Treatment for retinopathy of prematurity in Denmark in a ten-year period (1996 2005): is the incidence increasing?

Association of ACE and AGTR1 variants with retinopathy of prematurity: a case-control study and meta-analysis

Retinopathy of prematurity (ROP) is a major cause of childhood blindness worldwide, linked to gene variants in the renin-angiotensin-aldosterone system, including angiotensin-converting enzyme (ACE) and angiotensin II receptor type 1 (AGTR1). This study aims to evaluate the association between ACE insertion/deletion (I/D) and AGTR1 rs5186A > C variants with the occurrence and progression of ROP in a Polish cohort. A total of 377 premature infants were enrolled in the study. The ACE variant was evaluated using PCR, and AGTR1 was assessed using TaqMan probes. Clinical characteristics, including risk factors and comorbidities, were documented. A meta-analysis of the effects of the studied variants on ROP was also conducted. The AGTR1 rs5186C allele was significantly associated with both the progression of ROP and treatment outcomes. Homozygotes exhibited a 2.47-fold increased risk of developing proliferative ROP and a 4.82-fold increased risk of treatment failure. The impact of this allele increased at low birth weight. A meta-analysis, including 191 cases and 1661 controls, indicated an overall risk of 1.7 (95%CI 1.02-2.84) for the recessive effect of the rs5186C allele. The ACE variant did not show a significant association with ROP in our population; however, a meta-analysis of 996 cases and 2787 controls suggested a recessive effect of the insertion allele (an odds ratio of 1.21 (95%CI 1.00-1.60)). These results indicate that gain-of-function AGTR1 variants may play a crucial role in the development of ROP, potentially by promoting angiogenesis and pro-inflammatory effects. Screening for these variants could facilitate the development of personalized risk assessment and treatment strategies for ROP.

Visual impairment due to retinopathy of prematurity and concomitant disabilities in the Netherlands

AIM

Determine incidence of visual impairment due to retinopathy of prematurity (ROP) and concomitant disabilities between 2009 and 2018 in the Netherlands and compare data to four former similar studies. Secondly, monitor if infants were missed for ROP-screening since the adoption of stricter, risk factor guided criteria (2013).

METHODS

Retrospective inventory on anonymous data of infants diagnosed with ROP from Dutch visual impairment-institutes. Data including: best corrected visual acuity, ROP-treatment and concomitant disabilities: bronchopulmonary dysplasia, behavioral abnormalities, epilepsy, hearing deficit, developmental delay, cerebral palsy and cerebral visual impairment. During the study period, lower age limit for neonatal life support (2010) and higher oxygen saturation targets (2014) were implemented.

RESULTS

Records of 53 infants were analyzed. Visual impairment incidence due to ROP was 2.02 per 100.000 live births (2000-2009: 1.84, p = 0.643). Compared to earlier periods (1975-2000), a significant decrease was observed. The incidence of concomitant disabilities remained stable. Mean gestational age (GA) continued to decrease to 26.6 ± 1.9 weeks (2000-2009: 27.4 ± 2.0 weeks, p = 0.047). All patients met the screening inclusion criteria.

CONCLUSION

The incidence of visual impairment due to ROP and concomitant disabilities between 2009 and 2018 has not increased, despite lower GA and higher oxygen saturation targets. None of the infants were missed for ROP screening following introduction of more restricted screening inclusion criteria.

Nationwide inventory on retinopathy of prematurity screening in the Netherlands

PURPOSE

Provide up-to-date insight in incidence of retinopathy of prematurity (ROP), logistics of screening and treatment in the Netherlands and influence of the new national ROP guideline in which more stringent screening criteria were implemented and the early treatment for ROP criteria (ETROP) were emphasised.

METHODS

Multicentre prospective nationwide study including all preterm infants, born in the Netherlands in 2017, and considered eligible for ROP screening. Anonymised data from ophthalmologists and paediatricians were merged. Outcome data were compared with the first national ROP inventory (NEDROP-1, 2009).

RESULTS

In 2017, 1492 infants were live born with gestational age (GA) <32 weeks (2009: 1662); 1287 infants were eligible for screening (2009: 2033). Ophthalmologists screened 1085 infants, versus 1688 in 2009, corrected with factor 1.114 for the difference in number of live births, a 28.4% (479/1688) decrease in screened infants was seen. Among surviving infants with GA <32 week, ROP was found in 305/1492 babies, 20.4% (2009: 324/1662, 19.5%) of which 49/1492 stage ≥3, 3.3% (2009: 30/1662, 1.8%). In all infants, report on presence or absence of plus disease was provided, according to the ETROP criteria. Treatment was performed in 39 infants. Of infants with ROP stage ≥3, 3/49 (6.1%) progressed to retinal detachment (2009: 6/30, 20.0%).

CONCLUSION

The overall ROP incidence expressed as a percentage, remained stable but the number of infants that developed severe ROP nearly doubled. A near one-third reduction in screened infants shows satisfactory implementation of the new screening criteria. A notable decrease in retinal detachment delineates improved treatment outcome.

Management of retinopathy of prematurity (ROP) in a Polish cohort of infants

Retinopathy of prematurity (ROP) is potentially blinding, but screening and timely treatment can stop its progression. The data on treatment outcomes of ROP from Central and Eastern Europe are scarce. Therefore, we aimed to analyze the latest results of ROP management in Poznan medical center to update the data from this world region. In the years 2016–2019, 178 patients (350 eyes) received treatment for ROP (6.1% of the screened population). The mean gestational age was 26 weeks (range 22–31 weeks), the mean birth weight was 868 g (range 410–1890 g). The most frequent ROP stage at treatment was zone II, stage 3 + (34.9%). As the first line of treatment, 115 infants (226 eyes, 64.6%) underwent laser photocoagulation (LP); 61 infants (120 eyes, 34.3%) received intravitreal ranibizumab injections (IVR); and 2 infants (4 eyes, 0.6%) were treated simultaneously with LP and IVR. One hundred twenty-six eyes (36%) of 63 patients required retreatment: 20.4% treated with LP and 66.7% treated with IVR. Retinal detachment occurred in 14 eyes (4%). The incidence of ROP, ROP requiring treatment, and reoccurrence rates are higher in the Polish population than in Western Europe and the USA. The identified treatment patterns find increasing use of anti-VEGF agents.

Increase in treatment of retinopathy of prematurity in the Netherlands from 2010 to 2017

Purpose

Compare patients treated for Retinopathy of Prematurity (ROP) in two consecutive periods.

Methods

Retrospective inventory of anonymized neonatal and ophthalmological data of all patients treated for ROP from 2010 to 2017 in the Netherlands, subdivided in period (P)1: 1‐1‐2010 to 31‐3‐2013 and P2: 1‐4‐2013 to 31‐12‐2016. Treatment characteristics, adherence to early treatment for ROP (ETROP) criteria, outcome of treatment and changes in neonatal parameters and policy of care were compared.

Results

Overall 196 infants were included, 57 infants (113 eyes) in P1 and 139 (275 eyes) in P2, indicating a 2.1‐fold increase in ROP treatment. No differences were found in mean gestational age (GA) (25.9 ± 1.7 versus 26.0 ± 1.7 weeks, p = 0.711), mean birth weight (791 ± 311 versus 764 ± 204 grams, p = 0.967) and other neonatal risk factors for ROP. In P2, the number of premature infants born <25 weeks increased by factor 1.23 and higher oxygen saturation levels were aimed at in most centres. At treatment decision, 59.6% (P1) versus 83.5% (P2) (p = 0.263) infants were classified as Type 1 ROP (ETROP classification). Infants were treated with laser photocoagulation (98 versus 96%) and intravitreal bevacizumab (2 versus 4%). Retreatment was necessary in 10 versus 21 (p = 0.160). Retinal detachment developed in 6 versus 13 infants (p = 0.791) of which 2 versus 6 bilateral (p = 0.599).

Conclusion

In period 2, the number of infants treated according to the ETROP criteria (Type 1) increased, the number of ROP treatments, retinal detachments and retreatments doubled and the absolute number of retinal detachments increased. Neonatal data did not provide a decisive explanation, although changes in neonatal policy were reported.

Efficacy of the WINROP algorithm for retinopathy of prematurity screening in Southern China

AIM

To evaluate the predicting efficacy of severe retinopathy of prematurity (ROP) by the WINROP algorithm (http://winrop.com) in Southern China.

METHODS

All preterm infants with the gestational age (GA) less than 32wk were included. Their ROP screening results and serial postnatal body weight were analysed retrospectively. Weekly body weight was entered into and measured by the WINROP system. The outcomes were analysed, and the sensitivity, specificity, positive predictive value and negative predictive value (NPV) were calculated.

RESULTS

Totally 432 infants with a median GA of 30.0 (24.0-31.9)wk, and a median birth weight (BW) of 1360 (540-2700) g were included. Among these 432 infants, 50 were diagnosed as type 1 ROP but only 28 were identified by the WINROP algorithm. The sensitivity was 56% (28/50) and the NPV was 92% (252/274). However, for infants with BW <1000 g or GA <28wk, the sensitivity was 93.8% (15/16) and 93.3% (14/15), respectively. Meanwhile, with several postnatal complications added as additional risk factors, the sensitivity was increased to 96% (48/50).

CONCLUSION

The sensitivity of the WINROP algorithm from the Southern Chinese cohort is not as high as that reported in developed countries. This algorithm is effective for detecting severe ROP from extremely small or preterm infants. Modification of the algorithm with additional risk factors could improve the predictive value for infants with a GA>28wk in China.

A Good Way to Reduce Screening for Retinopathy of Prematurity: Development of the ROP Model in a China Preterm Population

Importance: Retinopathy of prematurity (ROP) is a preventable cause of blindness in children. Without treatment, more than 45% of eyes may suffer permanent vision loss. Current ROP screening guidelines, which include a range of birth weights (BWs) and gestational ages (GAs), may require screening many low-risk preemies who might develop severe ROP. Method: All high-risk infants in the neonatal intensive care unit (NICU) of the First Affiliated Hospital of Zhengzhou University from 2017 to 2021 were included in this retrospective cohort study. Each of the 27 candidate risk factors was evaluated in univariate analysis and adjusted for known risk factors (i.e., GA and BW). The significant results were analyzed in a backward selection multivariate logistic regression model. Receiver operating characteristic (ROC) curves and a nomogram were drawn. Results: The study included 2,040 infants who underwent ROP screening. The weight gain rate [OR, 2.65; 95% confidence interval (CI), 1.49-1.21 ≤ 12 g/d vs. > 18 g/d; P = 0.001], blood transfusion (OR, 2.03; 95% CI, 1.14-3.64; P = 0.017), invasive mechanical ventilation (OR, 1.74; 95% CI, 1.15-2.66; P = 0.009) and N-terminal segment of pro-B-type natriuretic peptide (NT-proBNP) ≥ 25,000 ng/L (OR, 1.51; 95% CI, 1.00-2.28; P = 0.048) were four new statistically independent risk factors in addition to GA and BW. The area under the curve (AUC) of the final multivariate model was 0.90 (95% CI, 0.88-0.92; P < 0.001). Conclusions and Relevance: These findings add to our understanding of ROP screening because they include all eligible infants rather than only high-risk infants, as in previous studies. Under the control of BW and GA, low weight gain rate, increased number of blood transfusion, invasive mechanical ventilation and NT-proBNP ≥ 25,000 ng/L were "new" statistically independent risk factors for ROP. The ROP risk can be calculated manually or represented by a nomogram for clinical use.

Risk Factors for Retinopathy of Prematurity in the Netherlands: A Comparison of Two Cohorts

INTRODUCTION

Retinopathy of prematurity (ROP) remains an important cause for preventable blindness. Aside from gestational age (GA) and birth weight, risk factor assessment can be important for determination of infants at risk of (severe) ROP.

METHODS

Prospective, multivariable risk-analysis study (NEDROP-2) was conducted, including all infants born in 2017 in the Netherlands considered eligible for ROP screening by pediatricians. Ophthalmologists provided data of screened infants, which were combined with risk factors from the national perinatal database (Perined). Clinical data and potential risk factors were compared to the first national ROP inventory (NEDROP-1, 2009). During the second period, more strict risk factor-based screening inclusion criteria were applied.

RESULTS

Of 1,287 eligible infants, 933 (72.5%) were screened for ROP and matched with the Perined data. Any ROP was found in 264 infants (28.3% of screened population, 2009: 21.9%) and severe ROP (sROP) (stage ≥3) in 41 infants (4.4%, 2009: 2.1%). The risk for any ROP is decreased with a higher GA (odds ratio [OR] 0.59 and 95% confidence interval [CI] 0.54-0.66) and increased for small for GA (SGA) (1.73, 1.11-2.62), mechanical ventilation >7 days (2.13, 1.35-3.37) and postnatal corticosteroids (2.57, 1.44-4.66). For sROP, significant factors were GA (OR 0.37 and CI 0.27-0.50), SGA (OR 5.65 and CI 2.17-14.92), postnatal corticosteroids (OR 3.81 and CI 1.72-8.40), and perforated necrotizing enterocolitis (OR 7.55 and CI 2.29-24.48).

CONCLUSION

In the Netherlands, sROP was diagnosed more frequently since 2009. No new risk factors for ROP were determined in the present study, apart from those already included in the current screening guideline.

Higher incidence of retinopathy of prematurity in extremely preterm infants associated with improved survival rates

AIM

This study assessed possible reasons for the increasing incidence of retinopathy of prematurity (ROP) since mid-2015 at our institution.

METHODS

Retrospective analysis of all preterm infants born July 2013 to June 2017 with a gestational age (GA) <29 completed weeks admitted to the neonatal intensive care unit at the University Hospital Zurich during the first 28 days of life. The primary outcome measures were severest ROP stage. Statistical analysis was performed using generalised additive models in R.

RESULTS

During the study period, survival increased in extremely preterm infants. Significant predictors for severest ROP stage were GA, days of mechanical ventilation and multiple gestation (P = .0322). A composite of severe comorbidities had no significant effect on severest ROP stage. GA was identified as the only significant risk factor the for severest ROP stage (P = .0045).

CONCLUSION

Increased survival rate of extremely preterm infants was associated with an increased incidence of ROP at our institution. Despite the increase, the incidence is still very low compared with other countries. No other additive factors were identified.

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.

Incidence of retinopathy of prematurity (ROP) and ROP treatment in Switzerland 2006-2015: a population-based analysis

BACKGROUND

Retinopathy of prematurity (ROP) is a severe complication of preterm birth and can lead to severe visual impairment or even blindness if untreated. The incidence of ROP requiring treatment is increasing in some developed countries in conjunction with higher survival rates at the lower end of gestational age (GA).

MATERIAL AND METHODS

The incidence of ROP and severe ROP (sROP) requiring treatment in Switzerland was analysed using the SwissNeoNet registry. We conducted a retrospective cohort analysis of very preterm infants with a GA below 32 weeks who were born between 2006 and 2015 in Switzerland. Patient characteristics were stratified according to GA.

RESULTS

9.3% and 1.8% of very preterm infants in Switzerland developed ROP of any stage and sROP, respectively. The incidence of ROP treatment was 1.2%. Patients with 24 and 25 weeks GA had the highest proportion of ROP treatment at 14.5% and 7.3%, respectively, whereas the proportion of treated infants at or above a GA of 29 weeks was 0.06%. Similarly, the risk of sROP declined strongly with increasing GA. During the observation period of 10 years, the incidence of ROP treatment ranged between 0.8% and 2.0%. Incidences of sROP or ROP treatment did not increase over time.

CONCLUSION

The incidence of ROP treatment in Switzerland is low and was stable over the analysed period. The low incidence of sROP in patients with a GA of 29 weeks or more leaves room for a redefinition of ROP screening criteria.

Ultra-low dose of intravitreal bevacizumab in retinopathy of prematurity

AIM

We aimed to investigate the effectivity of the 0.0625 mg dose of bevacizumab in patients with retinopathy of prematurity (ROP) and compare the results with 0.625 mg dose of intravitreal bevacizumab (IVB) injection.

METHODS

The medical records of the patients with type 1 ROP who received IVB monotherapy were retrospectively reviewed. Demographic and clinical characteristics of the patients were recorded. The patients were classified into two groups with respect to received dose of bevacizumab as follows: group F (n = 46) (full dose of bevacizumab-0.625 mg/0.025 ml) and group L (n = 45) (low dose (one tenth) of bevacizumab-0.0625 mg/0.025 ml).

RESULTS

Both treatment dose regimens have similar outcomes. Moreover, the mean retinal vascularization time seemed to be significantly higher in group F compared to group L, 168 ± 65 and 97 ± 29 days, respectively (p < 0.001). Disappearance of plus sign is observed earlier in group F (2.45 ± 1.7 vs 3.66 ± 2.46 days, respectively, p = 0.03).

CONCLUSIONS

The low dose (0.0625 mg) of IVB treatment was effective as full (0.625 mg) dose in ROP treatment. Moreover, our results showed that low-dose treatment might provide faster retinal vascularization than the regular used dose. On the other hand, disappearance of the plus sign takes longer time in patients treated with low dose compared to eyes treated with full dose of IVB that should be taken into account.

Pre-eclampsia and the risk of retinopathy of prematurity in preterm infants with birth weight <1500 g and/or <31 weeks' gestation

Objective

To evaluate the relationship between pre-eclampsia and development of retinopathy of prematurity (ROP) in infants with birth weight of <1500 g and/or gestation <31 weeks.

Methods

A retrospective cohort study comprising infants born to mothers with pre-eclampsia between January 2007 and June 2010 at a single tertiary care centre. Their ROP outcome was compared with infants born to the next two normotensive mothers with a ±1 week gestational age difference. Pearson χ² test was used for categorical variables and Mann-Whitney U test was used for continuous variables. Multivariable regression was used to estimate the OR of ROP with prenatal pre-eclampsia exposure and adjust for confounders.

Results

Of the 97 infants in the pre-eclampsia group, 27 (27%) developed ROP and of the 185 infants in the normotensive group, 50 (27%) developed ROP. On multivariable regression modelling, pre-eclampsia was not a risk factor for the development of ROP (OR 1.4, 95% CI 0.46 to 4.1). Gestational age, intrauterine growth restriction and blood transfusion were significant risk factors for the development of ROP.

Conclusions

In our cohort, pre-eclampsia was not a significant risk factor for the development of ROP. Intrauterine growth restricted infants of pre-eclamptic and normotensive mothers were at higher risk of ROP.

Early postnatal hyperglycaemia is a risk factor for treatment-demanding retinopathy of prematurity

BACKGROUND

To investigate whether neonatal hyperglycaemia in the first postnatal week is associated with treatment-demanding retinopathy of prematurity (ROP).

METHODS

This is a Danish national, retrospective, case-control study of premature infants (birth period 2003-2006). Three national registers were searched, and data were linked through a unique civil registration number. The study sample consisted of 106 cases each matched with two comparison infants. Matching criteria were gestational age (GA) at birth, ROP not registered and born at the same neonatal intensive care unit. Potential 'new' risk factors were analysed in a multivariate logistic regression model, while adjusted for previously recognised risk factors (ie, GA at birth, small for gestational age, multiple birth and male sex).

RESULTS

Hospital records of 310 preterm infants (106 treated; 204 comparison infants) were available. Nutrition in terms of energy (kcal/kg/week) and protein (g/kg/week) given to the preterm infants during the first postnatal week were statistically insignificant between the study groups (Mann-Whitney U test; p=0.165/p=0.163). Early postnatal weight gain between the two study groups was borderline significant (t-test; p=0.047). Hyperglycaemic events (indexed value) were statistically significantly different between the two study groups (Mann-Whitney U test; p<0.001). Hyperglycaemia was a statistically independent risk factor (OR: 1.022; 95% CI 1.002 to 1.042; p=0.031).

CONCLUSION

An independent association was found between the occurrence of hyperglycaemic events during the first postnatal week and later development of treatment-demanding ROP, when adjusted for known risk factors.

Assessment of WINROP algorithm as screening tool for preterm infants in Manitoba to detect retinopathy of prematurity

Objective

Developing less invasive methods for early detection of retinopathy of prematurity (ROP) is vital to minimizing blindness in premature infants. Lofqvist and colleagues developed a computer-based ROP risk algorithm (WINROP) (https://winrop.com), which detects downtrends in postnatal weight gain that correlate with the development of sight-threatening ROP. The aim of this study is to investigate the sensitivity and specificity of the WINROP algorithm to detect vision-threatening ROP.

Methods

This is a retrospective chart review study between January 2008 and December 2013. This study was conducted in the neonatal intensive care unit in Children's Hospital at Health Sciences Centre, Winnipeg, Manitoba, Canada. The study included preterm infants, less than 32 weeks' gestation, who were admitted to the hospital during the study period. The included 215 infants were eligible for ROP screening and had sufficient data to be entered into the WINROP algorithm. Infants were screened by a paediatric ophthalmologist for retinopathy of prematurity. The body weight of infants was measured weekly and entered into the WINROP algorithm; the sensitivity and the specificity of the WINROP algorithm were assessed.

Results

The mean gestational age was 28.6 ± 1.8 weeks. The mean body weight was 1244 ± 294 g. The sensitivity of the WINROP algorithm to detect vision-threatening retinopathy of prematurity in our cohort was 90% (P=0.021) with a specificity of 60% (P=0.002).

Conclusion

The WINROP algorithm lacks sufficient sensitivity to be used clinically in our population. The algorithm needs to be reassessed in contemporary populations.

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.

Neonatal Risk Factors for Treatment-Demanding Retinopathy of Prematurity: A Danish National Study

PURPOSE

One goal of the study was to identify "new" statistically independent risk factors for treatment-demanding retinopathy of prematurity (ROP). Another goal was to evaluate whether any new risk factors could explain the increase in the incidence of treatment-demanding ROP over time in Denmark.

DESIGN

A retrospective, register-based cohort study.

PARTICIPANTS

The study included premature infants (n = 6490) born in Denmark from 1997 to 2008.

METHODS

The study sample and the 31 candidate risk factors were identified in 3 national registers. Data were linked through a unique civil registration number. Each of the 31 candidate risk factors were evaluated in univariate analyses, while adjusted for known risk factors (i.e., gestational age [GA] at delivery, small for gestational age [SGA], multiple births, and male sex). Significant outcomes were analyzed thereafter in a backward selection multiple logistic regression model.

MAIN OUTCOME MEASURES

Treatment-demanding ROP and its associations to candidate risk factors.

RESULTS

Mechanical ventilation (odds ratio [OR], 2.84; 95% confidence interval [CI], 1.99-4.08; P < 0.01) and blood transfusion (OR, 1.97; 95% CI, 1.20-3.14; P = 0.01) were the only new statistically independent risk factors, in addition to GA at delivery, SGA, multiple births, and male sex. Modification in these prognostic factors for ROP did not cause an increase in treatment-demanding ROP.

CONCLUSIONS

In a large study population, blood transfusion and mechanical ventilation were the only new statistically independent risk factors to predict the development of treatment-demanding ROP. Modification in the neonatal treatment with mechanical ventilation or blood transfusion did not cause the observed increase in the incidence of preterm infants with treatment-demanding ROP during a recent birth period (2003-2008).

Retinal Oximetry with Scanning Laser Ophthalmoscope in Infants

Purpose

Dual wavelength retinal oximetry has been developed for adults, but is not available for infants. Retinal oximetry may provide insight into the pathophysiology of oxygen-mediated diseases like retinopathy of prematurity. More insight in the oxygen metabolism of the retina in infants may provide valuable clues for better understanding and subsequent prevention or treatment of the disease. The measurements of oxygen saturation are obtained with two fundus images simultaneously captured in two different wavelengths of light. The comparison in light absorption of oxygenated and deoxygenated hemoglobin can be used to estimate the oxygen saturation within the retinal vessels by means of a software algorithm. This study aims to make retinal oximetry available for neonates. The first step towards estimating retinal oxygen saturation is determining the optical density ratio. Therefore, the purpose of this study is to image healthy newborn infants with a scanning laser ophthalmoscope and determine the optical density ratio for retinal oximetry analysis.

Methods

Images of the retina of full-term healthy infants were obtained with an SLO, Optomap 200Tx (Optos), with two laser wavelengths (532nm and 633nm). The infant lay face down on the lower arm of the parent, while the parent supported the chest and chin with one hand, and stabilized the back with the other hand. No mydriatics or eyelid specula were used during this study. The images were analyzed with modified Oxymap Analyzer software for calculation of the Optical Density Ratio (ODR) and vessel width. The ODR is inversely and approximately linearly related to the oxygen saturation. Measurements were included from the superotemporal vessel pair. A paired t-test was used for statistical analysis.

Results

Fifty-nine infants, (58% female), were included with mean gestational age of 40 ± 1.3 weeks (mean ± SD) and mean post-natal age of 16 ± 4.8 days. A total of 28 images were selected for retinal oximetry analysis. The ODR was 0.256 ± 0.041 for the arterioles and 0.421 ± 0.089 for the venules (n = 28, p < 0.001). The measured vessel-width for the arterioles was 14.1 ± 2.7 pixels and for the venules 19.7 ± 3.7 pixels (n = 28, p < 0.001).

Conclusions

Retinal oximetry can be performed in newborn infants by combining an SLO and a dual-wavelength algorithm software. Sensitivity of the approach is indicated by the fact that the ODR measurements are significantly different between the arterioles and the venules. However, more variability in ODR is seen with the SLO approach in babies than is seen with conventional oximetry in adults. This approach is completely non-invasive, non-contact and even avoids the use of mydriatics or eyelid specula.

Refraction and visual acuity in a national Danish cohort of 4-year-old children of extremely preterm delivery

PURPOSE

A recent threefold increase in laser treatment for advanced retinopathy of prematurity (ROP) triggered a nationwide preschool ophthalmic and developmental status among extremely preterm survivors. Here, we discuss refraction and visual acuity.

METHODS

Survivors (n = 178) from a national birth cohort (February 2004 to March 2006) of gestational age <28 weeks (PT) and 56 full-term (FT) controls attended for evaluation at age 4 years. Cycloplegic refraction and keratometry were achieved by Retinomax autokeratorefractor and visual acuities by symbol recognition (HOTV, logMAR).

RESULTS

The refractive distribution presented a myopic tail (4.5%) and a hyperopic tail (11.9% ≥+2.5 D) as special preterm features, and corneas were more curved. Astigmatism and anisometropia were only marginally increased, and visual acuities were generally good. Best-corrected binocular median logMAR visual acuity was 0.1 in FT and 0.2 in PT, in Snellen equivalents 0.8 and 0.63. Snellen acuity ≤0.5 occurred across the ROP subgroups, but mainly in those with at least ROP stage 3. Two children had low vision.

CONCLUSIONS

The overall fair outcome for refraction and function is in accordance with other recent northern Europe experience. The results differ in particular from the poorer ophthalmic outcomes reported in the pioneer US treatment studies (cryotherapy for ROP and ETROP). The diode laser ablations (n = 32) appeared effective in our series; except one child, all treated subjects had good or fair social vision at the age of 4 years.

The usefulness of the Retinomax autorefractor for childhood screening validated against a Danish preterm cohort examined at the age of 4 years

BACKGROUND AND PURPOSE

Refractometers have gained a foothold in childhood screening for ophthalmic disorders. Given the results of an ophthalmic follow-up of an extremely preterm Danish cohort, the results of the Retinomax autorefractor were further evaluated.

MATERIALS AND METHODS

A nationwide cohort of infants born before gestational age 28 weeks (n=178) and 56 term controls were examined at the age of 4 years. Refraction was given as the cycloplegic Retinomax value. For this study, we analysed the equipment's confidence value on the printout and equipment-induced myopization (as the difference between refraction measured before and after topical cyclopentholate 1%), both items hypothetical with a view to having identified factual ophthalmic deviations.

RESULTS

Thirty-two of 42 eyes with visual acuity ≤0.4 had high Retinomax confidence values (8-9); the Retinomax values were also high in 10 of 12 children with strabismus and lack of stereopsis. Low values (1-6) were recorded in 11 single eyes, 5 of which were normal (false positives). Three children already known to have low vision were unable to cooperate. The overall mean value for equipment-induced myopization was 1.9 D (range, 0-6.87 D). Myopization showed no correlation with visual acuity and corneal curvature, and a weak positive correlation with refractive value disappeared when the myopic outliers were excluded.

CONCLUSIONS

The hand-held Retinomax seemed to be reliable for assessing refraction in 4-year-old children, provided a cycloplegic agent is applied; if used alone, the Retinomax would have missed several cases of ophthalmic deviation during screening. Equipment-induced myopization was not indicative.

Incidence of retinopathy of prematurity in the middle Black Sea region of Turkey over a 10-year period

PURPOSE

To report the incidence of retinopathy of prematurity (ROP) in babies with a birth weight of ≤1750 g over a 10-year period in the north of Turkey.

METHODS

The medical records of 2,365 preterm babies who had been referred for ophthalmological examination were retrospectively reviewed, and children with a birth weight of ≤1750 g were included. The incidence of ROP was compared between two successive 5-year periods: 2004-2008 and 2009-2013.

RESULTS

A total of 1,565 babies were included: 624 in the first period and 941 in the second. The incidence of ROP significantly increased during the second period compared to the first (35.3% vs 48.2% [P < 0.001]). The number of patients who required treatment was 11.9% in the first period and 11.4% in the second (P = 0.768).

CONCLUSIONS

Although the incidence of ROP increased during the latter period of study (2009-2013), the numbers of treatment-requiring cases were similar in both periods.

Risk factors for retinopathy of prematurity in extremely preterm Chinese infants

To investigate the incidence and risk factors of retinopathy of prematurity (ROP) and Type 1 ROP in extremely preterm Chinese infants. A retrospective review of medical records was performed of all extremely preterm neonates (gestational age, GA≤28 weeks) screened for ROP from 2007 to 2012 at an ophthalmology centre in Hong Kong. Thirty-three maternal and neonatal covariates were analyzed using univariate and multivariate regression analyses for both ROP and Type 1 ROP. The mean gestational age (GA) was 26.4±1.3 weeks and the birth weight (BW) was 855.0±199.0 g. The incidence of ROP development was 60.7% and 16.2% for Type 1 ROP. On univariate analysis, 6 risk factors were identified for ROP development including: lighter BW; lower GA; postnatal hypotension; inotrope use; surfactant use; and invasive mechanical ventilation (all P≤0.01). On multivariate analysis, neonatal congenital heart disease and greater GA were protective factors for ROP development (P≤0.04). On the other hand, 4 risk factors were associated with Type 1 ROP development in univariate analysis, including: lower GA, lighter BW, multiple pregnancies, and invasive mechanical ventilation (all P≤0.02); while there was no significant risk factors on multivariate analysis. A lighter BW and lower GA were the only common independent risk factors for both ROP and Type 1 ROP while neonatal congenital heart disease and greater GA were the protective factors against ROP.

"Oxygen with love" and diode laser treatment decreases comorbidity and avoidable blindness due to retinopathy of prematurity: results achieved in the past 12 years

AIM

To determine whether the "Oxygen with Love" (OWL) and diode laser treatment provided in a neonatal intensive care unit has reduced the risk of avoidable blindness caused by retinopathy of prematurity (ROP) over the past decade.

MATERIALS AND METHODS

A prospective observational cohort study was performed, in which 351 infants were examined for ROP. The inclusion conditions were as follows: preterm infants, birthweight <1500 g or <32 weeks' gestational age, and birth between 1 Jan 2000 to 31 August 2012. From mid-2009, the OWL program was implemented and the ventilation protocols for such infants were amended. We tested whether the incidence of unfavorable structural outcomes of ROP had decreased following these changes.

RESULTS

From 2004 to 2012, the survival rates of younger children increased (p < 0.003). From 2005 to 2012, laser treatment rather than cryotherapy was applied, and the incidence of unfavorable structural outcomes of ROP fell from 13% to 5.6% (not significant). From 2009 to 2012, the incidence of ROP decreased from 55% to 29% (p < 0.002). From 1 August 2009 to 31 August 2012, there was less need for ablative treatment for premature infants, with the rate falling from 11.81% to 3.9% (p < 0.03). This improvement was significantly associated with a reduction in the number of days of intubation (p < 0.0017), lower rates of sepsis (p < 0.003), and improvements in postnatal weight gain (p < 0.0002).

CONCLUSION

The introduction of the OWL program, together with lower rates of sepsis, improvements in postnatal weight gain, and the use of diode laser treatment, has reduced the incidence of unfavorable structural outcomes of ROP.

Treatment of retinopathy of prematurity in extremely premature infants over an 18-year period

BACKGROUND

To report the efficacy of laser diode therapy in the treatment of retinopathy of prematurity (ROP) in extremely premature (EP) infants over an 18-year period.

DESIGN

Retrospective study.

PARTICIPANTS

One hundred twenty-eight eyes in 66 infants treated between 23 and 25.6 weeks.

METHODS

Five hundred fifty-four infants between 23 and 25.6 weeks gestational age (GA) were admitted to The Royal Brisbane and Women's Hospital Neonatal Intensive Care Unit (NICU) between 1992 and 2009. Three hundred seventy-three patients survived to undergo screening, 304 were diagnosed with ROP, and 66 infants required diode laser therapy.

MAIN OUTCOME MEASURES

Success of treatment, visual and refractive outcomes.

RESULTS

One hundred twenty-eight eyes from 66 infants (18.8% of those screened) underwent laser treatment with a mean GA of 24.3 weeks and mean birth weight of 711.4g. Fifty-six eyes were treated at pre-threshold disease, and 72 eyes at threshold disease. Over the study period, the number of laser spots and regression rate of ROP increased, while the frequency of re-treatment decreased. At 40 weeks, 119 eyes had regressed ROP (93%), two advanced to stage 4a, three to stage 4b and four to stage 5. Aggressive posterior ROP (AP-ROP) occurred in 15 eyes (11.7% of those treated). Forty-three patients (65%) were followed up for a mean of 56.5 months. The number of laser spots correlated well with subsequent refractive error but poorly with corrected visual acuity.

CONCLUSIONS

In EP infants, laser diode therapy is an effective technique to halt the progression of ROP in most cases. AP-ROP is uncommon, even in this subgroup of extremely premature infants.

Treatment of retinopathy of prematurity: a review of conventional and promising new therapeutic options

Retinopathy of prematurity (ROP), a retinal vascular disease of premature infants, continues to be a major cause of preventable childhood blindness all over the world. The incidence of ROP varies among countries, being influenced by the quality of the level of neonatal intensive care. Here, we discuss the potential treatments that are now available or will soon or probably be available for ROP. Although ablation of the avascular retina with laser photocoagulation remains the current gold standard and well established therapy for ROP, some new therapeutic options including angiostatic therapies are being explored based on our knowledge of the pathophysiology of the ROP and complications and efficacy of laser treatment. However, prevention of the development of severe ROP and screening for ROP seem to be the best strategy in avoiding visual impairment caused by ROP in premature infants. New therapeutic interventions including vascular endothelial growth factor antibody administration, gene therapy and supplemental therapies should be supported with evidence-based data for the treatment of ROP.

[Ophthalmological screening for retinopathy of prematurity]

Retinopathy of prematurity (ROP) is one of the three leading causes of legal blindness in childhood in developed countries. Adequate screening is one of the most important steps towards successful treatment. During the last decades, international and national guidelines for ROP screening have been continually updated. These guidelines correspond to progress in neonatal care and to a better understanding of the relationship between different neonatal parameters and the risk of developing ROP. The present article surveys ROP classification, the current national and international guidelines and new aspects of ROP screening.

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.

Low gestational age and chronic lung disease are synergistic risk factors for retinopathy of prematurity

AIMS

This retrospective, population based study was designed to investigate risk factors for development of retinopathy of prematurity (ROP) and their possible interrelationships, in neonates of gestational age (GA) <32 weeks born in a well-defined geographical region. STUDY DESIGN-SUBJECTS: The study population included all preterm infants born alive with GA 24-32 weeks in Northwestern Greece during a 9-year period and hospitalised in the regional neonatal intensive care unit (NICU).

OUTCOME MEASUREMENTS

The association was assessed of the presence of ROP with maternal factors: age, pathology of pregnancy, in-vitro fertilisation, multiple gestation, mode of delivery, perinatal factors: gender, antenatal steroids, transportation, resuscitation, GA, birth weight (BW), small for GA status and postnatal morbidity: chronic lung disease (CLD), intraventricular haemorrhage (IVH), necrotizing enterocolitis (NEC), respiratory distress syndrome (RDS), maximum O(2) needs, hypoxic/hyperoxic episodes, patent ductus arteriosus (PDA), sepsis, using multiple logistic regression analysis.

RESULTS

Of 189 infants without congenital anomalies born at GA 24-32 weeks ROP was diagnosed in 24 (12.7%) (>grade 2: 6). Logistic regression analysis showed ROP to be strongly associated with GA, odds ratio (OR) 2.1, confidence interval (CI) 1.3-3.3, p<0.01 and CLD, OR 10.2, CI 2.3-44, p<0.01, respectively, independent of confounding factors. By estimating interaction on an additive scale it was shown that the combined risk effect of GA and CLD was larger than the sum of the individual risk effects, implying synergistic effect.

CONCLUSIONS

ROP was closely and independently related to both low GA and the diagnosis of CLD, which were interrelated in the development of ROP.

Late subsequent ocular morbidity in retinopathy of prematurity patients, with emphasis on visual loss caused by insidious 'involutive' pathology: an observational series

PURPOSE

This paper discusses late complications in eyes of surviving premature infants typically occurring years into the steady state attained after the initial ophthalmic events associated with preterm birth. The study focuses on insidious visual loss, as well as eventual vitreoretinal and anterior segment disorders.

METHODS

We carried out a retrospective uncontrolled study of a case series (n = 31) of late complications to early ocular changes associated with very preterm delivery. The birth years of our subjects extended back to 1941, but only 15 more recent cases fulfilled contemporary criteria for a diagnosis of retinopathy of prematurity (ROP).

RESULTS

Fourteen cases involved vitreoretinal pathology (median observation time 14 years, range 6-46 years) with late detachment and/or vitreous haemorrhage. Twelve cases primarily involved anterior segment pathology (median observation time 37 years, range 7-58 years). Eyes in the latter category often showed features of early arrested growth and anterior traction, which, in four eyes, eventually led to enucleation or exenteration as a result of a blind and painful terminal state. The last five cases (observation periods 22-38 years) were labelled 'miscellaneous'. Among the 31 patients, we identified a subgroup in which insidious visual loss was a common feature (n = 20). Initially, some of these cases showed evidence of cicatricial ROP and low vision from early in life. Others retained useful vision and did not present obvious ocular incidents related to the actual visual acuity decline.

CONCLUSIONS

Based on a variety of clinical ophthalmic preterm appearances, we propose the hypothesis that, in addition to increased structural vulnerability, a reduced functional reserve may pave the way for further abiotrophy or involution over time. This may manifest as reduced resistance to later ophthalmic events, such as disease or trauma, or simply the impact of age.

A new risk-based screening criterion for treatment-demanding retinopathy of prematurity in Denmark

OBJECTIVE

The aim of this study was to uncover the most effective and safe criterion to implement for retinopathy of prematurity screening in Denmark.

METHODS

This retrospective national cohort study is based on data from 3 national registers. These registers provided on infants treated for retinopathy of prematurity, infants in need of treatment but missed by the present screening program, and the candidate neonates for advanced retinopathy of prematurity development A nonlinear logistic regression model was fitted to the data, and various screening criteria were evaluated.

RESULTS

During the study period (2002-2006), 116 infants were treated for retinopathy of prematurity, no treatment-demanding retinopathy of prematurity infants were missed by the screening program, and 182 premature infants were candidates for developing treatment-demanding retinopathy of prematurity. Screening criteria combining gestational age at delivery and birth weight limits and new risk-based criteria were compared with regards to their effectiveness. The risk-based criteria were the most effective. Use of the 0.13% risk-based criterion to define the population to be screened resulted in the detection of all treated infants in the study period and 17.4% fewer infants to screen. The model predicted this criterion to result in 1 missed case of treatment-demanding retinopathy of prematurity every 11 years and 1 case of blindness every 18 years in Denmark.

CONCLUSIONS

Screening criteria based on risk estimates of developing treatment-demanding retinopathy of prematurity are the most effective for retinopathy-of-prematurity screening. The risk-based criterion of 0.13% can safely be implemented for future retinopathy-of-prematurity screening in Denmark.

The significance of neuronal and glial cell changes in the rat retina during oxygen-induced retinopathy

Retinopathy of prematurity is a devastating vascular disease of premature infants. A number of studies indicate that retinal function is affected in this disease. Using the rat model of oxygen-induced retinopathy, it is possible to explore more fully the complex relationship between neuronal, glial and vascular pathology in this condition. This review examines the structural and functional changes that occur in the rat retina following oxygen-induced retinopathy. We highlight that vascular pathology in rats is characterized by aberrant growth of blood vessels into the vitreous at the expense of blood vessel growth into the body of the retina. Moreover, amino acid neurochemistry, a tool for examining neuronal changes in a spatially complete manner reveals widespread changes in amacrine and bipolar cells. In addition, neurochemical anomalies within inner retinal neurons are highly correlated with the absence of retinal vessels. The key cell types that link blood flow with neuronal function are macroglia. Macroglia cells, which in the retina include astrocytes and Müller cells, are affected by oxygen-induced retinopathy. Astrocyte loss occurs in the peripheral retina, while Müller cells show signs of reactive gliosis that is highly localized to regions that are devoid of intraretinal blood vessels. Finally, we propose that treatments, such as blockade of the renin-angiotensin system, that not only targets pathological angiogenesis, but that also promotes re-vascularization of the retina are likely to prove important in the treatment of those with retinopathy of prematurity.

Early weight gain predicts retinopathy in preterm infants: new, simple, efficient approach to screening

BACKGROUND

The risk for sight-threatening retinopathy of prematurity is predicted by using gestational age and/or weight at birth. All infants below a threshold undergo serial ophthalmologic examinations for identification of those who would benefit from treatment (approximately 10%). We hypothesized that factoring in postnatal weight gain could identify children at risk for sight-threatening retinopathy of prematurity more specifically and earlier.

METHODS

Weekly weights from birth to postmenstrual week 36 were retrospectively entered into a surveillance system that gave an alarm when the rate of weight gain decreased to a certain level. For all children (N = 354) screened and/or treated for retinopathy of prematurity at Sahlgrenska University Hospital in 2004-2007, weekly weights were recorded. One child was excluded because of known nonphysiologic weight gain (hydrocephalus).

RESULTS

For 127 (36%) of 353 children, no alarm was given; for 40%, alarm at low risk was given after postmenstrual week 32. None of those children developed retinopathy of prematurity requiring treatment. Of the remaining 24% of children who received alarm at high or low risk before 32 postmenstrual weeks, 41% developed proliferative retinopathy of prematurity and 29% were treated because of sight-threatening disease. The median time from alarm to treatment was 9 weeks.

CONCLUSIONS

The weight, insulin-like growth factor, neonatal retinopathy of prematurity algorithm detected early 100% of infants who developed retinopathy of prematurity requiring treatment and correctly predicted the majority who did not require treatment. With this simple postnatal evaluation, costly stressful eye examinations can be markedly reduced (approximately 75% of infants). In addition, early identification of children at risk may lead to the initiation of interventions and possibly prevent sight-threatening retinopathy of prematurity.

Visual impairment is common in children born before 25 gestational weeks--boys are more vulnerable than girls

INTRODUCTION

Children born extremely preterm have high risk of visual impairment due to retinopathy of prematurity (ROP) and cerebral lesions.

OBJECTIVE

The aim of this study was to investigate the frequency of ROP and visual impairment as defined by the World Health Organization (WHO), with respect to gender in two hospital-based groups of children born at the limit of viability.

PATIENTS AND METHODS

A retrospective chart review was conducted for all children (n = 114), born before 25 gestational weeks and screened for ROP at Karolinska hospital in Stockholm and Sahlgrenska hospital in Gothenburg between 1990 and 2002. Maximal ROP stages, treatment for ROP and visual acuity (VA), with correction when needed at latest available visit, were recorded.

RESULTS

Altogether 97.4% had ROP, 74.6% developed proliferative disease (stage >/= 3) and 63.2% were treated with retinal ablation. Normal VA (>/=0.8) in at least one eye was found in 50.5% of all and in significantly more girls (61.5%) than boys (34.8%) (p = 0.006), while visual impairment (VA < 0.33) was more common in boys (32.6%) than in girls (9.2%) (p = 0.004).

CONCLUSION

A large proportion of children, especially boys, born at the level of viability are visually impaired with low vision or blindness. Development of preventive measures is urgent.