Screening criteria for the detection of retinopathy of prematurity in patients in a neonatal intensive care unit

Étude épidémiologique de la rétinopathie du prématuré : les facteurs de risque au CHU de Tours

BACKGROUND

A prospective analysis of the incidence of retinopathy of prematurity (ROP) by documenting clinical perinatal characteristics of affected infants, in an attempt to describe risk factors for ROP.

MATERIALS AND METHODS

Between March 2002 and April 2004, 161 infants, with a gestational age under 31 weeks and/or a birth weight under 1500 g, were screened according to CRYO-ROP guidelines, using direct ophthalmoscopy with a Layden contact lens. Risk factors for ROP were analyzed with the Student and Fischer tests.

RESULTS

ROP developed in 15% of the cases studied, with one out of five at prethreshold or threshold levels of ROP. Gestational age at birth (p<0.0001), low birth weight (p<0.0001), the length of the infant's stay in the neonatal intensive care unit (p<0.0001), the duration of mechanical ventilation (p<0.0001), the duration of oxygen provided (p<0.0001), blood transfusions (p<0.0001), hyaline membrane disease (p=0.0257), and bronchodysplasia (p=0.0012) were significant risk factors for ROP.

CONCLUSION

Despite progress in neonatal intensive care, ROP persists and can be explained by greater and greater prematurity and earlier screening. Effective screening, done between 4 and 6 weeks of life, taking risk factors into account, can improve prognosis.

Are we screening too many babies for retinopathy of prematurity?

A retrospective, hospital-records-based study of neonates screened for retinopathy of prematurity (ROP) was undertaken to determine whether the inclusion criteria for screening could have been safely altered to reduce the numbers of babies screened whilst not missing any stage III disease. Babies from six neonatal intensive care units in Birmingham were screened by a single examiner. Between November 1989 and November 1995, 1611 babies were examined and 1429 of these fell within the inclusion criteria of current guidelines for ROP screening produced by the Royal College of Ophthalmologists and the British Association of Perinatal Medicine--any baby < or = 1500 g birthweight or < or = 31 weeks gestational age. Thirty-nine (39) babies developed stage III ROP of which 31 (2.2%) were from Birmingham. In addition 8 babies with stage III ROP were referred from elsewhere. All 39 babies with stage III ROP had a birthweight < or = 1250 g or a gestational age of < or = 29 weeks, but 2 fell outside one criterion, indicating the need for both to be used. Had these inclusion criteria been utilised during this period, then 30% fewer babies would have been examined (432 of 1429). The importance of using both birthweight and gestational age as inclusion criteria is discussed, and the dangers of altering the indications for national screening on the basis of one study population is emphasised.

Towards a universal approach for screening of retinopathy of prematurity (ROP)

To improve the cost-benefit ratio of our current screening program for retinopathy of prematurity (ROP), the records of 312 infants who had been screened for ROP were studied retrospectively. Using a safety-index containing three well known risk factors (birthweight, gestational age, oxygen use), infants were classified to be at high risk or low risk for the development of ROP. When all high risk infants would have been screened extensively from the 5th postnatal week onwards and all low risk infants would have been screened once at the 7th postnatal week, a 9.8% reduction of ophthalmological examinations would have been obtained at the expense of missing 2.9% of non vision threatening ROP.

Screening for retinopathy of prematurity after surfactant treatment

Surfactant administration in premature infants is supposed to induce rapid changes in tissue oxygenation. It might therefore modify the risk of developing retinopathy of prematurity (ROP). We have been using the so-called safety index [equation see text] to calculate the number of infants at low risk to develop ROP stage 3 or higher (SI > or = 1) after administration of two preparations of a surfactant. The study population consisted of 255 prematures of < or = 2000 g birth weight treated with surfactant for respiratory distress syndrome in Switzerland between 1991 and 1993. Of these infants, 29 received a natural surfactant (Curosurf), and 226 infants were treated with the synthetic surfactant Exosurf. Reduction of fraction inspired oxygen (FiO2) was significant within 3 and 6 h and was more pronounced in infants having received natural surfactant. An SI > or = 1 was calculated in 106 of the 226 infants (47%) treated with Exosurf. Only one of these infants developed ROP stage 3 in one eye (no ROP in the fellow eye) whereas 12 infants with ROP stages 3 or 4 had an SI < 1. Seven of the 29 infants treated with natural surfactant had an SI > or = 1; none of these infants developed ROP > stage 2. According to this survey, the risk of developing severe stages of ROP does not increase in low birth weight infants who have been treated with surfactant. Irrespective of a surfactant therapy, the calculation of the SI is useful for substantially reducing the number of prematures who need intensive ophthalmological follow up.

Screening for retinopathy of prematurity: are a lid speculum and scleral indentation necessary?

We wanted to investigate the value of using a lid speculum and scleral indentation in performing binocular indirect ophthalmoscopy (BIO) in neonates at risk of retinopathy of prematurity (ROP). We performed a prospective masked comparison of BIO examinations using either a lid speculum and scleral indentation (SI) or no scleral indentation (NSI), in our neonatal intensive care unit. We did 57 consecutive BIO examinations of infants weighing less than 1500 g and/or having a gestational age of less than 32 weeks. With NSI, zone I ROP was reliably seen in 53 of 57 examinations; the superior, nasal, and temporal aspects of zone II were seen in 45 of 57 examinations; inferior zone II, in 22 of 57 examinations; and zone III in 1 of 57 examinations. SI facilitated complete peripheral fundus examination in all cases but had to be abandoned in two infants due to acute changes in oxygen saturation levels. Five infants developed threshold disease, and in two of them details of the active ROP ridge were missed with NSI. The gentle use of an eyelid speculum and globe rotation allows rapid and relatively atraumatic assessment of the peripheral fundus, even in babies who are being ventilated. Although threshold ROP may be diagnosed by observation of posterior retinal vessel dilation and tortuosity ("plus" disease), accurate grading of ROP is likely to require SI. In the absence of clearly developed "plus" disease, borderline or prethreshold disease may occasionally be missed using BIO with NSI. SI is necessary to examine the inferior midperipheral retinal vasculature (zone II) and the far peripheral temporal retina (zone III) and is associated with few complications.(ABSTRACT TRUNCATED AT 250 WORDS)

A population based, prospective study of the development of ROP in prematurely born children in the Stockholm area of Sweden

A prospective population based study including 260 children with a birth weight of 1500 g or less was performed in the Stockholm county. The total incidence of retinopathy of prematurity (ROP) was 40.4%, while severe ROP--that is, stage 3 or more, was seen in 20.0%. Cryotherapy was performed in 10.8%. Logistic regression analysis revealed independent association of both gestational age and birth weight with ROP. The association of gestational age and ROP was significantly stronger, indicating that the degree of immaturity of the eye is a main predictive factor for the development of ROP. The purpose of a general screening for ROP is to identify children requiring cryotherapy. Based on these results it seems appropriate to include children with a gestational age of 32 weeks or less in such a programme and a first examination at 5-6 weeks of postnatal age is suggested.

Retinopathy of prematurity--current diagnosis and management

Despite advances in ophthalmological care of premature infants, retinopathy of prematurity (ROP) remains a still unsolved problem for paediatricians as well as ophthalmologists. A survey of the current literature concerning drug therapy and surgical management as related to the different stages of ROP is given. The classification system for ROP according to the International Committee is presented as well as our screening policy in relation to the literature. The effectiveness in preventing severe cases of ROP and the toxicity of vitamin E supplementation in high-risk premature infants is still disputed and no recommendations can be given. Cryotherapy is recommended in symmetric cases of stage 3 + ROP. Nevertheless, quite a number of eyes still progress to more severe stages of ROP. Scleral buckling procedures and vitrectomy may lead to anatomical success in a few cases of retinal detachment, however, the visual outcome of such an operation is usually very poor despite reattachment of the central retina.

Screening for retinopathy of prematurity

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Natural history of retinopathy of prematurity: a prospective study

The natural history of retinopathy of prematurity (ROP) has been studied prospectively in 572 infants < or = 1,700 g birthweight using a protocol designed specifically to investigate the subtle features of this condition. Acute ROP developed in 50.9%. All ROP stages 1 and 2 underwent complete resolution and of the 27 (4.7%) infants with stage 3/4 disease, cicatricial sequelae developed in six. Incidence and severity increased with decreasing birthweight and gestational age. Onset was not confined to the temporal retina but exhibited a predilection to start first in the nasal retina of the most immature neonate. The vertical retinal regions were relatively spared. Retinal arteriolar tortuosity developed around three months postnatally and was related to ROP severity but not its presence. The age at onset and rate of progression of retinopathy were largely determined by the stage of development but were also modified by systemic and local factors. The relevance of these findings to ROP screening is discussed.

Follow up retrospective study of compliance with a standard of care for retinopathy of prematurity in one neonatal intensive care unit

A retrospective chart review was conducted to determine the impact of recently instituted guidelines on compliance with the standard of care for retinopathy of prematurity (ROP) in the Newborn Intensive Care Unit at the University of Utah Medical Center. In a previous study, it was found that infants eligible for participation in a National Institutes of Health-funded study of ROP were routinely receiving screening eye examinations, whereas infants who qualified for ROP screening according to the standard of care, but not eligible for the study, were seen infrequently. Consequently, a plan to improve the compliance with the standard of care for all infants who fit the standard criteria was implemented. The comparison revealed significant improvement in compliance rates. In one subgrouping of infants, compliance rose from three of 16 (18.75%) infants screened for ROP according to the standard of care, to nine of 11 (82%) infants screened for ROP according to the revised standard. This increase in compliance appears to be due to adherence to guidelines recommended in an earlier study, which included increasing staff awareness of the standard of care, designating a person to schedule and track infants who fit the screening criteria, and including the need for ROP screening on the admission and discharge summary.