Shares of Staar Surgical Co. fell more than 20 percent Thursday after the maker of implantable contact lenses’ said its auditor may warn that it could run out of cash.

Monrovia-based Staar Surgical’s shares fell $1.38 to $4.50 in late trading on Thursday. The company has had difficulty gaining approval for its implantable contact lenses, and last week announced it had retained Morgan Stanley to explore a “range of strategic and financial alternatives.” Late Wednesday, Staar said it expects its auditor to include a “going concern” warning in its fourth quarter financial statement to the Securities and Exchange Commission.

“Management appears to be flailing, pursuing several conflicting strategies, said Harris Nesbitt analyst Joanne Wuensch, in a research note. “(W)e perceive the company has its back against the wall.”

Staar reported a fourth-quarter net loss of $4.4 million (21 cents per diluted share), compared with a loss of $3.5 million (19 cents) for the like period a year earlier. Revenues increased to $14 million from $12.8 million.

The company said it ended the quarter with $9.3 million in cash and was taking steps to reduce its annual cash-burn rate by $3 million, including reducing its use of outside consultants.

The company also may seek to raise $8 to $10 million through a private placement, Wuensch wrote.