Abstract 1223 Poster Session IV, Tuesday, 5/4 (poster 253)

OBJECTIVE: Vasoproliferation is a critical process in the development of Retinopathy of Prematurity (ROP). In kittens the progression of oxygen induced retinopathy can be reduced by oxygen supplementation (Phelps Pediatr Res 24:106,1988). In preterm infants, supplemental oxygen given to improve weight gain decreased the rate of threshold ROP (Gaynon et al. J Perinatol 17:434,1977). Our investigation was designed to study prospectively the effectiveness of supplemental oxyge therapy in ameliorating proliferation of ROP.

DESIGN: All 286 surviving preterm infants with gestational age below 32 weeks (23 to 31 weeks) born in the Perinatal Center of Heidelberg between 1995 to 1997 were studied prospectively. Retina was examined weekly, beginning at 4 to 5 weeks of age. Arterial oxygen saturation (SaO2) was continuously measured by pulse oxymetry. Target levels of SaO2 were 96% to 98% for ROP stage 2 and 98% to 100% for ROP stage 3. The respective target levels of arterial oxygen pressure were 70 to 90 mmHg and 80 to 100 mmHg. Arterial oxygen pressure was determined sufficiently often to ensure that the values did not exceed the upper targets. Supplemental oxygen was discontinued when vascularization had proceeded to to zone III. A historical control group of 250 infants (gestational age 24 to 31 weeks) was born between 1992 and 1994. Ophthalmologic examination was comparable in the two groups, but the infants of the control group did not receive supplemental oxygen for ROP. The study was approved by the Ethics Committee of the Hospital Center Heidelberg and informed consent was obtained from all parents.

RESULTS: 27 of the 286 treated preterm infants reached stage 3 ROP (9.4%) and 5 (1.7%) reached threshold ROP (control group 11.6% and 5.2%, respectively). All infants with threshold ROP were treated using laser photocoagulation. None of the infants in the treatment group and 1 of the 13 control infants with threshold ROP developed stage 4 ROP or higher in spite of laser photocoagulation.

CONCLUSION: Supplemental oxygen for stage 2 ROP does not appear to prevent progression to stage 3. However, supplemental oxygen may decrease the progression of ROP to threshold disease.