Endothermal Pupilloplasty To Optimize Pupil Centration, Size, And Contour

Several pupilloplasty techniques exist for iris defect closure and iris edge apposition. However, the achievement of a well-centered, round, and appropriately sized pupil is often challenging because of tissue loss and asymmetrical iris tension. As a result, the functional and cosmetic outcomes of repair are often not ideal, leading to intolerable glare, photophobia, visual distortion, and poor cosmesis. More sophisticated techniques are required to address pupil centration, contour, and aperture size to optimize outcomes of pupilloplasty beyond just defect closure. We describe a new surgical approach for pupil reconstruction to achieve a more centered, smooth pupillary margin, and appropriately sized pupil using bipolar microendodiathermy.

All surgeries using the endodiathermal pupilloplasty (EDP) technique were performed at an academic ophthalmology center in Toronto, Ontario, Canada. Patients presenting with iris defects secondary to trauma, congenital, proliferative, and iatrogenic causes were included.

We use 10-0 polypropylene sutures with a double-armed CIF-4 needle to reapproximate the missing iris tissue. For a decentered pupil, a 23-gauge endodiathermy straight blunt tip bipolar cautery is applied in a sectoral fashion to the mid-iris stroma. The iris tissue contracts and the pupil is stretched in the meridian to which cautery was applied. For a small pupil, cautery is applied circumferentially to enlarge the pupil. The amount of tissue contraction dictates how much the pupil is enlarged, and is controlled by the energy level, duration of application and distance from the pupil margin. We recommend using lower power levels (<20%) and shorter application time (1 second), and to increase as necessary based on visible tissue reaction.

Endodiathermal pupilloplasty may be performed for cases of decentered pupils, irregular pupil shape, or small pupillary aperture secondary to traumatic iridodialysis or iris coloboma. Compared to vitrector or microscissors to cut the iris, EDP provides titratable contraction of peripupillary tissue and avoids irregular pupil margins. Cutting techniques also pose a risk for further trauma and bleeding due to excessive tissue manipulation or overstretching. Intraoperative bleeding did not occur in any eyes for EDP as it introduces minimal instrumentation into the anterior chamber, thereby reducing risk of trauma, endothelial damage, and iatrogenic damage. In long-term postoperative follow up, cautery application to the iris rarely regressed.

Although pupil defects are traditionally challenging to repair, this study presents a titratable technique to restore a normal pupil size and contour. Endodiathermal pupilloplasty is a simple and effective surgical technique to optimize pupilloplasty outcomes by improving centration, size, and contour of the pupillary margin. It minimizes instrumentation, tissue manipulation, and bleeding in the anterior chamber, thereby resulting in less risk of endothelial and iatrogenic damage compared with using vitrector microscissors to remove excess iris tissue. It may be added to an anterior segment surgeon’s armamentarium to achieve excellent functional, visual, and cosmetic outcomes, and can be readily accessible in most operating rooms.