The epinephrine used during surgery and the enzymatic solution for the ultrasonic bath used to clean surgical instruments were sterile. Medications with different lot numbers were used in each case. The surgeon is board certified and has 20 years of experience. The autoclave used to sterilize ophthalmic equipment of functioning normally. Single-use topical iodine antiseptic was used, and a new sterile tip for the corneal extraction was used for each patient.