Prevention is the next frontier in ROP research. It is highly plausible that β-blockers could be effective in preventing ROP. Pharmacokinetic studies indicate that topical betaxolol hydrochloride shows good ocular penetration and reaches the posterior aspect of the eye in good concentrations. By studying the effects of topical betaxolol in infants with birth weight less than 1000 g, we will focus on infants particularly likely to develop ROP. However, any study of the effects of β-blocker therapy must address the fragility of the patients to be tested and possible systemic and ocular adverse effects. Nevertheless, if topical β-blockers prove to be effective in preventing some cases of ROP, this opens the door for a more individualized approach to prevention of the disease, eg, using β-adrenergic receptor polymorphisms to guide ROP management.