New IOL solving PCO and offering new perspectives in toric ...



IC-57:Posterior capsulorhexis: Indications and surgical techniques

Routine posterior capsulorhexis and optic buttonholing

for after-cataract eradication in senile cataract patients:

a review of 1000 consecutive cases

R. Menapace, Medical University of Vienna, Austria

Advances in surgical technique and lens technology have significantly reduced the need for YAG laser capsulotomy. The latter is not only potentially harmful, but also costly, and access may be difficult for elderly people or even impossible for those living in underdeveloped countries. A recent retrospective analysis of intraocular lenses (IOLs) with full optic-rhexis overlap has revealed a cumulative 10-year YAG capsulotomy rate of 42 % for AcrySof® sharp-edged acrylic IOLs.1 This underlines the need for more effective alternatives for after-cataract prevention.

Performing a primary posterior capsulorhexis (PCR) adds a secondary barrier to the optic edge by removing the central posterior capsule as a scaffold for lens epithelial cell (LEC) migration. However, LECs can also migrate on the anterior vitreous, or on the posterior optic surface. This may result in partial or even complete secondary closure of a posterior capsulorhexis (PCR) opening.2

Therefore, alternatives were investigated that may prevent LECs from growing over the visual axis. Two approaches can potentially achieve this goal: The bag-in-the-lens concept forwarded by Tassignon, and posterior optic buttonholing (POBH) as introduced by Gimbel and Stegman for pediatric eyes.

The latter has been recently investigated as a routine means of after-cataract eradication in adult eyes. The technique and rationale, as well as the results and complication profile are the topic of this presentation.

Routine posterior capsulorhexis and optic buttonholing in adults3,4

Technique:   Under topical anesthesia, a well-centered 4-5 mm-in-diameter PCR is performed under low-viscosity hyaluronic acid as an ophthalmic viscoelastic device (OVD). After viscodissection of the residual peripheral posterior capsule and the anterior vitreous surface, the IOL is inserted with the haptics in the bag and the optic buttonholed posteriorly through the PCR opening. The OVD is rinsed out of the anterior chamber and the incision left unsutured.

Rationale:   The posterior capsule edge slips unto the anterior optic surface. Migrating LECs can no longer access the retrolental space. The residual posterior capsule is sandwiched between anterior capsule and optic surface. This prevents anterior LECs from taking up contact with the optic surface as the prerequisite for transdifferentiation into myofibroblasts. Fibrosis with capsular whitening and contraction will hence not ensue. Since the haptics reside in the capsular bag equator, centration of the buttonholed optic will always be perfect even within a not perfectly centered PCR opening.

Results:   In a first series of 1000 consecutive cases operated on between September 2004 and 2008, the PCR opening remained completely clear in all cases throughout the follow-up, and fibrosis remained mainly limited to the area where the PCR undercrosses the haptic junction and thus allows the anterior capsule to take up localized contact to the optic. With additional anterior LEC abrasion,5 no fibrosis was observed at all.

Complication profile:   As compared to standard in-the-bag (IB) survey, postoperative courses of intraocular pressure 6 and flare 7 were not different. As opposed to in-the-bag implantation, no anterior optic and thus myopic shift was observed.8 OCT revealed no differences regarding macular thickness or morphology.9 No case of clinical CME was reported. There was only one case of delayed spontaneous retinal detachment (RD) occurring four months postop in a highly myopic young male, which seemed unrelated to the POBH procedure.

Conclusion:   POBH is an effective and safe technique which completely eradicates central opacification, reduces fibrosis to a minimum especially when combined with anterior capsule polishing, and does not cause pressure, blood-aqueous or retinal complications. On the contrary, more posterior positioning of the buttonholed optic seems to stabilize the vitreous body which may counteract posterior vitreous detachment and thus explain the significantly lower RD-rate as compared to what is reported with IB implants10. As it does not require a special implant, it allows for conversion into any other type of fixation (full-bag, haptic in sulcus and optic buttonholed through anterior capsulorhexis opening) should POBH turn out not be non-feasible.

References

1. Vock L., Menapace R., Georgopoulos M., et al. (2007) Long-term YAG laser capsulotomy and after-cataract rates with the sharp edge Acrysof and round edge PhakoFlex intraocular lenses: 10 year results. Abstract ESCRS, Stockholm

2. Georgopoulos M., Menapace R., Findl O. et al. (2003) After-cataract in adults with primary posterior capsulorhexis: comparison of hydrogel and silicone intraocular lenses with round edges after 2 years. J. Cataract Refract. Surg. 29, 955-960

3. Menapace R (2006) Routine posterior optic buttonholing for eradication of posterior capsule opacification in adults: report of 500 consecutive cases. J. Cataract Refract. Surg. 32, 929-943

4. Menapace R. (2008) Posterior capsulorhexis combined with optic buttonholing: an alternative to standard in-the-bag implantation of sharp-edged intraocular lenses? A critical review of 1000 consecutive cases. Graefes Arch. Clin. Exp. Ophthalmol. 246, 787-801. Epub 2008 Apr 19. Review.

5. Menapace R., Di Nardo S. (2006) Aspiration curette for anterior capsule polishing: laboratory and clinical evaluation. J. Cataract Refract. Surg. 32, 1997-2003

6. Stifter E., Luksch A., Menapace R. (2007) Postoperative course of intraocular pressure after cataract surgery with combined primary posterior capsulorhexis with optic buttonholing. J. Cataract Refract. Surg. 33, 1585-1590

7. Stifter E., Menapace R., Luksch A., et al. (2007). Objective assessment of intraocular flare after cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing in adults. Br. J. Ophthalmol. 91, 1481-1484

8. Stifter E., Menapace R., Luksch A., Neumayer T, Sacu S. (2008) Anterior chamber depth and change of axial intraocular lens position after cataract surgery with primary posterior capsulorhexis and posterior optic buttonholing. J. Cataract Refract. Surg. 34, 749-754

9. Stifter E., Menapace R., Neumayer T, Luksch A. (2008). Macular morphology after cataract surgery with combined posterior capsulorhexis and optic buttonholing. Am. J. Ophthalmol. 146, 15-22. Epub 2008 Apr 24.

10. Ripandelli G, Coppé AM, Parisi V, Olzi D, et al. (2007) Posterior vitreous detachment and retinal detachment after cataract surgery. Ophthalmology 114, 692-697

[pic]

Fig.1 Optic buttonholed through PCR opening: Posterior capsule edge lying on top of optic edges (dark blue area) while PCR edge undercrosses haptic-optic junction (dotted blue line), thereby limiting anterior LEC transdifferentiation to area adjacent to haptic base

[pic]

Fig. 2: PCR with (left) and without posterior optic buttonholing (right).

Management of posterior capsule in children

Abhay Vassavada, Iladevi Cataract & IOL Research Centre, Ahmedabad, India

The most frequent and significant problem following pediatric cataract surgery is visual axis obscuration (VAO) 1-4. Younger the child, higher the incidence and earlier the onset of VAO. Maintenance of clear visual axis remains a high priority when planning management of posterior capsule in amblyogenic age range. Posterior capsulotomy can be performed with various approaches including manual posterior continuous curvilinear capsulorhexis (PCCC), vitrectorhexis, radiofrequency diathermy and fugo plasma blade5. Some prefer vitrectorhexis when vitrectomy is planned with primary posterior capsulotomy. However when anterior vitrectomy is not a planned procedure with posterior capsulotomy, manual PCCC is a must.

Our technique of PCCC is as follows :

After refilling capsular bag with Provisc, PCCC is initiated with the vertical element of a 26-gauge cystotome. Vertical element is held at a slant and with a swiping motion, the posterior capsule is engaged and simultaneously directed towards the left (in the direction of the 3 O’ clock position) and anteriorly (towards the microscope). Additional viscoelastic is injected in the area surrounding the puncture to make the posterior capsule concave or flat. Viscoelastic substance is not injected through the puncture towards the vitreous face. The left of the inferior end of the puncture is grasped with Kraff-Uttrata capsulorhexis forceps fashioning the PCCC in a clockwise manner. PCCC of approximately 3.5 – 4 mm is aimed6.

Despite this, iatrogenic AVF disturbance can occur. Our preferred approach is manual PCCC, even when we are planning to perform vitrectomy. Many investigators have observed that performing PCCC is technically difficult. A potential complication associated with this procedure is disruption of AVF. However, subtle signs of vitreous disturbance during PCCC can be easily overlooked.We have described the following signs to identify disturption of vitreous face during PCCC. They are : (1) visible strands that may be freely floating or may be adherent to the capsular flap,pupil or incision,(2)deformation of the capsulotomy margin,or (3) peaking of the pupil to angle of anterior chamber or incision7. Maintaining a high magnification with the operating microscope and dimming the lights in the operating room are suggested methods to aid capsulorhexis in difficult situations.

Identification of AVF disburbance is more relevant when surgeon is planning to perform posterior capsulotomy without an anterior vitrectomy. We use preservative free triamsolone acetonide to visualize vitreous for ensuring through and complete vitrectomy after performing a manual PCCC technique.The granules of triamcinolone acetonide are trapped on the surface of the vitreous body making it clearly visible under the surgical microscope. On completion of the PCCC, 0.1 ml of a suspension of preservative free triamcinolone acetonide (Aurocort, Aurolab) was injected within the PCCC margin and inside the anterior chamber for visualizing the anterior vitreous face as well as the presence and extent of vitreous in the anterior chamber. A two port limbal central core anterior vitrectomy was performed using a maximum cut rate of 800, AFR of 25 cc/min and vacuum of 400mmHg using Aurocort stained vitreous gel as a guide on the Infiniti™ phacoemulsification system (Alcon).. After removal of the residual viscoelastic, 0.1ml of Aurocort was again injected into the anterior chamber in order to visualize residual vitreous strands in the anterior chamber. Additional anterior vitrectomy was performed if vitreous strands were identified in the anterior chamber. Triamcinolone was then rinsed off with BSS.

This technique was found to be helpful in identifying the presence of vitreous and visualizing the vitreous during vitrectomy. We found that following the first injection of preservative free triamcinolone acetonide after completion of the PCCC, the vitreous gel was enhanced by capture of the triamcinolone particles by the gel. In the presence of AVF disturbance, these particles tended to become entrapped and impregnated in the vitreous gel making it clearly visible. With an intact vitreous face it appeared as a convex, bulging structure. Further with an intact vitreous face Aurocort suspension tended to swirl freely when injected within the rhexis margin. Secondly after performing a thorough, bimanual limbal anterior vitrectomy and IOL implantation, a second injection of Aurocort was introduced to identify for the presence of residual vitreous strands. It was identified as free floating strands, or strands extending to the incisions. We found Aurocort suspension primarly clinging to the superficial vitreous gel identified as residual strands of vitreous, which might otherwise have gone unnoticed. In eyes where residual vitreous strands were identified, a repeat anterior vitrectomy was performed until all the triamcinolone granules were removed. In conclusion, using an appropriate technique and viscoelastics, posterior capsulorhexis can be consistently performed during congenital cataract surgery.

References

1. Parks MM. Posterior lens capsulectomy during primary cataract surgery in children. Ophthalmology 1983;90:344-5.

2. Knight-Nanan D, O’ Keefe M, Bowell R. Outcomes and complications of intraocular lenses in children with cataract. J Cataract Refract Surg 1996; 22:730-6.

3. BenEzra D, Cohen E. Posterior capsulectomy in pediatric cataract surgery; the necessity of a choice. Ophthalmology 1997;104:2168-74.

4. Sharma N, Pushkar N, Dada T et al. Complications of pediatric cataract surgery and intraocular lens implantation. J Cataract Refract Surg 1999; 25:1585-8

5. Guo S, Wagner RS, Caputo A. Management of the anterior and posterior lens capsules and vitreous in pediatric cataract surgery J Pediatr Ophthalmol Strabismus 2004; 41:330-7.

6. Dholakia SA, Praveen MR, Vasavda AR, Nihalani B. Completion rate of primary posterior continuous curvilinear capsulorhexis and vitreous disturbance during congenital cataract surgery. J AAPOS 2006; 10; 351-356.

7. Praveen MR, Vasavada AR, Koul A, Trivedi RH, Vasavada VA, Vasavada VA.Subtle signs of anterior vitreous face disturbance during posterior capsulorhexis in pediatric cataract surgery. J Cataract Refract Surg. 2008 Jan;34(1):163-7.

New IOL solving PCO and offering new perspectives in toric correction and accommodation

M.J. Tassignon, University Hospital Antwerp, Belgium

Many techniques have been advocated to prevent posterior capsule opacification (PCO), the major cause of visual loss after cataract surgery. These include special IOL materials and designs,1-6 adhesive lens coatings,7 the use of chemical substances with the IOL,8-9 physical removal of remaining proliferative cells within the lens bag,10 physical techniques to destroy LECs,11 the use of antibodies against LECs,12 implantation of a capsular tension ring,13 and removal of the central part of the posterior capsule or a posterior continuous curvilinear capsulorhexis.14-18 These methods have substantially reduced the prevalence of PCO but have not eradicated it, especially in compromised eyes such as those of pediatric, uveitis, and diabetic patients.19

At present, the only efficient treatment for established PCO is surgically induced rupture of the opaque posterior capsule (i.e. capsulotomy) using a capsulotomy needle or a Q-switched neodymium:YAG (Nd:YAG) laser.20 These secondary capsulotomies, however, increase the complication rate after cataract surgery to nearly the level of the now mostly abandoned ICCE procedure. Complications of a Nd:YAG capsulotomy, including retinal detachment, glaucoma, cystoid macular edema, and IOL pitting, have been widely described.21-22

The surgical removal of the central part of the posterior capsule in the same surgical procedure is called planned primary continuous, circular and curvilinear capsulorhexis or PPCCC. This technique was used in the early ’90s in the hope to solve PCO but unfortunately did not prevent further cell proliferation, as expected.16-18 The reason is that LECs do not need the support of the posterior capsule to proliferate and reclose the PPCCC opening. We therefore proposed a new type of IOL consisting of a round optic part, surrounded by two haptics (anterior and posterior) defining a peripheral groove in which both the anterior and posterior capsules will take place (Fig. 1). This technique is called the bag-in-the-lens (BIL) technique. This lens could also be called the twin-capsulorhexis IOL to stress the crucial role of both the anterior and posterior capsulorhexis for proper IOL fixation.23

This new implantation technique is designed to solve the problem of PCO, based on the principle of capturing the remaining LECs in the equatorial space and by prohibiting their proliferation and transformation into myofibroblasts.24

The efficacy of the BIL implantation regarding PCO has been studied in 100 eyes with a follow-up ranging from 7 months to 6 years.25 Since the biomaterial used to manufacture the BIL is a hydrophylic acrylic with a water content of about 24 %, postoperative uveal response is expected to be very low. As shown in Fig. 2 the optical zone of the lens remains clear 6 to 9 months after surgery.

The ring caliper was introduced in 2005 to facilitate the sizing and centration of the anterior capsulorhexis along the alignment of the first and third Purkinje reflexes as observed under the microscope (Figs. 3-4-5).23 For the purpose of the BIL implantation the ring has an internal diameter of 5 mm.

The BIL implantation technique offers the surgeon the possibility to position the BIL in a surgeon-controlled way. To facilitate the correct sizing of the anterior capsulorhexis and the position of the IOL according to the first and third Purkinje reflexes as observed through the surgical microscope, we studied the BIL centration before and after the use of the ring caliper. These results show no significant difference between both calibration techniques.

The decentration of the BIL over time was studied in 180 eyes and showed very good centration stability over time (5 weeks, 6 months, 1 year).

Rotational stability of the BIL has been studied in 35 eyes showing less than 1.5° rotation over time (1 day, 5 weeks, 6 months), which means that the BIL can now go from monofocal to toric with high positional reliability.

The next step is to focus on accommodation by restoring the equatorial angle of the capsular bag and as a consequence the impact of the zonular fibers on the capsular bag during accommodation. This will optimize pseudo-accommodation, which can improve patient’s near vision of 2 to 3 diopters, which should be sufficient for daily life activities but not for prolonged reading activities.

Legends to the figures

1. Top: Schematic drawing of the twin-capsulorhexis IOL showing the main circular central optic surrounded by the haptic. The two haptics are oriented perpendicularly to each other to ensure optimal lens stability. Bottom: A side view showing the characteristic groove in which both lens capsules will settle (1 = optic; 2 = groove into which anterior and posterior capsules will settle; 3 = oval-shaped posterior haptic; 4 = oval-shaped anterior haptic; 5 = positioning holes [optional]).

2. Six months and nine months postoperative aspect after BIL implantation in two different eyes.

3. Insertion of the flexible poly(methyl methacrylate) ring caliper into the anterior chamber using a lens manipulator.

4. Tearing the anterior capsule along the ring caliper.

5. Matlab computer program to verify centration of the capsulorhexis relative to the pupil edge.

References

1. Sterling S., Wood T.O. (1986). Effect of intraocular lens optic design on posterior capsular opacification. J. Cataract Refract. Surg. 12, 655-657

2. Born C.P., Ryan D.K. (1990). Effect of intraocular lens optic design on posterior capsular opacification. J. Cataract Refract. Surg. 16, 188-192

3. Yamada K., Nagamoto T., Yozawa H., et al. (1995). Effect of intraocular lens design on posterior capsule opacification after continuous curvilinear capsulorhexis. J. Cataract Refract. Surg. 21, 697-700

4. Apple D.J. (2000). Influence of intraocular lens material and design on postoperative intracapsular cellular reactivity. Trans. Am. Ophthalmol. Soc. 98, 257-283

5. Nishi O., Nishi K., Wickström K. (2000). Preventing lens epithelial cell migration using intraocular lenses with sharp rectangular edges. J. Cataract Refract. Surg. 26, 1543-1549

6. Nishi O., Nishi K., Akura J., Nagata T. (2001). Effect of round-edged acrylic intraocular lenses on preventing posterior capsule opacification. J. Cataract Refract. Surg. 27, 608-613

7. Duncan G., Wormstone I.M., Liu C.S., et al. (1997). Thapsigargin-coated intraocular lenses inhibit human lens cell growth. Nat. Med. 3, 1026-1028

8. Legler U.F.C., Apple D.J., Assia E.I., et al. (1993). Inhibition of posterior capsule opacification: the effect of colchicine in a sustained drug delivery system. J. Cataract Refract. Surg. 19, 462-469

9. Power W.J., Neylan D., Collum L.M.T. (1994). Daunomycin as an inhibitor of human lens epithelial cell proliferation in culture. J. Cataract Refract. Surg. 20, 287-290

10. Rakic J.M., Galand A., Vrensen G.F.J.M. (1997). Separation of fibres from the capsule enhances mitotic activity of human lens epithelium. Exp. Eye Res. 64, 67-72

11. Van Tenten Y., Willekens B., De Wolf A., et al. (1998). Temperature threshold for cell death of lens epithelial cells in a capsular bag model (abstract 2126). Ophthalmic Res. 30, 133

12. Meacock W.R., Spalton D.J., Hollick E.J., et al. (2000). Double-masked prospective ocular safety study of a lens epithelial cell antibody to prevent posterior capsule opacification. J. Cataract Refract. Surg. 26, 716-721

13. Menapace R., Findl O., Georgopoulos M., et al. (2000). The capsular tension ring: designs, applications, and technique. J. Cataract Refract. Surg. 26, 898-912

14. Gimbel H.V. (1990). Posterior capsule tears using phaco-emulsification: causes, prevention and management. Eur. J. Implant. Refract. Surg. 2, 63-69

15. Galand A., Van Cauwenberge F., Moosavi J. (1996). Posterior capsulorhexis in adult eyes with intact and clear capsules. J. Cataract Refract. Surg. 22, 458-461

16. Tassignon M.J., De Groot V., Smets R.M.E., et al. (1996). Secondary closure of posterior continuous curvilinear capsulorhexis. J. Cataract Refract. Surg. 22, 1200-1205

17. Van Cauwenberge F., Rakic J.M., Galand A. (1997). Complicated posterior capsulorhexis: aetiology, management and outcome. Br. J. Ophthalmol. 81, 195-198

18. Tassignon M.J., De Groot V., Vervecken F., Van Tenten Y. (1998). Secondary closure of posterior continuous curvilinear capsulorhexis in normal eyes and eyes at risk for postoperative inflammation. J. Cataract Refract. Surg. 24, 1333-1338

19. Spalton D.J. (1999). Posterior capsular opacification after cataract surgery. Eye 13, 489-492

20. Aron-Rosa D., Aron J.J., Griesemann M., Thyzel R. (1980). Use of the neodymium:YAG laser to open the posterior capsule after lens implant surgery: a preliminary report. Am. Intra-Ocular Implant. Soc. J. 6, 352-355

21. Apple D.J., Solomon K.D., Tetz M.R., et al. (1992). Posterior capsule opacification. Surv. Ophthalmol. 37, 73-116

22. Ohadi C., Moreira H., McDonnell P. (1991). Posterior capsule opacification. Curr. Opin. Ophthalmol. 2, 46-52

23. Tassignon M.J., Rozema J.J., Gobin L. (2006). Ring-shaped caliper for better anterior capsulorhexis sizing and centration. J. Cataract Refract. Surg. 32, 1253-1255

24. De Groot V., Leysen I., Neuhan T., et al. (2006). One-year follow-up of the bag-in-the-lens intraocular lens implantation in 60 eyes. J. Cataract Refract. Surg. 32, 1632-1637

25. Leysen I., Coeckelbergh T., Gobin L., et al. (2006). Cumulative Neodymium:YAG laser rate after bag-in-the-lens and lens-in-the-bag implantation. J. Cataract Refract. Surg. 32, 2085-2090

Figures

Fig. 1

[pic] [pic]

Fig. 2 A-B

[pic] [pic] [pic]

Fig. 3-4-5

Management of posterior capsule in children

Abhay Vassavada, Iladevi Cataract & IOL Research Centre, Ahmedabad, India

The most frequent and significant problem following pediatric cataract surgery is visual axis obscuration (VAO) 1-4. Younger the child, higher the incidence and earlier the onset of VAO. Maintenance of clear visual axis remains a high priority when planning management of posterior capsule in amblyogenic age range. Posterior capsulotomy can be performed with various approaches including manual posterior continuous curvilinear capsulorhexis (PCCC), vitrectorhexis, radiofrequency diathermy and fugo plasma blade5. Some prefer vitrectorhexis when vitrectomy is planned with primary posterior capsulotomy. However when anterior vitrectomy is not a planned procedure with posterior capsulotomy, manual PCCC is a must.

Our technique of PCCC is as follows :

After refilling capsular bag with Provisc, PCCC is initiated with the vertical element of a 26-gauge cystotome. Vertical element is held at a slant and with a swiping motion, the posterior capsule is engaged and simultaneously directed towards the left (in the direction of the 3 O’ clock position) and anteriorly (towards the microscope). Additional viscoelastic is injected in the area surrounding the puncture to make the posterior capsule concave or flat. Viscoelastic substance is not injected through the puncture towards the vitreous face. The left of the inferior end of the puncture is grasped with Kraff-Uttrata capsulorhexis forceps fashioning the PCCC in a clockwise manner. PCCC of approximately 3.5 – 4 mm is aimed6.

Despite this, iatrogenic AVF disturbance can occur. Our preferred approach is manual PCCC, even when we are planning to perform vitrectomy. Many investigators have observed that performing PCCC is technically difficult. A potential complication associated with this procedure is disruption of AVF. However, subtle signs of vitreous disturbance during PCCC can be easily overlooked.We have described the following signs to identify disturption of vitreous face during PCCC. They are : (1) visible strands that may be freely floating or may be adherent to the capsular flap,pupil or incision,(2)deformation of the capsulotomy margin,or (3) peaking of the pupil to angle of anterior chamber or incision7. Maintaining a high magnification with the operating microscope and dimming the lights in the operating room are suggested methods to aid capsulorhexis in difficult situations.

Identification of AVF disburbance is more relevant when surgeon is planning to perform posterior capsulotomy without an anterior vitrectomy. We use preservative free triamsolone acetonide to visualize vitreous for ensuring through and complete vitrectomy after performing a manual PCCC technique.The granules of triamcinolone acetonide are trapped on the surface of the vitreous body making it clearly visible under the surgical microscope. On completion of the PCCC, 0.1 ml of a suspension of preservative free triamcinolone acetonide (Aurocort, Aurolab) was injected within the PCCC margin and inside the anterior chamber for visualizing the anterior vitreous face as well as the presence and extent of vitreous in the anterior chamber. A two port limbal central core anterior vitrectomy was performed using a maximum cut rate of 800, AFR of 25 cc/min and vacuum of 400mmHg using Aurocort stained vitreous gel as a guide on the Infiniti™ phacoemulsification system (Alcon).. After removal of the residual viscoelastic, 0.1ml of Aurocort was again injected into the anterior chamber in order to visualize residual vitreous strands in the anterior chamber. Additional anterior vitrectomy was performed if vitreous strands were identified in the anterior chamber. Triamcinolone was then rinsed off with BSS.

This technique was found to be helpful in identifying the presence of vitreous and visualizing the vitreous during vitrectomy. We found that following the first injection of preservative free triamcinolone acetonide after completion of the PCCC, the vitreous gel was enhanced by capture of the triamcinolone particles by the gel. In the presence of AVF disturbance, these particles tended to become entrapped and impregnated in the vitreous gel making it clearly visible. With an intact vitreous face it appeared as a convex, bulging structure. Further with an intact vitreous face Aurocort suspension tended to swirl freely when injected within the rhexis margin. Secondly after performing a thorough, bimanual limbal anterior vitrectomy and IOL implantation, a second injection of Aurocort was introduced to identify for the presence of residual vitreous strands. It was identified as free floating strands, or strands extending to the incisions. We found Aurocort suspension primarly clinging to the superficial vitreous gel identified as residual strands of vitreous, which might otherwise have gone unnoticed. In eyes where residual vitreous strands were identified, a repeat anterior vitrectomy was performed until all the triamcinolone granules were removed. In conclusion, using an appropriate technique and viscoelastics, posterior capsulorhexis can be consistently performed during congenital cataract surgery.

References

8. Parks MM. Posterior lens capsulectomy during primary cataract surgery in children. Ophthalmology 1983;90:344-5.

9. Knight-Nanan D, O’ Keefe M, Bowell R. Outcomes and complications of intraocular lenses in children with cataract. J Cataract Refract Surg 1996; 22:730-6.

10. BenEzra D, Cohen E. Posterior capsulectomy in pediatric cataract surgery; the necessity of a choice. Ophthalmology 1997;104:2168-74.

11. Sharma N, Pushkar N, Dada T et al. Complications of pediatric cataract surgery and intraocular lens implantation. J Cataract Refract Surg 1999; 25:1585-8

12. Guo S, Wagner RS, Caputo A. Management of the anterior and posterior lens capsules and vitreous in pediatric cataract surgery J Pediatr Ophthalmol Strabismus 2004; 41:330-7.

13. Dholakia SA, Praveen MR, Vasavda AR, Nihalani B. Completion rate of primary posterior continuous curvilinear capsulorhexis and vitreous disturbance during congenital cataract surgery. J AAPOS 2006; 10; 351-356.

14. Praveen MR, Vasavada AR, Koul A, Trivedi RH, Vasavada VA, Vasavada VA.Subtle signs of anterior vitreous face disturbance during posterior capsulorhexis in pediatric cataract surgery. J Cataract Refract Surg. 2008 Jan;34(1):163-7.

New IOL solving PCO and offering new perspectives in toric correction and accommodation

M.J. Tassignon, University Hospital Antwerp, Belgium

Many techniques have been advocated to prevent posterior capsule opacification (PCO), the major cause of visual loss after cataract surgery. These include special IOL materials and designs,1-6 adhesive lens coatings,7 the use of chemical substances with the IOL,8-9 physical removal of remaining proliferative cells within the lens bag,10 physical techniques to destroy LECs,11 the use of antibodies against LECs,12 implantation of a capsular tension ring,13 and removal of the central part of the posterior capsule or a posterior continuous curvilinear capsulorhexis.14-18 These methods have substantially reduced the prevalence of PCO but have not eradicated it, especially in compromised eyes such as those of pediatric, uveitis, and diabetic patients.19

At present, the only efficient treatment for established PCO is surgically induced rupture of the opaque posterior capsule (i.e. capsulotomy) using a capsulotomy needle or a Q-switched neodymium:YAG (Nd:YAG) laser.20 These secondary capsulotomies, however, increase the complication rate after cataract surgery to nearly the level of the now mostly abandoned ICCE procedure. Complications of a Nd:YAG capsulotomy, including retinal detachment, glaucoma, cystoid macular edema, and IOL pitting, have been widely described.21-22

The surgical removal of the central part of the posterior capsule in the same surgical procedure is called planned primary continuous, circular and curvilinear capsulorhexis or PPCCC. This technique was used in the early ’90s in the hope to solve PCO but unfortunately did not prevent further cell proliferation, as expected.16-18 The reason is that LECs do not need the support of the posterior capsule to proliferate and reclose the PPCCC opening. We therefore proposed a new type of IOL consisting of a round optic part, surrounded by two haptics (anterior and posterior) defining a peripheral groove in which both the anterior and posterior capsules will take place (Fig. 1). This technique is called the bag-in-the-lens (BIL) technique. This lens could also be called the twin-capsulorhexis IOL to stress the crucial role of both the anterior and posterior capsulorhexis for proper IOL fixation.23

This new implantation technique is designed to solve the problem of PCO, based on the principle of capturing the remaining LECs in the equatorial space and by prohibiting their proliferation and transformation into myofibroblasts.24

The efficacy of the BIL implantation regarding PCO has been studied in 100 eyes with a follow-up ranging from 7 months to 6 years.25 Since the biomaterial used to manufacture the BIL is a hydrophylic acrylic with a water content of about 24 %, postoperative uveal response is expected to be very low. As shown in Fig. 2 the optical zone of the lens remains clear 6 to 9 months after surgery.

The ring caliper was introduced in 2005 to facilitate the sizing and centration of the anterior capsulorhexis along the alignment of the first and third Purkinje reflexes as observed under the microscope (Figs. 3-4-5).23 For the purpose of the BIL implantation the ring has an internal diameter of 5 mm.

The BIL implantation technique offers the surgeon the possibility to position the BIL in a surgeon-controlled way. To facilitate the correct sizing of the anterior capsulorhexis and the position of the IOL according to the first and third Purkinje reflexes as observed through the surgical microscope, we studied the BIL centration before and after the use of the ring caliper. These results show no significant difference between both calibration techniques.

The decentration of the BIL over time was studied in 180 eyes and showed very good centration stability over time (5 weeks, 6 months, 1 year).

Rotational stability of the BIL has been studied in 35 eyes showing less than 1.5° rotation over time (1 day, 5 weeks, 6 months), which means that the BIL can now go from monofocal to toric with high positional reliability.

The next step is to focus on accommodation by restoring the equatorial angle of the capsular bag and as a consequence the impact of the zonular fibers on the capsular bag during accommodation. This will optimize pseudo-accommodation, which can improve patient’s near vision of 2 to 3 diopters, which should be sufficient for daily life activities but not for prolonged reading activities.

Legends to the figures

6. Top: Schematic drawing of the twin-capsulorhexis IOL showing the main circular central optic surrounded by the haptic. The two haptics are oriented perpendicularly to each other to ensure optimal lens stability. Bottom: A side view showing the characteristic groove in which both lens capsules will settle (1 = optic; 2 = groove into which anterior and posterior capsules will settle; 3 = oval-shaped posterior haptic; 4 = oval-shaped anterior haptic; 5 = positioning holes [optional]).

7. Six months and nine months postoperative aspect after BIL implantation in two different eyes.

8. Insertion of the flexible poly(methyl methacrylate) ring caliper into the anterior chamber using a lens manipulator.

9. Tearing the anterior capsule along the ring caliper.

10. Matlab computer program to verify centration of the capsulorhexis relative to the pupil edge.

References

26. Sterling S., Wood T.O. (1986). Effect of intraocular lens optic design on posterior capsular opacification. J. Cataract Refract. Surg. 12, 655-657

27. Born C.P., Ryan D.K. (1990). Effect of intraocular lens optic design on posterior capsular opacification. J. Cataract Refract. Surg. 16, 188-192

28. Yamada K., Nagamoto T., Yozawa H., et al. (1995). Effect of intraocular lens design on posterior capsule opacification after continuous curvilinear capsulorhexis. J. Cataract Refract. Surg. 21, 697-700

29. Apple D.J. (2000). Influence of intraocular lens material and design on postoperative intracapsular cellular reactivity. Trans. Am. Ophthalmol. Soc. 98, 257-283

30. Nishi O., Nishi K., Wickström K. (2000). Preventing lens epithelial cell migration using intraocular lenses with sharp rectangular edges. J. Cataract Refract. Surg. 26, 1543-1549

31. Nishi O., Nishi K., Akura J., Nagata T. (2001). Effect of round-edged acrylic intraocular lenses on preventing posterior capsule opacification. J. Cataract Refract. Surg. 27, 608-613

32. Duncan G., Wormstone I.M., Liu C.S., et al. (1997). Thapsigargin-coated intraocular lenses inhibit human lens cell growth. Nat. Med. 3, 1026-1028

33. Legler U.F.C., Apple D.J., Assia E.I., et al. (1993). Inhibition of posterior capsule opacification: the effect of colchicine in a sustained drug delivery system. J. Cataract Refract. Surg. 19, 462-469

34. Power W.J., Neylan D., Collum L.M.T. (1994). Daunomycin as an inhibitor of human lens epithelial cell proliferation in culture. J. Cataract Refract. Surg. 20, 287-290

35. Rakic J.M., Galand A., Vrensen G.F.J.M. (1997). Separation of fibres from the capsule enhances mitotic activity of human lens epithelium. Exp. Eye Res. 64, 67-72

36. Van Tenten Y., Willekens B., De Wolf A., et al. (1998). Temperature threshold for cell death of lens epithelial cells in a capsular bag model (abstract 2126). Ophthalmic Res. 30, 133

37. Meacock W.R., Spalton D.J., Hollick E.J., et al. (2000). Double-masked prospective ocular safety study of a lens epithelial cell antibody to prevent posterior capsule opacification. J. Cataract Refract. Surg. 26, 716-721

38. Menapace R., Findl O., Georgopoulos M., et al. (2000). The capsular tension ring: designs, applications, and technique. J. Cataract Refract. Surg. 26, 898-912

39. Gimbel H.V. (1990). Posterior capsule tears using phaco-emulsification: causes, prevention and management. Eur. J. Implant. Refract. Surg. 2, 63-69

40. Galand A., Van Cauwenberge F., Moosavi J. (1996). Posterior capsulorhexis in adult eyes with intact and clear capsules. J. Cataract Refract. Surg. 22, 458-461

41. Tassignon M.J., De Groot V., Smets R.M.E., et al. (1996). Secondary closure of posterior continuous curvilinear capsulorhexis. J. Cataract Refract. Surg. 22, 1200-1205

42. Van Cauwenberge F., Rakic J.M., Galand A. (1997). Complicated posterior capsulorhexis: aetiology, management and outcome. Br. J. Ophthalmol. 81, 195-198

43. Tassignon M.J., De Groot V., Vervecken F., Van Tenten Y. (1998). Secondary closure of posterior continuous curvilinear capsulorhexis in normal eyes and eyes at risk for postoperative inflammation. J. Cataract Refract. Surg. 24, 1333-1338

44. Spalton D.J. (1999). Posterior capsular opacification after cataract surgery. Eye 13, 489-492

45. Aron-Rosa D., Aron J.J., Griesemann M., Thyzel R. (1980). Use of the neodymium:YAG laser to open the posterior capsule after lens implant surgery: a preliminary report. Am. Intra-Ocular Implant. Soc. J. 6, 352-355

46. Apple D.J., Solomon K.D., Tetz M.R., et al. (1992). Posterior capsule opacification. Surv. Ophthalmol. 37, 73-116

47. Ohadi C., Moreira H., McDonnell P. (1991). Posterior capsule opacification. Curr. Opin. Ophthalmol. 2, 46-52

48. Tassignon M.J., Rozema J.J., Gobin L. (2006). Ring-shaped caliper for better anterior capsulorhexis sizing and centration. J. Cataract Refract. Surg. 32, 1253-1255

49. De Groot V., Leysen I., Neuhan T., et al. (2006). One-year follow-up of the bag-in-the-lens intraocular lens implantation in 60 eyes. J. Cataract Refract. Surg. 32, 1632-1637

50. Leysen I., Coeckelbergh T., Gobin L., et al. (2006). Cumulative Neodymium:YAG laser rate after bag-in-the-lens and lens-in-the-bag implantation. J. Cataract Refract. Surg. 32, 2085-2090

Figures

Fig. 1

[pic] [pic]

Fig. 2 A-B

[pic] [pic] [pic]

Fig. 3-4-5

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download