Presented by: Miltos Balidis MD, PhD, FEBOphth, ICOphth
Edited by: Penelope Burle de Politis MD
A round, normal-sized pupil is necessary for good-quality, comfortable vision. Permanent mydriasis due to total iris sphincter dysfunction, regardless of the cause (inherited or acquired), has both aesthetic and functional consequences for the patient, glare and photophobia being the most common complaints. Urrets-Zavalia syndrome corresponds to a fixedly dilated pupil occurring after anterior segment ophthalmic surgery and unresponsive to miotic agents.
Shaping a normally looking and -functioning pupil out of a fully dilated, atonic iris is one of the most challenging surgical procedures of the anterior ocular segment. Even the healthy iris is a fragile body that bleeds easily and suffers damage from the slightest touch. Because of its morphology, the iris is soft and retractile, thus less stable at handling than structures like the lens and cornea.
Pupilloplasty by iris cerclage is a technique that offers good results depending on the surgeon’s expertise and on the condition of the iris itself, working better in the absence of iridodialysis. It consists of a 360° one-layer continuous running suture along the pupil margin using a 10-0 monofilament polypropylene thread. The puncture points must be as close as possible to one another, and the surgeon must feel how the iris responds to traction, as stretchability and elasticity may vary among different segments of a dysfunctional iris diaphragm.
In this video, recorded in the main operating room of the Ophthalmica Eye Institute, in Thessaloniki, Greece, Dr. Miltos Balidis, MD, PhD, FEBOphth, ICOphth performs iris cerclage and toric IOL implantation in an eye previously undergoing penetrating keratoplasty. The surgical steps and timing in the video are as follows: A theoretical pupil circumference is marked as centrally as possible using a degree gauge and marker, observing the IOL axis alignment (00:12). A large capsulorhexis is fashioned with the goal of having it wider than the pupil and perfectly round (00:43). The iris borders are pulled towards the center of the pupillary area up to where they would normally be, with care not to cause further damage to the muscle fibers or cause iatrogenic iridodialysis (00:50). A straight transchamber needle is passed inside the anterior chamber through a limbal paracentesis (01:08). A purse-string suture is formed by traversing the iris margin at successive points with the same orientation (downwards), avoiding damage to the corneal endothelium (01:30). The suture is completed with the guiding of the suture needle into a syringe needle passed through the initial entrance (02:12). The knot is tied with great caution not to break the thread (02:45). The procedure ends with a satisfactorily round, centered, small-sized pupil (02:55).
“A narrow focus brings big results.” (Emma Morrison)