Management of Cataract and Iris Defect

A large iris defect may cause severe discomfort and visual side effects, such as glare, halos, and monocular double vision—especially if it is located inferiorly. Removal of cataract may sometimes aggravate the symptoms because more light then enters the eye and the image is sharper. Therefore, the surgeon should consider managing the iris defect at the time of cataract surgery.

CASE PRESENTATION
A 75-year-old man developed a localized iris malignant melanoma on his right eye. The melanoma was surgically removed in April 2007 with clear margins and no evidence of tumor metastases; however, the large iridal excision resulted in a large surgical coloboma that involved approximately 4 clock-hours of the inferior iris. A few months later, the patient complained of decreased vision and disturbing glare in his right eye. According to the patient's description, his ability to function outdoors, even with dark sunglasses on, was poor. Upon examination, his BCVA was 6/20. A central nuclear and posterior subcapsular cataract was evident (Figure 1).

After identifying the cataract, I had to decide between two treatment methods: (1) remove only the cataract or (2) manage both the cataract and iris defect. If I only removed the cataract, the glare (ie, the patient's main complaint) may have persisted. If I chose to simultaneously manage the cataract and iris defect, I would have to use iridoplasty, which did not seem practical because too much of the iris was missing. Alternatively, I could implant an iris prosthesis combined with an IOL or another additional device. Morcher GmbH (Stuttgart, Germay) provides three options, all of which are black: aniridia IOL with a 360° artificial iris, endocapsular ring iris implants, and partial aniridia implants to cover a localized iris defect. Ophtec GV (Groningen, Netherlands) also offers aniridia IOLs or partial aniridia implants in black, brown, green, and blue.

I chose option No. 2, removing the patient's cataract and managing his iris defect simultaneously. Because the patient's iris was a shade of blue-green, I thought the best choice would be to use Ophtec's green partial aniridia implant with a 4-mm pupil. The artificial iris implant is made of PMMA.

I performed the operation under sub-Tenon's anesthesia. First, I created the scleral tunnel, performed phacoemulsification, and enlarged the phaco incision to 5 mm to insert the one-piece PMMA IOL (Balance; Hanita Lenses, Kibbutz Hanita, Israel). Following IOL insertion, I implanted the artificial iris segment into the capsular bag. The larger incision was required for the second implant.

After surgery, the patient's vision improved to 6/10, and the eye was clear and quiet. He experienced persistent high intraocular pressure, which we treated with antiglaucoma drops. The iris implant covered the entire iris defect, with the exception of a narrow slit between the implant and the natural iris (Figure 2). The color of the implant did not match the patient's own iris; however, the patient said he did not mind the outcome. Conversely, the patient still complained of unbearable glare and repeatedly returned to the clinic, stating that it was "as if surgery was not done." A therapeutic trial with 2% pilocarpine did not show any clinical improvement.

The cause of the disabling glare was still unclear—the posterior subcapsular cataract was removed, and most of the coloboma was effectively covered. It seemed to me that the residual iris slit was too small to explain the severe glare complaints. The cornea was clear, and there were no signs of abrasion, dry eye, or a foreign body within the eye.

HOW WOULD YOU PROCEED?
My main concern was that the glare was caused not by the iris or corneal defects or the cataract, but rather was a symptom of another disease, such as uveal irritation, meningeal and neurological diseases, or a psychological condition. I took special caution in this case because the patient had undergone surgical removal of a malignant uveal melanoma.

Assuming that the cause of glare was not ocular, options to manage the disabling glare now included: (1) screening for tumor metastases or (2) referring the patient to another specialist for a neurological and psychological evaluation. Assuming that the cause of glare was ocular, my treatment options included: (1) treating the patient with more steroids, NSAIDs, and/or lubricants, (2) rotating the artificial iris segment to cover the remaining slit, (3) exchanging the partial iris implant with a complete iris prosthesis, (4) implanting an additional segment or ring, (5) constricting surgically the edge of the iris defect (ie, iridoplasty), or (6) waiting to see how the patient progressed.

If this were your patient, how would you proceed?

HOW I PROCEEDED
With the patient continually demanding a solution for his glare symptoms, I decided to again treat him surgically, this time performing a localized iridoplasty. Three months after the first operation, I sutured the iris (near the gap site) to the scleral wall (close to the limbus) with a 10-0 Prolene suture. The iris defect was effectively closed, and the central pupil was slightly constricted (Figure 3).

FOLLOW-UP
The next day, the patient's complaints of glare disappeared; they did not return. The patient's visual acuity remained 6/10, but he was happy with his visual results. Now, he complains about his cosmetic appearance (Figure 4).

WHAT HAVE I LEARNED FROM THIS CASE?
With every challenging case comes a new lesson to be learned. From treating this patient, I learned that: (1) clinically disturbing glare may result from even a small inferior iris defect and (2) the surgeon should always choose an iris prosthesis darker than the shade of the patient's natural iris.

Ehud I. Assia, MD, is a Professor of Ophthalmology, Sackler Faculty of Medicine, Tel Aviv University, Kfar Saba, Israel; Chairman, Department of Ophthalmology, Meir Medical Center; and Medical Director, Ein-Tal Eye Center, Tel Aviv. Professor Assia states that he has no financial interest in the products or companies mentioned; however, he is a consultant to Hanita Lenses. He may be reached at tel: +972 9 7471527; fax: +972 9 7472427; e-mail: Ehud.Assia@clalit.org.il or assia@netvision.net.il.