Botox may treat 'threads' in eyes

Botox injections may help treat a rare eye condition in which threadlike strands appear in patients' eyes, a new study says.

The study involved 33 patients with a condition called filamentary keratitis, in which dead cells on the eye's surface link together to form filaments, causing patients to feel as though they have something stuck in their eye.

After an average of two years of getting Botox injections administered into a muscle in the eyelid, 29 patients (88 percent) saw improvements in their condition, the researchers said.

All patients in the study had previously tried other treatments, including attempts to physically remove the strands or medications to lower eye inflammation, but they hadn't worked.

While no significant side effects were observed, one drawback to the treatment was many patients required several injections (four, on average) to see a therapeutic effect, the researchers said. Patients were evaluated every six to 12 weeks, and additional injections were given if needed.

The exact cause of filamentary keratitis is not known, but it most often accompanies the condition called dry eye, the researchers said. It is more common among women and the elderly.

Because the filaments adhere to the eyes' surfaces, blinking may exacerbate the condition, causing pain, chronic inflammation and tearing of the eye's surface, the researchers said. This leads to a vicious cycle in which the patient reflexively blinks in response to an object in the eye, only to make the condition worse.

"Breaking this vicious cycle is important for managing challenging cases of filamentary keratitis," the researchers, from the Baylor College of Medicine in Houston, wrote in the April issue of the journal Archives of Ophthalmology.

Botox may aid in treatment of the condition because it reduces blinking frequency and the pressure of the eyelid on the eye's surface, the researchers said.

Larger trials of the therapy are needed to verify the results, the researchers said.