The Optimal Time of First Ophthalmic Examination for Retinopathy of Prematurity Screening in Extremely Low Birth Weight Infants

PURPOSE: To determine the optimal time of first ophthalmic examination for early detection and proper treatment of retinopathy of prematurity (ROP) based on the chronological age or the postconceptional age. METHODS: Medical records of all extremely low birth weight infants(or=27 weeks). And we evaluated the time of first examination, the time of onset ROP, the time of peak stage and the time of threshold disease requiring cryotherapy or laser therapy. RESULTS: Among all 80 infant patients, 72 (90%) were found to have ROP. And 23 (29%) were treated for threshold disease with cryotherapy or laser therpy. There was no significant difference in incidence of ROP between two groups, and also no serious case of ROP was found. At time of first ophthalmic examination, onset ROP and threshold disease there was no difference of chronological age between two groups, but postconceptional age of Group II was considerably higher than Group I (P<0.05). CONCLUSION: ELBW infants less than 1,000 g should receive initial ROP screening using the chronological age guideline of 4 to 6 weeks rather than 31- to 33- week postconceptional age guideline.

Incidence, Timing of Screening Examinations and Perinatal Risk Factors for Retinopathy of Prematurity in Very Low Birth Weight Infants / 대한주산의학회잡지

OBJECTIVE: This study was conducted to evaluate the incidence, the optimal timing of screening examinations for retinopathy of prematurity(ROP) and to analyze perinatal risk factors associated with cryotherapy or lasertherapy(CT/LT) in ROP. METHODS: Medical records of 130 very low birth weight(VLBW) infants who admitted to the NICU of Wonkwang University Hospital from July 1997 to June 2002 were reviewed retrospectively. We evaluated the incidence and severity of ROP by gestational age(GA) and birth weight(BW). And the comparisons of perinatal risk factors between ROP with and without CT/LT have been made. RESULTS: Incidence of ROP was 36.9% and mean GA and BW were 29.1+/-1.99 weeks, 1,153+/-209 gm in VLBW infants respectively. ROP Stage II or greater was 15.4% of VLBW infants, 41.7% of ROP infants, and 27.1% of ROP infants were treated with CT/LT. All infants with BW <750gm or GA <26 weeks were developed ROP with stage II or greater and treated with CT/LT. First detection of ROP was performed at chronologic age(CA) 3 weeks, postconceptional age(PCA) 30 weeks, and first identification of threshold ROP needed with CT/LT were at CA 5 weeks and PCA 33 weeks. The perinatal risk factors with CT/LT for ROP were significant in GA, BW, Apgar score at 1 and 5 minutes and number of blood transfusion. The mean time of spontaneous regression is 13.4+/-8.8 weeks in the mild ROP infants without CT/LT. CONCLUSION: The incidence of ROP is 36.9% and the optimal timing of screening for ROP should be selected by earlier time in 2 guidelines of at 5 weeks of CA and 33 weeks of PCA in VLBW infants. And the related risk factors with CT/LT for threshold ROP were GA, BW and Apgar score at 1 and 5 minutes and number of blood transfusions.

Screening Examination for Retinopathy of Prematurity with Dual Parameter Protocol

So far most screening protocols for retinopathy of prematurity (ROP)have used a single parameter such as chronological age or postconceptional age. We attempted to test a screening protocol for ROP using dual parameter, chronological age and postconceptional age, to determine whether it could reduce the number of screening examinations safely.We retrospectively reviewed medical records of 23 infants (43 eyes)who had undergone laser treatment for threshold ROP.Mean gestational age at birth was 28 weeks and mean birth weight was 1055 gms.The mean age at which the study infants reached threshold ROP was 10 weeks in chronological age and 38 weeks in postconceptional age.Screening examinations as early as chronological age of 7 weeks or postconceptional age of 35 weeks could detect all threshold ROP while reducing the number of unnecessary early examinations.

Screening for Retinopathy of Prematurity: Optimal Timing of First Examination

PURPOSE: Early detection and proper treatment of retinopathy of prematurity (ROP) is crucial. The postnatal age of 4-6 weeks has been considered the most optimal time to screen the high risk infants for ROP. However, ROP rarely appears even before this period of age and we experienced several cases ROP detected before 4 weeks of age at NICU of Kyungpook University Hospital. This study was conducted to evaluate the most optimal time of first ophthalmic examination for ROP screening. METHODS: A retrospective analysis of ROP screening records of 106 infants who admitted to the NICU of Kyungpook University Hospital from January 1996 to March 1999 was performed. Infants with a gestational age or =1,500 gm) and Group II (birth weight <1,500 gm). Ophthalmic examinations were commenced between 3 weeks and 6 weeks postnatal age and recorded using the International Classification of ROP. RESULTS: Out of 106 infants screened, 35 infants were found to have some degree of ROP in at least one eye on at least 1 occasion. Of 35 infants with ROP, 11 infants were screened before the postnatal age 4 weeks. Eight ROP, including one stage 3 ROP, were detected at this first ophthalmic examination. Review for the time of first detection of ROP by postconceptional age revealed that stage 3 ROP and threshold ROP did not develop before 34 weeks. Postnatally ROP developed and progressed earlier in Group I than in Group II. The time of onset and highest stage represented by postnatal age in Group I and II were 28+/-7 days, 57+/-19 days and 32+/-15 days, 69+/-26 days respectively. The time of onset and highest stage represented by postconceptional age in Group I and II were 35.4+/-2.3, 36.3+/-2.9 weeks and 36.0+/-1.6, 38.0+/-3.6 weeks respectively, revealed no significant difference between two groups. CONCLUSION: These data indicate that the time of onset and progression of ROP are correlated more closely with postconceptional age than with postnatal age. In other words, the postconceptional age is superior to postnatal age in determining when to initiate ROP examination. Our study suggests that screening infants at 34 weeks postconceptional age seems to reliable for early detection of severe ROP in larger, and more mature preterm infants.

Study of the Normal Value of Neonatal Blood Pressure according to Postconceptional Age / 대한주산의학회잡지

OBJECTIVE: Neonatal blood pressure is one of the vital signs used to assess the general health of a newborn infant. But, it is difficult to measure and varies according to the model of sphygmomanometer, the used method, the postconceptional age, birth weight, asphyxia, postnatal age and activity. We have assessed the rnean value of blood pressure(BP) according to postconceptional age. Variations caused by the postconceptional age, birth weight, body surface area(BSA), postnatal age, and sex were analyzed to determine the rnost important factor influencing the neonatal BP. METHODS: This study included 448 normal fullterm infants and healthy preterm infants born from Jan. 1995 to Aug. 1997 at Ewha Dongdaemoon and Mokdong Hospital. The BP was taken on day 1, 3, 5 with the oscillometric device(Dinamap 1846 critikon Inc.), for premature infants BP was followed up every week afterward. RESULTS: The neonatal BP was related to the postconceptional age(R=0.204, P<0.05), BSA(R =0.191, P<0.05), birth weight(R=0.183, P<0.05) and the postnatal age in fullterm infants(R=0.022, P<0.05) but not with the sex of the infant. The postconceptional age was the most significant variable among those influencing the BP. The normal value of the systolic and the diastolic BP was expressed as mean+/-2SD according to the postconceptional age, less than 28 weeks(n=27) systolic/diastolic pressure 50.4+/-23.1mmHg/26.2+/-12.8mmHg, 28-32weeks(n= 63) 60.1+/- 30.6mmHg/33.6+/-16.7mmHg, 32-36weeks(n = 139) 63.2+/- 20.4mmHg/37.7+/- 19.8 mmHg, 36- 40weeks(n=543) 65.6+/-18.5mmHg/38.6+/-17.3mmHg, more than 40weeks(n= 136) 67.7+/-16,9mmHg/39.3+/- 15.8mmHg. The increase in blood prssure with the postconceptional age was statistically significant. CONCLUSION: The normal range of neonatal BP, especially preterm infants, was presented, and it would be much valuable for the evaluation of BP in neonate if standardized by postconceptional age.