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Cataract Surgery: Complex Case Management | Mar 2010

Phacodonesis and a Subluxated Crystalline Lens

The combination of advanced glaucoma and phacodonesis with lens subluxation suggests pseudoexfoliation (PXF) syndrome, which needs to be ruled out. Another potential cause is high myopia, in which significant phacodonesis is not uncommon. Cataract extraction is certainly indicated, not only to remove the opaque media but also because of the patient’s glaucoma. Anterior displacement of the unstable lens may play a role in the high IOP, and removal of the crystalline lens is often associated with decreased pressure.

Intracapsular cataract extraction and the implantation of either an ACIOL (angle or iris supported) or a suturefixated PCIOL are valid options. My preference, however, would be to preserve the posterior capsule by fixating the lens capsule to the scleral wall. The Cionni Rings for Sclera Fixation and the Ahmed Capsular Tension Segments (CTS) (both from Morcher GmbH, Stuttgart, Germany; distributed in the United States by FCI Ophthalmics, Marshfield Hills, MA) were shown to be highly effective for fixation of the capsular bag to the scleral wall.

I have developed with Hanita Lenses (Kibbutz Hanita, Israel) an alternative device, the AssiAnchor (not available in the United States), which clips to the anterior capsuleand is sutured to the scleral wall1,2 (Figure 3). After the lens is stabilized by the AssiAnchor, the surgeon performs phacoemulsification in the conventional manner. A capsular tension ring (CTR) may also be inserted to preserve the round contour of the capsular equator. My clinical experience (11 patients, 12 anchors) has been encouraging, and final follow-up (more than 2 years for four patients) revealed stable and central capsule-fixated IOLs in all eyes. This patient’s diabetic retinopathy should be well controlled prior to surgery to minimize postoperative macular edema.

The youth of this patient highlights the complexity of the case. Under most circumstances, I would recommend an ACIOL as a perfectly acceptable option for an eye with zonular laxity. I would not change this decision for mild glaucoma or well-controlled diabetes. The presented “gestalt” of this patient, however, suggests a high risk for worsening glaucomatous visual field loss and increasing diabetic ischemic disease, with rubeosis a significant possibility. These issues are relative contraindications for an anglefixated ACIOL. The choice is therefore between an irisfixated or a scleral-sutured PCIOL. I would defer the decision until after removing the cataract. The IOL would need to be acrylic with rounded edges at potential points of contact with uveal tissue. Due to potential problems with centration, the lens should be spherical or neutrally aspheric.

The specific technical aspect of the surgery is whether the capsule is capable of providing long-term assistance in the fixation of the IOL. As a general rule, I use a CTR at the start of a case only in the presence of significant phacodonesis, but I do not use a CTR if the lens is relatively stable despite the apparent zonular defect. If the zonules prove more resilient and remain intact with a gentle phacoemulsification (large capsulorhexis with either a supracapsular flip or, preferably, a well-controlled chop to preserve the zonules as much as possible), then the extent of the zonular abnormality can be assessed. If fewer than 3 to 4 clock hours are impaired, a CTR alone may be reasonable. More than 4 but fewer than 6 clock hours calls for scleral fixation in the region of zonular laxity, with a Cionni Ring for Sclera Fixation, a Henderson Capsular Tension Ring (Morcher GmbH; distributed in the United States by FCI Ophthalmics), or an Ahmed CTS. Otherwise, I would keep all incisions anterior to the limbus to preserve the conjunctiva.

If the zonules appeared pathologic and the lens seemed to be unstable as the case began, I would place retractors from the Mackool Cataract Support System (Duckworth & Kent Ltd., Hertfordshire, United Kingdom) as I performed the capsulorhexis. In this situation, the capsule would not likely help support the IOL, and iris-suture fixation would probably be the best option to minimize surgical trauma and spare the conjunctiva. Whether the capsule is useful or likely to be a nuisance could be decided at that point. I would carefully remove the ophthalmic viscosurgical device (OVD) at the end of the case.

My preference would be to pretreat this patient with Avastin or Lucentis (both from Genentech, Inc., South San Francisco, CA) and to administer intravitreal triamcinolone acetonide (only 1 mg) at the end of the case to minimize the impact of her diabetic condition.

I would administer a peribulbar block and create a superior primary incision. Next, I would inject Viscoat (Alcon Laboratories, Inc., Fort Worth, TX) into the region of absent zonule, stain the anterior capsule with trypan blue, and completely fill the anterior chamber with additional viscoelastic. I would then perform the capsulorhexis and insert at least five retractors from the Mackool Cataract Support System before phacoemulsification. The retractors should be inserted at 45° intervals where the zonule is absent and at 90° intervals where there is evidence of possible zonular laxity. I would insert a standard CTR and then place an Ahmed CTS in the inferior capsular fornix and suture it to the sclera. If the superior zonule were not adequate, I would use two Ahmed CTS. After removing the Cataract Support System’s retractors, I would perform endoscopic cyclophotocoagulation (ECP) for at least 270° using the E2 Microprobe Laser and Endoscopy System (Endo Optiks, Little Silver, NJ). Insertion of the IOL into the capsular sac would complete the procedure.

I would carefully monitor the IOP for 3 to 4 hours due to the eye’s advanced glaucomatous optic nerve damage. To reduce the possibility of a significant IOP spike, one could administer Miostat (Alcon Laboratories, Inc.) intraoperatively, ensure the complete removal of viscoelastic material, instill topical antiglaucoma medications at the end of the procedure, and administer oral acetazolamide.

There are several points of diagnostic interest in this case. First is the etiology of the lens subluxation. In the absence of any evidence of a systemic disease (including PXF), previous surgery, or trauma, one might assume simple ectopia lentis. Also intriguing is the patient’s potential acuity based on macular function, given her history of diabetic retinopathy. A potential acuity test would help set reasonable expectations on the part of the patient for cataract extraction. Posterior segment optical coherence tomography, perhaps already performed by the retina colleague mentioned, would help define the anatomical status of the macula. Finally, the severity of glaucoma and degree of its control would affect my surgical decisions. The number of medications and the presence of field loss suggest to me that adjunctive ECP at the time of cataract surgery might be indicated. The decision to perform ECP would depend on the target IOP and the likelihood of the patient’s ongoing adherence to medical therapy.

I would use my standard infection prophylaxis with a preoperative topical fluoroquinolone antibiotic and my routine preoperative anti-inflammatory protocol with a topical steroid and nonsteroidal anti-inflammatory drug beginning 3 days before surgery.

In the absence of vitreous prolapse, I would construct two trapezoidal single-plane incisions (each 1.4 mm internally) in the superior and inferior temporal quadrants in preparation for a biaxial microincisional approach to phacoemulsification. After filling the anterior chamber with a dispersive OVD, I would initiate the capsulorhexis centrally with a pinch-type forceps and complete the tear with a spiral-out technique (going inferiorly first).

After gentle hydrodissection, the insertion of a CTR distributes the equatorial forces on the bag and centers the lens. Depending on the degree of phacodonesis, a Cionni Ring for Sclera Fixation is probably necessary here. I would pass each arm of a 10°0 or 9°0 Prolene suture (Ethicon Inc., Somerville, NJ) through the eyelet of the ring and then into the eye, under the iris, and out through a Hoffman pocket-type incision inferiorly. I would then rotate the ring into the capsule.3 Because a vertical chopping technique applies minimal force to the zonule, it would permit phacoemulsification of this dense nucleus without damage to the capsule. Cortical cleanup would be facilitated by gentle tangential aspiration and biaxial I/A (which would allow a direct approach to 360° of the capsule).

I would favor a three-piece, monofocal, hydrophobic acrylic, square-posterior-edge IOL in this case. This IOL would provide a defense against capsular contraction, a high-quality image, and resistance to posterior capsular opacification (as well as compatibility with silicone oil). The IOL’s insertion would require a 2.8-mm temporal clear corneal incision. I would gladly perform limbal relaxing incisions if indicated for the correction of preexisting keratometric astigmatism (if with the rule, the inferior incision could be incorporated into the construction of the Hoffman pocket).

After the IOL’s implantation, I would perform ECP on 270° of the ciliary epithelium, thoroughly aspirate all of the OVD, and use stromal hydration to seal the incisions. Depending on the IOP on the first day after surgery, I would have the patient continue using one or two of her glaucoma medications and then re-evaluate her in a couple of weeks.

An early follow-up visit with the retina specialist would be a good idea. The perioperative injection of a vascular endothelial growth factor inhibitor might be indicated to forestall the development of macular edema or the resurgence of neovascularization.

Before approaching surgery, we would fully explore the systemic causes of the lens’ subluxation, because they may present risks for anesthesia. PXF typically causes inferior subluxation, but in the context of underlying glaucoma, PXF should also be considered, because this patient could be at risk of postoperative IOP spikes. The IOP might be slightly lower after cataract surgery alone, but because of her advanced cupping and need for three medications to maintain IOP control, the surgeon could consider a combined glaucoma-cataract procedure. In addition, given her advanced proliferative diabetic retinopathy, the patient would benefit from a preoperative retinal evaluation and treatment of any macular edema.

This patient likely has isolated ectopia lentis, a diffuse zonulopathy. Zonular loss may therefore extend farther than the 180° visible in the retroillumination photographs.

We would implant a single-piece, foldable acrylic IOL in the bag, with support provided by a combination of a CTR and one or two Ahmed CTS, sutured to the sclera using an implantation technique previously described4 (Figure 4). The generous use of an OVD and strict avoidance of a shallow anterior chamber throughout the case would be key to preventing vitreous from prolapsing anteriorly. We would perform the capsulorhexis with the support of iris hooks on its margin inferiorly, and we would carefully leave an adequate shelf of intact anterior capsule for the future placement of a CTS. Next, we would insert a CTR after viscodissection to facilitate later cortical removal. Under OVD protection, the CTS would be introduced into the bag inferiorly and retracted by one iris hook passed through its central eyelet (Figure 5). The remaining iris hooks could then be removed.

With the capsule supported at its equator by the CTS, we would complete phacoemulsification using a zonulefriendly chopping technique, followed by cortical removal and implantation of a foldable acrylic lens. We would then release the iris hook and temporarily move the CTS to the central anterior chamber to facilitate suture fixation. We would create an inferior limbal peritomy and partial-thickness scleral groove. Next, we would expand the inferior sulcus with an OVD to prevent capsular trauma during the suturing of the CTS to the sclera. A 26-gauge needle on a viscoelastic syringe would be passed through the scleral groove into the sulcus and advanced centrally. A double-armed 9–0 Prolene suture with a CIF-4 needle (straightened with two needle drivers) (Ethicon Inc.) would be introduced through the temporal corneal incision, passed through the eyelet of the CTS, and docked into the lumen of the 26-gauge needle (Figure 6). The docked needle complex would be withdrawn through the scleral groove, and the process would be repeated with the second arm of the suture (without its passing through the eyelet of the CTS).

We would then place the CTS back in the capsular bag and tie the suture externally using a slipknot, with its tension adjusted to achieve a centered IOL (Figure 7). Using a Sinskey hook, we would bury the knot in the sclera. If needed, a second CTS could be implanted, 180° from the first segment. After withdrawing the OVD via a dry-aspiration technique, we would suture the incisions to avoid inadvertent shallowing of the anterior chamber and vitreous prolapse.

If the capsular bag became unusable, alternative strategies include iris or scleral suture fixation of a PCIOL, enclavation of the Artisan IOL (Ophtec BV, Groningen Netherlands), or an ACIOL.

Section editor Bonnie A. Henderson, MD, is a partner in Ophthalmic Consultants of Boston and an assistant clinical professor at Harvard Medical School. Tal Raviv, MD, is an attending cornea and refractive surgeon at the New York Eye and Ear Infirmary and an assistant professor of ophthalmology at New York Medical College in Valhalla. Dr. Raviv may be reached at (212) 448-1005; tal.raviv@nylasereye.com.

Iqbal Ike K. Ahmed, MD, FRCSC, is an assistant professor at the University of Toronto and a clinical assistant professor at the University of Utah in Salt Lake City. He acknowledged no financial interest in the products or companies he mentioned. Dr. Ahmed may be reached at (905) 820-3937; ike.ahmed@utoronto.ca.

Ehud I. Assia, MD, is the director of the Department of Ophthalmology at Meir Medical Center in Kfar-Saba, medical director of the Ein-Tal Eye Center in Tel- Aviv, and a professor of ophthalmology at Sackler School of Medicine, Tel-Aviv University, Israel. He is the inventor of the AssiAnchor and a paid consultant to Hanita Lenses. Dr. Assia may be reached at +972 9 7471527; assia@netvision.net.il.

Steven Dewey, MD, is in private practice with Colorado Springs Health Partners in Colorado Springs, Colorado. He acknowledged no financial interest in the products or companies he mentioned. Dr. Dewey may be reached at (719) 475- 7700; sdewey@cshp.net.

Richard J. Mackool, MD, is the director of The Mackool Eye Institute and Laser Center in Astoria, New York. He is a consultant to Alcon Laboratories, Inc. Dr. Mackool may be reached at (718) 728-3400, ext. 256; mackooleye@aol.com.

Mark Packer, MD, is a clinical associate professor at the Casey Eye Institute, Department of Ophthalmology, Oregon Health and Science University, and he is in private practice with Drs. Fine, Hoffman & Packer, LLC. He acknowledged no financial interest in the products or companies he mentioned. Dr. Packer may be reached at (541) 687-2110; mpacker@finemd.com.

Devesh K. Varma, MD, is a clinical fellow at the University of Toronto. He acknowledged no financial interest in the products or companies he mentioned. Dr. Varma may be reached at deveshvarma@mac.com.

  1. Ton Y,Michaeli A.Assia EI.Repositioning and scleral fixation of the subluxated lens capsule using an intraocular anchoring device in experimental models.J Cat Refract Surg.2007;33(4):692-696.
  2. Assia EI,Ton Y,Michali A.Capsule anchor to manage subluxated lenses:initial clinical experience. J Cat Refract Surg. 2009;35:1372-1379.
  3. Hoffman RS,Fine IH,Packer M.Scleral fixation without conjunctival dissection.J Cataract Refract Surg.2006;32(11):1907-1912.
  4. Hasanee K,Butler M,Ahmed II.Capsular tension rings and related devices:current concepts.Curr Opin Ophthalmol. 2006;17(1):31-41.
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