Screening for retinopathy of prematurity: do former guidelines still apply?

Global Prevalence and Severity of Retinopathy of Prematurity over the Last Four Decades (1985-2021): A Systematic Review and Meta-Analysis

BACKGROUND

Retinopathy of prematurity (ROP) is a vasoproliferative disease of the retina that occurs in premature infants. The prevalence of ROP reported so far is inconsistent.

AIM

To conduct a systematic review to describe the trend of ROP prevalence between 1985 and 2021, and to determine the influence of countries' economic conditions on ROP prevalence.

METHODS

We searched PubMed, Embase, and Google Scholar for studies published between January 1985 and December 2021 using the following MeSH terms: "retinopathy of prematurity", "ROP", "incidence", and "prevalence". Two independent reviewers examined the articles to select studies that met the selection criteria and performed data extraction and study quality assessment. For the meta-analysis, the pooled prevalence was calculated using a random-effects model and R software.

RESULTS

Of 5,250 titles and abstracts, 139 original studies met the inclusion criteria; a total of 121,618 premature infants were included in these studies. The pooled prevalence of ROP was 31.9% (95% confidence interval [CI] 29.0-34.8) and that of severe ROP was 7.5% (6.5-8.7). In general, no significant differences in prevalence were found over the four decades; however, we found a higher prevalence in premature infants ≤28 weeks of gestational age. In addition, the highest ROP prevalence was found in lower-middle-income countries with high mortality rates. In contrast, the highest severe ROP prevalence was found in high-income countries.

CONCLUSION

ROP remains a common cause of morbidity in premature infants worldwide. Therefore, it seems necessary to maintain early identification strategies for patients at higher risk, particularly in low- and middle-income countries.

Cost and effects of risk factor guided screening strategies for retinopathy of prematurity for different treatment strategies

PURPOSE

To investigate the cost and effects of risk factor guided screening strategies for retinopathy of prematurity.

METHODS

Clinical data from the Netherlands Retinopathy of Prematurity study (NEDROP study) that included all infants screened for ROP and born in 2009 were used to assess the cost and effects of several screening strategies for ROP using different criteria: (1) gestational age (GA), (2) birthweight (BW), (3) combined GA-BW and (4) combined GA-BW and presence of risk factors. Two treatment strategies were evaluated: the infants actually treated in the NEDROP study (n = 17) and all infants detected with severe ROP (n = 29).

RESULTS

The most efficient screening strategy to include all infants treated for both treatment strategies is to screen all infants with a GA of 30 weeks or less and a BW of 1250 g or lower together with infants with a GA of 30-32 weeks and a BW of 1250-1500 g with at least one risk factor. The marginal cost ranged from €43 848 to € 226 914 per additional infant with improved vision.

CONCLUSION

The current Dutch guideline may be improved: the same effectiveness can be obtained for lower costs. Releasing the precondition that no infants with severe ROP might be missed will lead to lower costs, but this will also lead to a lower number of infants with improved visual acuity. The costs of detecting all infants with severe ROP seem acceptable for society when the QALY gain and savings from a societal perspective resulting from improved vision are taken into account.

Reduction in screening for retinopathy of prematurity through risk factor adjusted inclusion criteria

AIMS

To develop a new national screening guideline for retinopathy of prematurity (ROP).

METHODS

Included were infants of the 2009 prospective ROP inventory in The Netherlands with gestational age (GA) <32 weeks and/or birth weight (BW) <1500 g. Five models were studied, based on GA and BW in combination with no, one or a set of five risk factors for ROP. Risk factors were determined by logistic regression. In MEDLINE and EMBASE, additional risk factors were searched. A precondition was that no infants with severe ROP would be missed. Receiver operating characteristic curves or classical measures were used to determine diagnostic accuracy.

RESULTS

The model including all infants with severe ROP comprised screening of infants with GA <30 weeks and/or BW <1250 g and a selection of infants with GA 30-32 weeks and/or BW 1250-1500 g, with at least one of the following risk factors: artificial ventilation (AV), sepsis, necrotising enterocolitis (NEC), postnatal glucocorticoids or cardiotonica. This model would not detect 4.8% (95% CI 2.5% to 8.0%) of infants with mild ROP and would reduce infants eligible for screening by 29%.

CONCLUSIONS

In The Netherlands, screening may be safely reduced using a new guideline based on GA, BW, AV, sepsis, NEC, postnatal glucocorticoids and cardiotonica.

Complications affecting preterm neonates from 1991 to 2006: what have we gained?

AIM

In this study, we determined whether outcome of preterm neonates has improved over a period of 16 years.

STUDY DESIGN

Inborn neonates with a gestational age of 25.0-29.9 weeks were included. Patients with severe congenital malformations were excluded. Mortality and morbidity (chronic lung disease; CLD, intraventricular haemorrhage: IVH grade III or IV, cystic periventricular leukomalacia: cPVL, perforated necrotizing enterocolitis: NEC, severe retinopathy of prematurity needing surgery: ROP and cerebral palsy: CP) were compared in three periods (period 1: 1991-1996 n = 434; period 2: 1997-2001 n = 356; period 3: 2002-2006 n = 422).

RESULTS

Infant mortality decreased from 15.2% to 10.9%. CLD did not differ significantly between periods (14.1-14.8%). Perforated NEC decreased from 2.8% to 1.6%. IVH grade III and IV both remained at 5.7% in period 3, whereas cPVL decreased significantly from 4.5% to 1.6%. Cerebral palsy decreased from 5.8% to 3.5% in period 3. Two neonates in each period were in need of surgery for ROP.

CONCLUSION

Inborn preterm patients showed an improved survival and a significant reduction in cPVL and CP. Perforated NEC showed a trend to decrease. CLD and IVH grade III and IV remain a matter of concern.

Retinopathy of prematurity in extremely premature infants

INTRODUCTION

The incidence and severity of retinopathy of prematurity (ROP) in extremely premature infants have not been reported since publication of the Early Treatment of ROP study results. The survival rate of these infants continues to increase. We sought to determine the characteristics of ROP in a group of surviving infants <25 weeks estimated gestational age (EGA) at birth compared to a group 25 to 27 weeks EGA at birth.

METHODS

Retrospective review of infants born prior to 27 weeks EGA between January 2003 and July 2007 at a level-3 nursery at a regional academic medical center.

RESULTS

A total of 231 medical records were reviewed and found to have analyzable data. Of 79 infants <25 weeks EGA, 69 (87%) developed ROP, compared to 95 of 152 (62%) infants 25 to 27 weeks EGA. Type 1 ROP developed in 23% of infants in the <25 weeks EGA group, compared to 9% of infants in the 25 to 27 weeks EGA group. There was no difference in mean postmenstrual age when type 1 ROP was diagnosed. Lower birth weight predicted increased risk of type 1 ROP in the 25 to 27 weeks EGA group, but not in the <25 weeks EGA group.

CONCLUSIONS

Extremely premature infants are more likely to develop ROP and type 1 ROP, but the incidence may be lower than previously reported. Birth weight may not influence the incidence of type 1 ROP in this group of infants. Type 1 ROP does not develop at an earlier postmenstrual age in the extremely premature infant.

Retinopathy of prematurity: an optimum screening strategy

OBJECTIVE

We sought to find out whether birth weight of less than 1251 g or gestational age less than 30 weeks could provide a safe and efficient screening criteria of detecting treatable retinopathy of prematurity (ROP).

METHODS

Infants either with a birth weight less than 1500 g or gestational age less than 32 weeks were screened for ROP during an 8-year period.

RESULTS

In our study, the incidence of ROP was 36 of 187 (19.3%) infants. Although there was a slight increase in the number of infants screened over the years, the incidence of ROP of any stage remained stable. The maximum stage of ROP reached was stage 1 in 10 of 187 (5.3%), stage 2 in 8 of 187 (4.3%), and stage 3 in 18 of 187 (9.6%) infants. Among those with stage 3 disease, threshold ROP was present in 16 of 18 (88.9%). All infants with threshold ROP had a BW less than 1100 g and gestational age less than or equal to 28 weeks. Significantly fewer babies (105/187, or 56%) would have been examined had inclusion criteria of a birth weight of less than 1251 g and gestational age less than 30 weeks been applied. In addition, 31% (134/437) of screening examinations could have been avoided.

CONCLUSIONS

Our study suggests that a birth weight of less than 1251 g and gestational age less than 30 weeks can be safely and efficiently used to screen infants without missing a diagnosis of sight-threatening ROP in our catchment population.

[Comparison of the anatomical and functional outcome after laser or cryotherapy for retinopathy of prematurity (ROP)]

PURPOSE

To analyze and compare the anatomical and functional outcome following cryotherapy or laser therapy for ROP.

METHODS

Between April 1991 and February 2002, 127 eyes with ROP (65 patients) were treated after threshold ROP was reached. Ten additional eyes with zone I disease were treated with prethreshold. All patients were followed up until a stable retinal situation occurred.

RESULTS

An "unfavorable outcome," as described in the Cryo ROP study, occurred in 1 of 91 (1%) eyes with laser treatment and in 3 of 46 (6.5%) eyes with cryotherapy. Temporal dragging of vessels was noticed in 6 of 91 eyes (6.6%) with laser treatment vs 7 of 46 eyes (15.2%) with cryotherapy, respectively. Visual acuity > or =20/25 was achieved in 39.2% in eyes with laser therapy and in 17.6% with cryotherapy (p<0.05).

CONCLUSION

A strict screening protocol and treatment at onset of threshold disease results in an excellent anatomical and functional outcome. The results of laser therapy were superior over cryotherapy, indicating that laser treatment is the therapy of choice.

The effects of comfort care on the pain response in preterm infants undergoing screening for retinopathy of prematurity

OBJECTIVE

The aim of the study was to determine if pain and distress during the retinopathy of prematurity (ROP) screening examination could be ameliorated by providing comfort care.

STUDY DESIGN

This study was a prospective, randomized, controlled trial of 30 stable preterm infants who underwent initial ROP screening examinations. Fourteen study infants were swaddled, held, and given 24% sucrose solution during the examination. Sixteen controls were examined while lying in their cribs. Vital signs (i.e., pulse rate, respiratory rate, and oxygen saturation), crying time, and time for the vital signs to return to baseline values were recorded at different times during the examination.

RESULTS

The vital signs did not vary significantly between the two groups. The participants in the control group had a trend of longer crying time, but this trend did not reach a level of statistical significance. In addition, The time required for the vital signs to return to their baseline values did not vary significantly.

CONCLUSION

ROP screening is very distressful for preterm infants. The routine use of comfort care to reduce pain during the examination could not be supported by this study.

Retinopathy of prematurity--risk factors

OBJECTIVE

Improved survival of low birth weight, premature babies have increased the incidence of retinopathy of prematurity. This hospital-based, prospective, study was undertaken to determine its incidence and risk factors in our neonatal unit.

METHODS

Neonates with gestational age < or = 35 weeks and/or birth weight < or = 1500 gm born over a one-year period were examined by indirect ophthalmoscopy between 2 to 4 weeks after birth, and followed up till retinal vascularisation was complete. Maternal and neonatal risk factors were noted and data analyzed by statistical package SPSS-10.0.

RESULTS

Sixty babies were thus examined. The incidence of retinopathy was 21.7% in the cohort, 33.3% in babies < or = 32 weeks gestation and 36.4% in babies weighing < or = 1250 gm. Oxygen (p=0.01), sepsis (p=0.04) and apnoea (p=0.02) were independent risk factors. Retinopathy was significantly more severe in babies with hyaline membrane disease (p=0.02) and lower birth weight (p=0.02). Severe disease was never seen before 6.5 weeks of age.

CONCLUSION

Indirect ophthalmoscopy should be performed at 4 weeks of post natal age in all preterm babies with birth weight < or = 1500 gm, and intensified in the presence of risk factors like oxygen administration, apnoea and septicemia.

Screening for retinopathy of prematurity: results of a retrospective 3-year study of 502 infants

PURPOSE

To describe the surveillance, results of screening, and treatment of retinopathy of prematurity (ROP) in a university hospital setting in southeast France.

PATIENTS AND METHODS

Five hundred two premature infants were included in the screening protocol between January 1997 and December 1999. Criteria for inclusion in the study were a gestational age of 32 weeks or younger, a birth weight of less than 1,501 g, or both. The first fundus examination was performed between 4 and 6 weeks of life. Thereafter, fundus examination was performed in the absence of ROP every 2 weeks until complete retinal vasculature developed, gestational age of 50 weeks, or death. Examination was weekly in cases of retinopathy, biweekly if progression was ascertained, and less frequent only if regression was evident. Hospital records were reviewed to assess the presence or absence and eventual degree of ROP.

RESULTS

Stage 1 was observed in 32 infants, and stage 2 in 11 infants; all of these cases regressed. Three cases of bilateral stage 3 (two threshold and one prethreshold) disease underwent diode laser peripheral retinal ablation and regressed. One infant with bilateral stage 3 disease who underwent peripheral cryoablative surgery progressed to stage 4A in one eye and 4B in the other eye and then underwent scleral buckling surgery in the second eye.

CONCLUSIONS

Despite survival increasing with improved neonatal intensive care, the incidence of ROP does not appear to be increasing. In our center, the incidence appears to be lower than previously reported.

Retinopathy of prematurity in practice. I: screening for threshold disease

AIMS

To review an 11-year period of screening for retinopathy of prematurity (ROP) in the north of England by a single ophthalmologist. To identify the gestational ages and birth weights of babies reaching different stages of ROP. To investigate the workload involved in screening to detect threshold ROP, and that the practical outcomes had narrower inclusion criteria for screening. To identify babies treated for threshold disease.

METHODS

During the period August 1987-October 1998, babies were screened according to the national guidelines and the results were prospectively entered onto a computerised database. These data were then systematically reviewed.

RESULTS

Data were available for 484 babies: 203 (41.9%) developed any ROP, 46 (9.5%) reached stage 3 ROP, and 25 (5.2%) reached threshold and were treated. Data on 425 babies showed them to require an average of 2.3 screening examinations per baby. It took an average of 39 screening examinations to detect one case of threshold ROP. The more premature and lighter birth weight babies required the most examinations. Therefore, restricting the inclusion criteria for screening would only have reduced the total number of screenings modestly and could have allowed us to miss two of our threshold cases who were both of 30 weeks gestational age and >1400 g birth weight.

CONCLUSIONS

Screening is time consuming but worthwhile in view of the benefits of treatment. As applied to babies in the north of England, the current national screening criteria are satisfactory. The results of treatment of the babies identified in this study are presented in the accompanying paper.

Retinopathy of prematurity: are we screening too many babies?

PURPOSE

With advancement in neonatal care units, early detection of retinopathy of prematurity (ROP) in premature and very-low-birth-weight infants is important. Numerous studies have reported an increased risk of ROP in prematurely born infants, but only few have been long-term and strictly population-based. The aim of the present study was to find out whether birthweight <1251 grams and gestational age <30 weeks could provide a safe and efficient means of detecting treatable ROP. We have retrospectively tried to ascertain the incidence and associated risk factors that may contribute to the management of babies with ROP.

METHODS

Infants either with a birth weight below 1500 g or a gestational age of less than 32 weeks were screened for ROP during an 8-year period by a single examiner. Results An incidence of 64/205 (31.2%) ROP was noted. The mean age at detection was 5.5 +/- 2 weeks of life. The maximum stage reached was stage 1 in 27 (13.2%), stage 2 in 24 (11.7%) and stage 3 in 10 (4.8%) babies. Threshold ROP was present in three (1.5%) babies. Significantly fewer (150/205 = 73%) babies would have been examined had a birth weight of <1251 grams and a gestational age <30 weeks been applied. there were five (8%) babies with birth weight >1250 grams and eight (12%) babies with gestational age >30 weeks amongst babies with ROP but all were stage 1 or stage 2. All the stage 3 ROP and the threshold ROP cases were babies with birth weight <1000 grams and gestational age below 28 weeks.

CONCLUSION

Ophthalmic examination may be safely and efficiently concentrated in babies with birth weight <1251 grams and gestational age below 30 weeks. Birth weight (P < 0.005) and gestational age (P < 0.01) were the only significant risk factors. During this 8-year period there was no significant decrease in the number of babies screened for ROP and the overall incidence of all stages of the disease has remained constant. In the present series a lower incidence of severe ROP was noted compared to most previous studies. Our experience from this study suggests the need for further refinement of screening guidelines in order to focus screening on the vision-threatening stages of ROP.

New developments in neonatology: less severe retinopathy of prematurity?

PURPOSE

To determine the effects of surfactant replacement therapy (SRT), high-frequency oscillatory ventilation (HFOV), and general improvements in quality of care on the incidence of severe retinopathy of prematurity (ROP).

METHODS

Retrospective comparison of the incidence and severity of ROP in two groups of preterm infants admitted to our neonatal intensive care unit (NICU) in two consecutive 5-year periods (1986-1995) and screened for ROP. During the second study period, natural surfactant was introduced in the treatment of respiratory distress syndrome (RDS) and HFOV was used for treatment of respiratory insufficiency of any origin. The effects of these developments and general improvements on the incidence of severe ROP were analyzed with stepwise logistic regression.

RESULTS

The overall incidence of ROP from 1986-1990 was not significantly different from the incidence of ROP from 1991-1995. The incidence of severe ROP (ROP stage 3 or greater) was significantly lower in the second period (15.7% versus 6.4%, P=.015). For infants <1000 g, the incidence of overall ROP was increased significantly during the second study period (47.6% versus 60.1 %, P=.045), although the incidence of severe ROP remained unchanged. Only SRT was associated with a decreased risk for severe ROP; HFOV and general improvements in quality of care had no influence on the outcome. In patients with RDS, the incidence of severe ROP decreased significantly during the second period.

CONCLUSION

Of the recent new developments in neonatology, only SRT was associated with a decreased risk for severe ROP.

Should fewer premature infants be screened for retinopathy of prematurity in the managed care era?

OBJECTIVE

To determine appropriate upper limits for gestational age and birth weight when screening infants for retinopathy of prematurity (ROP).

DESIGN

Retrospective survey.

SETTING

Tertiary neonatal intensive care nursery.

PATIENTS

Seven hundred seven infants born July 1, 1990 to June 30, 1996 and screened for ROP according to the 1988 to 1996 American Academy of Pediatrics guidelines.

OUTCOME MEASURES

Maximum stage of ROP with respect to birth weight and gestational age.

RESULTS

No ROP more than Stage 1 was observed in infants with gestational ages >/=32 weeks or birth weights >/=1500 g. All cases of threshold and Stage 4 ROP were confined to infants with gestational ages </=30 weeks or birth weights <1200 g.

CONCLUSIONS

The latest American Academy of Pediatrics screening guidelines for ROP are discretionary for infants with birth weights >1500 g or gestational ages >28 weeks. If ROP screening is limited to infants with birth weights of </=1500 g, 34.2% fewer infants would require screening compared with the previous <1800 g recommendation, while missing no cases of ROP more than Stage 1. A gestational age cut-off of </=28 weeks, however, is less desirable, and could potentially miss several infants with more advanced retinopathy (including Stage 4). If ROP screening criteria were instead modified to include infants of gestational ages <32 weeks, the number of patients requiring screening could be reduced 29.1% compared with the previous recommendation of <35 weeks, again without missing any cases of ROP more than Stage 1. Use of such a screening strategy (birth weight <1500 g or gestational age <32 weeks) is predicted to save in excess of 1.5 million dollars annually in the United States, while missing no cases of ROP more than Stage 1.

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.