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Urrets-Zavalia syndrome another indication for single-pass four-throw pupilloplasty
The technique helps avoid possible contact lens complications and provides a permanent treatment option.
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Urrets-Zavalia syndrome, or UZS, is a clinical condition first described by Alberto Urrets-Zavalia in 1963 in six patients with wide and rigid pupils after penetrating keratoplasty.
Patients with UZS present with a fixed dilated pupil (Figures 1 and 2) that is hypothesized to occur due to acute iris ischemia after intraocular surgery or after an episode of acute rise in IOP either intraoperatively or in the immediate postoperative period. The use of intraocular air or gas has also been associated with this condition. Recently, UZS has also been reported to occur after a glued intrascleral fixation of IOL.
In UZS, the patient usually complains of decreased vision, glare and halos. On examination, the pupils are detected to be fixed and dilated, not responding to either miotics or mydriatics. The preoperative examination involves recording Snellen best corrected visual acuity, IOP measurements with applanation tonometry, gonioscopy to view the angles, and an anterior segment OCT (AS-OCT). Surgeons often attempt to choose a noninvasive option of fitting a cosmetic contact lens that helps to filter light and prevent glare. But often these cases do not resolve with only a cosmetic contact lens and need additional therapy to control increased IOP, which occurs due to angle crowding associated with the fallback of the iris tissue into the anterior chamber angle, leading to the formation of peripheral anterior synechia. Performing a surgical pupilloplasty causes mechanical traction and pulls up the iris from the angles. Therefore, assessment of the anterior chamber angles is important in cases with UZS. Such patients have typically been treated with trabeculectomy, with or without an antimetabolite, or a glaucoma drainage device. The way single-pass four-throw (SFT) pupilloplasty approaches the issue at hand is not by creating an additional route for drainage, but in fact by reopening the existing drainage route and normalizing outflow mechanics within the eye.
Source: Ashar Agarwal, MS, FRCS, Priya Narang, MS, and Amar Agarwal, MS, FRCS, FRCOphth
Pupilloplasty is the surgical repair of the pupil, and there are various forms of pupilloplasty that can be attempted in cases of iris defects, such as McCannel suture, modified Siepser knot, iris cerclage or SFT pupilloplasty. Among these, the simplest form of surgical treatment is the SFT technique as it involves only a single pass of a 10-0 needle inside the eye. The indications for SFT are vast, including optic capture, peripheral anterior synechiae, glued IOLs, endothelial keratoplasties and UZS. As such, there are no absolute contraindications to SFT. Relative contraindications include a phakic eye with a clear lens due to the possibility of lens touch and cataract formation, and an atrophic iris due to the possibility of an iridodialysis and increased iris damage. SFT can be performed in patients with a clear lens in conjunction with a lens extraction and IOL placement in the bag as lens extraction is currently deemed as one of the surgical maneuvers in patients with angle-closure glaucoma.
Surgical technique
The technique for SFT is simple, straightforward and easily reproducible. Fluid infusion inside the eye can be maintained with a trocar anterior chamber maintainer (ACM) or alternatively with a routine ACM. The use of viscoelastic should be restricted as these eyes are often associated with raised IOP.
In a case of UZS, before doing SFT, pupillary stretching is performed at every clock hour wherein the pupillary edge is pulled with end-opening forceps with an aim to release the pre-existing peripheral anterior synechiae from all quadrants of the angle. Once the iris has been released and is comparatively mobile, with one hand using intraocular forceps, grasp the edge of the pupil to be repaired. With the other hand, a 9-0 or 10-0 Prolene suture is taken through clear cornea and passed through the iris in the area concerned. This needle can be left alone for now. For the other end of the iris defect, again holding the iris with intraocular forceps, a 26-gauge needle can be passed through a paracentesis and then through the iris defect. The 10-0 needle is then threaded or docked into the 26-gauge needle, and the suture is externalized through the paracentesis. This process constitutes the single pass of the SFT technique. Now coming to the four throws part of the procedure, using a dialer or a Sinskey hook, we form a loop of the trailing end of the suture intraocularly. This loop can now be externalized using intraocular forceps. The loop is maintained immediately outside the paracentesis, taking care to see that the suture ends are straight and have not crossed over. The leading end of the suture is now passed through this loop four times, and both the leading and trailing ends of the suture are pulled apart. The resulting helical knot is now locked and self-retaining. The ends of the knot are cut with micro-scissors. This entails the four throws of SFT. This pupilloplasty can be repeated in as many quadrants as required, depending on the desired result.
Close monitoring of these patients is important. In the postoperative period, investigations should entail applanation tonometry, AS-OCT and gonioscopy. In patients with a preoperatively high IOP and closed angles, the SFT now acts as a mechanical miotic, holding the iris tight and in position and preventing the iris from occluding the angles again. In patients with preoperative glare and halos, the amount of light entering the eye is restricted and the pupil is given a more physiological size; hence, the patient is relieved of his symptoms.
The complications that can occur with pupilloplasty are intraocular hemorrhage due to iris damage, cataract formation in phakic patients, iridodialysis and iatrogenic iris damage in atrophic cases. These complications can be reduced with appropriate patient selection and careful handling of iris tissue.
In conclusion, SFT adds to our surgical arsenal in a majority of cases. From repairing closed angles to avoiding the debilitating effects of an optic capture to normalizing pupil size, SFT works in many ways. In UZS, to avoid the possible complications of contact lenses and to provide a permanent treatment option, we advocate the use of SFT. The learning curve for this procedure is short and easy to replicate. It is now up to us as surgeons to apply this technique to help as many patients as we can.
- References:
- Narang P, et al. Eur J Ophthalmol. 2017;doi:10.5301/ejo.5000922.
- Narang P, et al. Single pass four-throw (SFT) pupilloplasty for Urrets-Zavalia syndrome. Eur J Ophthalmol. Article in press.
- Narang P, et al. Indian J Ophthalmol. 2018;doi:10.4103/ijo.IJO_559_17.
- For more information:
- Amar Agarwal, MS, FRCS, FRCOphth, is director of Dr. Agarwal’s Eye Hospital and Eye Research Centre. Agarwal is the author of several books published by SLACK Incorporated, publisher of Ocular Surgery News, including Phaco Nightmares: Conquering Cataract Catastrophes, Bimanual Phaco: Mastering the Phakonit/MICS Technique, Dry Eye: A Practical Guide to Ocular Surface Disorders and Stem Cell Surgery and Presbyopia: A Surgical Textbook. He can be reached at 19 Cathedral Road, Chennai 600 086, India; email: dragarwal@vsnl.com; website: www.dragarwal.com.
- Priya Narang, MS, can be reached at Narang Eye Care & Laser Centre, Ahmedabad, India; email: narangpriya19@gmail.com.
Disclosures: The authors report no relevant financial disclosures.