Sir,

We read with interest the editorial response to our article. We wish to address some of the comments and also discuss evidence to support local anaesthesia combined with sedation as a safe and effective alternative in the management of preterm infants requiring treatment.

Our survey demonstrates a shift away from the use of topical anaesthesia alone (0%) compared to 23% in 1993.1 Practice may have been influenced by Haigh et al2, who found that the incidence of cardio-respiratory complications increased with the use of topical anaesthetic alone. However, they also demonstrated that the combination of sedation and analgesia was comparable, and at certain time points favourable, to general anaesthesia. In addition, in this study, all babies who were treated with cryotherapy, now largely superseded by laser. As Allegaert et al3 discuss in their correspondence to our article, the overall treatment insult is less and the ocular and systemic recovery is quicker, following laser treatment than cryotherapy.

The editorial states that neonates should be electively intubated and ventilated before laser treatment. The trend to treat infants, earlier coupled with advances in neonatology, presents us with an increasing cohort of vulnerable premature infants with severe disease who require treatment at younger ages. In those infants, general anaesthesia is associated with higher systemic complications and it may become difficult to wean off ventilation, particularly, if repeated treatment is required.4 The logistical issues that surround the organisation of general anaesthetic treatment including intra- or inter-hospital transfer, theatre time, coordination of neonatal anaesthetic support, and surgeon availability make treatment difficult to perform within the recommended 48-h time frame. Safe alternatives to general anaesthesia must therefore be considered.

We have audited the safety and efficacy of sub-Tenon's local anaesthesia combined with sedation using oral chloral hydrate. The mean cardio-respiratory index was 1.13 comparing favourably to the standards published. In all cases, full laser treatment was perfomed.5

The ‘gold’ standard in our unit and many others in the United Kingdom has evolved such that reintubation and ventilation have been rendered obsolete in the laser treatment of retinopathy of prematurity.