The challenge of screening for retinopathy of prematurity

Retrospective validation of the postnatal Growth and Retinopathy of Prematurity (G-ROP) criteria in a developing country

Background

The characteristics of premature infants vary from country to country rendering it challenging to apply retinopathy of prematurity (ROP) screening algorithm globally. The screening criteria for postnatal growth and ROP (G-ROP) for preterm infants are known to be beneficial, but it is not clear whether these criteria can be used universally.

Aim

The aim of this study is to validate the accuracy of the G-ROP criteria in screening preterm infants in Saudi Arabia.

Subjects and Methods

This single-center retrospective study included 300 premature infants (mean gestational age [GA], 28.72 ± 2.2 weeks; range, 21-36 weeks) at a referral center who were screened for ROP between 2015 and 2021. The inclusion criteria were the availability of data on ROP outcome and body weight up until day 40 after birth. The G-ROP 1 and G-ROP 2 models were examined for their ability and accuracy in identifying infants with any stage ROP and treatable ROP.

Results

The G-ROP 1 and G-ROP 2 models identified 233 and 255 infants for screening, respectively. The sensitivity of G-ROP 1 and G-ROP 2 for detecting treated ROP was 96.7% and 100%, respectively, and the specificity for detecting treatable ROP was 24.4% and 16.7%, respectively. Incorporation of the G-ROP 2 model, which did not miss any infant with type 1 ROP, would have reduced the number of screened infants by 15%.

Conclusion

G-ROP 2 was more sensitive than G-ROP 1 for identifying infants who required treatment and could potentially reduce the burden of ROP screening.

Latest Trends in Retinopathy of Prematurity: Research on Risk Factors, Diagnostic Methods and Therapies

Retinopathy of prematurity (ROP) is a vasoproliferative disorder with an imminent risk of blindness, in cases where early diagnosis and treatment are not performed. The doctors' constant motivation to give these fragile beings a chance at life with optimal visual acuity has never stopped, since Terry first described this condition. Thus, throughout time, several specific advancements have been made in the management of ROP. Apart from the most known risk factors, this narrative review brings to light the latest research about new potential risk factors, such as: proteinuria, insulin-like growth factor 1 (IGF-1) and blood transfusions. Digital imaging has revolutionized the management of retinal pathologies, and it is more and more used in identifying and staging ROP, particularly in the disadvantaged regions by the means of telescreening. Moreover, optical coherence tomography (OCT) and automated diagnostic tools based on deep learning offer new perspectives on the ROP diagnosis. The new therapeutical trend based on the use of anti-VEGF agents is increasingly used in the treatment of ROP patients, and recent research sustains the theory according to which these agents do not interfere with the neurodevelopment of premature babies.

[Primary vitrectomy in the treatment of retinopathy of prematurity with unfavorable progression]

PURPOSE

The study aims to determine the indications and evaluate the results of primary vitrectomy in unfavorable progression of stage III active retinopathy of prematurity (ROP).

MATERIAL AND METHODS

The control group consisted of 17 patients (28 eyes) with unfavorable progression of stage III ROP, who had the disease progress after coagulation of the avascular retina and underwent the second stage of treatment - vitrectomy. The main group consisted of 5 patients (10 eyes) with unfavorable progression of stage III ROP, who underwent primary vitrectomy. Gestational age at birth was 24-30 weeks, body weight ranged from 680 to 1250 g. According to spectral optical coherence tomography (SOCT) and OCT angiography (OCT-A), the initial state of the retina and vitreoretinal interface in patients of the main and control groups were identical.

RESULTS

A retrospective analysis of control patients, according to SOCT and OCT-A data, showed the spread of neovascularization beyond the retinal plane, its interaction with the posterior hyaloid membrane and vitreous body structures in the early stages of the disease, traction changes in the underlying retina, areas of retinoschisis, as well as thickening of the posterior hyaloid membrane. The tactics of treating patients with unfavorable progression of stage III ROP has changed since 2020. Primary vitrectomy was performed in case the signs listed above were identified. The transition of the disease to the inactive stage was recorded in all cases one month after primary vitrectomy. After one year the pathological process did not reactivate in any of the cases, and no pathological changes were found in the projection of the former proliferation ridge.

CONCLUSIONS

Extraretinal retinovitreal neovascularization, according to multimodal preoperative diagnostics, indicates the need for vitreoretinal surgery as a pathogenetically substantiated method of treatment for unfavorable progression of stage III active ROP.

Early and late onset sepsis and retinopathy of prematurity in a cohort of preterm infants

This study investigates the impact of antenatal and postnatal infection or inflammation on the onset and progression of Retinopathy of Prematurity (ROP). We retrospectively collected clinical and demographic data of preterm infants with birth weight ≤ 1500 g or gestational age < 30 weeks admitted to the neonatal intensive care unit of Verona from 2015 to 2019. Uni- and multivariable analysis was performed to evaluate the potential effect of selected variables on the occurrence of any stage ROP and its progression to severe ROP, defined as ROP requiring treatment. Two hundred and eighty neonates were enrolled and 60 of them developed ROP (21.4%). Oxygen need for 28 days and late-onset sepsis (LOS) increased the risk of any grade ROP after adjusting for birth weight and gestational age (OR 6.35, 95% CI 2.14–18.85 and OR 2.49, 95% CI 1.04–5.94, respectively). Days of mechanical ventilation and of non-invasive ventilation increased the risk of progression to severe ROP after adjusting for birth weight and gestational age (OR 1.08, CI 1.02–1.14 and OR 1.06, CI 1.01–1.11, respectively). Exposure to infection with production of inflammatory mediators may contribute to increase the risk of ROP occurrence in very preterm neonates.

Incidence and Characteristics of Retinopathy of Prematurity Patients With Late Gestational Age and Large Birth Weight in South China

Purpose

To investigate the incidence and characteristics of retinopathy of prematurity (ROP) premature infants with late gestational age (GA) and large birth weight (BW) and show a 7-year trend of ROP incidence in South China.

Methods

This retrospective, cross-sectional study included premature infants who received ROP screening in a 7-year period (from 2010 to 2016) at the Sun Yat-sen Memorial Hospital (SYSMH), Guangzhou, South China. Infants were screened if they had GA <37 weeks or BW <2,500 g. All screened infants were divided into two groups: Group 1 (with both GA ≥ 35 weeks and BW ≥ 1,750 g) and Group 2 (others). The characteristics of ROP infants in Group 1 were analyzed and compared with those in Group 2.

Results

A total of 911 premature infants were screened, with 282 infants in Group 1 and 629 in Group 2. Both the incidences of any ROP (6.7 vs. 8.3%, p = 0.50) and Type 1 ROP (1.4 vs. 1.7%, p = 0.72) in Group 1 were comparable with those in Group 2. Lower proportions of respiratory distress (15.8 vs. 71.2%, p < 0.001), blood transfusion (5.3 vs. 32.7%, p = 0.028), and oxygen administration (31.6 vs. 86.5%, p < 0.001) among ROP patients in Group 1 than those in Group 2 were revealed. Vaginal delivery [OR: 4.73 (1.83–12.26)] was identified as a factor associated with ROP among the infants in Group 1. Forty percent (6/15) of Type 1 ROP in this study would have been missed under the current screening criteria in China (GA ≤ 34 weeks and/or BW ≤ 2,000 g). Trends of increased incidence of Type 1 ROP and decreased BW were exhibited in the 7-year study period.

Conclusions

These findings indicate that even the premature infants with late GA and large BW also have a high risk of developing ROP, especially for those delivered by vagina. The findings may provide a significant reference for ROP screening and neonatal care in South China and other regions with similar conditions.

Evaluation and modification of French screening guidelines for retinopathy of prematurity

PURPOSE

To evaluate the current French screening guidelines for retinopathy of prematurity (ROP) and to suggest modifications to it.

METHODS

In this multicentric retrospective, noncomparative, interventional case series we included infants with a gestational age (GA) ≤32 weeks who were screened for ROP by fundus examination between 2011 and 2018. Main Outcome Measures were the presence of ROP and the need for treatment.

RESULTS

A total of 2246 children with a mean GA of 28.9 ± 2.0 weeks and mean birth weight (BW) of 1141.1 ± 332.0 g were screened. Retinopathy of prematurity (ROP) was found in 683 infants (30.4%), of whom 145 (6.5%) had type 2 ROP and 58 (2.6%) had type 1 ROP. Mean GA of infants with type 1 ROP needing treatment was 25.9 + 1.5 weeks (range: 23.6-30) and mean BW was 774.1 ± 173.7 g (range: 540-1400). Both GA and BW had an impact on the development of type 1 and 2 ROP. None of the infants needing treatment had a GA of 31 weeks or more. None of the children needed treatment before 33 weeks of postmenstrual age (PMA) or 6 weeks of postnatal age (PNA).

CONCLUSION

It seems possible to decrease the screening of premature infants to ≤31 weeks of GA and to start screening at 31 weeks PMA for infants having a GA < 26 weeks and at 6 weeks PNA for more mature children.

Assessment and management of retinopathy of prematurity in the era of anti-vascular endothelial growth factor (VEGF)

The incidence of retinopathy of prematurity (ROP) continues to rise due to the improved survival of very low birth weight infants in developed countries. This epidemic is also fueled by increased survival of preterm babies with variable use of oxygen and a lack of ROP awareness and screening services in resource-limited regions. Improvements in technology and a basic understanding of the disease pathophysiology have changed the way we screen and manage ROP, educate providers and patients, and improve ROP awareness. Advancements in imaging techniques, expansion of telemedicine services, and the potential for artificial intelligence-assisted ROP screening programs have created opportunities to improve ROP care in areas with a shortage of ophthalmologists trained in ROP. To address the gap in provider knowledge regarding ROP, the Global Education Network for Retinopathy of Prematurity (GEN-ROP) created a web-based tele-education training module that can be used to educate all providers involved in ROP, including non-physician ROP screeners. Over the past 50 years, the treatment of severe ROP has evolved from limited treatment modalities to cryotherapy and laser photocoagulation. More recently, there has been growing evidence to support the use of anti-vascular endothelial growth factor (VEGF) agents for the treatment of severe ROP. However, VEGF is known to be important in organogenesis and microvascular maintenance, and given that intravitreal anti-VEGF treatment can result in systemic VEGF suppression over a period of at least 1-12 weeks, there are concerns regarding adverse effects and long-term ocular and systemic developmental consequences of anti-VEGF therapy. Future research in ophthalmology to address the growing burden of ROP should focus on cost-effective fundus imaging devices, implementation of artificial intelligence platforms, updated treatment algorithms with optimal use of anti-VEGF and careful investigation of its long-term effects, and surgical options in advanced ROP. Addressing these unmet needs will aid the global effort against the ROP epidemic and optimize our understanding and treatment of this blinding disease.

Retinopathy of prematurity incidence and treatment modalities in moderate and late preterm infants: a study from two tertiary centers

OBJECTIVE

The aim of this study was to evaluate the incidence, severity, and treatment modalities of retinopathy of prematurity (ROP) in moderate and late preterm infants with a gestational age (GA) >31 + 6 weeks.

METHODS

ROP screening results of preterm infants with GA >31 + 6 weeks to 36 + 6 weeks between March 2013 and January 2019 were evaluated retrospectively. Infants were divided into 2 groups according to GA as 32-33 + 6 weeks (moderate preterm) and 34-36 + 6 weeks (late preterm). In these groups, any ROP and severe ROP (requiring treatment) development rates and ROP types and treatment modalities were evaluated.

RESULTS

A total of 4156 preterm infants, 1875 (45.1%) female and 2281 (54.9%) male, were included. Overall, 1466 (35.2%) of the infants were moderate preterm and 2690 (64.8%) were late preterm. The incidences of any ROP and severe ROP were 22% and 2.5%, respectively. The rate of severe ROP was 5.3% in moderate preterm infants and 0.9% in late preterm infants. Significant correlations were determined between duration of hospital stay, birth weight (BW), and GA with ROP development (r = +0.415, r = -0.258, r = -0.199, respectively; p < 0.001 for all). Of 102 patients (2.5%) requiring treatment, 64 (62.7%) had laser, 34 (33.3%) had intravitreal bevacizumab (IVB), 2 (1.9%) had sequential IVB and laser, and 2 (1.9%) had vitreoretinal surgery.

CONCLUSION

ROP seems to still be an important health problem in moderate and late preterm infants in our country according to data from screening high-risk preterm infants with a GA >31 + 6 weeks. In this cohort, ROP development correlates with GA, BW, and duration of hospitalization significantly.

Current Application of Digital Diagnosing Systems for Retinopathy of Prematurity

BACKGROUND AND OBJECTIVE

Retinopathy of prematurity (ROP), a proliferative vascular eye disease, is one of the leading causes of blindness in childhood and prevails in premature infants with low-birth-weight. The recent progress in digital image analysis offers novel strategies for ROP diagnosis. This paper provides a comprehensive review on the development of digital diagnosing systems for ROP to software researchers. It may also be adopted as a guide to ophthalmologists for selecting the most suitable diagnostic software in the clinical setting, particularly for the remote ophthalmic support.

METHODS

We review the latest literatures concerning the application of digital diagnosing systems for ROP. The diagnosing systems are analyzed and categorized. Articles published between 1998 and 2020 were screened with the two searching engines Pubmed and Google Scholar.

RESULTS

Telemedicine is a method of remote image interpretation that can provide medical service to remote regions, and yet requires training to local operators. On the basis of image collection in telemedicine, computer-based image analytical systems for ROP were later developed. So far, the aforementioned systems have been mainly developed by virtue of classic machine learning, deep learning (DL) and multiple machine learning. During the past two decades, various computer-aided systems for ROP based on classic machine learning (e.g. RISA, ROPtool, CAIER) became available and have achieved satisfactory performance. Further, automated systems for ROP diagnosis based on DL are developed for clinical applications and exhibit high accuracy. Moreover, multiple instance learning is another method to establish an automated system for ROP detection besides DL, which, however, warrants further investigation in future.

CONCLUSION

At present, the incorporation of computer-based image analysis with telemedicine potentially enables the detection, supervision and in-time treatment of ROP for the preterm babies.

Inflammation-associated gene polymorphisms and clinical variables in the incidence and progression of retinopathy of prematurity

Introduction

A growing body of evidence shows that genetics plays a vital role in the development and progression of retinopathy of prematurity (ROP). Perinatal inflammation is also considered an important risk factor of ROP. Therefore, understanding the interplay of genetics and susceptibility to inflammation might shed light on the pathogenesis of ROP and make its screening and treatment more effective in preventing visual impairment in premature infants.

Material and methods

This study investigated the correlation of inflammation-associated gene polymorphisms: IL-1β +3953 C>T, IL-1RN VNTR 86 bp, IL-6 -174 G>C, IL-6 -596 G>A, and TNF-α -308 G>A as well as demographic and clinical characteristics of ROP in preterm infants (n = 90).

Results

Our results demonstrate that IL-1RN rs2234663 1/1 genotype prevails in infants with ROP that regresses without intervention, when compared to those requiring laser photocoagulation/anti-VEGF injection (p = 0.031). Genotype 2/2 of IL-1RN occurs more frequently in children with severe ROP (28.6%) than in the group in which ROP regressed spontaneously (4.0%). The analysis revealed also differences between the genotypes of IL-1RN in ROP patients with intrauterine infection and in patients who had ROP without intrauterine infection; however, this was not statistically significant. Other studied polymorphisms were not associated with ROP development or its progression.

Conclusions

These results suggest that different genotypes of IL-1RN might have an impact on the course of ROP. Genotype 2/2 of IL-1RN gene may predispose to ROP progression.

Retinopathy of prematurity and neonatal gut microbiome: An interview with Professor Dimitra Skondra, Associate Professor of Ophthalmology and Vitreoretinal Surgeon at The University of Chicago (USA)

Retinopathy of prematurity (ROP) is a sight-threatening disorder of the retina affecting neonates of very low birth weight and gestational age, and is characterized by the development of abnormal blood vessel growth. According to Dr Dimitra Skondra, Associate Professor of Ophthalmology and Vitreoretinal Surgeon at the University of Chicago School of Medicine in Chicago, USA, the neonatal gut microbiome may be implicated in the neoangiogenesis process in the neonatal retina and this role may be one of the missing links in the pathogenesis of ROP. The human gut microbiome consists of bacteria, viruses, protozoa and fungi, which colonize the sterile fetal intestine, and differ depending on gestational age, mode of delivery, type of neonatal feeding, the usage of antibiotics and the requirement of neonatal intensive care. To date, it has been related to multiple nutritive, metabolic and immunological functions and has been implicated in the pathogenesis of several human diseases, such as the inflammatory bowel diseases, autoimmune and neurogenerative disorders, metabolic syndrome, cardiovascular diseases and various types of malignant neoplasias. Recent research has proposed that the neonatal gut microbiome profile in high-risk neonates who develop ROP is significantly enriched with Enterobacteriacaea species several weeks prior to the diagnosis of ROP. Further research using animal models is required to prove the causative or secondary role of the microbiome composition in the development and clinical course of ROP. If this role is proven, the gut microbiome could then be a target of intervention for personalized medicine in the prevention and therapeutic management of ROP in neonates.

Late-Onset Retinal Findings and Complications in Untreated Retinopathy of Prematurity

PURPOSE

To investigate late retinal findings and complications of eyes with a history of retinopathy of prematurity (ROP) that did not meet treatment criteria and did not receive treatment during infancy.

DESIGN

Retrospective, nonconsecutive, noncomparative, multicenter case series.

PARTICIPANTS

Three hundred sixty-three eyes of 186 patients.

METHODS

Data were requested from multiple providers on premature patients with a history of ROP and no treatment during infancy who demonstrated late retinal findings or complications and included age, gender, gestational age and weight, zone and stage at infancy, visual acuity, current retina vascularization status, vitreous character, presence of peripheral retinal findings such as lattice retinal tears and detachments (RDs), retinoschisis, and fluorescein findings.

MAIN OUTCOME MEASURES

Rate of RDs and factors conferring a higher risk of RDs.

RESULTS

The average age was 34.5 years (range, 7-76 years), average gestational age was 26.6 weeks (range, 23-34 weeks), and average birth weight was 875 g (range, 425-1590 g). Findings included lattice in 196 eyes (54.0%), atrophic holes in 126 eyes (34.7%), retinal tears in 111 eyes (30.6%), RDs in 140 eyes (38.6 %), tractional retinoschisis in 44 eyes (11.9%), and visible vitreous condensation ridge-like interface in 112 eyes (30.5%). Fluorescein angiography (FA) was performed in 113 eyes, of which 59 eyes (52.2%) showed leakage and 16 eyes (14.2%) showed neovascularization. Incomplete vascularization posterior to zone 3 was common (71.6% of eyes). Retinal detachments were more likely in patients with a gestational age of 29 weeks or less (P < 0.05) and in eyes with furthest vascularization to posterior zone 2 eyes compared with zone 3 eyes (P = 0.009).

CONCLUSIONS

Eyes with ROP not meeting the treatment threshold during infancy showed various late retinal findings and complications, of which RDs were the most concerning. Complications were seen in all age groups, including patients born after the Early Treatment for Retinopathy of Prematurity Study. Contributing factors to RDs included atrophic holes within peripheral avascular retina, visible vitreous condensation ridge-like interface with residual traction, and premature vitreous syneresis. We recommend regular examinations and consideration of ultra-widefield FA examinations. Prospective studies are needed to explore the frequency of complications and benefit of prophylactic treatment and if eyes treated with anti-vascular endothelial growth factor therapy are at risk of similar findings and complications.

Prediction of ROP Treatment and Evaluation of Screening Criteria in VLBW Infants-a Population Based Analysis

BACKGROUND

The incidence of retinopathy of prematurity (ROP) and ROP screening criteria differ between countries. We assessed whether ROP screening could be reduced based on the local ROP incidence.

METHODS

Observational cohort study of infants born in Switzerland between 2006 and 2015 <32 0/7 weeks. Chronological and postmenstrual ages at ROP treatment were analyzed. A model to identify ROP treatment on patients born between 2006 and 2012 (training set) was developed and tested on patients born between 2013 and 2015 (validation set).

RESULTS

Of 7817 live-born infants, 1098 died within the first 5 weeks of life. The remaining 6719 infants were included into analysis. All patients requiring ROP treatment would have been identified if screening had been performed before reaching 60 days of life or 37 3/7 weeks postmenstrual age, whichever came first. The training and validation sets included 4522 and 2197 preterm infants encompassing 56 and 20 patients receiving ROP treatment, respectively. All patients would have required screening to reach 100% sensitivity. To reach a sensitivity of 95.0% and a specificity of 87.6%, we predicted a reduction in 13.2% of patients requiring screening (c-statistic = 0.916).

CONCLUSIONS

A substantial reduction of infants requiring screening seems possible, but necessitates prospective testing of new screening criteria.

Prevalence and risk factors of retinopathy of prematurity in Iran: a systematic review and meta-analysis

Background

Retinopathy of prematurity (ROP) refers to the developmental disorder of the retina in premature infants and is one of the most serious and most dangerous complications in premature infants. The prevalence of ROP in Iran is different in various parts of Iran and its prevalence is reported to be 1–70% in different regions. This study aims to determine the prevalence and risk factors of ROP in Iran.

Methods

This review article was conducted based on the preferred reporting items for systematic review and meta-analysis (PRISMA) protocols. To find literature about ROP in Iran, a comprehensive search was done using MeSH keywords in several online databases such as PubMed, Ovid, Science Direct, EMBASE, Web of Science, CINAHL, EBSCO, Magiran, Iranmedex, SID, Medlib, IranDoc, as well as the Google Scholar search engine until May 2017. Comprehensive Meta-analysis Software (CMA) Version 2 was used for data analysis.

Results

According to 42 studies including 18,000 premature infants, the prevalence of ROP was reported to be 23.5% (95% CI: 20.4–26.8) in Iran. The prevalence of ROP stages 1, 2, 3, 4 and 5 was 7.9% (95% CI: 5.3–11.5), 9.7% (95% CI: 6.1–15.3), 2.8% (95% CI: 1.6–4.9), 2.9% (95% CI: 1.9–4.5) and 3.6% (95% CI: 2.4–5.2), respectively. The prevalence of ROP in Iranian girls and boys premature infants was 18.3% (95% CI: 12.8–25.4) and 18.9% (95% CI: 11.9–28.5), respectively. The lowest prevalence of ROP was in the West of Iran (12.3% [95% CI: 7.6–19.1]), while the highest prevalence was associated with the Center of Iran (24.9% [95% CI: 21.8–28.4]). The prevalence of ROP is increasing according to the year of study, and this relationship is not significant (p = 0.181). The significant risk factors for ROP were small gestational age (p < 0.001), low birth weight (p < 0.001), septicemia (p = 0.021), respiratory distress syndrome (p = 0.036), intraventricular hemorrhage (p = 0.005), continuous positive pressure ventilation (p = 0.023), saturation above 50% (p = 0.023), apnea (p = 0.002), frequency and duration of blood transfusion, oxygen therapy and phototherapy (p < 0.05), whereas pre-eclampsia decreased the prevalence of ROP (p = 0.014).

Conclusion

Considering the high prevalence of ROP in Iran, screening and close supervision by experienced ophthalmologists to diagnose and treat the common complications of pre-maturity and prevent visual impairment or blindness is necessary.

Pathophysiology, screening and treatment of ROP: A multi-disciplinary perspective

The population of infants at risk for retinopathy of prematurity (ROP) varies by world region; in countries with well developed neonatal intensive care services, the highest risk infants are those born at less than 28 weeks gestational age (GA) and less than 1 kg at birth, while, in regions where many aspects of neonatal intensive and ophthalmological care are not routinely available, more mature infants up to 2000 g at birth and 37 weeks GA are also at risk for severe ROP. Treatment options for both groups of patients include standard retinal laser photocoagulation or, more recently, intravitreal anti-VEGF drugs. In addition to detection and treatment of ROP, this review highlights new opportunities created by telemedicine, where screening and diagnosis of ROP in remote locations can be undertaken by non-ophthalmologists using digital fundus cameras. The ophthalmological care of the ROP infant is undertaken in the wider context of neonatal care and general wellbeing of the infant. Because of this context, this review takes a multi-disciplinary perspective with contributions from retinal vascular biologists, pediatric ophthalmologists, an epidemiologist and a neonatologist. This review highlights the latest insights regarding cellular and molecular mechanisms in the formation of the retinal vasculature in the human infant, pathogenesis of ROP, detection and treatment of severe ROP, the risks and benefits of anti-VEGF therapy, the identification of new therapies over the horizon, and the optimal neonatal care regimen for best ROP outcomes, and the benefits and pitfalls of telemedicine in the remote screening and diagnosis of ROP, all of which have the potential to improve ROP outcomes.

Retinopathy of Prematurity-assist: Novel Software for Detecting Plus Disease

Purpose

To design software with a novel algorithm, which analyzes the tortuosity and vascular dilatation in fundal images of retinopathy of prematurity (ROP) patients with an acceptable accuracy for detecting plus disease.

Methods

Eighty-seven well-focused fundal images taken with RetCam were classified to three groups of plus, non-plus, and pre-plus by agreement between three ROP experts. Automated algorithms in this study were designed based on two methods: the curvature measure and distance transform for assessment of tortuosity and vascular dilatation, respectively as two major parameters of plus disease detection.

Results

Thirty-eight plus, 12 pre-plus, and 37 non-plus images, which were classified by three experts, were tested by an automated algorithm and software evaluated the correct grouping of images in comparison to expert voting with three different classifiers, k-nearest neighbor, support vector machine and multilayer perceptron network. The plus, pre-plus, and non-plus images were analyzed with 72.3%, 83.7%, and 84.4% accuracy, respectively.

Conclusions

The new automated algorithm used in this pilot scheme for diagnosis and screening of patients with plus ROP has acceptable accuracy. With more improvements, it may become particularly useful, especially in centers without a skilled person in the ROP field.

A worldwide survey of retinopathy of prematurity screening

BACKGROUND

To ascertain which countries in the world have retinopathy of prematurity (ROP) screening programmes and guidelines and how these were developed.

METHODS

An email database was created and requests were sent to ophthalmologists in 141 nations to complete an online survey on ROP screening in their country.

RESULTS

Representatives from 92/141 (65%) countries responded. 78/92 (85%) have existing ROP screening programmes, and 68/78 (88%) have defined screening criteria. Some countries have limited screening and those areas which have no screening or for which there is inadequate knowledge are mainly Southeast Asia, Africa and some former Soviet states.

DISCUSSION

With the increasing survival of premature babies in lower-middle-income and low-income countries, it is important to ensure that adequate ROP screening and treatment is in place. This information will help organisations focus their resources on those areas most in need.

Colorado Retinopathy of Prematurity Screening Algorithm (CO-ROP): a validation study at a tertiary care center

PURPOSE

The Colorado Retinopathy of Prematurity Screening Algorithm (CO-ROP) recommends screening for infants meeting the following criteria for retinopathy of prematurity (ROP): gestational age ≤30 weeks, birth weight of ≤1500 g, and net weight gain of ≤650 g between birth and 4 weeks of age. This study was performed to evaluate the validity of CO-ROP in a tertiary referral county hospital.

METHODS

CO-ROP was used to retrospectively analyze the data from consecutive newborns screened for ROP using national screening guidelines at Parkland Hospital, Dallas, Texas, between April 1, 2009, to August 30, 2013. Sensitivities and specificities for identifying ROP were calculated.

RESULTS

A total of 374 infants were included, of whom 29 (7.8%) developed type 1 ROP and 12 (3.2%) developed type 2 ROP. The CO-ROP model would have decreased number of infants screened by 34% compared to current national screening criteria. CO-ROP had sensitivity of 93.1% (95% CI, 77.2-99.1) and 92.7% (95% CI, 61.5-99.8) for identifying type 1 and type 2 ROP, respectively. Of 29 patients who developed type 1 ROP, 2 were not identified using CO-ROP.

CONCLUSIONS

The CO-ROP model significantly reduced total number screened but failed to detect 2 infants with type 1 ROP, suggesting the need for further modification of the algorithm.

The neural retina in retinopathy of prematurity

Retinopathy of prematurity (ROP) is a neurovascular disease that affects prematurely born infants and is known to have significant long term effects on vision. We conducted the studies described herein not only to learn more about vision but also about the pathogenesis of ROP. The coincidence of ROP onset and rapid developmental elongation of the rod photoreceptor outer segments motivated us to consider the role of the rods in this disease. We used noninvasive electroretinographic (ERG), psychophysical, and retinal imaging procedures to study the function and structure of the neurosensory retina. Rod photoreceptor and post-receptor responses are significantly altered years after the preterm days during which ROP is an active disease. The alterations include persistent rod dysfunction, and evidence of compensatory remodeling of the post-receptor retina is found in ERG responses to full-field stimuli and in psychophysical thresholds that probe small retinal regions. In the central retina, both Mild and Severe ROP delay maturation of parafoveal scotopic thresholds and are associated with attenuation of cone mediated multifocal ERG responses, significant thickening of post-receptor retinal laminae, and dysmorphic cone photoreceptors. These results have implications for vision and control of eye growth and refractive development and suggest future research directions. These results also lead to a proposal for noninvasive management using light that may add to the currently invasive therapeutic armamentarium against ROP.

Expanded criteria for retinopathy of prematurity screening in moderately preterm infants: Single-center pilot study

BACKGROUND

While developed countries seek to lower the gestational age and birthweight parameters in retinopathy of prematurity (ROP) screening, older, larger infants still develop ROP in other parts of the world. The aim of this study was therefore to define criteria to identify potential ROP developers who are outliers of the common screening range.

METHODS

A retrospective medical record review was performed in 147 inborn moderately preterm infants admitted to the neonatal intensive care unit during the study period. Univariate and logistic regression analysis was carried out.

RESULTS

Forty-two infants developed ROP. Gestational age (31.4 ± 1.1 vs 32.4 ± 1.0 weeks, P = 0.000) and birthweight (1607.7 ± 339.4 vs 1846.4 ± 317.2 g, P = 0.000) were lower in those who developed ROP. Respiratory distress syndrome (P = 0.026) and documented sepsis (P = 0.003) were significant comorbidities on univariate analysis. Inotrope need >72 h starting in the first week of life (P = 0.004; OR, 5.181) and more than three transfusions of packed red blood cells (P = 0.028; OR, 3.891) were also significant, both on univariate and multivariate analysis.

CONCLUSIONS

In moderately preterm infants, status should be evaluated in order to effectively select candidates for ROP screening without missing potential ROP developers.

Retinopathy of prematurity screening criteria in Iran: new screening guidelines

OBJECTIVE

To test the applicability of existing retinopathy of prematurity (ROP) guidelines on Iranian patients and to develop novel ROP screening criteria in Iran.

METHODS

Both eyes of 1932 infants born ≤37 weeks of gestation and/or weighting ≤3000 g were included in this prospective cohort study that was conducted across nine neonatal intensive care units and a tertiary eye hospital ROP clinic. The patients were examined for ROP and the need for treatment (type 1 ROP or worse). All the patients were screened 4 weeks after birth or at 31 weeks of postmenstrual age, whichever was later. The patients were followed until retinal vascularisation was completed or the patients reached 50 weeks of gestational age (GA) without prethreshold ROP. A receiver operating characteristic curve was used to determine the best screening criteria for ROP. Screening criteria from other countries were applied to our patient data to determine their ability to appropriately detect ROP.

MAIN OUTCOME MEASURE

Patients with ROP requiring treatment.

RESULTS

The mean GA±SD and birth weight (BW)±SD of the screened patients were 32±2.7 weeks and 1713±516 g, respectively. Using criteria of GA≤32 weeks or BW ≤2000 yielded sensitivity and specificity of 100% and 26.7%, respectively, for treatment requiring ROP regardless of clinical comorbidities. Using screening recommendations of American Academy of Pediatrics would miss 25.4% of ROP and 8.4%ROP requiring treatment in our cohort.

CONCLUSIONS

Other countries screening recommendations would result in a significant amount of missed cases of treatment requiring ROP when applied to Iran. As a result, we have proposed new guidelines for premature babies in Iran.

Retinopathy of prematurity: Past, present and future

Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the retina occurring principally in new born preterm infants. It is an avoidable cause of childhood blindness. With the increase in the survival of preterm babies, ROP has become the leading cause of preventable childhood blindness throughout the world. A simple screening test done within a few weeks after birth by an ophthalmologist can avoid this preventable blindness. Although screening guidelines and protocols are strictly followed in the developed nations, it lacks in developing economies like India and China, which have the highest number of preterm deliveries in the world. The burden of this blindness in these countries is set to increase tremendously in the future, if corrective steps are not taken immediately. ROP first emerged in 1940s and 1950s, when it was called retrolental fibroplasia. Several epidemics of this disease were and are still occurring in different regions of the world and since then a lot of research has been done on this disease. However, till date very few comprehensive review articles covering all the aspects of ROP are published. This review highlights the past, present and future strategies in managing this disease. It would help the pediatricians to update their current knowledge on ROP.

Retinopathy of prematurity: New developments bring concern and hope

Blindness from retinopathy of prematurity (ROP) in Australian and New Zealand is an uncommon event although 3% of <31 weeks gestation infants receive treatment for the disease. New world-wide estimates of the incidence of blindness from ROP are much higher than previously at 20 000 children annually. The impact of severe ROP can be reduced through good evidence-based care of very preterm infants and careful organisation of eye examinations and follow-up services. Recent oxygen saturation targeting trial results might mean the adoption of higher targets than formerly in very preterm infants and will require vigilance to ensure all eligible infants are examined appropriately. A true screening examination for acute ROP might involve non-opthalmologists obtaining photographic retinal images and remote reading of these. Although treatment with laser gives good outcomes, there is interest in intravitreal anti-vascular endothelial factor agents, but issues concerning the systemic safety and retinal results of such treatment are unresolved.

Impact of retinopathy of prematurity on ocular structures and visual functions

The preterm baby may develop ophthalmic sequelae which can be due to prematurity per se, due to retinopathy of prematurity (ROP) or due to neurological damage. Focusing on the former two, we discuss how in high-income countries the risk of sight-threatening ROP is largely confined to babies <1000 g birth weight (BW), whereas in low-income or middle-income countries babies exceeding 2500 g BW can be blinded. The effects of prematurity and ROP are presented as regional and global estimates of acute-phase ROP and the consequent mild/moderate and severe visual impairment. We discuss sequelae and how they affect the eye and its shape, strabismus and finally consider their impact on visual functions, including visual acuity, the visual field, colour vision and contrast sensitivity.

The utility of serial plasma sE-selectin measurements in the prediction of retinopathy of prematurity in premature infants

BACKGROUND

sE-selectin has recently been suggested as a surrogate marker for prediction of ROP development.

AIMS

The possible role of serial plasma sE-selectin measurements in early prediction and diagnosis of ROP was evaluated.

STUDY DESIGN

Prospective observational study

SUBJECTS

Forty six preterm infants aged <34weeks of gestation and weighing <1500 g were enrolled. Of these, 26 constituted the ROP group and 20 constituted the no-ROP group. sE-selectin levels were measured serially in blood samples on the 1st day and on 14th and 28th postnatal days.

OUTCOME MEASURES

The primary outcome measure was to evaluate the role of sE-selectin concentrations in prediction of ROP.

RESULTS

The mean gestational age and birth weight were significantly lower in the ROP group. The mean sE-selectin concentrations in ROP group were significantly greater than those in no-ROP group at each time point (1st, 14th and 28th days of postnatal life). A receiver operating characteristic (ROC) analysis showed that at a plasma concentration of ≥86ng/mL on the 1st postnatal day, sE-selectin had a sensitivity of 100% and a specificity of 94.1% with a positive predictive value of 96.3% and a negative predictive value of 100%. Plasma sE-selectin concentrations were significantly greater in infants who developed ROP in three different time points.

CONCLUSIONS

This study shows for the first time that measurement of plasma sE-selectin concentrations as early as the first day of life might help identify preterm infants at risk of ROP.

Preterm-associated visual impairment and estimates of retinopathy of prematurity at regional and global levels for 2010

BACKGROUND

Retinopathy of prematurity (ROP) is a leading cause of potentially avoidable childhood blindness worldwide. We estimated ROP burden at the global and regional levels to inform screening and treatment programs, research, and data priorities.

METHODS

Systematic reviews and meta-analyses were undertaken to estimate the risk of ROP and subsequent visual impairment for surviving preterm babies by level of neonatal care, access to ROP screening, and treatment. A compartmental model was used to estimate ROP cases and numbers of visually impaired survivors.

RESULTS

In 2010, an estimated 184,700 (uncertainty range: 169,600-214,500) preterm babies developed any stage of ROP, 20,000 (15,500-27,200) of whom became blind or severely visually impaired from ROP, and a further 12,300 (8,300-18,400) developed mild/moderate visual impairment. Sixty-five percent of those visually impaired from ROP were born in middle-income regions; 6.2% (4.3-8.9%) of all ROP visually impaired infants were born at >32-wk gestation. Visual impairment from other conditions associated with preterm birth will affect larger numbers of survivors.

CONCLUSION

Improved care, including oxygen delivery and monitoring, for preterm babies in all facility settings would reduce the number of babies affected with ROP. Improved data tracking and coverage of locally adapted screening/treatment programs are urgently required.