Sir,

We report a case of chemical injury to an eye shortly following cataract extraction due to inadvertent instillation of flea drops.

At 3 days following uneventful cataract surgery, a lady of 76 years presented to the emergency eye clinic with a painful left eye and visual acuity of 6/60 (day one 6/12). Questioning revealed that her eye had become increasingly painful following repeated instillation of Good Girl Flea Repellent drops by her daughter instead of the G Maxitrol supplied by the hospital. Her daughter, who had not been wearing her reading glasses, was unable to read the labels on the bottles which were of similar appearance, and had confused them (Figure 1). The flea drops are a herbal formula containing a number of essential oils including eucalyptus, citronella, bitrex, and sesame oil.

Figure 1
figure 1

The drop bottles are of similar size and shape.

The eye was immediately irrigated with 700 ml of saline (pH=7). Examination revealed marked conjunctival injection, an inferior conjunctival epithelial defect, and a large subtotal epithelial corneal defect with Descemet's folds (Figure 2). Otherwise examination was unremarkable.

Figure 2
figure 2

Corneal appearance on admission.

She was treated with topical 0.5% prednisolone and chloramphenicol 6 × daily and cyclopentolate 1% t.d.s. After 4 days, the epithelial defect had healed and visual acuity had improved to 6/18. By 3 weeks, all injury signs had resolved.

While between 57 and 90% of patients report physical difficulties with drop administration,1, 2 40% also have difficulty with reading the labels of their eye drop.1 Many patients have their postoperative drops applied by a friend/relative and a large number of these carers also experience similar difficulties with drop administration.1 Of those instilling their own drops, 66% reported that their expectations of how they would manage differed from their actual experience.3

This case highlights the importance of ensuring that both the patient and the carer understand the postoperative drop regime and can correctly identify eye drop bottles. In order to minimise the risk of confusion, we suggest that patients should be warned that not all eye-drop style bottles contain eye drops, and that any other bottle of a similar size and shape to their own medication, should be removed or stored elsewhere to prevent the risk of inadvertent administration. In addition, identification of a particular eye drop may be encouraged using coloured bottle caps in order to furthermore reduce the risk of confusion. It goes without saying that we should all read the label on the bottle – if we still can!