Povidone-iodine prophylaxis of ophthalmia neonatorum.

O phthalmologists practising in the developed world at the beginning of the 21st century may be surprised to learn that visual loss from ophthalmia neonatorum was once a major public health problem. In England in the mid-1800s, there was a hospital devoted solely to the lavage of infants with gonococcal ophthalmia. Fortunately, the work of Crede, who developed prophylaxis with 2% silver nitrate in 1881, nearly eliminated visual loss from this disease in the West. Unfortunately, conjunctivitis in the first month of life remains a common threat to vision in much of the developing world. In areas without prophylaxis, the incidence of ophthalmia is as high as 23%. In Africa, between 1000 and 4000 are blinded each year. A variety of topical agents have been used for prophylaxis in the neonatal period. In the West, erythromycin and tetracycline have often been favoured because of their effectiveness against chlamydial infection. In the developing world, the expense of these agents, and of silver nitrate, can preclude their availability in many areas. Isenberg et al have previously demonstrated that 2.5% povidone-iodine, which can be reconstituted locally from powder at minimal cost, is an appropriate alternative. Ophthalmologists may be more familiar with this agent from its use in surgical scrubs and preps. It is well tolerated and has a broader spectrum than any other agent, and there has been no resistance demonstrated to date. Because it temporarily stains the conjunctiva brown, effective administration is easy to confirm. More important, povidone is even more effective than the more expensive alternatives. In an earlier study, Isenberg et al found the incidence of ophthalmia was reduced by 44% by povidone-iodine, compared to 34% by erythromycin and 24% by silver nitrate. It was more effective against chlamydia, similarly effective against gonococcus, and even effective against herpes virus and human immunodeficiency virus. In this issue of BJO (p 1449), they study the effectiveness of a second instillation of povidone-iodine during the first postnatal day. They conclude that the additional treatment, which increased eyelid oedema at the time of discharge, was of no benefit. Although this is essentially a negative outcome, its implication is that a single drop, obviously simpler to administer, is maximally effective. It is important to recognise that defining ophthalmia neonatorum in a large group of African newborns is problematic. More than 18% were returned by their parents for evaluation of ocular inflammation, yet only 8–10% were culture positive. Many may have had chemical conjunctivitis, and some with staphylococcal infection may have had infections acquired postnatally at home. Some may have had viral infections, or clinically insignificant inflammation. Perhaps the most important finding is that, among more than 700 infants studied, there was not a single case of gonococcus following either one or two drop prophylaxis with povidoneiodine. Improved prenatal care may be partially responsible for decreasing the incidence of this potentially blinding infection. The authors are to be congratulated for their contribution to the fight against childhood blindness. We encourage them to continue their research in this field.