Endophthalmitis, a feared complication of cataract surgery, is a severe inflammation of the structures inside the eye more often caused by infection. Although rare, it has the potential to cause blindness. To avoid the emergence of endophthalmitis, doctors usually use different antibiotics. Previous studies looked at the efficacy of antibiotic administration before surgery to assess their effectiveness. A Cochrane Review – one of the most well known evidence-based study reviewer organisation – found that usage of antibiotics should be recommended before cataract surgery.
Nevertheless, the timing of antibiotic administration is not well established. Now, a recent study published in the Journal of Cataract and Refractive Surgery gives a more definitive answer. A team of researchers lead by Dr. Martin Nentwich compared the effect of applying a solution of neomycin/polymyxin-B eye drops (antibiotics), 1 day and 1 hour before surgery, two common prevention protocols, in addition to standard disinfection with povidone-iodine.
The results showed that aerobic and microaerophilic conjunctival bacteria were significantly reduced in both groups, but the same could not be told for anaerobic bacteria. Moreover, both schedules (1 hour or 1 day before surgery) had equal efficacy, as measured by cultures of eye swabs collected at four time-points: without antibiotics, after antibiotic eye drop application, after povidone-iodine disinfection, and at the end of surgery. Nonetheless, the greatest bacterial reduction was achieved by the usage of povidone-iodine. In the end, no patients developed endophthalmitis after surgery or had any allergic side effects.
Until now, most ophthalmologists would counsel patients to do an antibiotic preparation either 1 day or 3 days before surgery. These regimens are sometimes difficult to cope with, especially for the often old population of patients undergoing cataract surgery. The eye drops are usually applied 4 times during the day before surgery which can be tedious and represent an additional cost both for patient and healthcare systems. This study helps patients without compromising the prevention of endophthalmitis as the drops can now be applied by the nurse while preparing the patient 1 hour before surgery thus increasing patients’ comfort.