Preventive eye medicines

Antibiotics are used in cataract surgery to prevent eye infections (called endophthalmitis). Although these infections are very rare, they can be very serious. Injecting an antibiotic into the eye during surgery is one of several things your eye surgeon will do to prevent infection. This is called an intracameral antibiotic. Antibiotic eye drops after surgery are usually not necessary if you have an injection.

Another type of eye drop (anti-inflammatory eye drops) may be used to reduce the risk of serious inflammation or swelling in the eyes. If your eye surgeon wants you to use anti‑inflammatory eye drops, they will discuss this with you and explain how to use the eye drops. With any eye drops, follow the dosing instructions carefully and only use them as long as you need to, to avoid using more than necessary.

Evidence-based guidelines recommend use of intracameral antibiotics^4,36,65 for endophthalmitis prophylaxis in preference to topical pre- or postoperative antibiotic eye drops. Therapeutic Guidelines: Antibiotic recommend cefazolin intracamerally as a single dose at the end of surgery, and avoiding use of quinolones or vancomycin, which lack evidence⁶⁵; consider the risk of antibiotic resistance. Prophylactic use of topical antibiotic solutions or eye drops is not recommended, and there is little evidence to support their use.^4,65 If no commercially prepared intracameral formulation is available, antibiotic eye drops may be considered to avoid the risk of dilution errors and contamination. Seek advice in the case of patients with hypersensitivity to penicillin or cephalosporins.⁶⁵ If postoperative antibiotic eye drops are used, chloramphenicol 0.5% eye drops are recommended. Stipulate the duration (maximum seven days) to avoid overuse.⁶⁵

Consider postoperative anti-inflammatory eye drops (corticosteroid eye drops, with or without non-steroidal anti-inflammatory drugs) for patients at high risk of developing cystoid macular oedema after cataract surgery, such as patients with diabetic retinopathy or other high-risk ocular comorbidities.^4,36 Discuss the possible benefits and harms of these eye medicines with the patient. If they are used, provide clear instructions for their use, including duration of use.

Potential adverse effects include allergic reactions to antibiotics, increased intraocular pressure with corticosteroids and, rarely, epithelial damage with non-steroidal anti‑inflammatories.³⁶

Ensure that clinicians have access to current evidence-based guideline recommendations for intracameral antibiotics and other postoperative eye drops, such as Therapeutic Guidelines: Antibiotic. Develop processes to measure compliance with guidelines.⁶⁵ Intracameral use of cefazolin is off-label, and its addition to the formulary will need to be approved by the local Drugs and Therapeutics Committee under routine use of an off‑label medicine.