Overtreatment with topical medications may spur toxic corneal ulcer development

Eur J Ophthalmol. 2009;19(6):916-922.

Excessive treatment with topical ophthalmic preparations may lead to the development of corneal toxic ulcers, according to a study.

"Toxic corneal ulcer is a frequent disease that can potentially lead to permanent visual impairment," the study authors said. "A high-dose regimen is the major risk factor for corneal toxic ulcer development and poor visual outcomes."

The retrospective study included 226 patients with corneal ulcers. Investigators statistically evaluated the relationship between clinical severity and healing time, corneal transparency and visual acuity. They also studied the number and categories of topical drugs used, number of daily instillations and duration of treatment.

Corneal ulcers were diagnosed in 21 patients (9%). The cornea immediately healed in all patients in 2 to 21 days after cessation of topical treatment. Longer healing time correlated with a higher number of topical drugs (P = .029), greater frequency of daily instillations (P = .042) and longer treatment time (P = .048). Data showed no appreciable correlation between drugs used and healing time.

After resolution of toxic corneal ulcers, investigators identified corneal scarring and diminished visual function in 16 of 21 patients. Severity of corneal haze correlated with number of drugs used (P = .023), frequency of daily instillation (P = .031) and healing time (P = .008).