[Optimal (screening) time for detection of therapy-relevant stages of retinopathia praematurorum].

Screening tests for retinopathy of prematurity (ROP) focus on the detection of children in whom the progression of ROP may require therapy. The stages needing therapy must be detected reliably and in time. The frequency of examinations should be limited to the amount needed. We tried to determine whether or not there is a specific time point that can be recommended for the first examination. From 1987 to 1991 we examined 343 children who had been premature or term babies. Only among the 178 immature children with a birth weight of < or = 1500 g were severe stages of ROP found. Of 51 children, 1 child (2%) with a birth weight of between 1500 and 1250 g showed ROP stage 3; 4 children had ROP stage 2 (8%). The birth weight was under 1250 g in 127 prematures. Among these children, ROP progression to stage 2 was found in 119 (15%) and stage 3 in 9 (7%) cases. Independent of the highest stage, stage 2 first occurred 4-24 weeks postnatally, stage 3 between 4 and 20 weeks postnatally. If the highest stage did not occur before menstruation age, stage 2 did not occur before week 34 and stage 3 not before 35 weeks. In comparison to the postnatal age, calculation based on the postmenstrual age allows better individual comparability regarding the onset of ROP stages requiring therapy. Our results suggest that the first ophthalmological examination should be between 32 and 34 weeks after the start of menstruation. Unnecessary examinations of very immature children can be avoided without missing the development of ROP requiring therapy.