Potential Rare Danger of Presumably Benign Artificial Tears

Abstract

Of all the medications we prescribe and procedures we perform as ophthalmologists, artificial tears are generally considered the most benign. The effectiveness of artificial tears is often debated, but until recently, few ophthalmologists had concerns regarding their safety. However, the current outbreak of Verona Integron-mediated Metallo-ßlactamase (VIM) and Guiana-Extended Spectrum-ß-Lactamase (GES)-producing carbapenem-resistant (VIM-GES-CRPA), a rare strain of extensively drug-resistant Pseudomonas aeruginosa, associated with the use of carboxymethylcellulose sodium (Ezri-Care) multidose preservative-free artificial tears may be a wakeup call for the field. The company's website currently states, "Urgent: Discontinue Use of EzriCare Artificial Tears Lubricant Eye Drops (Carboxymethylcellulose Sodium, 10 mg in 1 mL) in ½ fl. oz (15mL) containers (NDC: 79503-0101-15)." 1 This outbreak is a harsh reminder that all eye drops, including artificial tears, are medications with potential adverse effects, most commonly ocular but potentially systemic.Morelli et al 2 present a single case report that is representative of this outbreak. The patient in this report presented with a Pseudomonas aeruginosa-positive corneal ulcer that was complicated by a serous choroidal detachment and led to light perception vision. Although this patient had a history of metastatic breast cancer, her primary risk factor was the use of several over-the-counter multiuse eye drops, including 1 that grew the same strain of P aeruginosa as her corneal culture. This strain of P aeruginosa has not been previously reported in the US, but is similar to a strain previously associated with an endophthalmitis outbreak in India thought to be due to contaminated trypan blue dye. 3 As of February 21, 2023, the US Centers for Disease Control and Prevention (CDC) 4 had reported on 58 patients in 13 states included in the current outbreak, one of whom died. Although the source of infection was a topical eye drop, multiple patients had positive cultures from nonocular sites, including 13 sputum swabs or bronchial washes, 25 rectal swabs, 9 urine cultures, and 2 blood cultures. 4 Preservatives used in topical ophthalmic drops, most commonly benzalkonium chloride, have been associated with ocular surface toxicity, especially in patients using multiple eye drops for extended periods of time. 5 Due to this association, many ophthalmologists, especially cornea specialists, often recommend use of preservative-free eye drops. Traditionally, preservative-free eye drops are dispensed in single-use vials, which ensures sterility but