I read with great interest the article by Isenberg et al.¹ The authors deserve to be commended for their pioneering interest in childhood blindness. There are certain points that I would like to clarify and supplement with regard to their study.

(1) The authors have mentioned that only babies born by a vaginal delivery were studied, since the eyes of babies delivered by caesarean section were previously proved to be nearly always sterile. This would result in a gross underestimation of the incidence of ophthalmia neonatorum in this study, for the following reason.

By convention, ophthalmia neonatorum is defined as conjunctivitis arising within 1 month after birth. Hence, some of these conjunctival infections could originate from sources other than the maternal vaginal and cervical flora. In fact, some cases of ophthalmia neonatorum, especially those caused by Staphylococcus aureus, could have originated at home, as previously reported by the authors themselves. In the same study, no significant difference …