Retinopathy of prematurity: An optimum screening strategy

Letters to the Editor RETINOPATHY OF PREMATURITY: AN OPTIMUM SCREENING STRATEGY To the Editor: Shu Fen Ho and coauthors1 suggest that birth weight criteria ⬍1251 g and gestational age ⬍30 weeks can be “safely and efficiently used to screen infants without missing a diagnosis of sight-threatening retinopathy of prematurity (ROP).”1 They present data from 187 infants screened over 8 years. Their retrospective review of this small series found no infant ⬎1250 g or ⬎29 weeks who reached threshold ROP. According to the authors, when the new criteria for screening were applied, 82/187 infants would not have been examined, resulting in 44% fewer infants who would have been screened. Savings in time, money, and stress to the infants can be assumed. There are two points about this recommendation and these results that one should consider. First, the choice of screening infants ⬍1251 g that was used in many large multicenter trials was a design feature of those studies. It was not intended to be directed toward screening guidelines. Second, Shu Fen Ho and coauthors note that, of the 82 infants that would not have to be examined under their guidelines, none had sight-threatening ROP. N ⫽ 82 is a small number and the 95% confidence limits for sightthreatening ROP are 0 to 0.04. An upper limit as high as 4% indicates a need for caution before accepting the recommendation. Our experience screening an average of 285 infants/ year with birth weights ⬍1501 g or gestational age ⬍28 weeks in two level III neonatal intensive care units from 1988 to 2005 leads us to urge continued support for the AAP/AAO Guidelines for ROP Screening (2001). In that period of time, four infants with birth weights ⬎1250 g and gestational ages ⱖ30 weeks developed significant ROP, which required treatment. All had stage 3⫹ disease: one in zone 1, and three in zone 2. They were detected in 1994, 1997, 2002, and 2005, respectively. One infant developed a unilateral retinal detachment soon after laser treatment. If we had been using the criteria advanced in Mr. Ho’s article, while we would have screened an average of 60 fewer infants per year (a reduction of 1080 over 18 years), we would have missed these four cases. They represent roughly 1 of every 270 larger infants. The CRYO-ROP study demonstrated that a certain percentage of children will go blind from ROP without treatment and that treatment reduces the risk of blindness. The ETROP study showed that outcomes can be improved with earlier treatment for high-risk prethreshold ROP infants. These studies do not give any information on the course of ROP in infants ⬎1250 g. If, however, we make an assumption that the knowledge gained from these

studies applies to larger birth weight babies, changing screening criteria to exclude larger infants will place some infants at unnecessary risk of blindness. The purpose of a screening protocol is to capture all positive instances of the problem under surveillance, while minimizing the number of negative exams. The balance of cost versus benefit to society is one that must be weighed by all participants. Given the current medical-legal climate, and the liability faced by hospitals, neonatologists, and pediatricians for ROP screening, there seems to be no reason to liberalize ROP screening guidelines. Don L. Bremer, MDa Robert J. Hardy, MDb Richard E. McClead, MDc Mary Lou McGregor, MDa Gary L. Rogers, MDa a Department of Ophthalmology, Columbus Children’s Hospital, Columbus, Ohio; b School of Public Health, Coordinating Center for Clinical Trials, UT Houston Health Science Center, Houston, Texas; and c Department of Pediatrics, The Ohio State University, Columbus, Ohio References 1. Ho SF, Mathew MRK,Wykes W, Lavy T, Marshall T. Retinopathy of prematurity: An optimum screening strategy. J AAPOS 2005;9:584-8. doi:10.1016/j.jaapos.2006.11.010

REPLY To the Editor: We thank Dr. Bremer and coauthors for their interest in our article “Retinopathy of prematurity: an optimum screening strategy.”1 We agree that we would not alter a national screening policy (in our case for the United Kingdom) on the basis of this relatively small dataset alone. However, when our initial findings were presented at the Royal College of Ophthalmologists Annual Congress in the United Kingdom, we were encouraged to publish our data to add to the growing debate in the United Kingdom over revision of the guidelines by the College. We therefore published our data with that in mind. Dr. Bremer and coauthors’ response to our article is a further useful contribution to that debate. William Wykes, FRCOphth Department of Ophthalmology, Southern General Hospital, Glasgow, United Kingdom References

J AAPOS 2007;11:68-73. Copyright © 2007 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2007/$35.00 ⫹ 0 doi:10.1016/j.jaapos.2006.11.010

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1. Ho SF, Mathew MRK, Wykes W, Lavy T, Marshall T. Retinopathy of prematurity: An optimum screening strategy. J AAPOS 2005;9: 584-8. doi:10.1016/j.jaapos.2007.01.001

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