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Posterior capsulorhexis combined with optic buttonholing: an alternative to standard in-the-bag implantation of sharp-edged intraocular lenses? A critical analysis of 1000 consecutive cases.

Menapace R - Graefes Arch. Clin. Exp. Ophthalmol. (2008)

Bottom Line: Intraoperative removal of the central posterior capsule has been shown to be effective in further reducing LEC immigration.Postoperative pressure course was almost identical to that found after standard in-the-bag implantation of the IOL, as was flare, and macular thickness and morphology.Anterior LEC abrasion significantly reduced both the residual fibrosis and regeneratory LEC proliferation.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, University of Vienna Medical School, Waehringer Guertel 18-20, Vienna 1090, Austria. rupert.menapace@meduniwien.ac.at

ABSTRACT

Background: Current after-cataract prevention relies on optimizing the natural barrier effect of the optic rim against lens epithelial cell (LEC) migration. However, deficiencies in circumferential capsular bag closure caused by the intraocular lens (IOL) haptic or delayed secondary re-division of the fused capsules by Soemmering s ring formation lead to primary or secondary barrier failure. Consequently, surprisingly high posterior laser capsulotomy rates have been reported long-term, even with optimal capsular surgery and the most widespread hydrophobic acrylic IOLs, considered to be the most advanced. Intraoperative removal of the central posterior capsule has been shown to be effective in further reducing LEC immigration. However, efficacy has turned out to be limited because of the propensity of LECs to use the posterior optic surface as an alternative scaffold.

Technique: in pediatric cataract surgery, buttoning-in of the optic into an adequately-centered posterior capsulorhexis opening has been described previously. This technique was further elaborated and applied as the standard technique in a large series of adult eyes. In general, the diameter aimed at was 5-6 mm for the anterior, and 4-5 mm for the posterior capsulorhexis. Between September 2004 and June 2007, 1000 consecutive cases have thus been performed and systematically evaluated. One hundred and fifty eyes additionally underwent extensive anterior LEC abrasion. Another sub-series investigated the option of further reducing capsular fibrosis by creating an anterior capsulorhexis larger than the optic.

Evaluation: special scrutiny was applied to detect postoperative vitreous entrapment. Regeneratory and fibrotic after-cataract formation were both meticulously followed-up. Postoperative pressure course, anterior segment inflammation, macular thickness and morphology, as well as axial optic stability and optic centration, were evaluated in intraindividual comparison studies.

Results: A low rate of vitreous complications was found, which can be avoided by appropriate surgery. Vitreous entanglement occurred in six eyes, and vitreous herniation after PPCCC over-sizing in two. In three, anterior vitrectomy was performed. There was only one single case of retinal detachment-supposedly unrelated to the technique itself-and no case of cystoid macular edema. Retro-optical regenerate formation was completely abolished, while fibrosis was drastically reduced by the posterior capsule sandwiched in between the anterior LEC layer on the backside of the anterior capsule and the anterior optic surface, thereby blocking contact-mediated myofibroblastic LEC transdifferentiation. Additional capsular polishing further reduced residual fibrosis emerging from the anterior capsule contacting the optic adjacent to the haptic junction, as well as regeneratory LEC re-proliferation on the posterior capsule overlying the optic. Postoperative pressure course was almost identical to that found after standard in-the-bag implantation of the IOL, as was flare, and macular thickness and morphology. As opposed to bag-fixated IOLs, no axial movement of the optic was detected. IOL optics always perfectly centered even when the capsular opening was not optimally centered. Due to the exquisite stretchability and elasticity of the posterior capsule, the 6-mm IOL optic could safely be buttoned-in in a posterior capsulorhexis of 4 mm and smaller.

Conclusions: Posterior optic buttonholing (POBH) is a safe and effective technique which not only excludes retro-optical opacification, but also withholds capsular fibrosis by obviating direct contact between the anterior capsular leaf and the optic surface. Anterior LEC abrasion significantly reduced both the residual fibrosis and regeneratory LEC proliferation. Apart from pediatric cataract, POBH is currently recommended for eyes with pseudoexfoliation syndrome, high axial myopia, peripheral retinal disease, and multifocal IOL implantation. Toric IOLs and magnet-driven accommodative IOL systems are other potential applications. Generally, POBH holds promise for becoming a routine alternative to standard in-the-bag IOL implantation in the future.

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Schematic of interrelationship between capsule leaves and IOL. Loops residing in capsular fornix, optic buttoned-in in PPCCC. Posterior capsule lying on top of optic (crescent-shaped blue areas); this precludes optic contact and thus fibrosis of the anterior capsule (red lines: rim of ACCC). If the ACCC is smaller than the optic (bold line), anterior capsule fibrosis limited to area adjacent to the haptic junction (red area); if larger than the optic (hatched line), no fibrosis also in this area
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Fig2: Schematic of interrelationship between capsule leaves and IOL. Loops residing in capsular fornix, optic buttoned-in in PPCCC. Posterior capsule lying on top of optic (crescent-shaped blue areas); this precludes optic contact and thus fibrosis of the anterior capsule (red lines: rim of ACCC). If the ACCC is smaller than the optic (bold line), anterior capsule fibrosis limited to area adjacent to the haptic junction (red area); if larger than the optic (hatched line), no fibrosis also in this area

Mentions: The surgical technique comprises an additional step of sophisticated, but perfectly controlled capsular and viscosurgery. After performing a standard 5–6 mm anterior continuous curvilinear capsulorhexis (ACCC), and after removing the lens contents with phacoemulsification and meticulously cleaning the capsular bag, the posterior capsule is flattened and the capsular fornix collapsed by pushing the iris and anterior capsule backwards with a low-viscosity cohesive ocular viscoelastic device (OVD, preferably Healon®). Thereby, the pupil is additionally widened. Due to this pupil-dilating effect, all eyes with a pupil size larger than 4 mm under full pharmacological dilatation were amenable to the procedure. After incising the center of the posterior capsule with a 30-gauge hypodermic needle (Sterican® manufactured by B. Braun, Melsungen, or Fine-Ject® by Henke-Sass-Wolf, Tuttlingen, Germany), a small amount of OVD is injected through the capsular opening. Then, the edge of the incised capsule is taken up by Utrata forceps and the incision extended peripherally to create a well-centered 4–5 mm PPCCC opening. When after the first pass one quadrant of the PPCCC has been completed, OVD is again injected in order to separate the underlying anterior hyaloid surface from the posterior capsule. After completion of the PPCCC and removal of the flap, OVD is again injected, this time in order to ensure full circumferential separation of the anterior hyaloid membrane from the residual posterior capsule up to the very periphery. Adequate viscoseparation of capsule and hyaloid is considered crucial to allow safe buttoning-in of the optic, and will be addressed in more detail in the Discussion Section below. Then, an open-loop IOL is implanted through an injector and fixated in the capsular bag fornix. When both loops are placed in the bag, the optic is buttoned-in into the PPCCC opening by gently pressing it down. As the elastic posterior capsule thereby wraps around the optic periphery in between the haptic junctions, the distended capsule and the optic form a mechanically stable and watertight diaphragm (Figs. 2 and 3). Finally, the OVD is aspirated from the anterior chamber, the globe is tonisized, and the paracenteses are hydrated. The cataract incision is left unsutured. The surgery is performed under topical plus optional intracameral anesthesia (Lidocaine 4% plus Lidocaine unpreserved 1%) to ensure bright and stable retroillumination during the PPCCC manoeuvre. The HOYA AF-1 with a 6-mm optic is preferably used due to its particular haptic design (continuous optic-haptic transition: Fig. 4; “hopper loop”). Should the PPCCC result to be larger than the optic, as may occur in eyes with lax zonules or a large capsular bag, a 6.5-mm optic IOL should be resorted to, in order to ensure sealing of the diaphragm by sufficient circumferential capsular overlap. Additional implantation of a capsular tension ring facilitates estimation and performance of an appropriately sized and centered PPCCC in these eyes [9].Fig. 2


Posterior capsulorhexis combined with optic buttonholing: an alternative to standard in-the-bag implantation of sharp-edged intraocular lenses? A critical analysis of 1000 consecutive cases.

Menapace R - Graefes Arch. Clin. Exp. Ophthalmol. (2008)

Schematic of interrelationship between capsule leaves and IOL. Loops residing in capsular fornix, optic buttoned-in in PPCCC. Posterior capsule lying on top of optic (crescent-shaped blue areas); this precludes optic contact and thus fibrosis of the anterior capsule (red lines: rim of ACCC). If the ACCC is smaller than the optic (bold line), anterior capsule fibrosis limited to area adjacent to the haptic junction (red area); if larger than the optic (hatched line), no fibrosis also in this area
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2367393&req=5

Fig2: Schematic of interrelationship between capsule leaves and IOL. Loops residing in capsular fornix, optic buttoned-in in PPCCC. Posterior capsule lying on top of optic (crescent-shaped blue areas); this precludes optic contact and thus fibrosis of the anterior capsule (red lines: rim of ACCC). If the ACCC is smaller than the optic (bold line), anterior capsule fibrosis limited to area adjacent to the haptic junction (red area); if larger than the optic (hatched line), no fibrosis also in this area
Mentions: The surgical technique comprises an additional step of sophisticated, but perfectly controlled capsular and viscosurgery. After performing a standard 5–6 mm anterior continuous curvilinear capsulorhexis (ACCC), and after removing the lens contents with phacoemulsification and meticulously cleaning the capsular bag, the posterior capsule is flattened and the capsular fornix collapsed by pushing the iris and anterior capsule backwards with a low-viscosity cohesive ocular viscoelastic device (OVD, preferably Healon®). Thereby, the pupil is additionally widened. Due to this pupil-dilating effect, all eyes with a pupil size larger than 4 mm under full pharmacological dilatation were amenable to the procedure. After incising the center of the posterior capsule with a 30-gauge hypodermic needle (Sterican® manufactured by B. Braun, Melsungen, or Fine-Ject® by Henke-Sass-Wolf, Tuttlingen, Germany), a small amount of OVD is injected through the capsular opening. Then, the edge of the incised capsule is taken up by Utrata forceps and the incision extended peripherally to create a well-centered 4–5 mm PPCCC opening. When after the first pass one quadrant of the PPCCC has been completed, OVD is again injected in order to separate the underlying anterior hyaloid surface from the posterior capsule. After completion of the PPCCC and removal of the flap, OVD is again injected, this time in order to ensure full circumferential separation of the anterior hyaloid membrane from the residual posterior capsule up to the very periphery. Adequate viscoseparation of capsule and hyaloid is considered crucial to allow safe buttoning-in of the optic, and will be addressed in more detail in the Discussion Section below. Then, an open-loop IOL is implanted through an injector and fixated in the capsular bag fornix. When both loops are placed in the bag, the optic is buttoned-in into the PPCCC opening by gently pressing it down. As the elastic posterior capsule thereby wraps around the optic periphery in between the haptic junctions, the distended capsule and the optic form a mechanically stable and watertight diaphragm (Figs. 2 and 3). Finally, the OVD is aspirated from the anterior chamber, the globe is tonisized, and the paracenteses are hydrated. The cataract incision is left unsutured. The surgery is performed under topical plus optional intracameral anesthesia (Lidocaine 4% plus Lidocaine unpreserved 1%) to ensure bright and stable retroillumination during the PPCCC manoeuvre. The HOYA AF-1 with a 6-mm optic is preferably used due to its particular haptic design (continuous optic-haptic transition: Fig. 4; “hopper loop”). Should the PPCCC result to be larger than the optic, as may occur in eyes with lax zonules or a large capsular bag, a 6.5-mm optic IOL should be resorted to, in order to ensure sealing of the diaphragm by sufficient circumferential capsular overlap. Additional implantation of a capsular tension ring facilitates estimation and performance of an appropriately sized and centered PPCCC in these eyes [9].Fig. 2

Bottom Line: Intraoperative removal of the central posterior capsule has been shown to be effective in further reducing LEC immigration.Postoperative pressure course was almost identical to that found after standard in-the-bag implantation of the IOL, as was flare, and macular thickness and morphology.Anterior LEC abrasion significantly reduced both the residual fibrosis and regeneratory LEC proliferation.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, University of Vienna Medical School, Waehringer Guertel 18-20, Vienna 1090, Austria. rupert.menapace@meduniwien.ac.at

ABSTRACT

Background: Current after-cataract prevention relies on optimizing the natural barrier effect of the optic rim against lens epithelial cell (LEC) migration. However, deficiencies in circumferential capsular bag closure caused by the intraocular lens (IOL) haptic or delayed secondary re-division of the fused capsules by Soemmering s ring formation lead to primary or secondary barrier failure. Consequently, surprisingly high posterior laser capsulotomy rates have been reported long-term, even with optimal capsular surgery and the most widespread hydrophobic acrylic IOLs, considered to be the most advanced. Intraoperative removal of the central posterior capsule has been shown to be effective in further reducing LEC immigration. However, efficacy has turned out to be limited because of the propensity of LECs to use the posterior optic surface as an alternative scaffold.

Technique: in pediatric cataract surgery, buttoning-in of the optic into an adequately-centered posterior capsulorhexis opening has been described previously. This technique was further elaborated and applied as the standard technique in a large series of adult eyes. In general, the diameter aimed at was 5-6 mm for the anterior, and 4-5 mm for the posterior capsulorhexis. Between September 2004 and June 2007, 1000 consecutive cases have thus been performed and systematically evaluated. One hundred and fifty eyes additionally underwent extensive anterior LEC abrasion. Another sub-series investigated the option of further reducing capsular fibrosis by creating an anterior capsulorhexis larger than the optic.

Evaluation: special scrutiny was applied to detect postoperative vitreous entrapment. Regeneratory and fibrotic after-cataract formation were both meticulously followed-up. Postoperative pressure course, anterior segment inflammation, macular thickness and morphology, as well as axial optic stability and optic centration, were evaluated in intraindividual comparison studies.

Results: A low rate of vitreous complications was found, which can be avoided by appropriate surgery. Vitreous entanglement occurred in six eyes, and vitreous herniation after PPCCC over-sizing in two. In three, anterior vitrectomy was performed. There was only one single case of retinal detachment-supposedly unrelated to the technique itself-and no case of cystoid macular edema. Retro-optical regenerate formation was completely abolished, while fibrosis was drastically reduced by the posterior capsule sandwiched in between the anterior LEC layer on the backside of the anterior capsule and the anterior optic surface, thereby blocking contact-mediated myofibroblastic LEC transdifferentiation. Additional capsular polishing further reduced residual fibrosis emerging from the anterior capsule contacting the optic adjacent to the haptic junction, as well as regeneratory LEC re-proliferation on the posterior capsule overlying the optic. Postoperative pressure course was almost identical to that found after standard in-the-bag implantation of the IOL, as was flare, and macular thickness and morphology. As opposed to bag-fixated IOLs, no axial movement of the optic was detected. IOL optics always perfectly centered even when the capsular opening was not optimally centered. Due to the exquisite stretchability and elasticity of the posterior capsule, the 6-mm IOL optic could safely be buttoned-in in a posterior capsulorhexis of 4 mm and smaller.

Conclusions: Posterior optic buttonholing (POBH) is a safe and effective technique which not only excludes retro-optical opacification, but also withholds capsular fibrosis by obviating direct contact between the anterior capsular leaf and the optic surface. Anterior LEC abrasion significantly reduced both the residual fibrosis and regeneratory LEC proliferation. Apart from pediatric cataract, POBH is currently recommended for eyes with pseudoexfoliation syndrome, high axial myopia, peripheral retinal disease, and multifocal IOL implantation. Toric IOLs and magnet-driven accommodative IOL systems are other potential applications. Generally, POBH holds promise for becoming a routine alternative to standard in-the-bag IOL implantation in the future.

Show MeSH
Related in: MedlinePlus