Interrupted femtosecond laser delivery secondary to face mask–related fogging

Introduction: An increase in face mask utilization has been noted during the COVID-19 pandemic. A rare complication of keratorefractive surgery where interruption of femtosecond-laser delivery was noted secondary to face-mask related fogging of the patient interface is reported. Patient and clinical findings: Young patients with stable tear film and healthy ocular surface were advised femtosecond laser assisted laser in situ keratomileusis (3 eyes) and small-incision lenticule extraction (1 eye) for refractive errors. Intraoperative interruption of laser delivery was noted secondary to droplet condensation or fogging of the patient interface. The fogging developed secondary to the escape of humid exhaled breath. Diagnosis, intervention, and outcomes: Incomplete delivery of the laser required aborting the procedure with retreatment at a later date. In eyes where partial laser delivery was obtained, the flap was manually dissected from the underlying stroma and the procedure was completed in the same sitting. All eyes achieved a final uncorrected distance visual acuity of 20/20 with no long-term sequelae. Conclusions: Fogging of the patient interface is a rare complication secondary to face mask use. Sealing the top of the face mask with well-adhering micropore, readjustment of face masks, removing the mask prior to draping, and checking for droplet condensates on the interface prior to laser delivery may minimize the incidence.