Retinopathy of prematurity: recent advances in our understanding

Efficacy comparison of 21 interventions to prevent retinopathy of prematurity: a Bayesian network meta-analysis of randomized controlled trials

BACKGROUND

The objective of this study was to evaluate the comparative efficacy of current interventions for the prevention of retinopathy of prematurity (ROP) in premature infants.

METHODS

A network meta-analysis (NMA) was performed. We searched PubMed, Web of Science, Scopus, Embase, and the Cochrane Library for relevant studies from their inception to May 5, 2022. Publications were eligible for our study if they were randomized controlled trials (RCTs) involving preterm infants at <37 weeks of gestational age and reported the incidence of any-stage ROP treated with the interventions of interest. The overall effect was pooled using the random effects model.

RESULTS

We identified 106 RCTs (involving 23894 participants). This NMA showed that vitamin A supplementation markedly reduced the incidence of ROP, in comparison with placebo (odds ratio [OR] = 0.59, 95% credible interval [95% CrI] 0.33, 0.85), fish oil-based lipid emulsion (OR = 0.57, 95% CrI 0.24, 0.90), early erythropoietin (OR = 0.51, 95% CrI 0.34, 0.98), probiotics (OR = 0.48, 95% CrI 0.32, 0.97), and human milk (OR = 0.50, 95% CrI 0.21, 0.78). Vitamin A supplementation has the highest probability of being the best option for reducing the ROP risk compared with the other 20 interventions based on its surface under the cumulative ranking curve (SUCRA) value (SUCRA = 92.50%, 95% CrI 0.71, 1.00).

CONCLUSIONS

Our findings suggest that among 21 interventions, vitamin A supplementation might be the best method of preventing ROP. This NMA offers an important resource for further efforts to develop preventive strategies for ROP.

A Study of the Demographic Profile, Screening, and Management of Patients Visiting a Retinopathy of Prematurity Clinic

Background and objective Retinopathy of prematurity (ROP) is a retinal vasoproliferative disease affecting premature infants. Despite improvements in neonatal care and management, ROP still remains a major cause of childhood blindness worldwide. Studying the demographic profile and screening is essential to develop predictive models, to gain insights into the cause of retinal vascular diseases and diseases of prematurity, and to determine the future management and research in ROP. The objective of the present study was to estimate the incidence of ROP, to identify the risk factors that predispose to ROP, and to assess the outcome of these cases. Hence, this study was conducted in a tertiary care hospital in Maharashtra. Method A prospective, observational study was conducted from 10 August 2022 to 10 October 2022. Infants with gestational ages < 34 weeks, birth weights < 2000 g, infants who received supplemental oxygen therapy, or patients who required NICU stay were screened for ROP. Demographic details were recorded to assess the risk factors and treatment was given according to the severity of ROP grade. Result A total of 160 eyes of 80 infants were screened and analysed. The overall incidence of "any ROP" was 19 patients (38 eyes), i.e., 24%. Out of 80 patients, six were of 28 weeks gestational age, of whom four (67%) were positive for ROP. The mean birth weight of infants with ROP was 1331.58 ± 238.532 g (p < 0.0001). ROP stage 1 was seen in five patients (26.32%), stage 2 in 10 patients (52.63%), and stage 3 in four patients (21.0%), with no subjects in stages 4 & 5. Out of 19 patients, six (32%) had type 1 ROP, and 13 (68%) had type 2 ROP. Out of 19 cases, 13 (68%) received follow-up care based on the severity of their disease, and six (32%) were treated with panretinal photocoagulation (PRP) laser. Conclusion Incidence of any ROP was 24%. Prematurity, low birth weight, and oxygen therapy remain the most significant risk factors associated with the development of ROP. Early referral, diagnosis, and timely intervention will play a monumental role in improving the prognosis of this potentially blinding disease.

Artificial intelligence in retinal disease: clinical application, challenges, and future directions

Retinal diseases are a leading cause of blindness in developed countries, accounting for the largest share of visually impaired children, working-age adults (inherited retinal disease), and elderly individuals (age-related macular degeneration). These conditions need specialised clinicians to interpret multimodal retinal imaging, with diagnosis and intervention potentially delayed. With an increasing and ageing population, this is becoming a global health priority. One solution is the development of artificial intelligence (AI) software to facilitate rapid data processing. Herein, we review research offering decision support for the diagnosis, classification, monitoring, and treatment of retinal disease using AI. We have prioritised diabetic retinopathy, age-related macular degeneration, inherited retinal disease, and retinopathy of prematurity. There is cautious optimism that these algorithms will be integrated into routine clinical practice to facilitate access to vision-saving treatments, improve efficiency of healthcare systems, and assist clinicians in processing the ever-increasing volume of multimodal data, thereby also liberating time for doctor-patient interaction and co-development of personalised management plans.

Assessment of Role of Platelet Indices in the Occurrence of Retinopathy of Prematurity

PURPOSE

Platelets have a major role in the regulation of angiogenesis. Platelets have proangiogenic factors like vascular endothelial growth factor, which causes neovascularization of immature retina. However, there is no conclusive evidence to show that platelet indices have a role in retinopathy of prematurity (ROP). This study is aimed at assessing the role of platelet indices in the occurrence and need for treatment of ROP.

METHODS

This prospective cohort study included the screening of preterm babies (<37 weeks of gestation with birth weight <2000 g). The samples of platelet indices (mean platelet volume [MPV], platelet count [PLT], plateletcrit [PCT], and platelet distribution width [PDW]) collected within 1^st week of life were obtained from the electronic medical records and correlated to ROP status. Statistical analysis was done using SPSS version 22, and the Chi-square test and odds ratio were used for analysis.

RESULTS

A total of 300 preterm babies were screened, of whom, 55 (18.3%) babies had ROP changes. The association of the presence of ROP changes and platelet indices was not statistically significant (P value being MPV [0.22], PLT [0.58], PCT [0.98], and PDW [0.17]). Similarly, the requirement of treatment for ROP (Type I ROP) could not be correlated with abnormal platelet indices (odds ratio at 95% confidence interval - MPV [6 (0.44-81.44)], PLT [1.7 (0.25-11.37)], PCT [3 (0.44-20.90)], and PDW [0.32 (0.33-3.05)]).

CONCLUSION

Abnormal platelet indices did not show any significant risk with the occurrence or need for treatment of ROP.

Intravitreal administration of recombinant human opticin protects against hyperoxia-induced pre-retinal neovascularization

Opticin is an extracellular glycoprotein present in the vitreous. Its antiangiogenic properties offer the potential for therapeutic intervention in conditions such as proliferative diabetic retinopathy and retinopathy of prematurity. Here, we investigated the hypothesis that intravitreal administration of recombinant human opticin can safely protect against the development of pathological angiogenesis and promote its regression. We generated and purified recombinant human opticin and investigated its impact on the development and regression of pathological retinal neovascularization following intravitreal administration in murine oxygen-induced retinopathy. We also investigated its effect on normal retinal vascular development and function, following intravitreal injection in neonatal mice, by histological examination and electroretinography. In oxygen-induced retinopathy, intravitreal administration of human recombinant opticin protected against the development of retinal neovascularization to similar extent as aflibercept, which targets VEGF. Opticin also accelerated regression of established retinal neovascularization, though the effect at 18 h was less than that of aflibercept. Intravitreal administration of human recombinant opticin in neonatal mice caused no detectable perturbation of subsequent retinal vascular development or function. In summary we found that intraocular administration of recombinant human opticin protects against the development of pathological angiogenesis in mice and promotes its regression.

Addressing the Third Epidemic of Retinopathy of Prematurity Through Telemedicine and Technology: A Systematic Review

The rising prevalence of retinopathy of prematurity (ROP) in low- and middle-income countries has increased the need for screening at-risk infants. The purpose of this article was to review the impact of tele-medicine and technology on ROP screening programs. Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was performed using PubMed, Pro-Quest, and Google Scholar bibliographic search engine. Terms searched included retinopathy of prematurity, telemedicine, and tele-ophthalmology. Data regarding internet access and gross domestic product per capita were obtained from the World Bank. Information was also obtained about internet access, speeds, and costs in low-income countries. There has been increasing integration of telemedicine and technology for ROP screening and management. Low-income countries are using available internet options and information and communications technology for ROP screening, which can aid in addressing the unique challenges faced by low-income countries. This provides a promising solution to the third epidemic of ROP by expanding and improving screening and management. Although telemedicine systems may serve as a cost-effective approach to facilitate delivery of health care, programs (especially in lowand middle-income countries) require national support to maintain its infrastructure. [J Pediatr Ophthalmol Strabismus. 2021;58(4):261-269.].

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.

Comparison of the detection rates for retinopathy of prematurity (ROP) of the 2013 Philippine Academy of Ophthalmology (PAO) Revised Philippine Guidelines and the 2005 PAO-Philippine Pediatric Society (PPS) Guidelines for ROP screening in the Philippine General Hospital: a 5-year review

Objectives

Compare the detection rates of the 2013 Philippine Academy of Ophthalmology (PAO) guidelines for retinopathy of prematurity (ROP) screening and the 2005 PAO-Philippine Pediatric Society guidelines in identifying infants who develop ROP in the 5-year study period in the Philippine General Hospital (PGH). Secondary objectives include determination of ROP prevalence; correlation of gestational age (GA), birth weight (BW) and other risk factors to ROP; and identification of the most common intervention.

Methods and analysis

Retrospective cross-sectional study of ROP records between 1 December 2013 and 30 November 2018 from the Medical Retina Service of the Department of Ophthalmology and Visual Sciences of the institution was studied. Variables with p value <0.05 were considered significant. STATA V.14 was used for all analysis.

Results

Only 851 of 898 infants screened for ROP were included in the study. Of these 698 would have been screened based on 2005 guidelines. All 118 infants with ROP were identified by both guidelines. Detection rate was higher using the 2005 than the 2013 guidelines (16.9% vs 13.3%, p value=0.0496). ROP prevalence was 9.7%. Among those with ROP, 70% have at least one identified risk factor, topped by sepsis, pneumonia, hyaline membrane disease, blood transfusion and oxygen supplementation. Only 8% required intervention consisting of laser, anti-vascular endothelial growth factor injection, surgery or in combination.

Conclusion

In PGH, no infants with ROP were missed using the 2005 recommendations. There was no added benefit of increasing threshold for BW and GA as recommended by the 2013 PAO guidelines. Screening guidelines should, however, be tailored to institutional needs, requirements and experience.

Maternal history of recurrent pregnancy loss and future risk of ophthalmic morbidity in the offspring

OBJECTIVE

The objective of the study was to investigate whether maternal history of recurrent pregnancy loss (RPL) is associated with offspring childhood ophthalmic morbidity.

METHOD

A hospital-based cohort analysis comparing long-term offspring ophthalmic morbidity in women with and without a history of RPL was performed. Ophthalmic morbidity included hospitalizations involving a pre-defined set of ICD-9 codes. Offspring with congenital anomalies, perinatal mortality cases, and multifetal pregnancies were excluded from the analysis. Cumulative morbidity incidence was compared using Kaplan-Meier survival curves, and the risk of long-term ophthalmic morbidity was assessed by Cox proportional hazards model after adjustment for confounders.

RESULTS

During the study period, 242,187 newborns met the inclusion criteria; 5% (12,182) of them were offspring born to mothers with a history of RPL. Ophthalmic morbidity was significantly more common in the RPL group (1.3% vs 0.9%, p < .001, Kaplan-Meier log-rank p < .001). Adjustment for confounders, such as maternal age, gestational age, hypertensive disorders, and maternal diabetes, using Cox regression found that being born to a mother with RPL was independently associated with long-term ophthalmic morbidity (adjusted HR 1.35, 95% CI 1.15-1.59, p < .001).

CONCLUSION

Being born to a mother with RPL is independently associated with an increased risk of ophthalmic morbidity.

Norrie disease gene polymorphism in Indonesian infants with retinopathy of prematurity

OBJECTIVE

Retinopathy of prematurity (ROP) is a major cause of blindness in newborn infants, which also occurs in low-income and middle-income countries. Why ROP progresses in some infants while it regresses in others is still presently unknown. Studies suggest that genetic factors might be involved. Mutations in the Norrie disease (ND) gene are suspected to be related to advanced ROP development. Indonesia is a country with relatively high incidence of ROP, yet the role of these genetic factors in the pathogenesis of ROP cases is still unknown. The study aimed to investigate the presence of mutations in ND on the X chromosome in infants with both non-advanced and advanced ROP in Indonesia.

METHODS AND ANALYSIS

This is a case-control study of polymorphisms in six variants within the ND gene in exon 3, C597A, L108P, R121W, A105T, V60E and C110G, in preterm newborn infants in four major hospitals in Greater Jakarta, Indonesia.

RESULTS

We included 162 preterm newborn infants. ROP was diagnosed in 83 infants, and 79 infants served as controls. Among those with ROP, 57 infants had type 2, while others had type 1. We did not find any gene polymorphisms in any of the infants with ROP nor in the control group.

CONCLUSION

We conclude that it is very unlikely that the six polymorphisms in exon 3 of the ND gene studied in this paper are involved in the development or progression of ROP in preterm infants in our population sample in Indonesia.

Demographic profile and ocular characteristics of stage 5 retinopathy of prematurity at a referral center in Northwest China: implications for implementation

Background

Severe retinopathy of prematurity (ROP) with extremely unfavorable prognosis among infants can do great damage to individuals and bring tremendous social-economic burden. The purpose of this study is to describe the demographic and ocular characteristics of infants who presented with stage 5 ROP in order to identify reasons why they have become blind, and to identify contributing factors in order to focus great attention on the current ROP program and to inspire more effort in ROP screening in middle income countries.

Methods

A retrospective review of consecutive infants with stage 5 ROP from December 2010 to December 2016 in Department of Ophthalmology, Xijing Hospital. Various parameters retrieved included birthweight, gestational age, age at initial examination, postmenstrual age, screening details, check-up details and reasons for consultation. Ocular findings were recorded and also detected by ultrasonography.

Results

A retrospective review of 20 consecutive infants with stage 5 ROP are included. Mean birthweight was1712.3 ± 512.97 g and mean gestational age at birth was 32.1 ± 2.21 weeks. Median age at first consultancy was 9.7 month. Median postmenstrual age first consultancy was 52 weeks. All infants were never screened for ROP before they came to the referral center. Of twenty stage 5 ROP infants, 13 cases presented with bilateral stage 5 features. Of the 40 eyes of 20 infants, 33 eyes were diagnosed as stage 5. Leukocoric pupil, closed funnel configuration of retinal detachment (RD), posterior synechia, extraretinal fibrovascular proliferation and retinal folds were the most significant indicators of bad prognosis. Ten eyes appeared no fixation to light, while 30 eyes exhibited following to light or following to toys.

Conclusions

Our study shows that in relatively less-developed regions of China, more needs to be done to spread awareness about the disease among pediatricians, neonatologists and ophthalmologists as well as parents of premature infants. Thus, a comprehensive control system which is a whole network of propaganda, screening, treatment and follow-up are encouraged especially in less developed areas in China as well as worldwide.

Gestational age-specific sex difference in mortality and morbidities of preterm infants: A nationwide study

This study aims to determine whether male sex has adverse effect on mortality and morbidities in very low birth weight infants (VLBWI) <30 weeks of gestation and to ascertain this sex effect, stratified by gestational age, adjusting for perinatal risk factors. This is a population-based study from Korean Neonatal Network for VLBWI born at 23+0 and 29+6 weeks of gestation between January 2013 and December 2014. The primary outcome was gestation-specific sex difference in the occurrence of mortality, combined morbidities, and individual morbidity. A total of 2228 VLBWI were enrolled (males, 51.7%). Mortality was not different between sexes. The risk of bronchopulmonary dysplasia and combined morbidities was significantly higher in males ≤25 weeks of gestation (odds ratio [OR] 2.08, 95% confidence interval [CI] 1.35-3.20 and OR 2.00, CI 1.19-3.39, respectively). Males had a significantly higher incidence of periventricular leukomalacia at 23 and 29 weeks of gestation. The risk of severe retinopathy of prematurity was higher in females >25 weeks of gestation. Although both sexes have similar risk for mortality, male sex remains an independent risk for major morbidities, especially at ≤25 weeks of gestation. The risk of each outcome for males has a specific pattern with increasing gestational age.

Can a Risk Factor Based Approach Safely Reduce Screening for Retinopathy of Prematurity?

Objective. Current American retinopathy of prematurity (ROP) screening guidelines is imprecise for infants ≥ 30 weeks with birth weights between 1500 and 2000 g. Our objective was to evaluate a risk factor based approach for screening premature infants at low risk for severe ROP. Study Design. We performed a 13-year review from Intermountain Health Care (IHC) data. All neonates born at ≤32 weeks were reviewed to determine ROP screening and/or development of severe ROP. Severe ROP was defined by stage ≥ 3 or need for laser therapy. Regression analysis was used to identify significant risk factors for severe ROP. Results. We identified 4607 neonates ≤ 32 weeks gestation. Following exclusion for death, with no retinal exam or incomplete data, 2791 (61%) were included in the study. Overall, severe ROP occurred in 260 (9.3%), but only 11/1601 ≥ 29 weeks (0.7%). All infants with severe ROP ≥ 29 weeks had at least 2 identified ROP risk factors. Implementation of this risk based screening strategy to the IHC population over the timeline of this study would have eliminated screening in 21% (343/1601) of the screened population. Conclusions. Limiting ROP screening for infants ≥ 29 and ≤ 32 weeks to only those with clinical risk factors could significantly reduce screening exams while identifying all infants with severe ROP.

Factors Associated with Retinopathy of Prematurity in Hospitalized Preterm Infants in Sanandaj, Iran

Introduction

In the near future, retinopathy of prematurity (ROP) will be the most significant cause of blindness in upper and middle-income countries. Due to the increasing survival chances for premature and low birth weight infants and the importance of the diagnosis and treatment of ROP, this study was aimed at determining the prevalence of ROP and its related factors in Sanandaj, Iran, in 2014.

Methods

This cross-sectional study was performed on 47 preterm infants, weighing less than 2000 g or with a gestational age of less than of 34 weeks. The sampling method was census. From the first examination to 1 to 4 weeks later, until retinal vascularization completion, examinations were performed by the same ophthalmologist. Data were analyzed using SPSS version 20 and frequency, mean, SD and Chi-square tests.

Results

The prevalence of ROP in the infants was 10.6%. Prevalence among girls was 16% and among boys it was 4.5%. The results showed that 23.5% of infants with ROP needed mechanical ventilation. The difference between the two groups was statistically significant (p = 0.031).

Conclusion

In this study, the prevalence of ROP in the NICU and neonatal ward of Besat Hospital in Sanandaj was low. However, due to serious consequences of the disease in premature infants, timely screening, determination, and control of risk factors provided necessary support to manage the disease.

Association between VEGF polymorphisms (-460 T/C and +936 C/T) and retinopathy of prematurity risk: A meta-analysis

PURPOSE

Vascular endothelial growth factor (VEGF) contributes to the development of retinopathy of prematurity (ROP). A number of studies investigated the association of ROP with VEGF -460 T/C and +936 C/T polymorphisms but the results were conflicting. In order to derive a more precise estimation of the associations, we performed a meta-analysis of the relationship between VEGF -460 T/C and +936 C/T polymorphisms with ROP in all published studies.

METHODS

A literature search was performed systematically using electronic databases. Published literature from PubMed and other databases was retrieved. The odds ratio (OR) with 95% confidence interval (CI) was used to estimate the pooled effect. Each -460 T/C and +936 C/T polymorphism included four case-control studies including case/control 249/308 and 179/250 respectively.

RESULTS

Through literature search, we found that both VEGF -460 T/C and +936 C/T polymorphisms were not associated with ROP risk at allelic, co-dominant, dominant and recessive models.

CONCLUSIONS

This meta-analysis suggests that the VEGF -460 T/C and +936 C/T polymorphism might contribute to genetic susceptibility of ROP. The association between VEGF -460 T/C and +936 C/T polymorphism and ROP risk awaits further investigation.

Retinopathy of prematurity in Korean infants with birthweight greater than 1500 g

OBJECTIVE

To determine the incidence and clinical features of, and risk factors for, retinopathy of prematurity (ROP) in Korean infants with birthweight (BW) >1500 g.

METHODS

A total of 201 consecutive infants with BW >1500 g from January 2009 to December 2013 were included. The location and maximal stage of retinopathy observed were recorded for each infant. The associated systemic and maternal risk factors in infants with mild or absent ROP were compared with those in infants with treatment-requiring ROP.

RESULTS

The total incidence of ROP was 11.94% and that of treatment-requiring ROP was 3.98%. Two patients with gestational age (GA) >32 weeks and BW >1500 g had treatment-requiring ROP. 15 eyes from eight infants with type I ROP required laser photocoagulation. The mean BWs and GAs in the treatment-requiring ROP group were significantly lower than those in the no or mild ROP group. Total duration of oxygen supplementation, surfactant usage, respiratory distress syndrome, bronchopulmonary dysplasia, antibiotic use for more than 14 days and the number of ROP-associated risk factors significantly increased the likelihood of treatment-requiring ROP (p=0.002, p=0.008, p=0.008, p=0.000, p=0.015, and p=0.004, respectively).

CONCLUSION

Our study confirmed that treatment-requiring ROP does occur in infants with BW >1500 g. To avoid overlooking infants with vision-threatening ROP, an evaluation of the data from larger BW preterm infants is advisable so that screening guidelines in neonatal care units may be refined.

Incidence and main risk factors for severe retinopathy of prematurity in infants weighing less than 1000 grams in Brazil

OBJECTIVES

This study evaluated the incidence and risk factors for severe retinopathy of prematurity (ROP) in babies <1000 g at Porto Alegre, Brazil.

METHODS

Prospective cohort study including premature children with birth weight ≤1000 g was conducted. Main outcome was the occurrence of severe ROP needing treatment.

RESULTS

A total of 157 infants were included. Severe ROP occurred in 20 infants (12.7%). Nineteen patients were treated by laser photocoagulation. Main risk factors for severe ROP were gestational age (P = 0.029), infant's weight measured at sixth week of life (P < 0.001) and number of days of oxygen therapy under mechanical ventilation (P < 0.001). After logistic regression, infant's weight at sixth week of life and number of days in mechanical ventilation were associated to severe ROP.

CONCLUSIONS

We reported the incidence of 12.7% of severe ROP among babies born ≤ 1000 g in our institution. Laser photocoagulation was effective to stabilize the disease among 19 treated patients.

Awareness and screening for retinopathy of prematurity among paediatricians in Nigeria

BACKGROUND

Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the retina which occurs in premature babies due to defective vasculogenesis. There are established screening guidelines to enhance its early identification and prompt treatment. The aim of the study was to determine the level of awareness of the screening protocols for retinopathy of prematurity (ROP) among paediatricians in Nigeria.

METHODS

A questionnaire was administered to paediatricians and residents in paediatrics attending a continuous professional development (CPD) course in Benin City, Nigeria. Information on their knowledge of risk factors, screening guidelines and treatment modalities for ROP was obtained.

RESULTS

There were a total of 48 participants. The mean age of the participants was 34.5 ± 4.5 years of which 25 (52.1%) were females. A majority, 46 (95.8%) knew some risk factors for ROP. Fourteen (29.2%) participants knew the ROP screening guidelines while 10 (20.8%) had partial knowledge of these guidelines. Knowledge on the use of laser as a treatment modality of ROP was shown by 18 (37.5%) participants. The major reason given for not screening for ROP was being unaware of a referral centre in Nigeria in 43 (89.6%) participants.

CONCLUSION

The majority of paediatricians attending a CPD course in Nigeria though aware of retinopathy of prematurity, are currently poorly informed on the management of this condition and the need for screening. There is need to enlighten paediatricians in Nigeria on retinopathy of prematurity in order to prevent this treatable cause of blindness in children.

Role of the retinal vascular endothelial cell in ocular disease

Retinal endothelial cells line the arborizing microvasculature that supplies and drains the neural retina. The anatomical and physiological characteristics of these endothelial cells are consistent with nutritional requirements and protection of a tissue critical to vision. On the one hand, the endothelium must ensure the supply of oxygen and other nutrients to the metabolically active retina, and allow access to circulating cells that maintain the vasculature or survey the retina for the presence of potential pathogens. On the other hand, the endothelium contributes to the blood-retinal barrier that protects the retina by excluding circulating molecular toxins, microorganisms, and pro-inflammatory leukocytes. Features required to fulfill these functions may also predispose to disease processes, such as retinal vascular leakage and neovascularization, and trafficking of microbes and inflammatory cells. Thus, the retinal endothelial cell is a key participant in retinal ischemic vasculopathies that include diabetic retinopathy and retinopathy of prematurity, and retinal inflammation or infection, as occurs in posterior uveitis. Using gene expression and proteomic profiling, it has been possible to explore the molecular phenotype of the human retinal endothelial cell and contribute to understanding of the pathogenesis of these diseases. In addition to providing support for the involvement of well-characterized endothelial molecules, profiling has the power to identify new players in retinal pathologies. Findings may have implications for the design of new biological therapies. Additional progress in this field is anticipated as other technologies, including epigenetic profiling methods, whole transcriptome shotgun sequencing, and metabolomics, are used to study the human retinal endothelial cell.

Extremely low birth weight infants with patent ductus arteriosus: searching for the least invasiveness

Patent ductus arteriosus (PDA) is an important problem in premature infants. Extremely low birth weight infants (ELBWI) are so fragile with respect to surgical stress that minimally invasive procedures are required. We report 26 ELBWI cases with PDA who underwent surgical closure. All had failed indomethacin treatment, or it had been contraindicated. The mean gestational age at birth was 27 weeks (range, 24-38 weeks), and the mean birth weight was 960.96 g (range, 710-1440 g). The mean age at operation was 18.06 days (range, 7-34 days), and the mean body weight at operation was 989.42 g (range, 680-1460 g). There was no surgery-related mortality or morbidity. Our surgical procedures consisted of posterior muscle-sparing thoracotomy, clipping the PDA and no ligation, and closing the thorax without a tube thoracostomy. Muscle-sparing thoracotomy reduces the likelihood of long-term physical impairment and deformity, the clipping technique minimizes the dissection of surrounding PDA tissue, and the thorax is closed without a tube. Nursing care is simplified, costs are reduced, and the number of chest x-rays needed postoperatively is reduced. We believe that surgical closure of PDA without chest tube drainage can be accomplished safely in premature infants.

Associations of VEGF/VEGF-receptor and HGF/c-Met promoter polymorphisms with progression/regression of retinopathy of prematurity

PURPOSE

To determine the effect(s) of vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), hepatocyte growth factor (HGF), and HGF receptor (c-Met) polymorphisms on progression/regression of retinopathy of prematurity (ROP) in premature infants.

MATERIALS AND METHODS

This study comprised both a prospective analysis and a clinically relevant laboratory investigation. Enrolled were 123 Turkish preterm infants--gestational age (GA), ≤34 weeks; birth weight (BW), ≤1500 g--from a single tertiary care center. Infants were grouped as those who had undergone laser therapy (Group 1, n = 42), those with spontaneously regressed ROP (Group 2, n = 50), and those with no ROP (controls) (Group 3, n = 31). VEGF (-634) C and VEGF (-460) C polymorphisms were analyzed using the PCR-restriction fragment length polymorphism (RFLP) (PCR-RFLP) technique. VEGFR-2, HGF, and c-Met gene promoter polymorphisms were determined by direct sequencing.

RESULTS

Mean GAs and BWs of infants in Groups 1 and 2 were statistically significantly lower than those of Group 3 (p = 0.001). Frequencies of VEGF (-634) C and VEGF (-460) C polymorphisms were similar for all groups. We found a +32G→A single-nucleotide polymorphism (SNP) in the promoter region of the VEGFR-2 gene. HGF and c-Met gene promoter polymorphisms were not found in any group.

CONCLUSIONS

Our results indicate that there is no association between the carrier states of gene promoter polymorphisms VEGF (-634) C, VEGF (-460) C, and VEGFR-2, and progression or spontaneous regression of ROP in preterm infants. The absence of HGF and c-Met polymorphisms in our study groups suggests that polymorphisms in the minimal promoters of these genes are not involved in the pathogenesis of ROP.

A closed-loop system for control of the fraction of inspired oxygen and the positive end-expiratory pressure in mechanical ventilation

A system for automatic control of the fraction of inspired oxygen (F(IO2)), and positive end-expiratory pressure (PEEP) for patients on mechanical ventilation is presented. In this system, F(IO2) is controlled by using two interacting mechanisms; a fine control mechanism and a fast stepwise procedure used when patient's oxygen saturation level (S(pO2)) falls abruptly. The PEEP level is controlled automatically and in relation to F(IO2) to prevent hypoxemia. The system has been tested by using bench studies and computer simulations. The results show the potential of the system as an aide in effective oxygenation of patients on mechanical ventilation.

Expression and regulation of activated leukocyte cell adhesion molecule in human retinal vascular endothelial cells

Activated leukocyte cell adhesion molecule (ALCAM; CD166) is an immunoglobulin superfamily member that has been described in several non-ocular endothelial populations, but not in relation to endothelium within the eye. Studies in extraocular systems have implicated ALCAM in angiogenesis and leukocyte transendothelial migration, which are key processes in retinal vascular diseases. We investigated the expression of ALCAM in human retinal endothelium, and studied the regulation of expression by established angiogenic and inflammatory stimuli. Retinal endothelial expression of ALCAM was detected in primary retinal endothelial cultures isolated from human cadavers by RT-PCR (n = 4 donors) and Western blot (n = 4 donors), and in intact human retina by immunohistochemistry (n = 3 donors). In the 4 donors studied by RT-PCR, transcript encoding the truncated soluble isoform, sALCAM, was also detected. Quantitative real-time RT-PCR demonstrated significant up-regulation of ALCAM and sALCAM in response to stimulation with master cytokine, tumor necrosis factor (TNF)-α. However, general inflammatory stimulus, lipopolysaccharide (LPS), and the prototype Th1, Th2 and Th17 cytokines, interferon (IFN)-γ, interleukin (IL)-4 and IL-17A, respectively, did not impact ALCAM or sALCAM expression. In contrast, expression of ALCAM was significantly up-regulated by vascular endothelial growth factor (VEGF)(165). Up-regulation in the presence of VEGF and TNF-α, but not LPS, IFN-γ, IL-4 and IL-17A, suggests a potential role for ALCAM in human retinal angiogenesis in some settings.

The genetic control of avascular area in mouse oxygen-induced retinopathy

PURPOSE

The C57BL/6ByJ and BALB/cByJ inbred strains of mice are, respectively, susceptible and resistant to oxygen-induced retinopathy (OIR). The purpose of this work was to investigate the genetic control of the retinal avascular area in mouse OIR using a mapping cross.

METHODS

The central retinal avascular area was measured on postnatal day 16 (P16) in C57BL/6ByJ, BALB/cByJ, 101 (C57BL/6ByJ x BALB/cByJ)F₂, and 116 (BALB/cByJ x C57BL/6ByJ)F₂ mice that had been subjected to the OIR protocol. A genome-wide scan was performed of selected albino and non-albino mice to determine quantitative trait loci associated with weight and avascular area.

RESULTS

C57BL/6ByJ mice had significantly larger avascular areas than BALB/cByJ ones. Albino mice of the F₂ generation had smaller avascular areas than the non-albino mice. Genotyping was performed at 856 informative single nucleotide polymorphisms approximately evenly distributed across the genome from each of 85 selected F₂ mice. Weight, sex, and the paternal grandmother were found to act as additive covariates associated with the avascular area on P16; mapping analyses that used a model incorporating these covariates found a quantitative trait locus on chromosome 7 related to avascular area. Mapping analyses that used a model that did not incorporate covariates found a quantitative trait locus on chromosome 9 related to avascular area. A quantitative trait locus for bodyweight on P16 was mapped to chromosome 5.

CONCLUSIONS

The retinal avascular area in the mouse OIR model is under genetic control. Revascularization in OIR is related to the weight, strain of paternal grandmother, sex, and albinism. Our data support the existence of a quantitative trait locus on chromosome 5 that influences weight after exposure to hyperoxia, as well as quantitative trait loci on chromosomes 7 and 9 that modify susceptibility to OIR.

Analysis of incidence and risk factors of retinopathy of prematurity among very-low-birth-weight infants in North Taiwan

BACKGROUND

Although significant advances have been made in perinatal care, retinopathy of prematurity (ROP) remains a serious complication in prematurely born individuals. There have been limited studies on ROP in Taiwan, and most of those existing reports are outdated.

METHODS

This retrospective study included 252 very-low-birth-weight (VLBW) infants admitted to the neonatal intensive care unit of Chang Gung Children's Hospital over a 2-year period between July 2005 and June 2007. All infants were examined for ROP according to the guidelines published by the American Academy of Pediatrics. The relationship between clinical risk factors and the development of ROP was analyzed.

RESULTS

Of the 252 VLBW infants, 216 met the screening criteria. Of the 216, 99 (45.8%) had ROP. Compared with neonates born at 29 weeks of gestational age (GA) or later, those very premature infants of ≤25 weeks' and 26-28 weeks' GA had increased odds ratios (OR) of 8.49 and 3.19, respectively, for the development of severe ROP. No ROP was detected in infants of greater than 33 weeks' GA. The simultaneous presence of a low GA, low birth weight (LBW), lower Apgar scores, hypotension, patent ductus arteriosus, septicemia, intraventricular hemorrhage, ventilator dependence, and use of postnatal steroids was associated with severe ROP. Using multiple logistic regression analyses for ROP, only maternal preeclampsia [OR, 2.52; confidence interval (CI), 1.32-4.7]; duration of mechanical ventilation (OR, 1.06; CI, 1.04-1.08); and LBW (OR, 2.62; CI, 1.370-3.375) predicted the development of threshold ROP.

CONCLUSION

The incidence of ROP among VLBW infants was 45.8%; 19.0% had severe ROP. Infants of lower GAs and/or with LBW, whose mother had preeclampsia or who had a long duration of mechanical ventilation are at risk for the development of threshold ROP.

Maternal preeclampsia is associated with an increased risk of retinopathy of prematurity

OBJECTIVE

To determine the effect of maternal preeclampsia on development and severity of retinopathy of prematurity (ROP) in preterm infants.

METHODS

This prospective study consisted of two groups: the study group, which is composed of preterm infants (≤32 weeks) born to a mother with preeclampsia, and the comparison group, which is composed of preterm infants (≤32 gestational age) born to normotensive mothers. We used the International Classification of Retinopathy of Prematurity Revisited for classifying ROP. The first eye examination was performed at postnatal age of 4 weeks.

RESULTS

A total of 385 infants were included in the study. ROP was diagnosed in 109 infants (28%). The incidence of ROP in infants born to preeclamptic mothers (40.5%) was significantly higher compared with those born to normotensive mothers (22.4%) (P<0.05). The number of infants with stage 1, 2, and 3 ROP was significantly higher in infants born to preeclamptic mothers compared with the control group (P<0.05). In multiple logistic regression model, preeclampsia was found to predict ROP (odds ratio 1.78, 95% confidence interval 0.66-1.90).

CONCLUSION

Maternal preeclampsia was found to be associated with increased ROP development risk in premature infants. ROP was also more severe in infants born to pre-eclamptic mothers. The role of maternal preeclampsia in the occurrence and severity of ROP remains to be elucidated.

Basics and dynamics of neonatal and pediatric pharmacology

Understanding the role of ontogeny in the disposition and actions of medicines is the most fundamental prerequisite for safe and effective pharmacotherapeutics in the pediatric population. The maturational process represents a continuum of growth, differentiation, and development, which extends from the very small preterm newborn infant through childhood, adolescence, and to young adulthood. Developmental changes in physiology and, consequently, in pharmacology influence the efficacy, toxicity, and dosing regimen of medicines. Relevant periods of development are characterized by changes in body composition and proportion, developmental changes of physiology with pathophysiology, exposure to unique safety hazards, changes in drug disposition by major organs of metabolism and elimination, ontogeny of drug targets (e.g., enzymes, transporters, receptors, and channels), and environmental influences. These developmental components that result in critical windows of development of immature organ systems that may lead to permanent effects later in life interact in a complex, nonlinear fashion. The ontogeny of these physiologic processes provides the key to understanding the added dimension of development that defines the essential differences between children and adults. A basic understanding of the developmental dynamics in pediatric pharmacology is also essential to delineating the future directions and priority areas of pediatric drug research and development.

Genetic susceptibility to advanced retinopathy of prematurity (ROP)

Retinopathy of prematurity (ROP) is a vascular vitreoretinopathy that affects infants with short gestational age and low birth-weight. The condition is a multifactorial disease and is clinically similar to familial exudative vitreoretinopathy (FEVR), which is a bilateral hereditary eye disorder affecting full-term infants. Both of them are characterized by the abnormal vessel growth in the vitreous that can lead to vitreoretinal traction, retinal detachment and other complications resulting in blindness. Despite the recent advances in diagnosis and treatment, ROP remains a major cause of childhood blindness in developed countries. The etiology of pathogenesis of advanced ROP is currently unknown. In the past, many causative factors such as length of time exposed to supplemental oxygen, excessive ambient light exposure and hypoxia have been suggested but evidence for these as independent risk factors in recent years is not compelling. It is not clear why ROP in a subset of infants with low birth-weight progresses to a severe stage (retinal detachment) despite timely intervention whereas in other infants with similar clinical characteristics ROP regresses spontaneously. Recent research with candidate gene approach, higher concordance rate in monozygotic twins and other clinical and experimental animal studies, suggest a strong genetic predisposition to ROP besides environmental factors such as prematurity. Three genes, which are involved in the Wnt signaling pathway, are mutated in both FEVR and in a small percentage of ROP disorder. However, none of the genetic factors identified thus far in ROP, account for a substantial number of patient population. Future studies involving genomics, bioinformatics and proteomics may provide a better understanding of the pathophysiology and management of ROP.

Oxygen saturation in premature infants at risk for threshold retinopathy of prematurity

PURPOSE

We aimed to determine if oxygen saturation, desaturations, and saturation variability play a role in progression of retinopathy of prematurity (ROP) and need for laser treatment.

METHODS

This was a retrospective case-control study. We performed chart review of premature infants in a university hospital neonatal intensive care unit consecutively examined for ROP between May 2000 and December 2001. We compared birthweight, postmenstrual age, and oxygen saturation for 3 weeks before laser treatment for threshold ROP in group 1 (n=19) (average weight at treatment 2508 grams) and group 2 (n=18) before they reached 2500 grams. Outcome measures were retinopathy progression and need for treatment.

RESULTS

Adjusting for birthweight and postmenstrual age, known predictors of ROP progression, we found that babies requiring laser treatment (group 1) had lower average daily oxygen saturation levels in the study period, significantly on 5/20 days (25%). These babies had saturations below 95% on 18/20 days (90%). Babies not requiring laser (group 2) had saturations below 95% on 2/20 days (10%). The last day on which pretreatment saturations differed significantly was 2 days before laser. Group 1 had more desaturations below 80% (6.0±3.2) than group 2 (3.2±1.2), p=0.0002 (independent samples t tests). Saturations varied more for individual group 1 infants.

CONCLUSIONS

Decreased oxygen saturation as early as 3 weeks and as late as 2 days before laser, increased number of desaturations, and saturation variability were seen in babies eventually requiring laser treatment for ROP.

The use of medical orders in acute care oxygen therapy

The life of every living organism is sustained by the presence of oxygen and the acute deprivation of oxygen will, therefore, result in hypoxia and ultimately death. Although oxygen is normally present in the air, higher concentrations are required to treat many disease processes. Oxygen is therefore considered to be a drug requiring a medical prescription and is subject to any law that covers its use and prescription. Administration is typically authorized by a physician following legal written instructions to a qualified nurse. This standard procedure helps prevent incidence of misuse or oxygen deprivation which could worsen the patients hypoxia and ultimate outcome. Delaying the administration of oxygen until a written medical prescription is obtained could also have the same effect. Clearly, defined protocols should exist to allow for the legal administration of oxygen by nurses without a physicians order because any delay in administering oxygen to patients can very well lead to their death.

Retinopathy of prematurity: an eye toward better outcomes

Retinopathy of prematurity (ROP) results from the abnormal growth of blood vessels in the vascular bed supporting the developing retina. Estimated to cause up to 500 new cases of blindness in the U.S. each year, ROP affects primarily infants born at less than 1,500 g. Although its etiology is not well understood, ROP is thought to occur as a result of a complex interaction between oxygen and vascular growth factors. This article briefly reviews the history of ROP, discusses its pathophysiology, and addresses the risk factors and strategies for prevention.

Immaturity, perinatal inflammation, and retinopathy of prematurity: a multi-hit hypothesis

OBJECTIVE

To explore the relationship among markers of infection/inflammation in their association with retinopathy of prematurity (ROP).

METHODS

We studied clinical characteristics and 4 single nucleotide polymorphisms in infection/inflammation-associated genes in a group of 73 children with a gestational age<32 weeks. Forty-four children (60%) had ROP, of whom 13 (30% of those with ROP) progressed to stage 3 ROP. No child had grade 4 or 5 ROP. We employed both descriptive and analytic statistical methods.

RESULTS

Clinical variables of infection/inflammation were consistently associated with an increased risk of ROP. Among infants with ROP, they were also associated with progression to ROP grade 3. Genetic markers were not associated with ROP occurrence, but with progression to high grade disease. In tri-variable analyses exploring the effects of gestational age <29 weeks, clinical chorioamnionitis (CAM) and neonatal systemic inflammatory response syndrome (SIRS) on ROP occurrence, low gestational age was the most important antecedent, while additional individual or joint exposure to SIRS and CAM add appreciably to this risk of progression to high grade disease.

CONCLUSION

Both antenatal and neonatal exposure to inflammation appear to contribute to the increased ROP risk in preterm infants.

Pediatric ophthalmology in the developing world

PURPOSE OF REVIEW

It is estimated that of the 45 million people who are blind worldwide in 2000, 1.4 million are children from middle-income and low-income countries, the majority of whom live in the poorest regions of Africa and Asia. The focus of this paper is to discuss the status of pediatric ophthalmology in developing countries and the progress that has been made in the areas of avoidable childhood blindness and visual impairment, particularly corneal scarring as a result of vitamin A deficiency, congenital cataract and retinopathy of prematurity. In addition, we will review the prevalence of uncorrected refractive error and discuss the access to pediatric ophthalmologists in developing countries.

RECENT FINDINGS

Some developing countries have begun incorporating vitamin A supplementation and measles immunizations and have seen a decrease in xerophthtalmia. With improvement in vitamin A status, cataract is becoming a more apparent cause of treatable childhood blindness. Amblyopia and uncorrected refractive errors are important and inexpensively treatable causes of visual impairment, with myopia being most common. As neonatal intensive care services in middle-income developing countries improve the survival of premature infants, retinopathy of prematurity is emerging as a significant cause of childhood blindness.

SUMMARY

Childhood blindness and visual impairment in developing countries remains a significant public health issue, but recent initiatives have shown promise of future improvements.

Atypical persistence of tunica vasculosa lentis

The authors report an unusual case of persistent tunica vasculosa lentis in a patient with minimal retinopathy of prematurity (ROP). A 3-month-old male infant who had been born at 31 weeks' gestation presented with a significant amount of persistent tunica vasculosa lentis and arteriolar tortuosity with minimal ROP and no plus disease. After weekly observation and no surgical intervention, the arteriolar tortuosity lessened but the tunica vasculosa lentis persisted. Persistent tunica vasculosa lentis can be mistaken for iris vascular engorgement, suggesting plus disease and high-risk prethreshold ROP. Differentiation between tunica vasculosa lentis and iris vascular engorgement, as well as correct diagnosis of plus disease, is critical when considering laser treatment for high-risk prethreshold ROP.

AP-ROP in an infant with minimal oxygen exposure

Retinopathy of prematurity (ROP) is a multifactorial disease affecting the developing retinal vasculature and remains an important cause of blindness in very preterm infants. Rush disease, or aggressive posterior ROP (AP-ROP), progresses rapidly to stage 5 disease without exhibiting the classical course that includes stages 1-3. We describe an infant with minimal exposure to oxygen who developed AP-ROP that led to bilateral retinal detachments and a poor visual outcome, despite following current recommended screening guidelines.

Genetic susceptibility to retinopathy of prematurity: the evidence from clinical and experimental animal studies

Despite advances in management and treatment, retinopathy of prematurity remains a major cause of childhood blindness. Evidence for a genetic basis for susceptibility to retinopathy of prematurity is examined, including the influences of sex, ethnicity, and ocular pigmentation. The role of polymorphisms is explored in the genes for vascular endothelial growth factor and insulin-like growth factor-1, and of mutations in the Norrie disease gene. Insights into the genetic basis of retinopathy of prematurity provided by the animal model of oxygen induced retinopathy are examined. Evidence for a genetic component for susceptibility to retinopathy of prematurity is strong, although the molecular identity of the gene or genes involved remains uncertain.

Outcome of ligation of the persistently patent arterial duct in neonates as performed by an outreach surgical team

AIM

Our aim was to review the outcome of ligation of the persistently patent arterial duct in neonates as performed outside a paediatric cardiothoracic centre by an outreach surgical team.

METHODS

A retrospective observational study of all ligations of the persistently patent arterial duct performed in Cambridge between January, 1988, and December, 2002.

RESULTS

Over the period of 15 years studied, a persistently patent arterial duct was ligated in 43 neonates. The median gestational age at birth was 26 weeks, with a range from 23 to 35 weeks, and median weight at birth was 722 grams, with a range from 500 to 2100 grams. Median age at ligation, was 25 days, with a range from 10 to 89 days, and their weight was 963 grams, with a range from 568 to 2221 grams. Ligation was successful in 42 babies (98%), mortality at 30 days of 5%, and 29 of the babies (67%) surviving to be discharged from the hospital. The late deaths were due to complications of prematurity, rather than the procedure of ligation.

CONCLUSION

The persistently patent arterial duct can successfully be ligated by an outreach surgical team outside a paediatric cardiothoracic centre. There was an excellent 30 day survival.

Incidence and risk factors for retinopathy of prematurity in very low and in extremely low birth weight infants in a unit-based approach in southern Brazil

AIMS

To analyse the incidence and risk factors for retinopathy of prematurity (ROP) and survival rates among extremely low birth weight (ELBW) and very low birth weight (VLBW) preterm infants.

METHODS

A prospective cohort study of 352 infants admitted at a teaching hospital, Hospital de Clinicas de Porto Alegre, Brazil, between October 2002 and December 2006, was screened for ROP. The ELBW group comprised infants whose birth weight (BW) was < or = 1000 g and the VLBW group comprised those infants whose BW were > 1000 g and < or = 1500 g. Perinatal risk factors for ROP were assessed using univariate and multivariate analysis.

RESULTS

Of the 352 neonates screened, 88 were ELBW babies. Survival rates among ELBW and VLBW were 47.8 and 88.7%, respectively. ROP affected 48.9% of ELBW infants and 18.2% of VLBW babies. Threshold disease occurred in 21 patients, 15 of whom were born weighing < 1000 g. Only 2.3% of the neonates born with more than 1000 g developed treatable disease. Univariate analysis showed that gestational age (GA), BW, use of indomethacin and erythropoietin, blood transfusions, and intraventricular haemorrhage were associated with ROP. After logistic regression, the most important adjusted risk factors were BW (OR: 1.002;95% CI: 1.001-1.003; P=0.003), GA (OR: 1.254;95% CI: 1.082-1.455; P=0.003), and use of erythropoietin (OR: 2.486;95% CI: 1.182-5.231; P=0.016).

CONCLUSION

This study showed reduced survival rates, high incidence of ROP, and a greater need of treatment among ELBW infants as compared to VLBW babies admitted in this institution.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Retinopathy of prematurity in South Africans at a tertiary hospital: a prospective study

BACKGROUND AND OBJECTIVES

World Health Organization's vision 20/20 programme has recognized retinopathy of prematurity (ROP) as an important cause of childhood blindness in industrialized and middle-income countries. While ROP is virtually nonexistent in many African countries, ROP is seen in urban areas where facilities for neonatal care exist. The aim of this study is to establish the frequency of ROP in a cohort of patients screened for ROP and to establish if current screening criteria apply to our patients.

PATIENTS AND METHODS

Infants with birth weight (BW) of 1500 g or less and/or gestational age of 32 weeks or less were screened for ROP over a 2(1/2)-year period by a single examiner.

RESULTS

ROP was observed in 84 of 514 (16.3%) of infants included for analysis. Threshold disease (tROP) was noted in 1.6% of the total cohort although 41/84 babies with ROP were lost prior to regression or progression to tROP. Of the 43/84 adequately followed up, eight (18.6%) developed tROP. An estimated frequency of tROP was more likely to be 2.9%. There was no tROP noted in babies of BW greater than 1250 g. Gestational age was an unreliable risk parameter in our population.

CONCLUSION

The projected occurrence rate of tROP is similar to that found in black population in the Multicentre Cryotherapy for ROP Trial. Our data suggest that the screening criterion based on BW can safely be lowered to 1250 g in our population.