|Year : 2017 | Volume
| Issue : 3 | Page : 198-204
Visual outcome and complications of various techniques of secondary intraocular lens
Santosh Kumar1, Satyaprakash Singh1, Gyanendra Singh1, Nilesh S Rajwade1, Sushank A Bhalerao2, Vinod Singh1
1 Department of Ophthalmology, Regional Institute of Ophthalmology, Government M. D. Eye Hospital, Allahabad, Uttar Pradesh, India
2 Department of Comprehensive Ophthalmology, L.V. Prasad Eye Institute, Hyderabad, Telangana, India
|Date of Web Publication||5-Oct-2017|
Regional Institute of Ophthalmology, Government M. D. Eye Hospital, Dr. Katju Road, Allahabad - 211 003, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
BACKGROUND/AIMS: The purpose of this study was to compare and evaluate the visual outcome and complications of various techniques of secondary intraocular lens (IOL) (i.e., anterior chamber IOL [ACIOL], suture-fixated posterior chamber IOL [PCIOL], and glue-fixated PCIOL).
STUDY DESIGN AND SETTING: This was a randomized, prospective, interventional, comparative, clinical trial study.
SUBJECTS AND METHODS: Patients of either sex having aphakia and lacking posterior capsular support were included in the study, and patients having corneal or scleral pathology, optic atrophy, uncontrolled glaucoma, retinal detachment, and other retinal pathology were excluded from the study. The patients were divided into three groups after comprehensive ophthalmological examination – Group A (secondary ACIOL) included 44 patients, Group B (secondary scleral-fixated sutured PCIOL) included 32 patients, and Group C (fibrin glue-fixated sutured PCIOL) included 34 patients.
RESULTS: A total of 110 patients were included in this study, of which 59 (53.63%) were males and 51 (46.37%) were females. The best-corrected visual acuity (VA) after 6 weeks was in the range of 20/60–20/40 in 36.4% of Group A and 40.6% of Group B patients. In Group C, 52.9% of patients had best-corrected VA in the range of 20/30–20/20. The overall complications were less in glued PCIOL group.
CONCLUSION: It can be concluded that fibrin glue-assisted PCIOL implantation provides better visual outcome with minimal complications in eyes with deficient capsular support.
Keywords: Anterior chamber intraocular lens, aphakia, fibrin glue-fixated posterior chamber intraocular lens, posterior capsular support, suture-fixated posterior chamber intraocular lens
|How to cite this article:|
Kumar S, Singh S, Singh G, Rajwade NS, Bhalerao SA, Singh V. Visual outcome and complications of various techniques of secondary intraocular lens. Oman J Ophthalmol 2017;10:198-204
|How to cite this URL:|
Kumar S, Singh S, Singh G, Rajwade NS, Bhalerao SA, Singh V. Visual outcome and complications of various techniques of secondary intraocular lens. Oman J Ophthalmol [serial online] 2017 [cited 2020 Jan 26];10:198-204. Available from: http://www.ojoonline.org/text.asp?2017/10/3/198/215991
| Introduction|| |
Rehabilitation of aphakia following successful cataract extraction is difficult. Regarding the drawbacks of aphakic correction, intraocular lens (IOL) implantation with vitrectomy has attracted a lot of attention in recent years and is universally preferred over aphakic spectacles or contact lenses as a method for visual rehabilitation in aphakic eyes.
Wearing aphakic spectacles is the safest approach but the least physiologic method of optical correction and can only be pursued for a short time before patient acceptance and feasibility become issues. Use of this method is reasonable in the young amblyopic child who is undergoing extensive patching and is monocular most of the time.,
Fixation of IOLs in cases of insufficient or no capsular support is challenging and requires a large armamentarium of techniques to resolve different situations. Other indications include traumatic phakic lens dislocation (cataractous or clear), surgically aphakic eyes, or anterior chamber IOL (ACIOL) with complications (persistent hyphema, uveitis). In the absence of sufficient capsular support, ACIOL, sulcus-supported posterior chamber IOL (PCIOL), and posterior chamber sutured or glued IOLs can be used.
The management approach depends on surgeon preferences and individual case specifics, including integrity of capsule remnants, type of IOLs, and coexisting ocular pathology.,,, ACIOL implantation requires less surgical time and is less invasive as compared to implantation of scleral-fixated PCIOLs. Although there is no robust evidence of the superiority of scleral-fixated PCIOL over the open loop ACIOL, some surgeons prefer scleral-fixated PCIOLs to ACIOLs on the assumption that glaucoma, macular edema, and other complications occur less frequently with PCIOL implantation.
Scleral fixation techniques require passage of sutures and manipulation of IOL haptics near the vitreous base. Several studies advocated pars plana vitrectomy with the removal of as much anterior vitreous as possible before scleral-fixated PCIOL implantation to prevent vitreous entwinement around the lens haptic and suture site, which may result in retinal breaks from vitreous traction.
Fibrin glue-assisted PCIOL implantation is a new technique started in December 2007 in eyes with deficient capsular support. Externalization of the greater part of the haptics into the scleral tunnel along its curvature stabilizes the axial positioning of the IOL and thereby prevents any IOL tilt and the partial thickness scleral flaps are repositioned with fibrin glue.
The purpose of this study was to compare and evaluate visual outcome and complication profile of various techniques of secondary IOL (i.e., ACIOL, suture-fixated PCIOL, and glue-fixated PCIOL).
| Subjects and Methods|| |
This randomized, prospective, interventional, comparative, clinical trial study was carried out at our institute after taking permission from the Ethical Committee from September 2010 to August 2012. After discussing the benefits and risk, informed consent had been obtained before surgery in all patients. Patients of either sex having aphakia, lacking posterior capsular support, or having subluxated or dislocated IOL were included in the study, and patients having corneal or scleral pathology, optic atrophy, uncontrolled glaucoma, retinal detachment, and other retinal pathology were excluded from the study. Preoperative data included complete relevant history including name, age, sex, residence, and occupation, uncorrected and best-corrected visual acuity (VA), slit lamp examination, intraocular pressure, fundus examination of both eyes, keratometry, and A-scan biometry.
The patients were divided into three groups:
- Group A: This included 44 aphakic eyes of 44 patients, which underwent secondary ACIOL polymethylmethacrylate (PMMA) implantation after anterior vitrectomy
- Group B: This included 32 aphakic eyes of 32 patients, which underwent secondary scleral-fixated sutured PCIOL (PMMA) implantation after anterior vitrectomy
- Group C: This included 34 aphakic eyes of 34 patients, which underwent secondary fibrin glue-fixated PCIOL (multipiece IOL) implantation after anterior vitrectomy.
Anterior chamber intraocular lens
All procedures were performed by the same surgeon using the same surgical protocol in all cases. Under local anesthesia (peri- or retro-bulbar block), a 5.5 mm scleral tunnel incision was made 1 mm posterior to limbus and two paracenteses were performed at 10 o'clock and 2 o'clock positions.
Then, the pupil was constricted by an intracameral pilocarpine, which was then irrigated, and the AC was filled with an ophthalmic viscosurgical device and an ACIOL was inserted in the AC, rotated with a hook into an appropriate position, and centered over the pupil. The iris was hooked between the claw-like footplates to achieve perfect IOL centration over the pupil. Then, a peripheral iridectomy was performed at 12 o'clock position and the viscoelastic material was carefully removed. Finally, the incision was closed with three interrupted 10-0 nylon sutures.
Sutured posterior chamber intraocular lens
In eyes undergoing surgery, peribulbar anesthesia was used to complete IOL implantation. In all patients with vitreous loss, a complete anterior vitrectomy was performed.
For scleral-fixated intraocular lens (SFIOL) implantation, the surgeon used a modified ab externo technique, originally described by Lewis, in the following manner. A double-armed 10-0 polypropylene (Aurolene) suture with straight needles was used. Two fornix-based conjunctival peritomies were made from 2 to 4 o'clock and from 8 to 10 o'clock, respectively. The entry sites were marked 1.0–1.5 mm posterior to the limbus, 1.0 mm above and below the 3 to 9 o'clock horizontal meridian. The straight needle was passed through the sclera at the superior marking on one side and was retrieved within the barrel of a 26-gauge needle inserted through the inferior marking on the opposite side. The same needle then was reinserted into the eye through the superior marking and was retrieved through the inferior marking on the other side. The sutures were withdrawn through the corneal or scleral wound using a Sinskey hook and were cut in the middle. The two cut ends on each side were passed through the corresponding eyelet of the SFIOL and their ends were tied. A square knot was made to join the two cut ends on each side and then rotated into and out of the eye through the superior marking on each side.
After the SFIOL had been inserted into the posterior chamber, the sutures were tightened and tied with open knots. The corneal or scleral wound was closed with interrupted 10-0 nylon sutures (Ethicon). The open knots were converted to closed knots and then rotated through the inferior marking, which was the entry sites of the 26-gauge needle. The conjunctival peritomies were then closed.
Glued posterior chamber intraocular lens
Under peribulbar anesthesia, localized peritomy at the site of exit of the IOL haptics was done. Infusion cannula or AC maintainer was inserted. Positioning of the infusion cannula should be in the pars plana about 3 mm from the limbus (Anterior segment surgeons can use an AC maintainer or 23G trocar cannula infusion).
Two partial thickness limbal-based scleral flaps about 3 mm × 3 mm were created exactly 180° diagonally (using RK marker and pen) apart and about 1–1.5 mm from the limbus. This was followed by vitrectomy through pars plana or anterior route to remove all vitreous traction. Two straight sclerotomies with a 20-gauge needle were made about 1 mm from the limbus under the existing scleral flaps.
A corneoscleral tunnel incision was then prepared for introducing the IOL in the case of PMMA nonfoldable IOL. While the IOL is being introduced with one hand, an end gripping 23G micro rhexis forceps was passed through the opposite sclerotomy with the other hand. The tip of the leading haptic was then grasped with the micro rhexis forceps, pulled through the sclerotomy following the curve of the haptic, and was externalized under the scleral flap. Similarly, the trailing haptic was also externalized through the other sclerotomy under the scleral flap.
The haptic tips were tucked into the intralamellar scleral tunnel made with a 26-gauge needle at the point of externalization of the haptics on either side. Then, the reconstituted fibrin glue prepared was injected through the cannula of the syringe delivery system under the scleral flaps. Local pressure was given over the flaps for about 10–20 s for the formation of fibrin polypeptides. Corneoscleral wound was closed with 10-0 monofilament nylon in PMMA IOL. The AC maintainer or the infusion cannula was removed. Conjunctiva was closed with the fibrin glue in all eyes irrespective of the type of IOL.
All patients received postoperatively prednisolone acetate eye drop and moxifloxacin 0.3% eye drop 1 hourly for 2 days and then 4 times thereafter for 6 weeks. Patients were followed postoperatively at day 1st, day 7th, 2 weekly for 2 months, and then monthly till the end of the study.
The outcomes noted at day 1, 1 week, 6 weeks, and 6 months were uncorrected and best-corrected VA, intraocular pressure, slit lamp examination, direct and indirect ophthalmoscopy, and complications such as hyphema, corneal edema, secondary glaucoma, AC reactions, vitreous and choroidal hemorrhages, endophthalmitis, retinal detachment, cystoid macular edema, and suture erosion.
Statistical analysis was performed with the help of paired and unpaired Student's t-test; data were analyzed. P < 0.05 was considered statistically significant.
| Results|| |
A total of 110 patients were included in this study, of which 59 (53.63%) males and 51 (46.37%) females. Group A (ACIOL) had 44 patients comprising 20 (45.5%) males and 24 (54.5%) females. Group B (sutured PCIOL) had 32 patients comprising 21 (65.6%) males and 11 (34.4%) females. Group C contained 34 patients comprising 18 (52.9%) males and 16 (47.1%) females [Table 1].
Preoperative VA was examined. Majority of the patients in Group A (ACIOL) had best-corrected VA in the range of 20/200–20/80 (66%). In Group B, majority of patients had best-corrected VA in the range of 20/120–20/80 (68%). In Group C, majority of patients also had best-corrected VA in the range of 20/120–20/80 (62%). Only four patients of Group A (ACIOL) had best-corrected VA of hand movement; none of other groups had this much of less preoperative best-corrected VA [Table 2].
In Group A (ACIOL), the best-corrected VA of the majority of patients on the 1st day postoperative fell between 20/200 and 20/80, which showed slight improvement in best-corrected VA. The Group B (sutured PCIOL) and Group C (glued PCIOL) also showed some improvement from their preoperative best-corrected VA [Table 3] and [Figure 1].
|Figure 1: Comparative best-corrected visual acuity in all three groups on the 1st postoperative day|
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Postoperative 1-week follow-up revealed an improvement in VA, but still majority of the patients of these three groups (respectively 80%, 75%, and 60%) had best-corrected VA between 20/200 and 20/80 [Figure 2].
|Figure 2: Comparative best-corrected visual acuity in all three groups after the 1st postoperative week|
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As compared to the best-corrected VA after 1st postoperative week, there was significant improvement in the best-corrected VA after 6 weeks postoperatively. The best-corrected VA after 6 weeks in the range of 20/60–20/40 of both Group A (ACIOL) and Group B (sutured PCIOL) is 36.4% and 40.6%, respectively. However, in Group C (glued PCIOL), there was drastic improvement in VA as compared to other groups. In Group C, 52.9% patients had best-corrected VA in the range of 20/30–20/20 [Table 4] and [Figure 3].
|Figure 3: Comparative best-corrected visual acuity in all three groups after 6 weeks of surgical procedure|
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After the 6 months, we found no significant improvement in the best-corrected VA in all the three groups and it remained almost same as that of 6 weeks follow-up. Maximum number of intraoperative complications occurred in Group B patients [Table 5].
Postoperative complication profile
[Table 6] and [Table 7] show comparison of early (<1 month) and late (>1 month) postoperative complications, respectively. The decrease in best-corrected VA in ACIOL group in the late postoperative period is mainly because of cystoids macular edema. In case of sutured PCIOL group, the main causes of decrease in best-corrected VA were suture erosion, IOL decentration, and cystoids macular edema. The overall complications were less in glued PCIOL [Table 7].
| Discussion|| |
ACIOLs have been closely associated with a variety of complications in the past which have caused physicians to feel reticent about their use. Use of closed-loop ACIOLs marketed during the 1970s and 1980s was associated with complications. However, modern advancement in ACIOL design may provide a safe, effective alternative to PCIOLs. Malbran et al. were the first to describe transsulcus scleral fixation of PCIOL in aphakia eyes that had previously undergone ICCE in 1986.
Fibrin glue-assisted PCIOL implantation is a new technique started in December 2007 in eyes with deficient capsular support. Our technique differed from other sutureless methods by the externalization of haptics under the scleral flaps instead of sclerotomy and also the use of fibrin glue. We preferred biological glue to stick the flaps as it prevents formation of subconjunctival bleb, which may happen when the scleral flaps are sutured. The risk of bleb-related endophthalmitis and suture-related complications are less when the flaps are closed with fibrin glue.
The commercially available tissue glue we used was Tisseel (Baxter, Deerfield, IL, USA). Tisseel is plasma derived. The commercial product is a two-component system. The first component contains highly concentrated fibrinogen, factor XIII, and fibronectin. The second component contains thrombin, calcium chloride, and aprotinin. Mixing of the two components promotes the formation and cross-linking of fibrin. Fibrin glue has been shown to provide airtight closure, and by the time, the fibrin starts degrading, surgical adhesions would have already occurred in the scleral bed. Although complete scleral wound healing with collagen fibrils may take up to 3 months,, since the haptic is snugly placed inside a scleral pocket, the IOL remains stable.
As compared to the best-corrected VA after 1st postoperative week, there was significant improvement in the best-corrected VA at final follow-up. The best-corrected VA after 6 months in the range of 20/60–20/40 of both Group A (ACIOL) and Group B (sutured PCIOL) is 36.4% and 40.6%, respectively. However, in Group C (glued PCIOL), there was drastic improvement in VA as compared to other groups. In Group C, 52.9% of patients had best-corrected VA in the range of 20/30–20/20 [Figure 4] and [Figure 5].
|Figure 4: Preoperative slit lamp image of a patient before glued intraocular lens implantation|
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|Figure 5: Intraoperative image of a patient after glued intraocular lens implantation|
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Our study showed 40% of Group A (ACIOL) patients achieved best-corrected VA of 20/60 or better. These results were consistent with the study of Dadeya et al., who achieved best-corrected VA of 20/60 or better in 36.6% (11/30) of patients in ACIOL group and 30% (9/30) of patients in 11 SFIOL group after a mean follow-up of 3 years. Fasih et al. reported 63.33% of secondary ACIOL implantation achieved best-corrected VA > 20/60. We had poor visual outcome than this study that may be associated with complicated surgery, increased inflammation, and macular pathology such as cystoid macular edema.
About 50% eyes in secondary scleral-fixated PCIOL group (Group B) achieved postoperative best-corrected VA of 20/60 or better in our study. These results were comparable with the previous study carried out by Hahn et al. that reported a rate of 57.1%. This percentage was 76% in a study carried by Lee et al. The decrease in best-corrected VA in our study was probably due to longer operative time, early and late postoperative complications such as corneal edema, secondary glaucoma, AC reaction, and cystoids macular edema. Our patients were of generally older age groups and might have endothelial cell decompensation, leading to decrease in best-corrected VA in final follow-up.
In Group C (glued PCIOL), there was drastic improvement in VA (67.6% patients had best-corrected VA more than 20/60) as compared to other groups. These results were comparable to results of the study conducted by Agarwal et al. The improvement in the best-corrected VA in this group was mainly because of less intra- and post-operative complications. The risk of bleb-related endophthalmitis and suture-related complications was less because flaps were closed with fibrin glue.
In this study, we also noticed that overall intraoperative complications were more common in sutured PCIOL group, and out of the various complications, intraoperative hypotony was most common which 40.6% in case of sutured PCIOL was. It was also found in glued PCIOL group (26.5%) but not as common as sutured group and was least in ACIOL group. This complication was mainly because of complexity of procedure and longer intraoperative time taken. The result of this study was comparable with the study by Bellucci et al., who had shown a complication rate of 6% in both ACIOL and sutured SFIOL, whereas more intraoperative and postoperative complications in SFIOL.
In our study, corneal edema, AC reaction, and increased intraocular pressure were the common complications in early postoperative period among Group A (ACIOL) patients, which was 20%, 25%, and 25%, respectively. In case of Group B (sutured PCIOL), the most common complication encountered was corneal edema (40.6%) and rest of other complications were minimal. In this group, the other important complications observed were endophthalmitis, retinal detachment, and iris capture and pupil deformation (6.25% each). In Group C (glued PCIOL), early corneal edema was the most common problem (32.3%) and other less severe complications were hyphema, increased intraocular pressure, and AC reactions.
In our study, we also compared the rate of complications in the late postoperative period (>1 months after surgery) and found that complications rate was reduced as compared to early postoperative period. We noticed that cystoid macular edema was most common in Group A (ACIOL) patients (25%). In other two groups, it was lesser (15.62% in sutured PCIOL and 20.5% in glued PCIOL). There were five patients (15.62%) in Group B (sutured PCIOL) who had IOL decentration which was probably due to suture erosion and inadequate suture tying with sclera. The lens may rest in an unpredictable position with tilting of lens commonly inducing significant astigmatism and spherical aberration, which leads to reduction in best = corrected VA in sutured PCIOL group. The result of this study was comparable with the study done by Donaldson et al.
Since the introduction of glued IOL procedure, the frequent complications of secondary IOL implantation such as secondary glaucoma, cystoid macular edema, or bullous keratopathy are minimized. Another important advantage of this technique is the prevention of suture-related complications such as suture erosion, suture knot exposure, or dislocation of IOL after suture disintegration or broken suture. IOL explantation in malpositioned PCIOL is totally removed as the same IOL can be repositioned with this method.
The limitations of this study were as follows: Analysis of only nonfoldable PMMA IOLs was done and the postoperative outcomes of other IOLs such as different types of foldable IOL need to be reported. Longer follow-up of patients might be required to confirm the long-term outcome of the study. This study did not have any control group to compare the visual outcome and complications of each group.
| Conclusion|| |
It can be concluded that fibrin glue-assisted PCIOL implantation provides better visual outcome with minimal complications in eyes with deficient capsular support. It is also evident from our study that gain in best-corrected VA in ACIOL group is poor. It is mainly because of postoperative complications which encountered were cystoids macular edema, secondary glaucoma, and pupil decentration in late follow-up. However, further studies including larger number of patients, more stringent criteria, and longer follow-up are warranted.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Johnston RL, Charteris DG, Horgan SE, Cooling RJ. Combined pars plana vitrectomy and sutured posterior chamber implant. Arch Ophthalmol 2000;118:905-10.
McDonald MB, Leach DH. Epikeratophakia: Human and synthetic. Ophthalmol Clin North Am 1992;5:683-93.
Cheng KP. Treatment of pediatric cataracts. Ophthalmol Clin North Am 1996;9:239-47.
Anand R, Bowman RW. Simplified technique for suturing dislocated posterior chamber intraocular lens to the ciliary sulcus. Arch Ophthalmol 1990;108:1205-6.
Chan CK, Agarwal A, Agarwal S, Agarwal A. Management of dislocated intraocular implants. Ophthalmol Clin North Am 2001;14:681-93.
Kim SS, Smiddy WE, Feuer W, Shi W. Management of dislocated intraocular lenses. Ophthalmology 2008;115:1699-704.
Kazemi S, Wirostko WJ, Sinha S, Mieler WF, Koenig SB, Sheth BP. Combined pars plana lensectomy-vitrectomy with open-loop flexible anterior chamber intraocular lens (AC IOL) implantation for subluxated lenses. Trans Am Ophthalmol Soc 2000;98:247-51.
Mello MO Jr., Scott IU, Smiddy WE, Flynn HW, Feuer W. Surgical management and outcomes of dislocated intraocular lenses. Ophthalmology 2000;107:62-7.
Schein OD, Kenyon KR, Steinert RF, Verdier DD, Waring GO 3rd
, Stamler JF, et al.
A randomized trial of intraocular lens fixation techniques with penetrating keratoplasty. Ophthalmology 1993;100:1437-43.
Tsunoda K, Migita M, Nakashizuka T, Kohzuka T. Treatment of anterior vitreous before suturing and intraocular lens to the ciliary sulcus. J Cataract Refract Surg 1996;22:222-6.
Kumar DA, Agarwal A, Agarwal A, Prakash G, Jacob S. Glued intraocular lens implantation for eyes with defective capsules: A retrospective analysis of anatomical and functional outcome. Saudi J Ophthalmol 2011;25:245-54.
Malbran ES, Malbran E Jr., Negri I. Lens guide suture for transport and fixation in secondary IOL implantation after intracapsular extraction. Int Ophthalmol 1986;9:151-60.
Ferguson AW, Malik TY. Pseudophakic posterior iris chafing syndrome. Eye (Lond) 2003;17:451-2.
Teichmann KD, Teichmann IA. The torque and tilt gamble. J Cataract Refract Surg 1997;23:413-8.
Dadeya S, Kamlesh, Kumari Sodhi P. Secondary intraocular lens (IOL) implantation: Anterior chamber versus scleral fixation long-term comparative evaluation. Eur J Ophthalmol 2003;13:627-33.
Fasih U, Ahmed I, Shaikh A, Fahmi MS. Comparison of complications after primary and secondary anterior chamber intraocular lens implantation. Pak J Ophthalmol 2010;26:57-64.
Hahn TW, Kim MS, Kim JH. Secondary intraocular lens implantation in aphakia. J Cataract Refract Surg 1992;18:174-9.
Lee VY, Yuen HK, Kwok AK. Comparison of outcomes of primary and secondary implantation of scleral fixated posterior chamber intraocular lens. Br J Ophthalmol 2003;87:1459-62.
Agarwal A, Kumar DA, Jacob S, Baid C, Agarwal A, Srinivasan S. Fibrin glue-assisted sutureless posterior chamber intraocular lens implantation in eyes with deficient posterior capsules. J Cataract Refract Surg 2008;34:1433-8.
Bellucci R, Pucci V, Morselli S, Bonomi L. Secondary implantation of angle-supported anterior chamber and scleral-fixated posterior chamber intraocular lenses. J Cataract Refract Surg 1996;22:247-52.
Donaldson KE, Gorscak JJ, Budenz DL, Feuer WJ, Benz MS, Forster RK. Anterior chamber and sutured posterior chamber intraocular lenses in eyes with poor capsular support. J Cataract Refract Surg 2005;31:903-9.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]