UK population based study of severe retinopathy of prematurity: screening, treatment, and outcome

The Association between Gestational Age and Risk for Long Term Ophthalmic Morbidities among Offspring Delivered in Different Preterm Subgroups

Objective: To investigate whether there is a linear association between the degree of prematurity and the risk for long-term ophthalmic morbidity among preterm infants. Study design: A population-based, retrospective cohort study, which included all singleton deliveries occurring between 1991 and 2014 at a single tertiary medical center. All infants were divided into four groups according to gestational age categories: extremely preterm births, very preterm births, moderate to late preterm births and term deliveries (reference group). Hospitalizations of offspring up to 18 years of age involving ophthalmic morbidity were evaluated. Survival curves compared cumulative hospitalizations and regression models controlled for confounding variables. Results: During the study period, 243,363 deliveries met the inclusion criteria. Ophthalmic-related hospitalization rates were lower among children born at term (0.9%) as compared with extremely preterm (3.6%), very preterm (2%), and moderate to late preterm (1.4%) born offspring (p < 0.01; using the chi-square test for trends). The survival curve demonstrated significantly different hospitalization rates between the gestational ages (p < 0.001). The regression demonstrated an independent risk for ophthalmic morbidity among extremely preterm born offspring (adjusted hazard ratio 3.8, confidence interval 1.6−9.2, p < 0.01), as well as very preterm and moderate to late preterm (adjusted hazard ratio 2.2 and 1.5, respectively) as compared with term deliveries. Conclusions: The risk for long-term ophthalmic-related hospitalization of preterm offspring gradually decreases as the gestational age increases.

Differential age-dependent development of inter-area brain connectivity in term and preterm neonates

BACKGROUND

Among preterm infants, higher morbidities of neurological disturbances and developmental delays are critical issues. Resting-state networks (RSNs) in the brain are suitable measures for assessing higher-level neurocognition. Since investigating task-related brain activity is difficult in neonates, assessment of RSNs provides invaluable insight into their neurocognitive development.

METHODS

The participants, 32 term and 71 preterm neonates, were divided into three groups based on gestational age (GA) at birth. Cerebral hemodynamic activity of RSNs was measured using functional near-infrared spectroscopy in the temporal, frontal, and parietal regions.

RESULTS

High-GA preterm infants (GA ≥ 30 weeks) had a significantly stronger RSN than low-GA preterm infants and term infants. Regression analyses of RSNs as a function of postnatal age (PNA) revealed a steeper regression line in the high-GA preterm and term infants than in the low-GA infants, particularly for inter-area brain connectivity between the frontal and left temporal areas.

CONCLUSIONS

Slower PNA-dependent development of the frontal-temporal network found only in the low-GA group suggests that significant brain growth optimal in the intrauterine environment takes place before 30 weeks of gestation. The present study suggests a likely reason for the high incidence of neurodevelopmental impairment in early preterm infants.

IMPACT

Resting-state fNIRS measurements in three neonate groups differing in gestational age (GA) showed stronger networks in the high-GA preterm infants than in the term and low-GA infants, which was partly explained by postnatal age (PNA). Regression analyses revealed a similar PNA-dependence in the development of the inter-area networks in the frontal and temporal lobes in the high-GA and term infants, and significantly slower development in the low-GA infants. These results suggest that optimal intrauterine brain growth takes place before 30 weeks of gestation. This explains one of the reasons for the high incidence of neurodevelopmental impairment in early preterm infants.

Incidence, Long-Term Visual Outcomes, and Mortality in Retinopathy of Prematurity in Korea: A Nationwide Population-Based Study

Purpose

To evaluate the incidence, visual prognosis, and mortality in retinopathy of prematurity (ROP) in Korea.

Methods

We used the National Health Insurance and the Korean Disability Registry database, which covers the entire newborn population in 2006 to 2014 and includes information on all newborns diagnosed with ROP until 2016. Using these databases, we evaluated the incidence, rate of visual impairment (VI), and mortality in patients with ROP according to the birth weight categories and treatment modalities.

Results

The ROP incidence per 1000 newborns was 1.99, which broke down into 317.14 in the very low birth weight (VLBW) less than 1500 g population, 25.45 in the 1500 to 2499 g population, and 0.29 in the 2500 g or greater population. When assessed at age 10, the VI rate was 2.2 per 100 person-years, which was highest at 4.5 per 100 person-years in the VLBW population compared with the population in other birth weight categories. Among treated cases, the proportion of VI in patients undergoing laser photocoagulation or cryotherapy was 1.6% (42/2595), which was lower than the 2.9% (2/68) of patients treated with anti-vascular endothelial growth factor injection, and 32.2% (82/255) of patients undergoing vitrectomy or scleral buckling. The mortality rate was 4.8 per 1000 person-years, which was highest in the VLBW population, but similar across treatment modalities.

Conclusions

The ROP incidence in Korea was approximately 1 in 500 among all newborns, and 1 in 3 in the VLBW population. As the first nationwide population-based study of long-term visual prognosis in ROP, we report the higher VI rate in ROP than previously determined in other studies. Differences in visual outcomes and comparable mortality risks between treatment modalities require further verification.

Involution of retinopathy of prematurity and neurodevelopmental outcomes after intravitreal bevacizumab treatment

This single-centered, retrospective cohort study investigated the timing of involution of retinopathy of prematurity (ROP) and retinal vascularization to zone III after intravitreal bevacizumab (IVB) treatment and its possible impacts on postnatal growth and neurodevelopment. Premature infants with birth weight ≤1500 g, born between 2008 to 2014 and diagnosed with ROP were enrolled. All patients with type 1 ROP underwent IVB as 1st line treatment and were recruited as the study group; those with any stage of ROP except type 1 ROP without treatment served as controls. Neurodevelopmental outcomes were assessed using the Bayley Score of Infant Development (BSID) editions II or III. The study group included 35 eyes from 18 patients; the control group included 86 patients. Twenty-three eyes (65.7%) exhibited ROP regression after a single dose of IVB. The majority of plus sign and extraretinal neovascularization regressed within two weeks. The length of time for retinal vascularization to reach zone III was significantly longer in the treatment group compared with the control (mean post-menstruation age 54.5 vs. 47.0 weeks, p<0.001). Long-term follow-up showed no significant differences in body weight and neurodevelopment between the study and control groups up to the 2-year corrected age.

Incidence and risk factors of retinopathy of prematurity in three neonatal intensive care units in Palestine

BACKGROUND

Severe Retinopathy of Prematurity (ROP) is a serious vasoproliferative disorder that can affect extremely premature infants. It continues to be one of the most important preventable causes of blindness in children. Our study is aimed at finding the incidence of ROP and its association with some risk factors in Palestine.

METHODS

From the 1st of January 2016 to 31st December 2016, a total number of 115 infants who met the criteria for ROP screening in three neonatal intensive care units were included in the study. The medical records of infants were reviewed retrospectively and multiple factors that may be associated with the development of ROP were collected manually.

RESULTS

The incidence of ROP and severe type 1 ROP that require treatment was 23.5 and 11.3% respectively. After conducting univariate analysis of risk factors, statistically significant risk factors affecting the development of ROP in our study were: low gestational age, low birth weight, type of multiple gestation, the presence of affected sibling, low level of Hemoglobin at birth, respiratory distress syndrome, low Hemoglobin level, blood transfusion and days on oxygen supplements with either mechanical, non-mechanical methods or both combined. High bilirubin levels were found as a protective factor against the development of ROP. However, when a multivariate analysis was performed, only low gestational age, total days on oxygen supplement and high bilirubin levels were significant regarding the development of ROP.

CONCLUSION

The incidence of ROP is considered a relatively low percentage compared to neighboring countries that have higher levels of human development index. Statistically significant risk factors need to be considered when clinicians deal with premature infants.

Estimate of incidence of ROP requiring treatment in extreme preterms and impact on service-7 year review in tertiary unit

BACKGROUND/OBJECTIVES

Retinopathy of prematurity (ROP) is a potentially blinding disorder affecting premature infants. Our Eye Unit supports two neonatal intensive care units (NICUs), one provides neonatal surgical and medical facilities and the other is exclusively medical. Our objectives were to (1) to identify the annual rate of ROP treatments during the period 2009-2015 and (2) to estimate the incidence of ROP treatment in babies born very prematurely (<27 weeks).

SUBJECTS/METHODS

Records for all infants treated for ROP by our unit during the period 2009-2015 were reviewed. We calculated numbers treated in each year. Records of babies born under 27 weeks of gestation and cared for in the non-surgical NICU were also reviewed. Their requirement for laser treatments for ROP was calculated by the week of gestation at birth.

RESULTS

In the two NICUs combined, 95 infants were treated for ROP between 2009 and 2015. The numbers treated increased from 9/158 (5.7%) of babies screened in 2009 to 22/159 (13.8%) in 2015 (p_trend = 0.004). The rate of laser treatment for ROP increased as gestation at birth decreased: from 12/100 (12%) of babies born at 26 weeks to 17/29 (59%) of babies born at 23 weeks (p_trend = 0.001).

CONCLUSION

The number of laser treatments for ROP carried out by this unit has increased steadily between 2009 and 2015 and this may in part be due to the increased need for ROP treatment in extremely preterm babies, whose survival has increased in the same period. These data may aid planning for ROP services.

Ocular Findings in Low Birthweight and Premature Babies in the First Year: Do We Need to Screen?

Purpose

There is no standardized approach for the ophthalmic care follow-up of children screened for retinopathy of prematurity (ROP). The authors report the ocular findings at 12 months in preterm and low birthweight babies screened for ROP over a 5-year period (1998–2003).

Methods

The case notes of 211 babies were retrospectively reviewed for birth details, maternal details, presence of ROP, and findings at follow-up screening which included visual acuity, refraction at 12 months, presence of squint, and any other ocular problems.

Results

At 1 year follow-up, 16.6% of ROP positive children failed a screening visit because of squint (6.66%), refractive error (6.66%), and optic nerve abnormalities (3.33%). At 1 year follow-up, 10% of ROP negative children had failed a screening visit because of squint (3.75 %), refractive error (3.75%), and other pathology (2.5%).

Conclusions

The authors recommend screening all babies with ROP at 12 months to identify amblyogenic factors such as squint and refractive error. Parents of infants who do not develop ROP should be advised of the increased risk of visual problems in their children and to have their child examined in the preschool period.

Treatment trends for retinopathy of prematurity in the UK: active surveillance study of infants at risk

OBJECTIVES

To estimate the incidence of severe retinopathy of prematurity (ROP) requiring treatment and describe current treatment patterns in the UK.

DESIGN

Nationwide population-based case ascertainment study via the British Ophthalmic Surveillance Unit and a national collaborative ROP special interest group. Practitioners completed a standardised case report form (CRF).

SETTING

All paediatric ophthalmologists providing screening and/or treatment for retinopathy in the UK were invited to take part.

PARTICIPANTS

Any baby with ROP treated or referred for treatment between 1 December 2013 and 30 November 2014, treated with laser, cryotherapy, vascular endothelial growth factor (VEGF) inhibitor or vitrectomy/scleral buckling, or a combination.

MAIN OUTCOME MEASURE

Incidence of ROP requiring treatment.

RESULTS

We received 370 CRFs; 327 were included. Denominator from epidemiological data: 8112 infants with birth weight of <1500 g. The incidence of ROP requiring treatment was 4% (327/8112, 95% CI 3.6% to 4.5%). Median gestational age was 25 weeks (IQR 24.3-26.1), and median birth weight 706 g (IQR 620-821). Median age at first treatment was 80 days (IQR 71-96). 204 right eyes (62.39%) had type 1 ROP, and 27 (8.26%) had aggressive posterior ROP. Infants were also treated for milder disease: 9 (2.75%) right eyes were treated for type 2 ROP, and 74 (22.63%) for disease milder than type 1 with plus or preplus, which we defined here as 'type 2 plus' disease. First-line treatment was diode laser photoablation of the avascular retina in 90.5% and injection of VEGF inhibitor in 8%.

CONCLUSIONS

ROP treatment incidence in the UK is 2.5 times higher than previously estimated. 8% of treated infants receive intravitreal VEGF inhibitor, currently unlicensed. Research is needed urgently to establish safety and efficacy of this approach. Earlier treatment and increasing numbers of surviving premature infants require an increase in appropriate eye care facilities and staff.

TRIAL REGISTRATION NUMBER

NCT02484989.

Bedside ROP screening and telemedicine interpretation integrated to a neonatal transport system: Economic aspects and return on investment analysis

BACKGROUND AND AIM

Peter Cerny Ambulance Service - Premature Eye Rescue Program (PCA-PERP) uses digital retinal imaging (DRI) with remote interpretation in bedside ROP screening, which has advantages over binocular indirect ophthalmoscopy (BIO) in screening of premature newborns. We aimed to demonstrate that PCA-PERP provides good value for the money and to model the cost ramifications of a similar newly launched system.

METHODS

As DRI was demonstrated to have high diagnostic performance, only the costs of bedside DRI-based screening were compared to those of traditional transport and BIO-based screening (cost-minimization analysis). The total costs of investment and maintenance were analyzed with micro-costing method. A ten-year analysis time-horizon and service provider's perspective were applied.

RESULTS

From the launch of PCA-PERP up to the end of 2014, 3722 bedside examinations were performed in the PCA covered central region of Hungary. From 2009 to 2014, PCA-PERP saved 92,248km and 3633 staff working hours, with an annual nominal cost-savings ranging from 17,435 to 35,140 Euro. The net present value was 127,847 Euro at the end of 2014, with a payback period of 4.1years and an internal rate of return of 20.8%. Our model presented the NPVs of different scenarios with different initial investments, annual number of transports and average transport distances.

CONCLUSIONS

PCA-PERP as bedside screening with remote interpretation, when compared to a transport-based screening with BIO, produced better cost-savings from the perspective of the service provider and provided a return on initial investment within five years after the project initiation.

Screening Retinopathy of Prematurity in Extremely Low Birth Weight Infants in China and the Need for Earlier Screening Times

Purpose. To convey the need for a revised screening strategy for retinopathy of prematurity (ROP) for extremely low birth weight (ELBW) infants in China. Design. A retrospective longitudinal study. Methods. The medical charts of infants with a birth weight (BW) of less than 1 kg were reviewed. The infants were divided into three groups: group A, without ROP; group B, with ROP but not up to type 1 prethreshold or threshold ROP; group C, with type 1 prethreshold or threshold ROP. Data collected included gender, gestational age (GA), BW, postmenstrual age (PMA), age of onset of ROP, and age at which treatment was carried out, if required. Results. A total of 77 infants were involved. Fifty-six infants developed ROP at any stage and 38 infants developed type 1 prethreshold or threshold ROP. The mean BW and GA of infants in group A were significantly different compared with groups B and C. The mean PMA of onset of ROP in infants who developed mild ROP was 37 weeks compared with 34 weeks for infants who developed severe ROP. Conclusion. ELBW infants have a higher incidence of ROP in China which highlights the need for optimizing neonatal care for these infants. In ELBW infants, ROP tends to develop more severely when it occurs earlier. It is necessary for ELBW infants, especially for those with a BW less than 800 g or a GA less than 25 weeks, to be initially screened at an earlier time.

Characteristics of Severe Retinopathy of Prematurity in Infants with Birth Weight above 1500 Grams at a Referral Center in Turkey

PURPOSE

To demonstrate the clinical characteristics and treatment outcomes of severe retinopathy of prematurity (ROP) in preterm infants with birth weight (BW) above 1500 g in Turkey.

METHODS

A retrospective review of 5920 ROP records was performed in Zeynep Kamil Maternity and Children's Diseases Training and Research Hospital. The records were obtained from ROP treatment center of the same institute between 2011 and 2016. The data comprised the demographic and clinical characteristics including, gestational age, BW, systemic risk factors, zone and stage of ROP, ROP type, treatment modality, treatment outcomes and inborn/outborn status of the babies.

RESULTS

A total of 36 infants (71 eyes) with severe ROP and BW> 1500 g were retrieved. There were 30 infants (83.3%) with type 1 ROP and 6 infants (16.7%) with aggressive posterior ROP (APROP). 3 infants (8.3%) were born at our hospital whereas 33 (91.7%) were referred from outer private neonatal intensive care unit (NICU) centers. Zone I APROP was detected during the initial screening. 21 infants (58.3%) underwent laser treatment while 15 (41.7%) received intravitreal bevacizumab (IVB) injections. No unfavorable structural outcome was observed following either treatment modality.

CONCLUSION

Severe ROP may occur in heavier preterm infants. Laser treatment and IVB injections were useful in selected cases. Presence of APROP at first examination suggests an earlier screening in heavier babies. Standardization of private NICU centers as well as establishing a national ROP protocol is necessary in Turkey.

Sight-Threatening Retinopathy of Prematurity: Changing Trends in Treatment

PURPOSE

To study the incidence and treatment of severe retinopathy of prematurity (ROP) in infants younger than 30 weeks' gestational age (GA) in New South Wales and the Australian Capital Territory, Australia, from 2003 to 2008. These data were then compared to data from previously reported epochs (1986 to 1987, 1992 to 1997, and 1998 to 2002).

METHODS

Data were divided into two sub-epochs (2003 to 2005 and 2006 to 2008) to study trends and combined to compare over 22 years.

RESULTS

From 2003 to 2008, 2,550 of 3,004 (84.9%) infants survived, 200 (7.8%) were diagnosed as having severe ROP, and 119 (59.5%) required laser therapy. No significant difference in the incidence of severe ROP or treatment rate in infants younger than 27 and 30 weeks' GA from 2003 to 2005 and 2006 to 2008 occurred. Similarly, between 1986 and 2008 there was no difference in the incidence of severe ROP. However, the treatment rate significantly increased during this time.

CONCLUSIONS

The incidence of severe ROP has been stable since 1986. However, laser treatment significantly increased to include 8 infants with stage 2 ROP from 2003 to 2008.

Comparison of Refractive Error Changes in Retinopathy of Prematurity Patients Treated with Diode and Red Lasers

Aim: To compare refractive error changes in retinopathy of prematurity (ROP) patients treated with diode and red lasers. Methods: A randomized double-masked clinical trial was performed, and infants with threshold or prethreshold type 1 ROP were assigned to red or diode laser groups. Gestational age, birth weight, pretreatment cycloplegic refraction, time of treatment, disease stage, zone and disease severity were recorded. Patients received either red or diode laser treatment and were regularly followed up for retina assessment and refraction. The information at month 12 of corrected age was considered for comparison. Results: One hundred and fifty eyes of 75 infants were enrolled in the study. Seventy-four eyes received diode and 76 red laser therapy. The mean gestational age and birth weight of the infants were 28.6 ± 3.2 weeks and 1,441 ± 491 g, respectively. The mean baseline refractive error was +2.3 ± 1.7 dpt. Posttreatment refraction showed a significant myopic shift (mean 2.6 ± 2.0 dpt) with significant difference between the two groups (p < 0.001). There was a greater myopic shift among children with zone I and diode laser treatment (mean 6.00 dpt) and a lesser shift among children with zone II and red laser treatment (mean 1.12 dpt). The linear regression model, using the generalized estimating equation method, showed that the type of laser used has a significant effect on myopic shift even after adjustment for other variables. Conclusion: Myopic shift in laser-treated ROP patients is related to the type of laser used and the involved zone. Red laser seems to cause less myopic shift than diode laser, and those with zone I involvement have a greater myopic shift than those with ROP in zone II.

Ultrasonographic demonstration of the superior ophthalmic vein in the orbit of premature infants with and without retinopathy of prematurity

Retinopathy of prematurity (ROP), which develops due to abnormal retinal vascularization in premature babies, can lead to irreversible vision loss. B-scan ocular ultrasonography is a noninvasive examination which makes it possible to image the eye and orbit. Our purpose was to echographically assess the orbit of premature babies with and without retinopathy of prematurity (ROP), with a focus on the superior ophthalmic vein (SOV) which is normally not detected by orbital ultrasound. A prospective study design was used after approved by the local institutional review board. ROP was diagnosed by routine ophthalmoscopic exam. Orbital ultrasound was performed by a single experienced ophthalmologist and ultra-sonographer who was masked to the routine ROP screening results. The results of the ophthalmoscopic exam were compared to the orbital ultrasound findings. The study group was divided into those diagnosed with ROP and those not diagnosed with ROP and were found to be comparable by age and weight at the time of the US examination. The SOV was dilated in 21 of 22 eyes (95.4%) with ROP and in only 5 of 32 eyes (15.6%) without ROP. The present study suggests an association between ROP and dilatation of the SOV.

Predictors for the development of referral-warranted retinopathy of prematurity in the telemedicine approaches to evaluating acute-phase retinopathy of prematurity (e-ROP) study

IMPORTANCE

Detection of treatment-requiring retinopathy of prematurity (ROP) involves serial eye examinations. An ROP prediction model using predictive factors could identify high-risk infants and reduce required eye examinations.

OBJECTIVE

To determine predictive factors for the development of referral-warranted (RW) ROP.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter observational cohort study included secondary analysis of data from the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity Study. Infants included in the study had a birth weight (BW) of less than 1251 g.

EXPOSURES

Serial ROP examinations of premature infants who had 2 or more ROP examinations.

MAIN OUTCOMES AND MEASURES

Incidence of RW-ROP (defined as the presence of plus disease, zone I ROP, or ROP stage 3 or greater in either eye) and associations with predictive factors.

RESULTS

Among 979 infants without RW-ROP at first study-related eye examination (median postmenstrual age, 33 weeks; range, 29-40 weeks) who underwent at least 2 eye examinations, 149 (15.2%) developed RW-ROP. In a multivariate model, significant predictors for RW-ROP were male sex (odds ratio [OR], 1.80; 95% CI, 1.13-2.86 vs female), nonblack race (OR, 2.76; 95% CI, 1.50-5.08 for white vs black race and OR, 4.81; 95% CI, 2.19-10.6 for other vs black race), low BW (OR, 5.16; 95% CI, 1.12-7.20 for ≤500 g vs >1100 g), younger gestational age (OR, 9.79; 95% CI, 3.49-27.5 for ≤24 weeks vs ≥28 weeks), number of quadrants with preplus disease (OR, 7.12; 95% CI, 2.53-20.1 for 1-2 quadrants and OR, 18.4; 95% CI, 4.28-79.4 for 3-4 quadrants vs no preplus disease), stage 2 ROP (OR, 4.13; 95% CI, 2.13-8.00 vs no ROP), the presence of retinal hemorrhage (OR, 4.36; 95% CI, 1.57-12.1 vs absence), the need for respiratory support (OR, 4.99; 95% CI, 1.89-13.2 for the need for controlled mechanical ventilator; OR, 11.0; 95% CI, 2.26-53.8 for the need for high-frequency oscillatory ventilation vs no respiratory support), and slow weight gain (OR, 2.44; 95% CI, 1.22-4.89 for weight gain ≤12 g/d vs >18 g/d). These characteristics predicted the development of RW-ROP significantly better than BW and gestational age (area under receiver operating characteristic curve, 0.88 vs 0.78; P < .001).

CONCLUSIONS AND RELEVANCE

When controlling for very low BW and prematurity, the presence of preplus disease, stage 2 ROP, retinal hemorrhage, and the need for ventilation at time of first study-related eye examination were strong independent predictors for RW-ROP. These predictors may help identify infants in need of timely eye examinations.

Visual impairment due to retinopathy of prematurity (ROP) in New Zealand: a 22-year review

AIM

To evaluate retinopathy of prematurity (ROP)-related visual impairment in New Zealand children.

METHODS

22-year retrospective review of medical records of children with moderate to severe visual impairment registered with the Blind and Low Vision Education Network New Zealand. The cohort was divided into two periods (1991-2004; 2005-2012) for analysis.

RESULTS

232 children with ROP were treated in the study period (109 in period 1, 123 in period 2). 36 children, 63.9% of whom were of male sex, were identified with subsequent significant visual impairment (27 in period 1, 9 in period 2). The incidence of new cases of visual impairment from ROP declined from 271.6 infants/100 000 live very preterm births per annum (period 1) to 146.1 per annum (period 2). Mean gestational age and mean birth weight were comparable between the two study periods. 75% of children with visual impairment from ROP received treatment for their condition (period 1, 74.1%; period 2, 77.8%) and modalities used changed significantly over time. The modal visual outcome overall was Snellen visual acuity <6/18-6/60 (55.6%) (period 1, 51.9%; period 2, 66.7%). The proportion of children with no light perception bilaterally decreased over time (period 1, 3.7%; period 2, 0%).

CONCLUSIONS

There has been a reduction in the incidence of infants with significant visual impairment from ROP over time in New Zealand, likely due to progress in clinical management of ROP. Our study suggests the current ROP screening criteria of <31 weeks' gestation or <1250 g are of sufficient breadth.

Incidence and treatment of retinopathy of prematurity in England between 1990 and 2011: database study

AIMS

To study the incidence and treatment of retinopathy of prematurity (ROP) in England, 1990-2011.

METHODS

English national Hospital Episode Statistics were analysed, for babies born in hospital and for inpatient admissions, to obtain annual rates of diagnosis of, and treatment for, babies with ROP. National data on low birthweight (LBW) babies, born <1500 g and therefore eligible for ROP screening, were used as denominators in calculating rates of ROP per 1000 babies at risk.

RESULTS

The recorded incidence of ROP increased tenfold, from 12.8 per 1000 LBW babies in 1990 to 125.5 per 1000 LBW babies in 2011. Tretment rates for ROP by cryotherapy or laser rose from 1.7 to 14.8 per 1000 LBW babies between 1990 and 2011. In 1990, 13.3% of babies with ROP were treated with cryotherapy, which fell to 0.1% in 2011. Rates for laser treatment rose from 1.8% of babies with ROP in 1999 to 11.7% in 2011.

CONCLUSIONS

Increased neonatal survival, improved awareness of ROP and dissemination of guidance on screening and treatment of ROP will all have contributed to the substantial rise in recorded incidence of ROP between 1990 and 2011. Retinal ablation is now almost always performed using laser treatment rather than cryotherapy.

Vascular endothelial growth factor (VEGF-634G/C) polymorphism and retinopathy of prematurity: a meta-analysis

PURPOSE

Vascular endothelial growth factor polymorphism (VEGF-634G/C, rs 2010963) has been considered a risk factor for the development of retinopathy of prematurity (ROP). However, the results remain controversial. Therefore, the aim of the present meta-analysis was to determine the association between VEGF-634G/C polymorphism and ROP risk.

METHODS

Published literature from PubMed and other databases were retrieved. All studies evaluating the association between VEGF-634G/C polymorphism and ROP risk were included. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using random or fixed effects model. A total of six case-control studies including 355 cases and 471 controls were included.

RESULTS

By pooling all the studies, we found that VEGF-634G/C polymorphism was not associated with ROP risk at co-dominant and allele levels and no association was also found in dominant and recessive models. While stratifying on ethnicity level no association was observed in Caucasian and Asian population.

DISCUSSION

This meta-analysis suggests that VEGF-634G/C polymorphism may not be associated with ROP risk, the association between single VEGF-634G/C polymorphism and ROP risk awaits further investigation.

Retinopathy of prematurity

The immature retinas of preterm neonates are susceptible to insults that disrupt neurovascular growth, leading to retinopathy of prematurity. Suppression of growth factors due to hyperoxia and loss of the maternal-fetal interaction result in an arrest of retinal vascularisation (phase 1). Subsequently, the increasingly metabolically active, yet poorly vascularised, retina becomes hypoxic, stimulating growth factor-induced vasoproliferation (phase 2), which can cause retinal detachment. In very premature infants, controlled oxygen administration reduces but does not eliminate retinopathy of prematurity. Identification and control of factors that contribute to development of retinopathy of prematurity is essential to prevent progression to severe sight-threatening disease and to limit comorbidities with which the disease shares modifiable risk factors. Strategies to prevent retinopathy of prematurity will depend on optimisation of oxygen saturation, nutrition, and normalisation of concentrations of essential factors such as insulin-like growth factor 1 and ω-3 polyunsaturated fatty acids, as well as curbing of the effects of infection and inflammation to promote normal growth and limit suppression of neurovascular development.

New insight into the pathogenesis of retinopathy of prematurity: assessment of whole-genome expression

BACKGROUND

Retinopathy of prematurity (ROP) is one of the most common preventable causes of blindness and impaired vision among children in developed countries. The aim of the study was to compare whole-genome expression in the first month of life in groups of infants with and without ROP.

METHODS

Blood samples were drawn from 111 newborns with a mean gestational age of 27.8 wk on the 5th, 14th, and 28th day of life (DOL). The mRNA samples were evaluated for gene expression with the use of human whole-genome microarrays. The infants were divided into two groups: no ROP (n = 61) and ROP (n = 50).

RESULTS

Overall, 794 genes were differentially expressed on the 5th DOL, 1,077 on the 14th DOL, and 3,223 on the 28th DOL. In each of the three time points during the first month of life, more genes were underexpressed than overexpressed in the ROP group. Fold change (FC), which was used in analysis of gene expression data, ranged between 1.0 and 1.5 in the majority of genes differentially expressed.

CONCLUSION

Pathway enrichment analysis revealed that genes in four pathways related to inflammatory response were consistently downregulated due to the following variables: ROP and gestational age.

Retinopathy of prematurity: Recommendations for screening

Retinopathy of prematurity (ROP) is a disorder of the developing retinal blood vessels of the preterm infant. New recommendations for screening and treatment of ROP have been published in the past few years. Current evidence suggests that screening infants with gestational ages of 30 6/7 weeks or less (regardless of birth weight) and birth weights of 1250 g or less is a strategy with a very small likelihood that an unscreened baby would have treatable ROP. Individual centres may choose to extend birth weight screening criteria to 1500 g. Initial screening should be performed at 31 weeks' postmenstrual age in infants with gestational ages of 26 6/7 weeks or less at birth, and at four weeks' chronological age in infants with gestational ages of 27 weeks or more at birth by an ophthalmologist skilled in the detection of ROP. Follow-up examinations are conducted according to the ophthalmologist's recommendation. Infants with high-risk prethreshold ROP and threshold ROP are referred for retinal ablative therapy. Developing processes for ROP screening, documenting results and communicating results to parents as well as health professionals involved in the infant's care are important responsibilities for all nurseries providing care for preterm infants.

Braille use among Norwegian children from 1967 to 2007: trends in the underlying causes

PURPOSE

The aim of the study was to estimate the occurrence, diagnoses and time trends among Norwegian children that have received education in braille from 1967 to 2007.

METHODS

We used a retrospective population-based study design. The health care system is free for all inhabitants in Norway. We included all children that had received braille education the last four decades. From each student's record, we abstracted year born, country of birth, gender, year diagnosed, diagnosis, classification of visual impairment and type of reading media.

RESULTS

We identified 287 children (137 girls and 150 boys) that had received braille education over the last 40 years. Of these, 262 (91.3%) children were born in Norway, 145 (53.7%) were diagnosed within the first year of life and 59 (20.6%) from age of one to five. The most frequent diagnoses were Retinopathy of Prematurity (ROP), Juvenile Ceroid Lipofuscinoses (JNCL), Lebers Congenital Amaurosis (LCA) and Retinitis Pigmentosa (RP). Among the children, 63% (N = 170) used braille only, 9% (N = 25) braille and print, but priority braille, and 27% (N = 73) braille and print, priority print. The number of children with ROP using braille had a peak in 1977, then the number declined. The number diagnosed with LCA increased from 1987 to 1992. The number of braille users among children diagnosed with JNCL tended to increase substantially after 1992.

CONCLUSION

Braille education seemed to be dependent of trends in diagnoses as well as trends in recommendations from professional educators.

Educational paper: Retinopathy of prematurity

Retinopathy of prematurity (ROP) is a proliferative retinal vascular disease affecting the premature infant with an incompletely vascularized retina. The spectrum of ophthalmological findings in ROP exists from minimal sequelae, which do not affect vision, to bilateral retinal detachment and total blindness. With the increased survival of very small infants, retinopathy of prematurity has become one of the leading causes of childhood blindness. Over the past two decades, major advances have been made in understanding the pathogenesis of ROP, to a large extent as a result of changes in clinical risk factors (oxygen and non-oxygen related) and characteristics observed in ROP cases. This article provides a literature review on the evolution in clinical characteristics, classification and treatment modalities and indications of ROP. Special attention is hereby paid to the neonatal factors influencing the development of ROP and to the necessity for everyone caring for premature babies to have a well-defined screening and treatment protocol for ROP. Such screening protocol needs to be based on a unit-specific ROP risk profile and, consequently, may vary between different European regions.

CONCLUSION

Retinopathy of prematurity is an important cause of ocular morbidity and blindness in children. With better understanding of the pathogenesis, screening and treatment guidelines have changed over time and are unit specific.

Retinopathy of prematurity: an example of a successful screening program

Retinopathy of prematurity (ROP) is a persistent and often devastating morbidity associated with premature and low birth weight infants. It continues to be a frequent diagnosis in the neonatal intensive care unit, despite technologic advances and increased knowledge. The American Academy of Pediatrics (AAP) has issued practice guideline recommendations for ROP screening and treatment that aid in creating a consistent and reliable ROP protocol. Challenges exist in screening for and treating ROP, including delayed or omitted exams, lack of qualified examiners, lack of parental compliance with follow-up care, and fear of litigation. This article provides a detailed example of a successful ROP program based on the AAP recommendations and utilizing a multidisciplinary approach to ensure optimal ROP care for the preterm infant. It also discusses the role of the ROP coordinator assigned to the NICU.

The influence of gestational age on the dynamic behavior of other risk factors associated with retinopathy of prematurity (ROP)

Background

Improved survival of preterm neonates has increased the incidence of retinopathy of prematurity (ROP) in many middle-income countries.

Aim

This study aimed to verify the main risk factors for the development of ROP according to different gestational age (GA) groups.

Methods

A prospective cohort study including infants weighing ≤1,500 g or GA ≤32 weeks at birth was conducted. The main clinical outcomes were the occurrence of any stage of ROP and severe ROP. The perinatal variables considered for the study were: birth weight; GA; gender; to be small for GA (SGA); weight gain from birth to the sixth week of life; use of oxygen in mechanical ventilation or nasal CPAP; multiple gestations; therapeutic use of surfactant, indomethacin, and erythropoietin; occurrence of sepsis, meningitis, intraventricular hemorrhage, and patent ductus arteriosus; need for and volume of blood transfusion; and 10-min Apgar score. The patients were divided into three groups according to GA: (group 1) infants of GA ≤28 weeks at birth (n = 100); (group 2) infants of GA = 29–31 weeks at birth (n = 215); and (group 3) infants of GA ≥32 weeks at birth (n = 152).

Results

A total of 467 newborn infants were included. Mean BW and GA in the total cohort were 1,216.5 g (±278.3) and 30.3 weeks (±2.2), respectively. Gestational age groups were not matched for BW and SGA. Any stage of ROP occurred in 111 patients (23.8%) and 24 (5.1%) patients developed severe ROP. Only BW and volume of blood transfusion were significant factors for the occurrence of any stage of ROP in all groups. In group 1, GA, the twin situation, and use of erythropoietin were statistically significant factors. In group 2, only GA and need for blood transfusion were significant. In group 3, use of oxygen in mechanical ventilation, sepsis, and need for blood transfusion were significant for ROP onset. The logistic regression determined that patients in groups 2 and 3 were less likely to develop ROP than patients in group 1.

Conclusions

Patients in groups 1 and 2 developed ROP due to general immaturity, whereas bigger babies, of GA ≥32 weeks, developed ROP because they were “sicker” babies with more comorbidities.

Retinopathy of prematurity in extremely low birth weight infants in Malaysia

PURPOSE

To identify differences in incidence, risk factors, and outcomes of retinopathy of prematurity (ROP) between 2 birth weight categories within a cohort of extremely low birth weight (ELBW) infants in Malaysia.

METHODS

This was a prospective study of infants in the Special Care Nursery at the University of Malaya Medical Centre between 2003 and 2005. Outcome measures were presence or absence of ROP, most severe stage of ROP observed, and whether laser treatment was performed. Risk factors for treatment were analyzed in this cohort of treated patients, who were further divided into groups of birth weight <751 g and birth weight 751-1,000 g.

RESULTS

The study protocol identified 70 qualifying ELBW infants. Of these, 41 (58.6%) developed ROP and 23 (32.9%) required laser treatment. Mean birth weight was 806.8 g (SD +/- 142.5); mean gestation was 27.4 weeks (SD +/- 2.2). Infants with birth weight <750 g were twice as likely to require treatment (OR = 2, p = 0.038). The risk factors for laser treatment by bivariate analysis were gestation <28 weeks (OR = 1.8, p = 0.001), duration of ventilation >1 week (OR = 1.5, p = 0.012), and intraventricular hemorrhage (OR = 2.5, p = 0.010). Zone 1 ROP was observed only in infants <751 g.

CONCLUSIONS

The incidence of ROP in ELBW infants in Malaysia is comparable to that seen in the ETROP and CRYO-ROP studies. Within this group, birth weight <750 g doubled the likelihood that treatment would be required.

Must screening examinations for retinopathy of prematurity necessarily be painful?

PURPOSE

This study investigates the impact of the length of the examination, the insertion of eyelid specula, and the indentation of the globe on the pain and stress sensation of premature infants.

METHODS

Ninety-two premature infants in three neonatal wards were included. In two wards, the patients were examined using eyelid specula and scleral indentation as recommended in the official guidelines. In the third ward, the investigation time was minimized and ophthalmoscopy was performed without eyelid specula and scleral indentation. Physical and mental disturbance of the patients was assessed by the Neonatal Infant Pain Score and by monitoring the heart rate. The results were divided into two groups: in the one, eyelid specula and scleral indentation were used, whereas in the other one, they were not used. An independent-samples t-test was performed, which allowed us to calculate the correlation between the way the examination was executed and the condition of the patients.

RESULTS

Demographic data and baseline values of heart rate and pain score did not differ between the two groups. Heart rate and pain score during and after the investigation were significantly higher and increased significantly with the duration of the examination for the patients who were investigated using lid specula and scleral indentation.

CONCLUSION

Our study shows that indirect ophthalmoscopy without specula causes significantly less stress to infants than screening with lid specula and scleral indentation.

Severe retinopathy of prematurity and visual outcomes in British Columbia: a 10-year analysis

OBJECTIVE

To describe the incidence trend and long-term visual outcomes of infants diagnosed with stages 3 to 4 retinopathy of prematurity (ROP) or laser-treated ROP born in British Columbia (Canada).

STUDY DESIGN

Data from all (n=1384) neonates with birth weight (BW) <1250 g, admitted to British Columbia Children's Hospital between period 1 (January 1992 to December 1996) and period 2 (January 1997 to December 2001) were analyzed. Ophthalmologic records of infants with stages 3 to 4 ROP or laser-treated ROP were abstracted. chi(2)- and t-test were used to compare neonatal characteristics between periods. Logistic regression was used to identify risk factors associated with visual impairment (defined as visual acuity <or=20/60 or visual field restriction of 20 degrees binocularly).

RESULT

Of 1159 surviving infants, 887 were examined for acute ROP (473 in period 1, 414 in period 2). Stages 3 to 4 ROP or laser-treated ROP were present in 35 infants in period 1 (7%) and 59 in period 2 (14%), P<or=0001. Infants born in period 2 had lower mean BW and gestational age. Among infants who developed severe ROP or laser-treated ROP, binocular visual impairment was present in eight children in period 1 and seven in period 2. Refractive errors, including myopia and astigmatism, were increased in period 2. Children who developed periventricular leucomalacia had the highest risk of visual impairment at 4 to 6 years of age.

CONCLUSION

During the 10-year study period, a significant increase in rates of stages 3 to 4 or laser-treated ROP was not associated with increases in visual impairment rates.

The clinical role of vascular endothelial growth factor (VEGF) system in the pathogenesis of retinopathy of prematurity

BACKGROUND

Recent experimental studies suggest that vascular endothelial growth factor (VEGF) can play an important role in the development of retinopathy of prematurity (ROP). There are interesting observations of VEGF concentration in the serum, depending on its gene polymorphism which can have an impact on abnormal vessel development in the retina.

AIM

Analysis of: (1) association of VEGF gene polymorphisms and the incidence of ROP, (2) correlation between serum concentration of VEGF and soluble VEGF receptor 1 (sVEGFR-1) during the 1st month of life and the risk of ROP, and (3) correlation between VEGF gene polymorphisms and VEGF serum concentrations.

METHODS

A sample of 181 newborns with mean birthweight 1054 g (range: 500-1500 g) was prospectively evaluated. Molecular analysis of VEGF -460T>C and 405G>C polymorphisms were performed in the whole studied population, and concentrations of VEGF and sVEGFR-1 were measured by Elisa assay in the 2nd, 3rd and 4th weeks of life in the group of 128 children. The infants were divided into 3 groups: A) no ROP (n = 101), B) ROP not requiring treatment (n = 20), and C) ROP requiring laser or cryotherapy (n = 60).

RESULTS

The frequency of VEGF 405G>C polymorphism was similar in all studied groups. The carriage of polymorphic allele -460 T was significantly overrepresented in ROP newborns who required treatment as compared to the no ROP group (54.2% vs 42.6%; OR: 1.63; 95% CI: 1.03-2.55). VEGF serum concentrations in the patients ascribed to different groups depending on the 405G>C or -460 T>C polymorphisms were similar. VEGF and sVEGFR-1 concentration on the 10th day of life did not differ significantly between the studied groups. Consecutive measurements showed a gradual increase in VEGF serum concentration in children without ROP, whereas in children with ROP requiring treatment the levels remained low.

CONCLUSIONS

Based on our observations and previously published data, the association of the VEGF gene promoter polymorphisms and the risk of advanced ROP is weak. VEGF serum concentration assessment as early as on the 20th day of life appears to be a promising approach to recognize newborns at risk of the development of advanced ROP.

Predicting long-term visual outcome in children with birth weight under 1001 g

PURPOSE

To examine the visual acuity development of extremely low birth weight children and to determine factors that are predictive of long-term outcome.

METHODS

This is a prospective observational longitudinal cohort study of children with birth weight less than 1001 g. One hundred thirty-nine children were recruited. Retinopathy of prematurity (ROP) examinations were graded according to the International Classification for ROP. Grating acuity was assessed monocularly with Teller acuity cards. All children were assessed before 24 months corrected age; 123 of the cohort had a grating acuity assessment at over 3 years. For the children who were capable, an assessment of recognition acuity was measured with the Electronic Visual Acuity system.

RESULTS

Data are presented for the right eye and the ages reported are adjusted for prematurity to allow comparison with normative data. Initial grating acuity was compared with the late grating and recognition acuity, but in both cases analysis showed no statistically significant association. However, the relative risk analysis showed that, if the slope was abnormal, there was a 5.5 times higher risk of abnormal recognition acuity. Eyes with zone 1 disease were associated with a worse visual acuity outcome, but zone 1 disease also occurred more frequently in children with lower birth weight and gestational age.

CONCLUSIONS

Early measurements of visual acuity may be misleading in terms of the visual prognosis. The factor that was most predictive of a poor late visual acuity outcome was the rate of development, as calculated by the slope of the early visual acuity measurements.

Childhood blindness: a UK epidemiological perspective

The purposes of this short paper are to introduce the reader to the aims of ophthalmic epidemiology and its relevance to clinical practice in ophthalmology and to vision science research. Summarise what is known currently about the epidemiology of severe visual impairment and blindness in childhood in the UK. Highlight the key gaps in our knowledge in this area and identify some of the most pressing challenges in terms of research.

Severe retinopathy of prematurity in infants <30 weeks' gestation in New South Wales and the Australian Capital Territory from 1992 to 2002

BACKGROUND

Retinopathy of prematurity (ROP) significantly increased in New South Wales (NSW) from 1986 to 1994, but more recent data suggest that there has now been a decrease.

OBJECTIVE

To study the incidence and treatment of severe ROP (stage >or=3) in NSW and the Australian Capital Territory (ACT) from 1992 to 2002.

METHODS

Data collected prospectively from the Neonatal Intensive Care Units' (NICUS) Data Collection over an 11-year period in infants <30 weeks' gestation were divided into four epochs and analysed retrospectively. The incidence and treatment of severe ROP were compared for gestational ages <or=24 weeks', 25-26 weeks' and 27-29 weeks' gestation over the four epochs.

RESULTS

In infants <or=24 weeks' gestation the incidence of severe ROP and those treated increased significantly (stage >or=3: from 17 (41.5%) to 41 (53.9%), p=0.052; treated: from 8 (19.5%) to 25 (32.9%), p<0.05 (first and fourth epoch)). In infants 25-26 weeks' gestation the incidence of severe ROP decreased significantly whereas there was a non-significant increase in those treated (stage >or=3: from 55 (26.2%) to 46 (19.3%), p<0.05; treated: from 19 (9.0%) to 32 (13.4%)). In infants 27-29 weeks' gestation, there was no significant change in the incidence of severe ROP or those treated (stage >or=3: from 30 (4.1%) to 17 (2.4%); treated: from 14 (1.9%) to 8 (1.1%)).

CONCLUSION

In infants <or=24 weeks' gestation there has been a significant increase in severe ROP, and in infants <27 weeks' gestation the numbers treated for severe ROP increased.

D-Penicillamine administration and the incidence of retinopathy of prematurity

OBJECTIVE

We compared the development of retinopathy of prematurity (ROP) among 49 preterm neonates:; 15 who were treated during the first 2 weeks of life with D-penicillamine and 34 who were not.

METHODS

During a 15-month period beginning 1 March, 2005, 15 preterm neonates <1000 g birth weight or < or =29 weeks gestation enterally received a 14-day course of D-penicillamine, and 34 did not, in an open-label non-randomized trial. We compared the outcomes of developing 'ROP any stage' and 'ROP requiring surgery' in the recipients vs the non-recipients. Potential toxicities of the D-penicillamine were examined by comparing specific laboratory tests, growth velocities, transfusion requirements, discharge hemoglobin concentrations and supplemental O(2) at discharge.

RESULTS

The 34 non-treated and the 15 D-penicillamine treated patients were of similar gestational age (26.5+/-1.8 vs 26.6+/-2.2 weeks, mean+/-s.d.) and birth weight (887+/-222 vs 849+/-187 g). Four of the 34 non-recipients died. Eighteen of the 30 survivors (60%) developed ROP and seven of the 30 (23%) had ROP surgery. One of the 15 D-penicillamine recipients died. Three of the 14 survivors (21%) developed ROP (P=0.01 vs non-recipients) and all three had ROP laser surgery. No increase in elevated creatinine, direct or indirect bilirubin, thrombocytopenia or neutropenia was apparent in those treated with D-penicillamine. The D-penicillamine recipients did not receive more transfusions and did not have lower hemoglobin concentrations at discharge. They did not have lower velocities of weight gain at 14, 28 and 56 days, and were not discharged on supplemental O(2) at a rate exceeding that of the non-recipients.

CONCLUSIONS

In this non-randomized, single-centered comparison analysis, a 14-day course of D-penicillamine resulted in no apparent short-term toxicity. The treatment was associated with elimination of Stage I and Stage II ROP, decreasing the overall odds of developing ROP from 60 to 21%. However, this approach did not reduce the odds of ROP surgery. Perhaps higher doses of D-penicillamine or longer treatment periods or other prophylactic approaches will be required to reduce ROP surgery among the most immature neonates.

A pilot trial testing the feasibility of administering D-penicillamine to extremely low birth weight neonates

OBJECTIVE

We enterally administered a 14-day course of 3-mercapto-D-valine (D-penicillamine) to five extremely low birth weight (ELBW) neonates, as a step toward assessing this therapy as a means of reducing the incidence or severity of retinopathy of prematurity (ROP).

METHODS

The study drug (100 mg/ml) was given by nasogastric tube at a dose of 100 mg/k every 8 h for three days, and then 50 mg/k once per day for 11 additional days. Logbooks were maintained by the bedside nurses to record signs of possible immediate intolerance. Laboratory tests assessed hepatic, renal, and hematologic toxicity. ROP was scored according to the ICROP guidelines. Comparisons were with a cohort of 139 consecutive recent neonates of the same birth weight and gestational age range.

RESULTS

Five neonates were enrolled in the study, and all received the full course of study drug as planned. Signs of immediate intolerance of the study drug were not observed in any. The study patients did not have a higher incidence, than that of the cohort group, in creatinine elevation, thrombocytopenia, neutropenia, hyperbilirubinemia, or abnormal liver function test. Four of the five had no ROP and one developed transient stage 1, compared with a 54% occurrence of ROP in the cohort.

CONCLUSIONS

It is feasible to enterally administer a 14-day course of 3-mercapto-D-valine to ELBW neonates and the suspension appears to be well tolerated. These results suggest that phase II safety and preliminary efficacy trials can be undertaken.