A intraocular lens used for cataract surgery.

Bausch + Lomb has announced plans to return its enVista intraocular lenses to the market, just weeks after a voluntary recall related to rising reports of adverse health effects.

The lenses, typically used during cataract surgery to replace a patient’s natural lens, were initially recalled in March over concerns surrounding the development of toxic anterior segment syndrome (TASS).

But Bausch + Lomb now says that it has identified the issue that led to the rising TASS cases. The company announced last week that it had traced the origin of the issue to raw material from a different vendor used in certain enVista lots.

The company determined that 90% of the reported TASS cases were connected to those lots.

“We voluntarily recalled these lenses because patient safety dictates every decision we make,” CEO Brent Saunders said in a statement. “We wouldn’t bring them back without full confidence in the enVista safety profile, which has been established over years and hundreds of thousands of implants.”

While the enVista products are set to return to use in the United States in the coming weeks, Bausch + Lomb said reentry in other countries will be determined “on a case-by-case basis in collaboration with health authorities.”

enVista Lenses Recalled Following Rising Complication Rates

Bausch + Lomb initially issued a voluntary recall for some of its enVista intraocular lenses in late March after reports of TASS after surgery spiked.

TASS is an inflammatory condition that can result after a toxic substance comes into contact with the eye. Symptoms, which include vision issues, can begin just hours after the substance is introduced.

According to data released by Bausch + Lomb, the rate of TASS among enVista lenses had been less than 0.001%. That number unexpectedly jumped to 0.25%, with more than 100 cases reported between October and January.

Bausch + Lomb then issued its recall for several different types of enVista intraocular lenses. At the time of the recall, the company said all reported TASS cases had responded to treatment and that none had required removal of the lens.

Lawyers are currently investigating cases for patients who may have been impacted.

Bausch + Lomb Had Previously Settled Eye Fungus Claims

Bausch + Lomb faced litigation over recalled products in the past. By 2009, the company had paid out hundreds of millions of dollars in settlements following a recall of its ReNu with MoistureLoc lens cleaner product.

Hundreds of people claimed that they developed a serious fungal eye infection after using the solution.

According to ABC News, seven people needed to have an eye removed as a result of the infection, with dozens more requiring corneal transplants.