Ekstrem Prematüre Bebeklerde Tip-1 Prematüre Retinopatisi İnsidansı

1. 1Baskent Üniversitesi Tip Fakültesi, Göz Hastaliklari Anabilim Dali, Ankara, Türkiye
2. 2Baskent University Faculty Of Medicine, Department Of Pediatrics, Division Of Neonatology, Ankara, Turkey
3. 3Baskent University Faculty Of Medicine, Department Of Ophthalmology, Ankara, Turkey

Sorumlu Yazar: Retinopathy of prematurity is caused by abnormal postnatal retinal development. Low serum IGF-1 levels and poor postnatal weight gain are associated with the development of severe ROP in clinical and animal studies.16-19 The WINROP algorithm uses both factors to identify infants who are at high risk for developing severe ROP and is able to identify all children (100% sensitivity) who were diagnosed with severe ROP.16 In our study, we analyzed SGA and AGA groups of premature infants. In our cohort, we retrospectively investigated the incidence of any-stage ROP, type 1ROP and PMA at type 1 ROP in SGA-(group A) and AGA (group B) infants. Variations in ROP incidence have been previously reported.19 GA of our study groups differed between 24-34 weeks. The incidence of any-stage ROP for comparable GA differed between 46.2% and 100%.18,20-24 In the ETROP study, the incidence of any-stage ROP in infants with GA In group A, the incidence for type 1 ROP of 17.6% was comparable with the results of Filho et al. of 14%, which are higher than Teed et al.’s results of 9% but lower than the results of Kumar et al. with 28.2%.21,22,26,27 In group B, the incidence of type 1 ROP was 15.3% and was similar to the results reported by Kumar et al. (14.4%) but lower than the results reported by Isaza et al. or Teed et al. (23% vs. 24.4%).21,22,26 Results after using WINROP algorithm - severe ROP developed in 8.8%, with requiring treatment in 4.1%. In the WINROP cohort, the median GA of the infants at birth was 25 weeks (range, 23-30 weeks), and the median BW was 770 g (range, 450-850 g).20 In our study, we also used the screening guidelines as in WINROP group.6 Additionally, due to the fact that findings suggest that larger, more mature infants are developing severe ROP in countries with low/moderate levels of development compared with highly developed countries, we included infants ≤ 34 estimated gestational weeks in our screening for ROP.9 In our cohort, the range for BW in group A was 495-1010 g and for GA - 24-34 weeks. In group B, the range for BW was 500-2250g and for GA - 24-34 weeks. In our cohort, we used ETROP criteria for treatment and there was no difference in the timing of laser treatment. The earliest diagnosis of type 1 ROP was 31 weeks PMA in Group A (BW: 495 g; GA 26 weeks), the latest diagnosis of type 1 ROP was 43 weeks PMA (BW: 940 g, GA 31 weeks) also in group A. In groups A and B, type 1 ROP incidence was 17.6% vs. 15.3% with no difference between the groups. An incidence of type 1 ROP with 17.6% vs. 15.3% in our cohort is much higher than the severe ROP incidence with 8.8% in the WINROP group. It has been well documented that babies born SGA have an increased risk of developing severe ROP and this is confirmed in our small series, with 17.6% of the SGA babies requiring treatment for ROP comparable with 18.2% of other studies.28-31 In our study, the PMA for the onset of type 1 ROP was in SGA infants in mean 35.3±3.6 (min-max 31-43) weeks and in AGA-infants in 33.8±2.6 (min-max 32-42) weeks. There was no significant difference between groups A and B concerning PMA at type 1 onset (p=0.23). The overall mean PMA at type 1 ROP onset of 35.3 vs. 33.8 weeks in mean found in this study is similar to median PMA prethreshold ROP onset of 36.1 weeks in the ETROP study. The mean PMA for onset of type 1 ROP at32 weeks PMA in SGA infants was reported by Misra et al.31 Reynolds et al. reported the mean PMA of onset of type 1 ROP in all patients and in each individual study group within the window between 30.9-45 weeks for the development of prethreshold or worse ROP.5 In developed countries, termination of acute phase ROP screening can occur when the risk for developing serious ROP has passed. As already stated, prethreshold ROP precedes the development of threshold ROP, and 99% of prethreshold ROP has developed by 45 weeks’ PMA for the nursery populations studied herein. Thus, acute phase ROP screening can conclude by at least 45 weeks’ PMA as long as prethreshold or worse acute ROP is not present. This value is an extreme and is based only on age rather than on retinal findings. It is far more likely that the child’s ROP will progress to serious ROP at an earlier age or that retinal maturity or ROP regression will occur earlier than 45 weeks’ PMA. Typically, ROP regression begins by 39 weeks’ PMA, and 90% of cases show involution by 44 weeks’ PMA.32,33 In our study, the window for PMA of onset of type 1 ROP for SGA and AGA groups was between 31-43 weeks. According to expectation, the earliest PMA of 31 weeks (BW: 495 g; GA: 26 weeks) was in group A of SGA infants, but unexpected, the latest PMA of 43 weeks also in SGA infant collective. Furthermore, in group B infants, the latest PMA of onset of type 1 ROP was 42 weeks of premature infant with GA of 33 and BW of 1410 g. These results indicate, that in developing countries, infants of higher GA and BW may also be affected from severe ROP requiring treatment.9-12,34 In conclusion, concerning incidence of any-stage ROP, we can say that in the present study population, the incidence of any-stage ROP is in SGA-group as well as in AGA group, in children >30 weeks, remarkably higher than in western countries. In our cohort, the results suggest that in SGA- and AGA-infant groups, more larger and mature infants may develop type 1 ROP with no difference between the groups and require treatment. Screening protocols covering more mature infants can be designed especially for countries with low/moderate levels of development after extended analyses. Address for Correspondence/Yazisma Adresi: Imren Akkoyun MD, Baskent University Faculty of Medicine, Department of Ophthalmology, Ankara, Turkey Phone: +90 312 215 03 49 E-mail: retina95akk@yahoo.de Received/Gelifl Tarihi: 05.03.2013 Accepted/Kabul Tarihi: 30.04.2013