Shares in Glaukos (NYSE:GKOS) have fallen today after the ophthalmic medical tech company posted first quarter earnings that saw profits swing to losses, despite topping The Street’s expectations.

The San Clemente, Calif.-based company posted losses of $2.7 million, or 8¢ per share, on sales of $40.1 million for the three months ended March 31, seeing an over 400% swing into red on the bottom-line while sales grew 11.8% compared with the same period during the previous year.

Losses per share were ahead of the 11¢ consensus on Wall Street, where analysts expected too see sales of $37.6 million for the quarter, which the company topped.

“Our first quarter 2018 results reflect a strong start to the year as we continue to expand globally. We remain focused on strengthening our beachhead position in the combination-cataract segment while advancing our comprehensive pipeline of next-generation surgical devices and sustained pharmaceutical therapies for standalone glaucoma procedures,” prez & CEO Thomas Burns said in a press release.

Glaukos reaffirmed its 2018 net sales guidance for the year, expecting to post between $160 million and $165 million.

Shares in Glaukos have dropped 5% today, at $33.24 as of 11:15 a.m. EDT.