[Use of cryotherapy in retinopathy of prematurity]

To present our experiences in cryotherapy for ROP.

From October 1991 to August 1995, transscleral cryotherapy was applied in 128 eyes of 70 babies with ROP. There were 34 girls and 36 boys with birth weight between 650 g and 1990 g and gestational age from 24 to 36 weeks. In above 90% of cases, ROP reached zone II and stage 3 with "plus" disease. In 84% of the eyes the extent of ROP was greater than 5 clock hours. Prethreshold severity was diagnosed in 7 and threshold in 110 eyes. In 11 eyes these categories could not be seventy determined. The chronologic age of infants at cryotherapy ranged from 8 to 22 weeks, mean 12 weeks. In all cases, cryotherapy was carried out under general anesthesia using a technique described in CRYO-ROP study. No serious complications during or after cryotherapy were observed.

Favorable structural outcome was found in 119 eyes of 70 treated infants. In 82 eyes of 46 infants, with at least 12-month follow-up examination, also functional outcome was evaluated, basing on the examination with the Teller Acuity Card Procedure; the results were favorable in 57% of the eyes. Structural and functional outcomes were in agreement in 47 of the 82 eyes and discordant in 33.

Our experience confirms the benefit of cryotherapy in the treatment of active ROP. In most cases cryotherapy should be applied in threshold ROP but in some cases especially in those with very rapid progression it should be done earlier. Because of the unpredictability of the natural course of ROP it is essential to use the scheme of ophthalmological examinations proposed by CRYO-ROP Study.