 1950 as a twostep procedure, a few months after the patient had undergone an ECCE. From his very first cases, Sir Ridley encountered two major problems: IOL malposition and posterior capsule opacification (PCO). The main reasons for the decentration were the excessive weight of the implant, inappropriate fixation haptics, and irregular and insufficient anterior capsule. Despite awareness of the etiology of the development of PCO, limitations in the removal of cortex with the available techniques limited the resolution of this complication.3

In order to circumvent the two mentioned complications, there was a movement toward a second generation of IOLs, the early anterior chamber (AC) IOLs, which were implanted after intracapsular cataract extraction (ICCE) (Figure 2-1D). During this period of time, some

surgeons began placing minus power AC IOLs in phakic eyes to correct myopia. Benedetto Strampelli was the first surgeon to report this in 1953.4 The Strampelli lens had a radius of curvature of 13 mm but was thick and rigid (Figure 2-2). It was implanted in the AC using the iridocorneal angle for support. Complications due to the inability to match the anterior chamber diameter and lens length resulted in excessive lens movement with subsequent endothelial cell damage, corneal decompensation, iritis, and pupillary and peripheral iridectomy block.5 To avoid this pupillary block, an improved model was designed by Cogan and Boberg-Ans (Figure 2-3)5; however, complications still occurred.

Other lenses were later developed in an attempt to decrease these complications, such as the Dannheim lens (Figure 2-4),5 which solved the problems of thickness, weight, and elasticity inherent in the Strampelli lens. However, it was still hard to match the lens length with the AC diameter, and unfortunately, the same problems remained.

In 1959, Joaquin Barraquer optimistically reported 239 implantations in phakic myopic eyes. The chief difference in the Barraquer lens (Figure 2-5) was that its support was curved and the haptics were more elastic, providing a better fit into the AC.5 Unfortunately, many of the lenses implanted by Barraquer had to be removed because of similar complications, including corneal edema, chronic iridocyclitis, and hyphema.6 Peter Choyce in 19647 started to use implants with thinner haptics and reported a significant decrease in corneal dystrophies and other complications.

14 Chapter 2

Figure 2-1A. Sir Harold Ridley of London, 1990 (reprinted with permission from Apple D, Auffarth G, Peng Q, Vissessook N. Foldable Intraocular Lenses: Evolution, C l i n i c o p a t h o l o g i c Correlations, and Complications. Thorofare, NJ: SLACK Incorporated; 2002).

Figure 2-1C. Position of the Ridley lens in the posterior chamber (reprinted with permission from Apple D, Auffarth G, Peng Q, Vissessook N. Foldable Intraocular Lenses: Evolution, Clinicopathologic Correlations, and Complications.

Thorofare, NJ: SLACK Incorporated; 2002).

Figure 2-2. Strampelli lens (reprinted with permission from Barraquer J. Anterior chamber plastic lenses. Results of and conclusions from a five years' experience. Ophthalmol Soc UK. 1959;79:393-424).

Figure 2-1B. Ridley's original posterior chamber lens (reprinted with permission from Apple D, Auffarth G, Peng Q, Vissessook N. Foldable Intraocular Lenses: Evolution, Clinicopathologic Correlations, and Complications. Thorofare, NJ: SLACK Incorporated; 2002).

Figure 2-1D. Movement to anterior chamber intraocular lenses. Notice the close proximity of the lens to the corneal endothelium (reprinted with permission from Apple D, Auffarth G, Peng Q, Vissessook N. Foldable Intraocular Lenses: Evolution, Clinicopathologic Correlations, and Complications. Thorofare, NJ: SLACK Incorporated; 2002).

Figure 2-3. Cogan Boberg-Ans fenestrated lens (reprinted with permission from Barraquer J. Anterior chamber plastic lenses. Results of and conclusions from a five years' experience. Ophthalmol Soc UK. 1959;79:393-424).

Figure 2-4. The Dannheim lens (reprinted with permission from Barraquer J. Anterior chamber plastic lenses. Results of and conclusions from a five years' experience. Ophthalmol Soc UK. 1959;79:393-424).

Figure 2-5. The Barraquer lens (reprinted with permission from Barraquer J. Anterior chamber plastic lenses. Results of and conclusions from a five years' experience. Ophthalmol Soc UK. 1959;79:393-424).

Despite the improvements, the use of negative power phakic IOL implantation for high myopia correction was abandoned for two reasons8: faulty lens design (solid lenses with thick periphery) and faulty surgical technique. There was no concept of endothelial vitality, no viscoelastic substances used to form the AC, no miotics used in many cases, and no effort to avoid traumatizing the natural crystalline lens.

Drews later reviewed some of Barraquer’s explanted lenses, which had been preserved by an operating room nurse in Barcelona. He found the lenses were coarse and of poor quality, with 1-mm thick haptics that were poorly polished.9

Thus, the concept of IOLs in the phakic eye was deemed unsuccessful. The US Food and Drug Administration (FDA) and the ophthalmic profession had, in general, assumed a negative posture on phakic IOLs and they were condemned as being untenable and abandoned for almost the latter third of the twentieth century.

Over the years, the AC lenses underwent a remarkable change. The haptics became thinner and more flexible and the surfaces of the lenses more polished. Surgical techniques had improved markedly due to the advent of microsurgery and the invention of viscoelastic substances. As a result, the concept of minus-power IOL implantation in phakic myopes was revived in the 1980s with the emergence of new lens styles implanted in informal clinical trials. Four ophthalmic surgeons were prominent in the revival of interest in phakic IOLs: Fechner of Germany, who in 1986 suggested new designs for phakic IOLs based on the lens of Worst of the Netherlands, whose iris-claw lens had been used for the correction of aphakia and was modified to correct myopia; Baïkoff of France, who modified the four-point, angle fixation, multiflex AC lens to

correct myopia; and Fyodorov of Russia, who introduced a plate-style IOL for insertion in the PC with fixation in the ciliary sulcus.

In 1986, Dvali reported the use of AC angle supported lenses to correct myopia in phakic eyes.10 In that same year, Baïkoff presented his new angle-supported AC IOL to correct high myopia in phakic eyes. It was derived from the Kelman-type implant to correct aphakia.11 The lens was a multiflex style, angle supported, one-piece, polymethylmethacrylate (PMMA) lens. It had a solid haptic with four-point contact in the angle and a prominent anterior vault with a concave optic. This first model with angular support was the ZB implant (Figure 2-6). In 1988, Baïkoff and Joly presented the first results obtained after the implant of the ZB lens for the correction of high myopia. Optical quality was excellent, precision very good, and correction stable over time. Nevertheless, severe endothelial loss appeared in the first 2 years12,13 and clinical investigation was suspended.

Worst and Fechner14-16 doubted whether the AC angle was the correct place for the fixation of an artificial lens and decided to adopt a different approach. Based on the historical corneal decompensation associated with pupillary fixated aphakic IOLs, they chose a peripheral iris-claw haptic carrier based on the Worst design in 197717 (Figure 2-7A) and constructed the Worst-Fechner biconcave myopia lens in 1986 (Figure 2-7B).16 By incarceration of the midperiphery of the iris into the haptic, the PMMA lens is kept suspended in front of the pupil. Earlier pupillary fixated pseudophakic lenses were associated with uveal inflammation, cystoid macular edema, pupillary membrane formation, and corneal decompensation due to endothelial cell trauma caused by the contact between the endothelium and the edge of theses lenses.3 In contrast,

Figure 2-7A. Iris-claw lens, standard model (reprinted with permission from Alpor JJ, Fechner PU. Intraocular lenses. In: Intraocular Lenses. New York: Thieme; 1986:328-335).

Figure 2-7B. Worst-Fechner biconcave lens (reprinted with permission from Fechner PU, Strobel J, Wiechmann W. Correction of myopia by implantation of a concave Worst iris-claw lens into phakic eyes. Refract Corneal Surg. 1991;7(4):286-298).

the Worst-Fechner lenses were attached to the peripheral iris, which is relatively immobile and provides a more stable anchor than the pupillary margin. In addition, the lensiris diaphragm is intact in the phakic eye so that the vitreous does not propel movements of the lens.

In November 1986, Fechner implanted the first minus power iris-claw lenses into two highly myopic phakic eyes of one patient. The original biconcave IOL (made by Ophtec BV, Groningen, Netherlands) of PMMA was concave on the side facing the crystalline lens to provide space for the latters convexity. The anterior surface was also concave, thus contributing to the total refractive power.18 In 1991, after the end of series implantations, Ophtec changed the IOL design to a convex-concave model, which is now the only model available (Figures 2- 8A and 2-8B) (trade name in the United States is Artisan phakic IOL [Ophtec BV, Groningen, Netherlands]).18,19

Because Baïkoff’s angle-supported ZB lens initial failure related to endothelial damage was presumed to be due to excessive contact between the lens and the endothelium, the ZB model was redesigned as the Chiron/Domilens Model ZB 5M. The optic was moved backward, away from the corneal endothelium, and provided with a more flexible loop as well as a reduced optic thickness (Figure 2-9). However, despite the improvements and decreased incidence of complications, including endothelial decompensation, pupillary ovalization and halos/glare were reported.20 As a result of the latter complications, further modifications were made to create a third generation of Baïkoff’s AC IOL. The Bausch & Lomb Surgical/Chiron Vision Model NuVita MA20 (Figure 2-10) offered a redesigned optic, loop, and footplate to eliminate refracted glare; an arched shape; and a more convex anterior face

Figure 2-8A. Artisan lens (courtesy of Ophtec BV).

Figure 2-8B. Artisan lens in a myopic eye (courtesy of Ophtec BV).

Figure 2-10. Baïkoff's third-generation lens: the NuVita Lens (reprinted with permission from Baïkoff G. Intraocular phakic implants in the anterior chamber. Int Ophthalmol Clin. 2000;40(3):223-235).

in order to decrease the peripheral rubbing of the lens against the iris, which was attributed as the main cause of pupillary ovalization. Finally, after undergoing all of these changes, satisfactory results were obtained.20,21

The original idea of moving toward the PC surged in 1986 after the Russian surgeon Svyatoslov Fyodorov designed a silicone PC phakic IOL made of one-piece silicone collar button with a 500 to 600 nm Teflon coat capable of fitting in the PC in an attempt to correct high myopia in phakic patients (Figure 2-11).22,23 Problems with cataract formation and uveitis lead to multiple refinements in lens design and use of more biocompatible materials. The original implant served eventually as the basis for STAAR’s intraocular contact lens, commonly known today as the Implantable Contact Lens (ICL) (STAAR Surgical AG, Monrovia, Calif). The first ICL surgery was performed in Italy. At that time, the ICL was similar to a plate-haptic lens and the design was called “soap-bar.”24 Users of the ICL modified the design because the vaulting was not sufficient to create an acceptable space between the ICL and the crystalline lens. Complications, such as pupillary block, postimplantation secondary cataract, and pigment dispersion, have been described.25 The V2, V3, and V4 models were successively developed in order to improve the design and decrease complications. Initially, the V1 model had the same dimension for the optic diam-

Figure 2-11. Fyodorov lens (reprinted with permission from Kaya V, Kevser MA, Yilmaz ÖF. Phakic posterior chamber plate intraocular lenses for high myopia. J Refract Surg. 1999;15(5): 581).

Figure 2-13. STAAR implantable contact lens (reprinted with permission from Zaldivar R, Oscherow S, Ricur G. The STAAR posterior chamber phakic intraocular lens. Int Ophthalmol Clin. 2000; 40(3):237-244).

eter and variable dimensions for the foot-plate. In the V2 model, the footplate dimensions remained constant and the optic diameter was variable. The optic diameter was inversely proportional to the diopter strength. The optical diameter was optimized in the V3 model. By changing the concave base radius to 11.0 mm, increased anterior vaulting of the ICL was introduced in the V4 model in 1998.24 The ICL is now available for the treatment of myopia and hyperopia.26

Currently, there are three main types of phakic IOLs for the treatment of myopia and hyperopia in clinical use: AC angle-fixated IOLs, PC IOLs, and iris-supported IOLs.

The AC lens is represented by the Baïkoff or NuVita lens (Bausch & Lomb Surgical, Rochester, NY).20 Other AC phakic lenses have also been developed, such as the Phakic 6 (Ophthalmic Innovations International Inc, Ontario, Canada) and ZSAL (Morcher GMBH, Stuttgart,

Germany) implants, which have 6-mm optics in order to reduce halos. Foldable AC implants have also been described, although there is some concern regarding their stability. The composite AC implant involves an unfoldable supporting haptic made of PMMA and a foldable optic of hydrophilic acrylic that can be introduced into the AC through a 3.2-mm self-sealing incision (Figure 2-12). This lens was design by Baïkoff in an attempt to provide better stability to a foldable AC lens.21

PC sulcus-fixated IOLs, such as the ICL (Figure 2-13), are foldable and offer the advantage of insertion through a small incision.

AC iris-fixated lenses, such as the Worst iris-claw lens (which is represented in the United States by the Artisan phakic IOL) (see Figures 2-7A and 2-7B) are undergoing FDA-supervised trials for use in phakic eyes in the United States.9,18

SUMMARY

The development of phakic IOLs has been one of trial and error throughout the past century. Despite multiple disappointing complications and due to the perseverance of admirable surgeons, they have become a promising alternative for the treatment of high degrees of myopia and hyperopia available today.

REFERENCES

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