Periocular CO₂ laser resurfacing: severe ocular complications from multiple unintentional laser impacts on the protective metal eye shields

Background and objectives: A 36-year-old woman underwent CO₂ laser resurfacing for periocular rhytides using protective stainless steel Cox II ocular shields. Immediately after the treatment, corneal lesions were seen in both eyes. The left eye subsequent developed corneal ulceration and scarring, a deformed iris, cataract, and lower eye lashes showing signs of acute burns. The right cornea had a small inferior mid-peripheral superficial lesion and concomitant lower mid-peripheral burned eye lashes. Our objective was to determine the most likely cause of these ocular complications.

Study: We estimated temperature-time combinations that could induce corneal injury and cataract. Heat conduction effects from a heated cornea to the lens and from a heated ring of periocular skin to the cornea were computed. The temperature response of a shield following CO₂ laser irradiation was determined.

Results: We computed that cataract can develop when the corneal temperature reaches, for example, 80 °C for 14 seconds. A periocular ring of heated skin contributes little to the corneal temperature. After 7 pulses of consecutive CO₂ laser bursts in 7.5 seconds, the total shield area already reached a homogeneous temperature of 63 °C.

Conclusion: Despite uncertainties in procedural details and modeling of cataract temperatures, the eye injuries were caused beyond doubt by heating of tear-covered metal eye shields by at least 10 consecutive but unintentional laser impacts. Lasers Surg. Med. 50:980-986, 2018. © 2018 Wiley Periodicals, Inc.