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Transscleral fixation of a single-piece hydrophilic foldable acrylic intraocular lens
Transscleral fixation of a single-piece hydrophilic foldable acrylic intraocular lens Muhittin Taskapili, MD; Gokhan Gulkilik, MD; Gunay Engin, MD; Mehmet Selim Kocabora, MD; Cemil Yilmazli, MD; Mustafa Ozsutcu, MD; Hasan Kucuksahin, MD ABSTRACT • RÉSUMÉ
Background: To evaluate the results of transscleral fixation of foldable hydrophilic acrylic intraocular lenses (IOLs). Methods: Twenty eyes of 16 patients, aphakic after phacoemulsification (PE) surgery and with at least 6 months follow-up, were included in the study.All eyes were implanted with single-piece hydrophilic foldable acrylic lenses by transscleral fixation, either with PE surgery (2 eyes) or secondarily. Results: Follow-up was 11.6 months (SD 4.85, range 6–20 mo).Age was 62.3 years (SD 12.95, range 18–78 y); 10 patients were women. Preoperative best corrected visual acuity (BCVA) was 0.20 (SD 0.14, range 0.1–0.3) in eyes with primary IOL implantation and 0.53 (SD 0.12, range 0.3–0.7) in secondary implantation. Astigmatism was 1.4 D (SD 1.19, range 0.25 to 5.0 D). Postoperatively, transient corneal edema developed in 6 eyes (30%) and transient IOP elevation in 2 eyes (10%). BCVA was 0.69 (SD 0.15, range 0.4–0.9), astigmatism was 0.84 D (SD 0.80, range 0.25 to 3.0 D), both p < 0.01. Spherical refractive error was –0.38 D (SD 0.47, range +0.75 to –1.25 D). Cystoid macular edema was observed in 2 eyes (10%). No IOL decentration was observed on biomicroscopy in any eye with undilated pupil; IOL decentration with no effect on vision was observed in 3 eyes (15%) after pupil dilation. No IOL tilt, retinal detachment, suture exposure, or endophthalmitis was observed. Interpretation: Scleral fixation of foldable IOLs may be preferred in eyes with insufficient zonular and capsular support.This technique reduces surgery time and complications, and it provides early visual rehabilitation. Contexte : Évaluer les résultats de la fixation transclérale des lentilles intraoculaires (LIO) pliables en acrylique hydrophiles. Méthodes : Vingt yeux de 16 patients aphakiques après une phacoémulsification (PÉ) et au moins six mois de suivi ont fait l’objet de l’étude. Les yeux avaient tous reçu l’implant de lentilles pliables en acrylique hydrophile avec fixation transsclérale, par phacoémulsification (2 yeux) ou intervention secondaire. Résultats : Le suivi a été de 11,6 mois (ÉT 4,85, écart 6–20 mois). L’âge moyen était de 62,3 ans (ÉT 12,95, écart 18–78 ans); le groupe comptait 10 patientes. La meilleure acuité visuelle corrigée (MAVC) préopératoire était de 0,20 (ÉT 0,14), écart 0,1–0,3) dans les yeux dont l’implantation de la LIO était primaire et de 0,53 (ÉT 0,12, écart 0,3–0,7) dans ceux dont l’implantation était secondaire. L’astigmatisme était de 1,4 D (ÉT 1,19, écart 0,25 à 5,0 D). Après l’opération, un œdème passager de la cornée s’est développé dans 6 yeux (30%) et une hausse passagère de la PIO est survenue dans 2 yeux (10%). La MAVC était de 0,69 (ÉT 0,15, écart 0,4–0,9), l’astigmatisme, de 0,84 D (ÉT 0,80, écart 0,25 à 3,0 D), p < 0,01 dans les deux cas. L’erreur réfractive sphérique était –0,38 D (ÉT 0,47, écart +0,75 à –1,25 D). On a observé un œdème maculaire cystoïde dans 2 yeux (10%). Aucun décentrement de la LIO n’a été observé par biomicroscopie dans les yeux sans dilatation de la pupille; un décentrement de la LIO sans effet sur la vision a été observée dans 3 yeux (15%) après dilatation de la pupille. Aucune inclinaison de la LIO, ni décollement de la rétine ni exposition de suture ni endophtalmie n’ont été observés. Interprétation : La fixation sclérale des LIO pliables est peut-être préférable pour les yeux qui ont un soutien zonulaire ou capsulaire insuffisant. La technique réduit la durée de l’opération et les complications et offre une réadaptation visuelle rapide. From the S.S.K. Vakif Gureba Education and Research Hospital, Istanbul, Turkey Originally received July 26, 2005. Revised June 5, 2006 Accepted for publication Aug. 25, 2006
Correspondence to: Muhittin Taskapili, MD, Akdeniz Caddesi Kalaycioglu, Apt. 47-49/2, 34260 Fatih Istanbul, Turkey; fax 90-212-5212517; [email protected] This article has been peer-reviewed. Cet article a été évalué par les pairs. Can J Ophthalmol 2007;42:256–61 doi: 10.3129/can.j.ophthalmol.i07-003
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Scleral fixation of foldable IOLs—Taskapili et al
S
cleral fixation of intraocular lenses (IOLs) is preferred by most surgeons to correct aphakia in eyes in which IOLs cannot be implanted into the bag or sulcus because of insufficient capsular support. Implantation may be performed either during the cataract surgery or secondarily after the surgery. Wide polymethylmethacrylate (PMMA) lenses or foldable acrylic lenses may be used for transscleral fixation. The use of PMMA lenses requires a wider incision and may lead to undesirable results, such as hypotony, increased vitreous loss, or high postoperative astigmatism. The implantation of foldable lenses maintains the advantages of small-incision surgery and working with a closed system, as well as resulting in less vitreous loss, lower astigmatism, faster wound healing, and earlier visual rehabilitation after surgery. In this prospective and noncomparative case series, we evaluated the early and late-term results of transscleral fixation of single-piece hydrophilic foldable acrylic IOLs to correct aphakia. METHODS
The study included 20 eyes of 16 patients who had been left aphakic for various reasons and were being implanted with single-piece hydrophilic foldable acrylic lenses by transscleral fixation at the Vakif Gureba Education Hospital between July 2002 and August 2004. Approval from the hospital ethics committee was obtained. The patients received full preoperative ophthalmologic examination and 5.75 mm × 12.50 mm, biconvex, modified C lenses (OcuFlex, RYCF, Ocular Technology Inc.). Those patients with at least 6 months follow-up were included in the study.
incision was widened to 3.5 mm. A 27-gauge tuberculin needle was passed from the middle of the scleral flap towards the pupil area, the anterior chamber was entered from the incision area with the needle attached to one of the haptics being held with a needle holder, inserted into the end of the tuberculin needle in the pupil area, and passed from the flap area by moving both together. The same process was carried out for the other haptic, and sutures tied to the haptics were thus passed from the flap area. Healon was applied to the anterior chamber. IOLs were folded, paying close attention to suture installation, and were then inserted into the anterior chamber and released. Haptics were pulled to the posterior chamber by pulling the sutures from the flap area and the lens was inserted into the posterior chamber with the help of a spatula. IOL position was adjusted and centralized by gently pulling on both sutures. At this point the suture at one end was held tightly over the scleral flap area by an assistant with the aim of preventing slipping, and the needle attached to the suture at the other end was passed through the sclera in the flap area, and the ends of the looped suture tied together, forming a knot under the scleral flaps. Close attention was again paid to centralization as the same process was performed inside the other end. The anterior chamber was cleaned with aspiration. Scleral flaps were sutured with one 8-0 silk suture. The conjunctiva was also closed with 8-0 sutures. Surgery was completed with subconjunctival steroid and antibiotic injection. Topical steroid, antibiotic, and cycloplegic drops were administered postoperatively. Cycloplegic was halted after 1 week, and the steroid and antibiotic drops reduced and used for 1 month. Topical or oral antiglaucomatous medication was used in those cases with increased intraocular pressure (IOP).
Surgical technique
Surgery was performed using retrobulbar anesthesia. After conjunctival peritomy, blunt dissection of the episcleral tissue and slight cauterization was performed. Triangular scleral flaps were made from oblique quadrants and 0.5–1 mm from the limbus in such a way as to be 180° apart. The anterior chamber was entered by performing a 3-mm three-plane corneal incision from the perpendicular astigmatic axis. In eyes with vitreous in the anterior chamber and pupillary plane, anterior vitrectomy was performed. One long needle with looped 10-0 polypropylene suture (MANI brand, model 245IL) was passed through the hole in the single-piece foldable hydrophilic lens haptic and tightened by passing the needle from outside the haptic and inside the loop (Fig. 1). This process was repeated with the second needle in the other haptic. The IOL was thus made ready for implantation by being sutured to the haptics (Fig. 2). The
Fig. 1—Suture being passed through the hole of the intraocular lens haptic.
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Postoperative examinations were performed on days 1, 3, 7, 15, and 30, with follow up at 6-month intervals. At every consultation we measured best corrected visual acuity (BCVA) and IOP, recorded keratometric measurements, and performed anterior segment biomicroscopy and fundus examinations. At every examination the centralization of the IOL was evaluated after full mydriasis. Wilcoxon signed rank test was used for statistical analysis. RESULTS
Twenty eyes of 16 patients who had had phacoemulsification (PE) surgery and were left aphakic for various reasons were included in the study. Ten of the patients were women and 6 were men, and their mean (SD) age was 62.3 (12.95) years (range 18–78). Primary IOL implantation with scleral fixation was performed at the same session as PE surgery in 2 eyes, and secondary implantation after cataract surgery was performed on all other eyes. The mean follow-up period was 11.6 (4.85) months (range 6–20). Subluxed cataracts were present in 5 of the 9 eyes on which cataract surgery was performed. Capsular support was inadequate in the eyes due to zonular dialysis widening or the development of posterior capsular tearing. Mean preoperative BCVAs were 0.20 (SD 0.14, range 0.1–0.3) in eyes with primary IOL implantation, and 0.53 (SD 0.12, range 0.3–0.7) with secondary IOL implantation. Mean preoperative astigmatism was 1.4 D (SD 1.19, range 0.25 to 5.0 D). Postoperatively, transient corneal edema developed in
6 eyes (30%) and transient IOP rise in 2 eyes (10%). These eyes all quickly ameliorated as the result of topical therapy. Postoperative BCVAs were 0.4 in 3 eyes (15%). Clinically evident cystoid macular edema (CME) that failed to respond to treatment developed around the 3rd month in 2 of these eyes, with age-related macular degeneration in the other. BCVA was 0.6 or better in the other 17 eyes (85%), and 0.8 and better in 9 eyes (45%). Mean postoperative BCVA was 0.69 (SD 0.15, range 0.4–0.9). Mean postoperative astigmatism was 0.84 D (SD 0.80, range 0.25 to 3.0 D). The differences from preoperative values for both BCVA and astigmatism were statistically significant (p < 0.01) (Table 1). The mean postoperative spherical refractive error was –0.38 D (SD 0.47, range +0.75 to –1.25 D) and mean spheric equivalent was –0.78 D (SD 0.70, range +0.75 to –2.00 D) at the final examination (Table 2). Acute or chronic inflammation was not observed in any eyes, and no evident hypotony occurred. Pupil irregularity was observed in 2 eyes (10%). On biomicroscopy, no IOL decentralization was observed in any eye when the pupil was not dilated. IOL decentralization with no effect on vision was observed in 3 eyes after pupil dilation. No IOL tilt, retinal detachment (RD), suture exposure, or endophthalmitis was observed in any eyes. INTERPRETATION
Although the aim after cataract surgery must be the implantation of the IOL in the posterior chamber (PC), IOL implantation into the capsular bag or sulcus is impossible in eyes with inadequate zonular and capsular support. There are several approaches for IOL implantation in cases without capsular support: an angle-supported anterior chamber (AC) IOL, an iris-fixated ACIOL, an iris-sutured or iris-fixated posterior chamber IOL, and a transsclerally sutured PCIOL.1 In these cases Table 1—Preoperative and postoperative astigmatism Mean (SD), range Astigmatism, D Preoperative Postoperative
1.4 (1.19), 0.25–5.0 0.84 (0.80), 0.25–3.0
Best corrected visual acuity 0.5 (0.15), 0.1–0.7 0.69 (0.15), 0.4–0.9
Difference before and after implantation significant at p < 0.01.
Table 2—Postoperative refraction Mean (SD), D
Fig. 2—Intraocular lens with sutures passed.
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Refractive error Spheric equivalent
–0.38 (0.47) –0.78 (0.70)
Range, D + 0.75 to –1.25 + 0.75 to –2.00
Scleral fixation of foldable IOLs—Taskapili et al
transscleral IOL fixation is widely accepted to provide and facilitate visual rehabilitation in aphakic eyes and to avoid complications related to ACIOL implantation, like secondary glaucoma and progressive endothelial cell loss. Dick and Augustine1 stated that implantation of modern ACIOLs, like the refined open-loop or iris-fixated claw (toric) ACIOLs, have regained popularity and provide a valuable alternative to sutured PCIOLs. They also added that in the absence of capsular support, the transsclerally sutured PCIOL offers numerous advantages for certain eyes and is particularly appropriate for eyes with compromised cornea, peripheral anterior synechiae, shallow AC, or glaucoma. Moreover, sutured PCIOLs are appropriate if the patient with aphakia has a life expectancy of 10 years or more.1 The literature supports the safe and effective use of open-loop AC, scleral-sutured PC, and irissutured PCIOLs for the correction of aphakia in eyes without adequate capsular support for placement of a PC lens in the capsular bag or ciliary sulcus. At this time, there is insufficient evidence to demonstrate the superiority of one lens type or fixation site.2 In a study by Evereklioglu et al, it was stated that both the ACIOLs and PCIOLs were safe and effective for secondary implantation to correct aphakia, but secondary implantation of the scleral-fixated PCIOL seemed to provide a more favourable outcome and a lower complication rate than the open-loop ACIOL in complicated cataract cases with inadequate capsular and zonular support.3 Kaynak et al stated that transscleral fixation of foldable IOLs is an option that is comfortable for the surgeon, less time-consuming, and provides the chance to work in a closed system.4 In a previous study by Mimura et al, it was reported that very few complications had occurred after 10 years follow up of secondary transscleral fixation of IOLs.5 When the IOL cannot be implanted into the sulcus because of insufficient capsular support, scleral fixation may be considered. When 6.0 mm or 7.0 mm haptic sized PMMA IOL implantation is considered during the same session it is technically difficult to maintain the tunnel incision because it is necessary to widen the incision. When secondary IOL implantation with scleral fixation is considered, vitreous loss will increase due to a wide incision, and more anterior vitrectomy will be required. Excessive vitreous loss will increase the development of complications, such as CME, peripheral retinal tears, choroidal detachment, and intraoperative hypotony, and will make surgery difficult.6–8 More recently, foldable acrylic lenses have been preferred since these maintain the advantages of small-incision surgery. Regillo and Tidwell used the 4.0-mm small-incision technique for PCIOL suturation.9 Tsai and Tseng
reported that they performed transscleral foldable lens implantation using the Lewis method on 2 eyes with subluxed crystalline lenses after pars plana lensectomy and adequate vitrectomy.10,11 Packer et al performed lensectomy from inside a 3.0-mm clear corneal incision on a 5-year-old child with severe ectopia lentis and sutured a single-piece acrylic lens.12 Ahn et al performed transscleral suturing of 3-piece foldable acrylic lenses in 21 aphakic, vitrectomized eyes.13 Oshima et al used 3piece acrylic IOLs with transscleral fixation from a 3.5mm incision in 30 eyes of 28 patients.14 Kaynak et al used 3-piece acrylic IOLs with transscleral fixation in 20 eyes (16 hydrophobic and 4 hydrophilic).4 Jacobi et al performed secondary foldable lens implantation with scleral fixation in 26 aphakic eyes of 26 children and young adults, using multifocal IOLs in 12 eyes and monofocal IOLs in 14 eyes.15 In our study, we carried out foldable acrylic lens implantation with scleral fixation in 20 eyes of 16 patients. Two of these were implanted during PE surgery, the rest were implanted secondarily. Primary implantation at the same session as cataract surgery can be done in suitable eyes. Different quadrants and methods may be employed in scleral fixation of IOLs. Kaynak et al applied the Lewis method using a 10-0 suture (Ethicon ZW-1713) and tied the suture to the 3-piece lens haptics. They first employed 2–3 looped knots to prevent slippage and also cauterized the end of the haptics.4 In their studies, Packer, Ahn, Oshima, and Jacobi also used the Lewis method.12–15 Three-piece foldable acrylic hydrophobic lenses were generally used in the studies (mainly Acrysof ). Only Packer used a single-piece foldable acrylic lens (Acrysof SA30AL) on 2 eyes of 1 patient.12 We preferred the oblique quadrants and adjusted the corneal incision according to patient astigmatism and aimed to reduce astigmatism in this way. The design of the hydrophilic acrylic lens we used provides the advantage of the suture being attached and fixed to the haptic, and eliminates the risk of the suture slipping and opening. Moreover, we experienced no apparent difficulties with regard to IOL centralization and stability. In our suturing technique, we used a tuberculin needle and aimed at an exit to the flap area without the suture damaging the ciliary body and angle, which we believe will reduce complications. Greater damage to surrounding tissues (retina, ciliary body, iris, anterior chamber angle) will result from the needle being passed directly through the anterior chamber and being extracted from the flap area. The reason for our choosing a foldable acrylic lens is to benefit from the advantages of small-incision surgery and avoid the complications of wide-incision surgery. A smallincision surgery will not give rise to additional astigma-
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tism and may even reduce it if performed on the steep axis. In addition, small-incision surgery enhances early wound stabilization, which may contribute to rapid IOP stabilization and reduce the risks of choroidal detachment, recurrent bleeding, and exogenous infections.14 Before the IOL is sutured, sufficient anterior vitrectomy must be performed in all eyes, and residual lens capsule and anterior vitreous in the pupil area must be removed. This will reduce the occurrence of retinal complications. Tsunoda et al recommended that suturing the IOL after an extensive anterior vitrectomy to prevent postoperative complications.16 Retinal detachment was not observed in the present study, as seen in many previous studies.4,5,14,15,17,18 Unexpected visual outcomes may occur if the pupil is larger than the lens. In their study, Zetterström et al reported that the IOL was subluxed to the anterior chamber in 2 eyes.19 IOL subluxation to the anterior chamber may be related to pupil diameter, floppy iris, asymmetric suture configuration, or IOL tilt. Equal and adequate tension at the sutures is maintained to prevent IOL tilting. Hayashi et al found that both IOL tilt and decentration were more extensive with the scleral-fixated IOL than with the out-of-the-bag and in-the-bag fixated IOLs.20 Holladay found that decentration greater than 1.0 mm causes radial astigmatism and tilt greater than 15 degrees causes coma aberration that can not be fully corrected with spectacles.21 Clinically significant tilt and decentration are rare after transscleral IOL implantation.22. Hayashi and Durak et al measured the tilt and decentration quantitatively.20,22 Kaynak et al reported neither tilt nor decentration in their series.4 Jacobi et al reported light to moderate IOL decentration in 5 eyes; 1 eye needed revision because the tilt caused visual disturbance.15 Although we did not use ultrasound biomicroscopy or other methods for quantitative evaluation of the tilt of the IOL, we did not observe any IOL tilt that could be determined by biomicroscopic evaluation. Suto et al reported that power of the IOL should be decreased by 1.0 D if it is intended to be implanted into the sulcus or fixated transsclerally.23 In the present study, we have decreased the power of the IOL 0.5 D to 1.0 D. As the BCVAs improved postoperatively and the refractive errors and the spheric equivalent values were not high, we speculate that there was no IOL tilt causing clinical symptoms. Some surgeons have reported that suturation can be done without forming a scleral flap, (24) but we performed surgery by raising the scleral flap and believe that this reduces the risk of infection and inflicts no damage on the eye. We encountered no suture exposure in any of our patients. Clinically significant CME may be observed after PE
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surgery and CME frequency rises after cataract surgery with complications (anterior hyaloid defect, vitreous loss, cortex residue, vitreous bands in the incision site, dislocated lens, insufficient would healing, and chronic inflammation).25 These levels rise when angiography is performed.26 In our study vision remained at the 4/10 level in 2 eyes in which CME resistant to treatment occurred. In their study Kaynak et al reported that CME that responded to treatment developed in 2 eyes.4 We did not perform an endothelial cell count; however, no bullous keratopathy occurred in any eyes. In conclusion, scleral fixation of foldable IOLs may be preferred in eyes with insufficient zonular and capsular support. This technique provides the surgeon with the advantages of working in a closed system and with a small-incision surgery, reduces surgery time and complications, and provides early visual rehabilitation. The use of appropriate IOLs and sutures will reduce complications, for which care must be taken in suturing and IOL centralization, and will achieve better functional results. Determination of the stability of these lenses requires a larger prospective, comparative, randomized clinical trial. The authors have no propriety or financial interest in the research or instruments described in this article. This study was performed in the S.S.K. Vakif Gureba Education and Research Hospital without any additional private or public financial support.
REFERENCES 1. Dick HB, Augustin AJ. Lens implant selection with absence of capsular support. Curr Opin Ophthalmol 2001;12:47–57. 2. Wagoner MD, Cox TA, Ariyasu RG, Jacobs DS, Karp CL. Intraocular lens implantation in the absence of capsular support: a report by the American Academy of ophthalmology. Ophthalmology 2003;110:840–59. 3. Evereklioglu C, Er H, Bekir NA, Borazan M, Zorlu F. Comparison of secondary implantation of flexible open-loop anterior chamber and scleral-fixated posterior chamber intraocular lenses. J Cataract Refract Surg 2003;29:301–8. 4. Kaynak S, Ozbek Z, Pasa E, Oner FH, Cingil G. Transscleral fixation of foldable intraocular lenses. J Cataract Refract Surg 2004;30:854–7. 5. Mimura T, Amano S, Sugiura T, et al. 10-year follow-up study of secondary transscleral ciliary sulcus fixated posterior chamber intraocular lenses. Am J Ophthalmol 2003;136:931–3. 6. Yoshida A, Ogasawara H, Jalkh AE, Sanders RJ, McMeel JW, Schepens CL. Retinal detachment after cataract surgery. Surgical results. Ophthalmology 1992;99:460–5. 7. Pendergast SD, Margherio RR, Williams GA, Cox MS Jr. Vitrectomy for chronic pseudophakic cystoid macular edema. Am J Ophthalmol 1999;128:317–23. 8. Davison JA. Acute intraoperative suprachoroidal hemorrhage in capsular bag phacoemulsification. J Cataract Refract Surg 1993;19:534–7.
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9. Regillo CD, Tidwell J. A small-incision technique for suturing a posterior chamber intraocular lenses. Ophthalmic Surg Lasers 1996;27:473–5. 10. Tsai Y-Y, Tseng S-H. Transscleral fixation of foldable intraocular lens after pars plana lensectomy in eyes with a subluxated lens. J Cataract Refract Surg 1999;25:722–4. 11. Lewis JS. Ab externo sulcus fixation. Ophthalmic Surg 1991; 22:692–5. 12. Packer M, Fine IH, Hoffman RS. Suture fixation of a foldable acrylic intraocular lens for ectopia lentis. J Cataract Refract Surg 2002;28:182–5. 13. Ahn JK, Yu HG, Chung H, Wee WR, Lee JH. Transscleral fixation of a foldable intraocular lens in aphakic vitrectomized eyes. J Cataract Refract Surg 2003;29:2390–6. 14. Oshima Y, Oida H, Emi K. Transscleral fixation of acrylic intraocular lenses in the absence of capsular support through 3.5 mm self-sealing incisions. J Cataract Refract Surg 1998;24: 1223–9. 15. Jacobi PC, Dietlein TS, Jacobi FK. Scleral fixation of secondary foldable multifocal intraocular lens implants in children and young adults. Ophthalmology 2002;109:2315–24. 16. Tsunoda K, Migita M, Nakashizuka T, Kohzuka T. Treatment of anterior vitreous before suturing intraocular lens to the ciliary sulcus. J Cataract Refract Surg 1996;22:222–6. 17. Bardorf CM, Epley KD, Lueder GT, Tychsen L. Pediatric transscleral sutured intraocular lenses: Efficacy and safety in 43 eyes followed an average of 3 years. J AAPOS 2004;8:318–24. 18. Baykara M, Avci R. Prevention of suture knot exposure in posterior chamber intraocular lens implantation by 4-point scleral
19.
20.
21. 22.
23.
24. 25.
26.
fixation technique. Ophthalmic Surg Lasers Imaging 2004;35:379–82. Zetterström C, Lundvall A, Weber H Jr, Jeeves M. Sulcus fixation without capsular support in children. J Cataract Refract Surg 1999;25:776–81. Hayashi K, Hayashi H, Nakao F, Hayashi F. Intraocular lens tilt and decentration, anterior chamber depth, and refractive error after trans-scleral suture fixation surgery. Ophthalmology 1999;106:878–82. Holladay JT. Evaluating the intraocular lens optic. Surv Ophthalmol 1986;30:385–90. Durak I, Öner HF, Kocak N, Kaynak S. Tilt and decentration after primary and secondary transsclerally sutured posterior chamber intraocular lens implantation. J Cataract Refract Surg 2001;27:227–32. Suto C, Hori S, Fukuyama E, Akura J. Adjusting intraocular lens power for sulcus fixation. J Cataract Refract Surg 2003;29:1913–7. Lewis JS. Sulcus fixation without flaps. Ophthalmology 1993;100:1346–50. Spaide RF, Yannuzzi LA, Sisco LJ. Chronic cystoid macular edema and predictors of visual acuity. Ophthalmic Surg 1993;24:262–7. Jaffe NS, Jaffe MS, Jaffe GF. Cataract Surgery and its Complications. 6th ed. St Louis, Mo: Mosby; 1997:319–33.
Key words: phacoemulsification, intraocular lens, hydrophilic, scleral fixation
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Background: To evaluate the results of transscleral fixation of foldable hydrophilic acrylic intraocular lenses (IOLs). Methods: Twenty eyes of 16 patients, aphakic after phacoemulsification (PE) surgery and with at least 6 months follow-up, were included in the study.All eyes were implanted with single-piece hydrophilic foldable acrylic lenses by transscleral fixation, either with PE surgery (2 eyes) or secondarily. Results: Follow-up was 11.6 months (SD 4.85, range 6–20 mo).Age was 62.3 years (SD 12.95, range 18–78 y); 10 patients were women. Preoperative best corrected visual acuity (BCVA) was 0.20 (SD 0.14, range 0.1–0.3) in eyes with primary IOL implantation and 0.53 (SD 0.12, range 0.3–0.7) in secondary implantation. Astigmatism was 1.4 D (SD 1.19, range 0.25 to 5.0 D). Postoperatively, transient corneal edema developed in 6 eyes (30%) and transient IOP elevation in 2 eyes (10%). BCVA was 0.69 (SD 0.15, range 0.4–0.9), astigmatism was 0.84 D (SD 0.80, range 0.25 to 3.0 D), both p < 0.01. Spherical refractive error was –0.38 D (SD 0.47, range +0.75 to –1.25 D). Cystoid macular edema was observed in 2 eyes (10%). No IOL decentration was observed on biomicroscopy in any eye with undilated pupil; IOL decentration with no effect on vision was observed in 3 eyes (15%) after pupil dilation. No IOL tilt, retinal detachment, suture exposure, or endophthalmitis was observed. Interpretation: Scleral fixation of foldable IOLs may be preferred in eyes with insufficient zonular and capsular support.This technique reduces surgery time and complications, and it provides early visual rehabilitation. Contexte : Évaluer les résultats de la fixation transclérale des lentilles intraoculaires (LIO) pliables en acrylique hydrophiles. Méthodes : Vingt yeux de 16 patients aphakiques après une phacoémulsification (PÉ) et au moins six mois de suivi ont fait l’objet de l’étude. Les yeux avaient tous reçu l’implant de lentilles pliables en acrylique hydrophile avec fixation transsclérale, par phacoémulsification (2 yeux) ou intervention secondaire. Résultats : Le suivi a été de 11,6 mois (ÉT 4,85, écart 6–20 mois). L’âge moyen était de 62,3 ans (ÉT 12,95, écart 18–78 ans); le groupe comptait 10 patientes. La meilleure acuité visuelle corrigée (MAVC) préopératoire était de 0,20 (ÉT 0,14), écart 0,1–0,3) dans les yeux dont l’implantation de la LIO était primaire et de 0,53 (ÉT 0,12, écart 0,3–0,7) dans ceux dont l’implantation était secondaire. L’astigmatisme était de 1,4 D (ÉT 1,19, écart 0,25 à 5,0 D). Après l’opération, un œdème passager de la cornée s’est développé dans 6 yeux (30%) et une hausse passagère de la PIO est survenue dans 2 yeux (10%). La MAVC était de 0,69 (ÉT 0,15, écart 0,4–0,9), l’astigmatisme, de 0,84 D (ÉT 0,80, écart 0,25 à 3,0 D), p < 0,01 dans les deux cas. L’erreur réfractive sphérique était –0,38 D (ÉT 0,47, écart +0,75 à –1,25 D). On a observé un œdème maculaire cystoïde dans 2 yeux (10%). Aucun décentrement de la LIO n’a été observé par biomicroscopie dans les yeux sans dilatation de la pupille; un décentrement de la LIO sans effet sur la vision a été observée dans 3 yeux (15%) après dilatation de la pupille. Aucune inclinaison de la LIO, ni décollement de la rétine ni exposition de suture ni endophtalmie n’ont été observés. Interprétation : La fixation sclérale des LIO pliables est peut-être préférable pour les yeux qui ont un soutien zonulaire ou capsulaire insuffisant. La technique réduit la durée de l’opération et les complications et offre une réadaptation visuelle rapide. From the S.S.K. Vakif Gureba Education and Research Hospital, Istanbul, Turkey Originally received July 26, 2005. Revised June 5, 2006 Accepted for publication Aug. 25, 2006
Correspondence to: Muhittin Taskapili, MD, Akdeniz Caddesi Kalaycioglu, Apt. 47-49/2, 34260 Fatih Istanbul, Turkey; fax 90-212-5212517; [email protected] This article has been peer-reviewed. Cet article a été évalué par les pairs. Can J Ophthalmol 2007;42:256–61 doi: 10.3129/can.j.ophthalmol.i07-003
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Scleral fixation of foldable IOLs—Taskapili et al
S
cleral fixation of intraocular lenses (IOLs) is preferred by most surgeons to correct aphakia in eyes in which IOLs cannot be implanted into the bag or sulcus because of insufficient capsular support. Implantation may be performed either during the cataract surgery or secondarily after the surgery. Wide polymethylmethacrylate (PMMA) lenses or foldable acrylic lenses may be used for transscleral fixation. The use of PMMA lenses requires a wider incision and may lead to undesirable results, such as hypotony, increased vitreous loss, or high postoperative astigmatism. The implantation of foldable lenses maintains the advantages of small-incision surgery and working with a closed system, as well as resulting in less vitreous loss, lower astigmatism, faster wound healing, and earlier visual rehabilitation after surgery. In this prospective and noncomparative case series, we evaluated the early and late-term results of transscleral fixation of single-piece hydrophilic foldable acrylic IOLs to correct aphakia. METHODS
The study included 20 eyes of 16 patients who had been left aphakic for various reasons and were being implanted with single-piece hydrophilic foldable acrylic lenses by transscleral fixation at the Vakif Gureba Education Hospital between July 2002 and August 2004. Approval from the hospital ethics committee was obtained. The patients received full preoperative ophthalmologic examination and 5.75 mm × 12.50 mm, biconvex, modified C lenses (OcuFlex, RYCF, Ocular Technology Inc.). Those patients with at least 6 months follow-up were included in the study.
incision was widened to 3.5 mm. A 27-gauge tuberculin needle was passed from the middle of the scleral flap towards the pupil area, the anterior chamber was entered from the incision area with the needle attached to one of the haptics being held with a needle holder, inserted into the end of the tuberculin needle in the pupil area, and passed from the flap area by moving both together. The same process was carried out for the other haptic, and sutures tied to the haptics were thus passed from the flap area. Healon was applied to the anterior chamber. IOLs were folded, paying close attention to suture installation, and were then inserted into the anterior chamber and released. Haptics were pulled to the posterior chamber by pulling the sutures from the flap area and the lens was inserted into the posterior chamber with the help of a spatula. IOL position was adjusted and centralized by gently pulling on both sutures. At this point the suture at one end was held tightly over the scleral flap area by an assistant with the aim of preventing slipping, and the needle attached to the suture at the other end was passed through the sclera in the flap area, and the ends of the looped suture tied together, forming a knot under the scleral flaps. Close attention was again paid to centralization as the same process was performed inside the other end. The anterior chamber was cleaned with aspiration. Scleral flaps were sutured with one 8-0 silk suture. The conjunctiva was also closed with 8-0 sutures. Surgery was completed with subconjunctival steroid and antibiotic injection. Topical steroid, antibiotic, and cycloplegic drops were administered postoperatively. Cycloplegic was halted after 1 week, and the steroid and antibiotic drops reduced and used for 1 month. Topical or oral antiglaucomatous medication was used in those cases with increased intraocular pressure (IOP).
Surgical technique
Surgery was performed using retrobulbar anesthesia. After conjunctival peritomy, blunt dissection of the episcleral tissue and slight cauterization was performed. Triangular scleral flaps were made from oblique quadrants and 0.5–1 mm from the limbus in such a way as to be 180° apart. The anterior chamber was entered by performing a 3-mm three-plane corneal incision from the perpendicular astigmatic axis. In eyes with vitreous in the anterior chamber and pupillary plane, anterior vitrectomy was performed. One long needle with looped 10-0 polypropylene suture (MANI brand, model 245IL) was passed through the hole in the single-piece foldable hydrophilic lens haptic and tightened by passing the needle from outside the haptic and inside the loop (Fig. 1). This process was repeated with the second needle in the other haptic. The IOL was thus made ready for implantation by being sutured to the haptics (Fig. 2). The
Fig. 1—Suture being passed through the hole of the intraocular lens haptic.
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Postoperative examinations were performed on days 1, 3, 7, 15, and 30, with follow up at 6-month intervals. At every consultation we measured best corrected visual acuity (BCVA) and IOP, recorded keratometric measurements, and performed anterior segment biomicroscopy and fundus examinations. At every examination the centralization of the IOL was evaluated after full mydriasis. Wilcoxon signed rank test was used for statistical analysis. RESULTS
Twenty eyes of 16 patients who had had phacoemulsification (PE) surgery and were left aphakic for various reasons were included in the study. Ten of the patients were women and 6 were men, and their mean (SD) age was 62.3 (12.95) years (range 18–78). Primary IOL implantation with scleral fixation was performed at the same session as PE surgery in 2 eyes, and secondary implantation after cataract surgery was performed on all other eyes. The mean follow-up period was 11.6 (4.85) months (range 6–20). Subluxed cataracts were present in 5 of the 9 eyes on which cataract surgery was performed. Capsular support was inadequate in the eyes due to zonular dialysis widening or the development of posterior capsular tearing. Mean preoperative BCVAs were 0.20 (SD 0.14, range 0.1–0.3) in eyes with primary IOL implantation, and 0.53 (SD 0.12, range 0.3–0.7) with secondary IOL implantation. Mean preoperative astigmatism was 1.4 D (SD 1.19, range 0.25 to 5.0 D). Postoperatively, transient corneal edema developed in
6 eyes (30%) and transient IOP rise in 2 eyes (10%). These eyes all quickly ameliorated as the result of topical therapy. Postoperative BCVAs were 0.4 in 3 eyes (15%). Clinically evident cystoid macular edema (CME) that failed to respond to treatment developed around the 3rd month in 2 of these eyes, with age-related macular degeneration in the other. BCVA was 0.6 or better in the other 17 eyes (85%), and 0.8 and better in 9 eyes (45%). Mean postoperative BCVA was 0.69 (SD 0.15, range 0.4–0.9). Mean postoperative astigmatism was 0.84 D (SD 0.80, range 0.25 to 3.0 D). The differences from preoperative values for both BCVA and astigmatism were statistically significant (p < 0.01) (Table 1). The mean postoperative spherical refractive error was –0.38 D (SD 0.47, range +0.75 to –1.25 D) and mean spheric equivalent was –0.78 D (SD 0.70, range +0.75 to –2.00 D) at the final examination (Table 2). Acute or chronic inflammation was not observed in any eyes, and no evident hypotony occurred. Pupil irregularity was observed in 2 eyes (10%). On biomicroscopy, no IOL decentralization was observed in any eye when the pupil was not dilated. IOL decentralization with no effect on vision was observed in 3 eyes after pupil dilation. No IOL tilt, retinal detachment (RD), suture exposure, or endophthalmitis was observed in any eyes. INTERPRETATION
Although the aim after cataract surgery must be the implantation of the IOL in the posterior chamber (PC), IOL implantation into the capsular bag or sulcus is impossible in eyes with inadequate zonular and capsular support. There are several approaches for IOL implantation in cases without capsular support: an angle-supported anterior chamber (AC) IOL, an iris-fixated ACIOL, an iris-sutured or iris-fixated posterior chamber IOL, and a transsclerally sutured PCIOL.1 In these cases Table 1—Preoperative and postoperative astigmatism Mean (SD), range Astigmatism, D Preoperative Postoperative
1.4 (1.19), 0.25–5.0 0.84 (0.80), 0.25–3.0
Best corrected visual acuity 0.5 (0.15), 0.1–0.7 0.69 (0.15), 0.4–0.9
Difference before and after implantation significant at p < 0.01.
Table 2—Postoperative refraction Mean (SD), D
Fig. 2—Intraocular lens with sutures passed.
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Refractive error Spheric equivalent
–0.38 (0.47) –0.78 (0.70)
Range, D + 0.75 to –1.25 + 0.75 to –2.00
Scleral fixation of foldable IOLs—Taskapili et al
transscleral IOL fixation is widely accepted to provide and facilitate visual rehabilitation in aphakic eyes and to avoid complications related to ACIOL implantation, like secondary glaucoma and progressive endothelial cell loss. Dick and Augustine1 stated that implantation of modern ACIOLs, like the refined open-loop or iris-fixated claw (toric) ACIOLs, have regained popularity and provide a valuable alternative to sutured PCIOLs. They also added that in the absence of capsular support, the transsclerally sutured PCIOL offers numerous advantages for certain eyes and is particularly appropriate for eyes with compromised cornea, peripheral anterior synechiae, shallow AC, or glaucoma. Moreover, sutured PCIOLs are appropriate if the patient with aphakia has a life expectancy of 10 years or more.1 The literature supports the safe and effective use of open-loop AC, scleral-sutured PC, and irissutured PCIOLs for the correction of aphakia in eyes without adequate capsular support for placement of a PC lens in the capsular bag or ciliary sulcus. At this time, there is insufficient evidence to demonstrate the superiority of one lens type or fixation site.2 In a study by Evereklioglu et al, it was stated that both the ACIOLs and PCIOLs were safe and effective for secondary implantation to correct aphakia, but secondary implantation of the scleral-fixated PCIOL seemed to provide a more favourable outcome and a lower complication rate than the open-loop ACIOL in complicated cataract cases with inadequate capsular and zonular support.3 Kaynak et al stated that transscleral fixation of foldable IOLs is an option that is comfortable for the surgeon, less time-consuming, and provides the chance to work in a closed system.4 In a previous study by Mimura et al, it was reported that very few complications had occurred after 10 years follow up of secondary transscleral fixation of IOLs.5 When the IOL cannot be implanted into the sulcus because of insufficient capsular support, scleral fixation may be considered. When 6.0 mm or 7.0 mm haptic sized PMMA IOL implantation is considered during the same session it is technically difficult to maintain the tunnel incision because it is necessary to widen the incision. When secondary IOL implantation with scleral fixation is considered, vitreous loss will increase due to a wide incision, and more anterior vitrectomy will be required. Excessive vitreous loss will increase the development of complications, such as CME, peripheral retinal tears, choroidal detachment, and intraoperative hypotony, and will make surgery difficult.6–8 More recently, foldable acrylic lenses have been preferred since these maintain the advantages of small-incision surgery. Regillo and Tidwell used the 4.0-mm small-incision technique for PCIOL suturation.9 Tsai and Tseng
reported that they performed transscleral foldable lens implantation using the Lewis method on 2 eyes with subluxed crystalline lenses after pars plana lensectomy and adequate vitrectomy.10,11 Packer et al performed lensectomy from inside a 3.0-mm clear corneal incision on a 5-year-old child with severe ectopia lentis and sutured a single-piece acrylic lens.12 Ahn et al performed transscleral suturing of 3-piece foldable acrylic lenses in 21 aphakic, vitrectomized eyes.13 Oshima et al used 3piece acrylic IOLs with transscleral fixation from a 3.5mm incision in 30 eyes of 28 patients.14 Kaynak et al used 3-piece acrylic IOLs with transscleral fixation in 20 eyes (16 hydrophobic and 4 hydrophilic).4 Jacobi et al performed secondary foldable lens implantation with scleral fixation in 26 aphakic eyes of 26 children and young adults, using multifocal IOLs in 12 eyes and monofocal IOLs in 14 eyes.15 In our study, we carried out foldable acrylic lens implantation with scleral fixation in 20 eyes of 16 patients. Two of these were implanted during PE surgery, the rest were implanted secondarily. Primary implantation at the same session as cataract surgery can be done in suitable eyes. Different quadrants and methods may be employed in scleral fixation of IOLs. Kaynak et al applied the Lewis method using a 10-0 suture (Ethicon ZW-1713) and tied the suture to the 3-piece lens haptics. They first employed 2–3 looped knots to prevent slippage and also cauterized the end of the haptics.4 In their studies, Packer, Ahn, Oshima, and Jacobi also used the Lewis method.12–15 Three-piece foldable acrylic hydrophobic lenses were generally used in the studies (mainly Acrysof ). Only Packer used a single-piece foldable acrylic lens (Acrysof SA30AL) on 2 eyes of 1 patient.12 We preferred the oblique quadrants and adjusted the corneal incision according to patient astigmatism and aimed to reduce astigmatism in this way. The design of the hydrophilic acrylic lens we used provides the advantage of the suture being attached and fixed to the haptic, and eliminates the risk of the suture slipping and opening. Moreover, we experienced no apparent difficulties with regard to IOL centralization and stability. In our suturing technique, we used a tuberculin needle and aimed at an exit to the flap area without the suture damaging the ciliary body and angle, which we believe will reduce complications. Greater damage to surrounding tissues (retina, ciliary body, iris, anterior chamber angle) will result from the needle being passed directly through the anterior chamber and being extracted from the flap area. The reason for our choosing a foldable acrylic lens is to benefit from the advantages of small-incision surgery and avoid the complications of wide-incision surgery. A smallincision surgery will not give rise to additional astigma-
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tism and may even reduce it if performed on the steep axis. In addition, small-incision surgery enhances early wound stabilization, which may contribute to rapid IOP stabilization and reduce the risks of choroidal detachment, recurrent bleeding, and exogenous infections.14 Before the IOL is sutured, sufficient anterior vitrectomy must be performed in all eyes, and residual lens capsule and anterior vitreous in the pupil area must be removed. This will reduce the occurrence of retinal complications. Tsunoda et al recommended that suturing the IOL after an extensive anterior vitrectomy to prevent postoperative complications.16 Retinal detachment was not observed in the present study, as seen in many previous studies.4,5,14,15,17,18 Unexpected visual outcomes may occur if the pupil is larger than the lens. In their study, Zetterström et al reported that the IOL was subluxed to the anterior chamber in 2 eyes.19 IOL subluxation to the anterior chamber may be related to pupil diameter, floppy iris, asymmetric suture configuration, or IOL tilt. Equal and adequate tension at the sutures is maintained to prevent IOL tilting. Hayashi et al found that both IOL tilt and decentration were more extensive with the scleral-fixated IOL than with the out-of-the-bag and in-the-bag fixated IOLs.20 Holladay found that decentration greater than 1.0 mm causes radial astigmatism and tilt greater than 15 degrees causes coma aberration that can not be fully corrected with spectacles.21 Clinically significant tilt and decentration are rare after transscleral IOL implantation.22. Hayashi and Durak et al measured the tilt and decentration quantitatively.20,22 Kaynak et al reported neither tilt nor decentration in their series.4 Jacobi et al reported light to moderate IOL decentration in 5 eyes; 1 eye needed revision because the tilt caused visual disturbance.15 Although we did not use ultrasound biomicroscopy or other methods for quantitative evaluation of the tilt of the IOL, we did not observe any IOL tilt that could be determined by biomicroscopic evaluation. Suto et al reported that power of the IOL should be decreased by 1.0 D if it is intended to be implanted into the sulcus or fixated transsclerally.23 In the present study, we have decreased the power of the IOL 0.5 D to 1.0 D. As the BCVAs improved postoperatively and the refractive errors and the spheric equivalent values were not high, we speculate that there was no IOL tilt causing clinical symptoms. Some surgeons have reported that suturation can be done without forming a scleral flap, (24) but we performed surgery by raising the scleral flap and believe that this reduces the risk of infection and inflicts no damage on the eye. We encountered no suture exposure in any of our patients. Clinically significant CME may be observed after PE
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surgery and CME frequency rises after cataract surgery with complications (anterior hyaloid defect, vitreous loss, cortex residue, vitreous bands in the incision site, dislocated lens, insufficient would healing, and chronic inflammation).25 These levels rise when angiography is performed.26 In our study vision remained at the 4/10 level in 2 eyes in which CME resistant to treatment occurred. In their study Kaynak et al reported that CME that responded to treatment developed in 2 eyes.4 We did not perform an endothelial cell count; however, no bullous keratopathy occurred in any eyes. In conclusion, scleral fixation of foldable IOLs may be preferred in eyes with insufficient zonular and capsular support. This technique provides the surgeon with the advantages of working in a closed system and with a small-incision surgery, reduces surgery time and complications, and provides early visual rehabilitation. The use of appropriate IOLs and sutures will reduce complications, for which care must be taken in suturing and IOL centralization, and will achieve better functional results. Determination of the stability of these lenses requires a larger prospective, comparative, randomized clinical trial. The authors have no propriety or financial interest in the research or instruments described in this article. This study was performed in the S.S.K. Vakif Gureba Education and Research Hospital without any additional private or public financial support.
REFERENCES 1. Dick HB, Augustin AJ. Lens implant selection with absence of capsular support. Curr Opin Ophthalmol 2001;12:47–57. 2. Wagoner MD, Cox TA, Ariyasu RG, Jacobs DS, Karp CL. Intraocular lens implantation in the absence of capsular support: a report by the American Academy of ophthalmology. Ophthalmology 2003;110:840–59. 3. Evereklioglu C, Er H, Bekir NA, Borazan M, Zorlu F. Comparison of secondary implantation of flexible open-loop anterior chamber and scleral-fixated posterior chamber intraocular lenses. J Cataract Refract Surg 2003;29:301–8. 4. Kaynak S, Ozbek Z, Pasa E, Oner FH, Cingil G. Transscleral fixation of foldable intraocular lenses. J Cataract Refract Surg 2004;30:854–7. 5. Mimura T, Amano S, Sugiura T, et al. 10-year follow-up study of secondary transscleral ciliary sulcus fixated posterior chamber intraocular lenses. Am J Ophthalmol 2003;136:931–3. 6. Yoshida A, Ogasawara H, Jalkh AE, Sanders RJ, McMeel JW, Schepens CL. Retinal detachment after cataract surgery. Surgical results. Ophthalmology 1992;99:460–5. 7. Pendergast SD, Margherio RR, Williams GA, Cox MS Jr. Vitrectomy for chronic pseudophakic cystoid macular edema. Am J Ophthalmol 1999;128:317–23. 8. Davison JA. Acute intraoperative suprachoroidal hemorrhage in capsular bag phacoemulsification. J Cataract Refract Surg 1993;19:534–7.
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9. Regillo CD, Tidwell J. A small-incision technique for suturing a posterior chamber intraocular lenses. Ophthalmic Surg Lasers 1996;27:473–5. 10. Tsai Y-Y, Tseng S-H. Transscleral fixation of foldable intraocular lens after pars plana lensectomy in eyes with a subluxated lens. J Cataract Refract Surg 1999;25:722–4. 11. Lewis JS. Ab externo sulcus fixation. Ophthalmic Surg 1991; 22:692–5. 12. Packer M, Fine IH, Hoffman RS. Suture fixation of a foldable acrylic intraocular lens for ectopia lentis. J Cataract Refract Surg 2002;28:182–5. 13. Ahn JK, Yu HG, Chung H, Wee WR, Lee JH. Transscleral fixation of a foldable intraocular lens in aphakic vitrectomized eyes. J Cataract Refract Surg 2003;29:2390–6. 14. Oshima Y, Oida H, Emi K. Transscleral fixation of acrylic intraocular lenses in the absence of capsular support through 3.5 mm self-sealing incisions. J Cataract Refract Surg 1998;24: 1223–9. 15. Jacobi PC, Dietlein TS, Jacobi FK. Scleral fixation of secondary foldable multifocal intraocular lens implants in children and young adults. Ophthalmology 2002;109:2315–24. 16. Tsunoda K, Migita M, Nakashizuka T, Kohzuka T. Treatment of anterior vitreous before suturing intraocular lens to the ciliary sulcus. J Cataract Refract Surg 1996;22:222–6. 17. Bardorf CM, Epley KD, Lueder GT, Tychsen L. Pediatric transscleral sutured intraocular lenses: Efficacy and safety in 43 eyes followed an average of 3 years. J AAPOS 2004;8:318–24. 18. Baykara M, Avci R. Prevention of suture knot exposure in posterior chamber intraocular lens implantation by 4-point scleral
19.
20.
21. 22.
23.
24. 25.
26.
fixation technique. Ophthalmic Surg Lasers Imaging 2004;35:379–82. Zetterström C, Lundvall A, Weber H Jr, Jeeves M. Sulcus fixation without capsular support in children. J Cataract Refract Surg 1999;25:776–81. Hayashi K, Hayashi H, Nakao F, Hayashi F. Intraocular lens tilt and decentration, anterior chamber depth, and refractive error after trans-scleral suture fixation surgery. Ophthalmology 1999;106:878–82. Holladay JT. Evaluating the intraocular lens optic. Surv Ophthalmol 1986;30:385–90. Durak I, Öner HF, Kocak N, Kaynak S. Tilt and decentration after primary and secondary transsclerally sutured posterior chamber intraocular lens implantation. J Cataract Refract Surg 2001;27:227–32. Suto C, Hori S, Fukuyama E, Akura J. Adjusting intraocular lens power for sulcus fixation. J Cataract Refract Surg 2003;29:1913–7. Lewis JS. Sulcus fixation without flaps. Ophthalmology 1993;100:1346–50. Spaide RF, Yannuzzi LA, Sisco LJ. Chronic cystoid macular edema and predictors of visual acuity. Ophthalmic Surg 1993;24:262–7. Jaffe NS, Jaffe MS, Jaffe GF. Cataract Surgery and its Complications. 6th ed. St Louis, Mo: Mosby; 1997:319–33.
Key words: phacoemulsification, intraocular lens, hydrophilic, scleral fixation
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