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Clinical Alert

February 12, 1988

Clinical Alert to Pediatric Ophthalmologists, Retinal Specialists, Neonatologists, and Directors of Neonatal Intensive Care Units

Dear Colleague:

This letter is to inform you of significant new findings from the clinical trial, Cryotherapy for Retinopathy of Prematurity (CRYO-ROP). This study is sponsored by the National Eye Institute, a component of the National Institutes of Health. One purpose of the trial is to determine the safety and efficacy of trans-scleral cryotherapy of the peripheral retina in certain low birth weight infants with retinopathy of prematurity.

Analysis of the accumulating early followup data in this trial has led to the preliminary finding that cryotherapy substantially reduces the number of unfavorable three-month retinal outcomes (defined as retinal detachment, retinal fold involving the macula, or retrolental tissue) in properly selected cases. All infants in the study will be followed to monitor long-term results, and no additional infants will be enrolled in the study.

The findings will be reported in detail in the April/May issues of the Archives of Ophthalmology and Pediatrics, with recommendations for timing of examinations and selection criteria for patients and eyes appropriate for cryotherapy. In the interim, it is suggested that any premature infants encountered in your practice who may be a candidate for this therapy be considered for referral to one of the study centers.

This announcement is being sent in advance of journal publication only to physicians likely to encounter infants with ROP. An official announcement and press conference will be held in conjunction with the publication of study results.


Carl Kupfer, M.D.
National Eye Institute

Earl A. Palmer, M.D.
CRYO-ROP Study Chairman
Department of Ophthalmology
Oregon Health Sciences University

Department of Health and Human Services NIH, the National Institutes of Health