Sir,

We concur with Kontos et al,1 stating that screening for retinopathy of prematurity (ROP) in extremely premature infants can be postponed. Further, and as indicated by the authors, we believe that a change in guidelines should preferably be on the basis of studies of the natural course of ROP in the population per se.

In Sweden, a national study of extremely preterm infants, born with a gestational age (GA) of <27 weeks during the years 2004–2007, showed that no infant developed ROP stage 3 before 31 weeks postmenstrual age (PMA) and no infant was treated before 32 weeks PMA.2 On the basis of this study, and in alignment with American guidelines, the first ROP examination in infants below a GA of 27 weeks was postponed to PMA 31 weeks in Sweden, 2010.

Guidelines for ROP screening should continuously be evaluated and modified. In Sweden, this is carried out with the help of SWEDROP, a national register for ROP with a coverage of 95% of all children screened in the country. Repeated studies have revealed that no infant during the years 2008–2012 has been treated for ROP before 32 weeks PMA.3, 4, 5 Hence, our guidelines suggesting the start of examination in very premature infants at 31 weeks PMA, still seem safe in our country. Also, as stated by Kontos et al,1 this saves many tiny babies from stressful examinations and also several ophthalmologists from unnecessary work.