November 2011

NEWS & OPINION

Anterior segment grand rounds

A puzzle missing a few pieces


by Steven G. Safran, M.D.

Case presentation

A 65-year-old woman is status post iridocyclectomy in the left eye eight years previously for a ciliary body melanocytoma. She presents with the complaint of decreasing vision and glare in this eye presumably due to a progressive cataract and iris defect. She has 3 diopters of stable regular astigmatism in this eye and is missing the zonules completely in the area of her previous surgery. She has 2-3+ nuclear sclerosis and a normal macula on SD-OCT.

Steven G. Safran, M.D., ASGR editor

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A 65-year-old woman presented with a complaint of decreasing vision and glare in the left eye, presumably due to a progressive cataract and iris defect Source: Steve Safran, M.D.

A custom-matched silicone iris prosthesis is placed in the bag with an IOL and a CTR in this post-iridocyclectomy patient. Top left: pre-op OS; top right: post-op OS; and bottom: mid-face post-op Source: Steve Safran, M.D.

The patient's post-op image taken at 1 month Source: Steve Safran, M.D.

The patient's final image taken at 1 year post-op Source: Steve Safran, M.D.

Roundtable discussion

I presented the case to

Samuel Masket, M.D., Lisa Arbisser, M.D., and Michael Snyder, M.D. Here are their responses.

Dr. Masket commented: "This case type, partial surgical zonulectomy, carries an excellent surgical prognosis, as the remaining zonular fibers are likely to be intact and strong. Once the contents of the bag have been removed, a standard CTR can be placed, as needed. Given that only two clock hours of the zonule have been removed, sutured devices are not necessary. Regarding the IOL, I would opt for an AcrySof Toric (Alcon, Fort Worth, Texas), likely the T6 model, after a full evaluation of corneal cylinder.

Management of the iris defect would require both iris repair and an artificial iris device. Because Morcher (Stuttgart, Germany) devices are not available in the U.S., a non-custom black silicone foldable iris diaphragm from HumanOptics(Erlangen, Germany) would be my choice management of the iris defect (after obtaining FDA permission); it would require both iris repair and an artificial iris device. I would place it in the sulcus so as not to disturb the capsule bag alignment of the toric IOL. Because the pupil is blunted and irregular, I would close the iris defect in the manner of an iridodialysis. However, I would only tension the sutures enough to create a round pupil; this would leave a residual iris defect nasally, which would be 'covered' by the underlying artificial iris."

Dr. Arbisser agreed with the use of a toric lens in this case and added her perspective on dealing with the iris defect. "This is the perfect case for the Morcher aniridia ring segment, which I have used for many years on a compassionate use basis as it is not FDA approved. The ring provides two functions: It blocks out the missing iris segment creating a black PMMA opaque area to prevent stray light and edge glare while at the same time providing a capsular tension ring function. It is very cost-effective. The FDA has recently stopped its compassionate use. When I had the Morcher ring available a few months ago I would have approached the case in the following way. (Perhaps some day I will do the same with a standard CTR and HumanOptics artificial iris in the bag or a section sewn into the sulcus.) The meridian of astigmatism is appropriately marked for a toric lens. I would place an iris hook (or my preferred Yamaguchi capsule expander hook) on the iris edge in the meridian of the iridocyclectomy. If there is any doubt about vitreous around the zonules at the start of the case it should first be identified with triamcinolone acetonide and removed with bimanual vitrectomy through a pars plana incision with anterior irrigation or pushed back, if possible with OVD. Once the CCC is complete and the bag stabilized with the hook my routine vertical chop technique is unremarkable. The bag is then well expanded with cohesive OVD, the partial Morcher aniridia ring (96 F) inserted. Next a one-piece hydrophobic acrylic toric IOL is inserted under the Morcher ring segment. This patient should do very well."

Dr. Snyder agreed that a toric IOL (or even a multifocal with the use of LRIs to control astigmatism) should be considered and that a CTR "will be required." He further elaborated on the options for iris augmentation. "Iris augmenting devices can be broken down into in-the-bag devices or rigid, sulcus-fixated iris prostheses. I try to avoid the larger rigid devices in these vulnerable eyes, as the 9.5 mm incisions required preclude the control of the small incision, thereby increasing risks for vitreous prolapse, along with the other attendant challenges of large wounds. Three styles of in-the-bag devices exist. Morcher makes a series of black PMMA elements on a CTR backbone that can cover the aphakic and focally aniridic space. They can be placed through small incisions and have a long track history. While Ophtec (Groningen, the Netherlands) makes a multi-piece (Hermeking IPS) iris device, the colors are suboptimal for an iris of this coloration, and the devices and locking element require extraordinary dexterity to place, challenging even the most experienced surgeon. HumanOptics/Dr. Schmit Intraocularlinsen makes the Customflex, a custom-made silicone device colored to match a photo of the residual iris. It can be injected into the capsular bag through a small incision. We have used each of these devices in iridocyclectomy patients (paper in submission for publication) with highly satisfactory results. As none of the devices are currently FDA approved, each was used under FDA compassionate use exemption (CUDE). Recently, the FDA has indicated that it will not approve CUDE requests for the Morcher iris devices for the indefinite future. We will soon be launching a multicenter FDA IDE study for the HumanOptics device."

Treatment

This patient's surgery was performed 18 months ago, prior to my discussion with this expert panel. As was agreed by all, iris retractors were used to control the iris, a CTR was placed after phaco, and a toric IOL was used. The phacoemulsification went uneventfully and almost routinely.

Take-home points

When planning the placement of the toric lens it became clear to me that the broad haptic would be in a position to block some stray light rays from entering a peripheral iris defect, so my surgical repair of the iris was planned to take advantage of this. The iris defect was repaired by suturing the iris to the scleral wall at an angle rather than directly. The tension on the mattress suture used to suture the iris to the sclera was adjusted to reduce deformation of the pupil (as Dr. Masket suggested doing). The remaining peripheral iris defect was almost completely blocked by the position of the broad haptic of the AcrySof Toric T5 IOL (Alcon), the highest power available at the time. The patient was 20/20-2 uncorrected immediately after surgery, and she has experienced no glare problems since. She is very pleased with the cosmetic and visual outcome of the procedure.

Dr. Snyder commented on what was done and the outcome: "This patient achieved an awesome result. Fortunately, the iris was elastic enough to cover the IOL edges, preventing glare. This patient's brown iris is much more forgiving cosmetically than the similarly affected light blue iris." Dr. Arbisser commented: "It is very clever how you sutured the iris. I still think a Morcher ring in the bag would have been the safest and most effective option, however, were it available. I prefer to use a double-armed prolene and suture ab interno for both bites of the horizontal mattress suture rather than come in and then out, but this is style alone. Also I don't make a flap or groove but rather rotate the knot intrascleral. I might have stabilized the capsule as well as the iris with the hook during lens removal and replacement. Congratulations on a wonderful case."

Editors' note: Drs. Arbisser, Masket, and Snyder have no financial interests related to this article.

Contact information

Safran: safran12@comcast.net

A puzzle missing a few pieces A puzzle missing a few pieces
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