Canadian comedian Colin Mochrie is postponing several upcoming shows due to a medical emergency.

According to a notice posted on social media, the “Whose Line Is It Anyway?” star underwent emergency surgery for a detached retina on Friday.

“His medical team is optimistic about his full recovery, but he needs time to rest and heal,” a note posted on Mochrie’s Instagram page explained. “We are currently working on rescheduling the shows, and all tickets will be honoured for the new dates.”

Mochrie is currently participating in a pair of comedy tours. His Hyprov tour features hypnotized audience members participating in improvised sketches with the help of hypnotist Asad Mecci. A pair of Hyprov shows in Niagara Falls, Ont. on Jan. 2 and 3 have already been postponed. The Hyprov tour was previously scheduled to run until the end of April, with stops in the U.S., New Zealand and Australia.

Anyone unable to attend the rescheduled performances will be eligible for a refund.

Mochrie is also on an improv comedy tour alongside his “Whose Line Is It Anyway?” co-star Brad Sherwood, with the next show scheduled for Jan. 9 in Walnut Creek, Calif.

Mochrie and Sherwood’s “Asking For Trouble” tour was planned to run until mid-October. Cancellations for the Asking For Trouble tour have not yet been announced.

Born in Scotland in 1957, Mochrie moved to Canada with his family when he was seven years old. The actor and comedian rose to prominence in the ’90s as a cast member of both the U.K. and American versions of the improv sketch comedy show “Whose Line Is It Anyway?”

Retinal detachment occurs when the thin layer of tissue at the back of the eye is pulled away from its normal position, separating the retina from blood vessels that provide oxygen to the eye. If left untreated, a detached retina can result in permanent vision loss.

According to the American Academy of Ophthalmology, it can take four to six weeks for vision to improve after surgery. Those recovering from surgery need wear an eye patch and be less active for several weeks.

“Colin is incredibly grateful for your support and well wishes,” the Instagram note said. “He looks forward to being back on stage and sharing many more laughs with all of you in the near future.”