Ocular sequelae in extremely premature infants at 5 years of age

Prevalence and causes of ocular disorders and visual impairment among preterm children in Ethiopia

OBJECTIVE

The aim of this study was to determine the prevalence, causes of ocular disorders and visual impairment among preterm children previously admitted to neonatal intensive care units in Addis Ababa, Ethiopia.

METHODS AND ANALYSIS

A prospective screening survey was conducted from February to June 2019 at the paediatric eye clinic of Menelik II Hospital. Children who were preterm at birth and who attended the eye clinic were included in the study. Data on demographic and neonatal characteristics, neonatal and maternal comorbidities and ocular disorders were collected. OR and univariate analysis were used to identify predictors of ocular diseases and visual impairment.

RESULTS

There were 222 children included in the study with a mean age at presentation of 2.62 years (range 2.08-6.38 years), mean gestational age 34.11 weeks (range 30-36) weeks and mean birth weight 1941.72 g (range 953-3500 g). Nearly two-thirds had ocular disorders with refractive error (51.8%), strabismus (11.3%) and a history of retinopathy of prematurity (ROP) (7.2%) being more common. One-fourth of the children had visual impairment, and the prevalence of amblyopia was 40.1%. Uncorrected refractive errors, strabismus and ROP were causes for visual impairment.

CONCLUSION

Visual impairment and amblyopia are common in Ethiopia. There is a need to develop a screening protocol for ocular disorders for preterm children to enhance early detection and prevention of childhood visual impairment.

Ophthalmological findings in relation to auxological data in moderate-to-late preterm preschool children

PURPOSE

To evaluate ophthalmological findings in preschool children born moderate-to- late preterm (MLP) and relate the findings to auxological data at birth and at 5.5 years of age.

METHODS

Seventy-eight MLP children [gestational age (GA) 32-36 weeks; 34 girls; mean age 5.7 years] were investigated. Gestational age, weight, length and head circumference at birth and at the time of assessment were registered. Visual acuity (VA), refraction, orthoptic evaluation, slit-lamp examination and ophthalmoscopy were conducted, and a history of visuoperceptual problems was recorded. The data were compared with age- and sex-matched controls born full term (n = 35).

RESULTS

Ophthalmological abnormalities were noted in 82% of MLP children and 47% of controls (p = 0.0004). There was a significant difference with regard to impaired motility (p = 0.03), heterophoria at distance (p = 0.006) and refraction expressed as spherical equivalent dioptre (p = 0.01). Amongst auxological data at birth, birthweight (BW) was the strongest predictor to ophthalmological abnormalities (p = 0.0003). In a stepwise logistic regression, GA was the strongest predictor of VA outcome at time of assessment (p = 0.0036). Moderate-to-late preterm birth showed a 2.4-fold increased risk of refractive errors compared with full-term children (RR 2.39: 95% CI 1.10-5.20; p = 0.02).

CONCLUSION

Based on our findings, MLP birth may be associated with increased ocular morbidity compared with their full-term counterparts. Auxological data at birth, especially BW, seems to be an important factor when conducting an ophthalmological diagnosis in preschool MLP children, and an increased VA was correlated to a higher GA.

Flash visual evoked potentials in preterm infants

OBJECTIVE

To describe the development of flash visual evoked potentials (FVEPs) in preterm infants from 1 to 18 months and to determine if the maturation of FVEPs is similar to that of term infants.

DESIGN

Longitudinal follow-up study.

PARTICIPANTS

Twenty very low birth weight (VLBW) preterm infants, 42 low birth weight (LBW) preterm infants, and 41 term infants underwent FVEP recordings and neurodevelopmental examinations at 1, 3, 6, 9, 12, and 18 months of corrected and chronological ages.

METHODS

The FVEP recordings were carried out with the VikingQuest-IV neuroelectrophysiological device (VikingQuest, Nicolet, WI), and neurodevelopmental assessments were made by the Development Screen Test and Bayley Scales of Infant Development, Second Edition.

MAIN OUTCOME MEASURES

At 1, 3, 6, and 9 months of age, neurodevelopment was measured with the Mental Index and Developmental Quotient. At 12 and 18 months, neurodevelopment was assessed using the Mental Developmental Index and Psychomotor Developmental Index. Two FVEP values were analyzed: the P2 amplitude (peak to peak from the preceding N2 wave) and the latency of the P2 wave.

RESULTS

There was no significant difference for age-dependent decreased pattern of FVEP P2 latency between preterm infants and the control group. This pattern consisted of a rapid decrease in the first 6 months of life, a gradual decline from 6 to 12 months of age, and a steady reduction from 12 to 18 months of age. The P2 latencies were prolonged significantly at all 6 recorded times in the VLBW group compared with the controls and showed a delay in the LBW group at 1 and 3 months of corrected age. The maturation of P2 latency in LBW infants is similar to that of the controls at 3 months of corrected age, but the maturation of P2 latency in VLBW children remained delayed when compared with the controls until 18 months of corrected age.

CONCLUSIONS

Although the FVEP development pattern of preterm infants was similar to that of healthy full-term infants, the former had deficits in visual electrophysiologic maturation, especially for VLBW children.

Visual function in 6 to 7 year-old children born extremely preterm: a population-based study

PURPOSE

Progress in neonatal care has caused an increased survival of children born extremely preterm. The aims of this study were to examine the long-term visual function and ocular development in an unselected cohort of extremely preterm infants and relate the results to neonatal morbidity and long-term neurodevelopmental outcome.

METHODS

All children with gestational age of 22-27 completed weeks or birth weight of 500-999 g born in the years 1999-2000 in two counties of Western Norway (n = 52) were invited to an eye examination that included visual acuity, refractive error, binocular function, accommodative amplitude and fundus examination. Cognitive function was assessed with the WPSSI-R test and motor abilities with the ABC movement test.

RESULTS

Neonatal morbidities and neurodevelopmental outcome were known for all, while 37 of the 52 children underwent the eye examination. None were blind or visually impaired, but 46% had subnormal visual acuity (logMAR ≥0.1). Ninety per cent were emmetropic or slightly hypermetropic (0 to +3D), while 10% had manifest and 51% latent strabismus. Performance IQ on the WPSSI-R test and ABC total score were associated with best visual acuity (p = 0.03 and p < 0.01, respectively). In a multiple linear regression model, visual acuity in the best eye was significantly associated with performance IQ (p = 0.03) and ABC total score (p = 0.02).

CONCLUSION

This study suggests a more favourable long-term prognosis on important ocular and visual parameters in survivors of extreme prematurity than expected from similar reports on children born less prematurely and that performance IQ and motor function are related to visual acuity.

One-year experience in the retinopathy of prematurity: frequency and risk factors, short-term results and follow-up

AIM

As a result of the increase in premature births and the advances in neonatal intensive care, retinopathy of prematurity (ROP) remains one of the most important causes of childhood blindness worldwide. The main factors in the development of ROP are gestational age, birth weight and oxygen therapy. ROP continues to gain importance due to the increasing survival rates of more immature babies.

METHODS

Between January 2007 and October 2008, 203 premature infants treated at the Neonatal Intensive Care Unit (NNICU) were prospectively enrolled and the relationship between known risk factors and the occurance of ROP was studied.

RESULTS

ROP in various stages developed in 86 cases (42.4%). Statistically significant correlations were found between the development of ROP and birth weight (P<0.0001) gestational age (P<0.0001), oxygen treatment and its duration (P<0.0001 and P=0.002), mechanical ventilation (MV) and its duration (P=0,0001 and P=0.0001), apnea (P=0.001), intraventricular hemorrhage (IVH) (P=0.046), sepsis (P=0.0001), use of erythropoietin (EPO) (P=0.003), the number of blood transfusions and frequency (P=0.0001 and P=0.0001), surfactant application (P=0.0001), the presence of patent ductus arteriosus (PDA) (P=0.001) or bronchopulmonary dysplasia (BPD) (P=0.0001). No significant correlations were found between the occurance of ROP and maternal pre-eclampsia (P=0.293), multiple pregnancy (P=0.218), or hyperbilirubinemia (P=0.494). Severity of ROP was related significantly with birth weight (P=0.0001), but no significant correlation between severity of ROP and gestational age was present.

CONCLUSION

Early description and reduction of the risk factors related with the occurance of ROP with the help of routine screening programs may warrant the prevention of visual loss, however early ophthalmic diagnosis and treatment are still mandatory to provide better visual rehabilitation.

An analysis of neonatal risk factors associated with the development of ophthalmologic problems at infancy and early childhood: a study of premature infants born at or before 32 weeks of gestation

BACKGROUND

To determine the frequency of ophthalmologic problems and the risk factors that affect the occurrence of these problems in premature newborns with a gestational age of 32 weeks or less.

METHODS

Premature newborns observed at a neonatal intensive care unit between January 2002 and March 2006 were included. A control visit including an ophthalmologic examination was performed at 10 months of age or later. Primary ocular morbidities were studied, and the association between these parameters and prenatal, perinatal, and neonatal characteristics were evaluated.

RESULTS

A total of 169 premature newborns were included in the study, and they were examined at a mean age of 25.85 ± 11.79 months (range: 10 to 42 months). There was complete vision loss (blindness) in 1 (0.6%) case, strabismus in 15 (8.9%) cases, and refractive errors in 10 (5.9%) cases. Twenty (77%) cases with any abnormality and 50 (35%) cases with a normal examination at follow-up had a history of retinopathy of prematurity (ROP) at any stage during the neonatal period (P = .001). Short gestational age (P = .018), low birth weight (P = .002), and the presence of ROP requiring retinal surgery during the neonatal period (P = .007) were determined to be significant risk factors for the development of vision loss, strabismus, and refractive errors.

CONCLUSION

Neonates with a gestational age of 32 weeks or less, especially those younger than 30 weeks, should not only be screened for ROP in the neonatal period, but should also have regular follow-up examinations to check for the development of other ophthalmologic problems during infancy and early childhood.

Flash visual evoked potentials at 2-year-old infants with different birth weights

BACKGROUND

Increased prevalence of visual impairments has been reported in preterm populations. However, it remains unclear about the long-term visual electrophysiological outcomes and their association with visual cognitive functions in premature infants. We investigated visual electrophysiological outcome of 2-year-old infants of different birth weights by flash visual evoked potentials (FVEPs) in order to explore the correlation between visual cognitive functions and FVEPs and to assess the application of FVEPs in evaluating the visual capability of an infant.

METHODS

The FVEPs of 77 infants, including 25 very low birth weight (VLBW) premature infants, 16 low birth weight (LBW) premature infants and 36 full-term infants, were tested with a visual electrophysiological testing device. Neuromotor development was assessed with the Bayley Scales of Infant Development, Second Edition (BSID-II). The visual cognitive functions were evaluated by scoring the proportion passed of 12 items chosen from the BSID-II for infants at 23 to 25 months of age.

RESULTS

The second prominent positive wave (P2) was the major component presented in all three groups. The mean latency of P2 in the VLBW, LBW and full-term groups was 149.65+/-23.79 ms, 129.39+/-8.70 ms, and 126.14+/-7.73 ms respectively. There was no significant difference in mean latency of P2 wave between the LBW and full-term groups; the mean latency of the P2 wave in the VLBW group was delayed more significantly than those of the other two groups. The difference in amplitude of the P2 peak to the preceding N2 peak (N2P2) between the three groups was not statistically significant. The latency of the P2 main wave was negatively correlated with mental developmental index (MDI) (r'(MDI) = -0.35) and visual cognitive capability (r'(visual capability) = -0.21).

CONCLUSIONS

The latency of the P2 main wave on FVEPs was delayed more significantly in premature infants than in full-term infants at 2 years of corrected age. The visual functional development was delayed in premature infants, especially in VLBW infants (gestational age <32 weeks). The FVEPs were reported low but there were statistically significant correlations between measures of visual cognition and P2 peak latency. As a noninvasive and convenient method, FVEPs are useful in assessing certain aspects of an infant's visual development and visual function.

Risk of refractive pathology after spontaneously regressed ROP in emmetropic patients

PURPOSE

To evaluate the development of refractive error abnormalities after a normal first examination in children with spontaneously regressed retinopathy of prematurity (ROP).

METHODS

Two hundred twenty-six children with a history of spontaneously regressed ROP who had a cycloplegic refraction prior to 18 months of age were examined by a pediatric ophthalmologist. Children with a history of threshold ROP, strabismus, or a structural abnormality of the eye were excluded. A normal cycloplegic retinoscopy was defined as plano to less than +3.5 diopters of hypermetropia, less than +1.50 of symmetric astigmatism, and no anisometropia greater than 1.5 diopters in any meridian.

RESULTS

Of the 226 children, 87 had a second examination and cycloplegic refraction at a mean of 2 years after the initial visit. In 63 of the children, the second examination and refraction remained normal. Three (3.4%) children had significant refractive error and were treated with spectacles: two had anisometropia and one had myopic astigmatism. Twenty-one had symmetric low magnitude myopia that did not warrant treatment.

CONCLUSION

Children with spontaneously regressed ROP and no significant refractive error on cycloplegic retinoscopy at first follow-up examination have a risk of developing ametropia that is similar to that of the general population. Such children can likely be observed with a verbal vision screening in the pediatrician's office at 3 to 4 years of age.

Long term ophthalmic sequelae of prematurity

There are numerous reports of an increase in refractive errors and amblyogenic factors in the low birth weight population relative to children born at full term. This raises the question of whether additional long term ophthalmic screening is required. The current provision of follow up care for preterm infants in the UK is haphazard and varies in terms of its availability, the type of assessment, age at assessment and age at discharge. This issue needs to be addressed to provide the best care for these children however there are different possible methodologies. One key aspect of a screening programme is the age at testing as this dictates the possible tests used which impacts on the efficacy. However, although the prevalence of strabismus and refractive errors is well documented the development of these conditions is poorly understood so for this and other reasons it is difficult to devise the most effective screening programme.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Eye-hand co-ordination skills in very preterm infants <29 weeks gestation at 3 years: Effects of preterm birth and retinopathy of prematurity

INTRODUCTION

Preterm infants are known to have low gross motor and fine motor skills. We questioned whether poor eye-hand coordination skills are associated with moderate to severe stages of Retinopathy of Prematurity (ROP).

AIMS

The aim of this study was to examine development, with specific reference to eye-hand coordination skills, among preterm infants <29 weeks gestation with different stages of ROP at 3 years of age.

METHODS AND MATERIALS

Fifteen preterm infants (<29 weeks gestation) who developed Stage 3 ROP were matched for gestation, birthweight and gender with infants who developed Stage 2 and Stage 1/no ROP. Developmental (Griffiths Mental Development Scales and Peabody Developmental Motor Scales) and ophthalmic assessments in the 3 matched groups of 15 were performed at 3 years of age.

RESULTS

1) Whilst the eye-hand coordination scores and Peabody fine motor scores were lower in the Stage 3 ROP group, they were not significantly lower than the other ROP groups. 2) Locomotor, Peabody gross motor skills and hearing and speech were significantly lower in the infants with Stage 3 ROP. The other developmental domains were not significantly different to the severe ROP group. 3) All 3 groups (of preterm infants) had lower eye-hand coordination and Peabody fine motor scores compared to test norms. 4) There were 8 of 15 infants with Stage 3 ROP who developed moderate visual problems by 3 years of age.

CONCLUSION

In preterm infants, low eye-hand coordination/fine motor scores are likely to be due to their extreme prematurity.

Prevalence of myopia at 9 months in infants with high-risk prethreshold retinopathy of prematurity

PURPOSE

To examine the prevalence of myopia and high myopia at 9 months corrected age in premature infants who participated in the multicenter randomized trial of Early Treatment for Retinopathy of Prematurity (ETROP).

DESIGN

Randomized, controlled clinical trial.

PARTICIPANTS

Four hundred one infants with birth weights of <1251 g in whom prethreshold ROP developed in one or both eyes and who were determined to have a significant risk (> or =15%) of poor structural outcomes without treatment, based on the risk management for ROP program.

INTERVENTION

Infants with bilateral high-risk prethreshold ROP (n = 317) had 1 eye randomized to early treatment, and the fellow eye was managed conventionally. In asymmetric cases (n = 84), the eye with high-risk prethreshold ROP was randomized to early treatment or conventional management (control). Eyes randomized to early treatment at high-risk prethreshold ROP and eyes randomized to conventional management in which threshold ROP developed received peripheral retinal photocoagulation or cryotherapy. Conventionally managed eyes in which threshold ROP did not develop were observed. Cycloplegic retinoscopy data were obtained at 9 months corrected age from 321 eyes treated early and 307 eyes managed conventionally.

MAIN OUTCOME MEASURES

Prevalence of myopic (spherical equivalent > or = 0.25 diopters [D]) and highly myopic (> or =5.00 D) eyes in each group.

RESULTS

The prevalence of myopia (64.5% vs. 69.4%; P = 0.06) and high myopia (25.5% vs. 28.3%; P = 0.20) was similar between eyes treated at high-risk prethreshold and high-risk prethreshold eyes managed conventionally. Among high-risk eyes managed conventionally, the prevalence of myopia (78.2% vs. 53.3%) and high myopia (37.6% vs. 11.2%) was higher when threshold ROP developed than when regression without treatment occurred. Among eyes treated at high-risk prethreshold ROP, the prevalence of myopia (93.3% vs. 91.7% vs. 60.6%) and of high myopia (53.3% vs. 33.3% vs. 20.8%) was higher in eyes with abnormal angle of temporal retinal vessels or macular ectopia than in eyes with no retinal residua. This also held true for conventionally managed eyes.

CONCLUSIONS

Early treatment at high-risk prethreshold did not place eyes at greater risk of myopia and high myopia than did conventional management of eyes with high-risk prethreshold ROP.

Can Screening for Retinopathy of Prematurity Be Reduced?

BACKGROUND

As screening for retinopathy of prematurity (ROP) is costly, time-consuming for the ophthalmologist and discomforting for the neonate, the minimum number of infants should be screened for ROP, without missing infants with severe ROP, at risk for threshold ROP.

OBJECTIVES

To develop a diagnostic screening guideline for ROP that would safely reduce the number of ROP screening funduscopies in our department.

METHODS

Data of 275 infants admitted between 1996 and 2000 and screened for ROP according to our Dutch National guideline were studied. Significant risk factors for ROP were calculated, using logistic regression analysis and used to develop a guideline. The discriminative power of the guideline was evaluated using the area under the curve for the receiver operating characteristic curve.

RESULTS

Significant risk factors for ROP were: gestational age, birth weight and number of erythrocyte transfusions within the first 4 weeks of life. The combination of these 3 factors resulted in the highest area under the curve: 0.793. Using these 3 factors, a diagnostic screening guideline for ROP was developed: if birth weight + 2 x (gestational age - 20) - 6 x erythrocyte transfusion value within the first 4 weeks of life >or=34, no screening for ROP is necessary. Using this guideline, 22.2% of the infants of the study group could have been excluded from screening; 3.8% of the infants with ROP stages 1-2 would have been missed.

CONCLUSION

In our department, ROP screening can be safely reduced using our diagnostic screening guideline.

Visual function in low birthweight children

AIM

To determine the visual functions, at age 10-12 years, of a geographically based cohort of children of birth weight less than 1701 g. The results were compared to a group of children born at full term.

METHODS

572 low birthweight (LBW) "low birthweight cohort" children who had been examined in the neonatal period were invited for review at 10-12 years of age. 169 11 year old schoolchildren born at full term were also recruited, "school cohort." Visual acuity (at distance and near), contrast sensitivity, colour vision, and visual fields were measured.

RESULTS

293 of the original 572 participants consented to a further examination. Compared to the school cohort of children born at term the low birthweight cohort showed significantly lower near and distance acuities and contrast sensitivity (p<0.001 for all uniocular and binocular measures). Retinopathy of prematurity (ROP) was a very poor predictor of outcome and multivariate analysis did not identify any key neonatal factors as predictors of long term visual outcome.

CONCLUSIONS

Low birthweight children have a small but statistically significant deficit in both visual acuity and contrast sensitivity. Low birth weight and ROP both impact on long term visual functions.

Emmetropisation following preterm birth

BACKGROUND/AIMS

Even in the absence of retinopathy of prematurity (ROP), premature birth signals increased risk for abnormal refractive development. The present study examined the relation between clinical risk factors and refractive development among preterm infants without ROP.

METHODS

Cycloplegic refraction was measured at birth, term, 6, 12, and 48 months corrected age in a cohort of 59 preterm infants. Detailed perinatal history and cranial ultrasound data were collected. 40 full term (plus or minus 2 weeks) subjects were tested at birth, 6, and 12 months old.

RESULTS

Myopia and anisometropia were associated with prematurity (p<0.05). More variation in astigmatic axis was found among preterm infants (p<0.05) and a trend for more astigmatism (p<0.1). Emmetropisation occurred in the preterm infants so that at term age they did not differ from the fullterm group in astigmatism or anisometropia. However, preterm infants remained more myopic (less hyperopic) than the fullterm group at term (p<0.05) and those infants born <1500 g remained more anisometropic than their peers until 6 months (p<0.05). Infants with abnormal cranial ultrasound were at risk for higher hyperopia (p<0.05). Other clinical risk factors were not associated with differences in refractive development. At 4 years of age 19% of the preterm group had clinically significant refractive errors.

CONCLUSION

Preterm infants without ROP had high rates of refractive error. The early emmetropisation process differed from that of the fullterm group but neither clinical risk factors nor measures of early refractive error were predictive of refractive outcome at 4 years.

The long term ophthalmic morbidity of low birth weight children: a review

Low birth weight infants are at greater risk of ophthalmic morbidity compared to children born at term. There are numerous studies detailing the outcome of low birth weight infants and the purpose of this paper is to discuss and summarize these studies, focusing on the long term effects on visual function and the prevalence of strabismus. The variation in study design will be discussed with regard to the subsequent effect on results. Despite the significant variation between studies, they all report an increase in the prevalence of strabismus and reduced visual acuity. This increase in ophthalmic morbidity is due in part to retinopathy of prematurity (ROP), but not all ophthalmic morbidity can be attributed to ROP.

Retinopathy of prematurity in infants < 32 weeks' gestation at birth in New South Wales in 1993 and 1994

OBJECTIVE

To study the incidence and severity of retinopathy of prematurity (ROP) in infants < 32 weeks' gestation.

DESIGN

Review of the records maintained in the New South Wales Neonatal Intensive Care Unit Study (NICUS) database on infants admitted to the neonatal intensive care units (NICU) in NSW from 1 January 1993 to 31 December 1994.

RESULTS

In the more premature infants, 23-26 weeks' gestation, 65% developed ROP (102 of 157 examined for ROP). Forty-four infants (28%) developed severe ROP (Stage ≥ 3 ROP), 19 infants (12.1%) required cryo/laser therapy and one infant (0.6%) in this group had a retinal detachment. One hundred and fifty-seven of 159 surviving infants (98.7%) were examined for ROP. In the infants 27-28 weeks' gestation, 38.3% developed ROP (103 of 269 examined for ROP). Fifteen infants (5.6%) developed severe ROP, seven infants (2.6%) required cryo/laser therapy for threshold ROP and three infants (1.1%) in this group had a retinal detachment. Two hundred and sixty-nine of 299 surviving infants (90%) were examined for ROP. In the infants 29-31 weeks' gestation, 10.8% developed ROP (48 of 443 examined for ROP). Six infants (1.4%) developed severe ROP, one infant (0.2%) required cryo/laser therapy for threshold ROP and no infant in this group had a retinal detachment. However, only 443 of 681 surviving infants (65.1%) in this group were examined for ROP. Of the four infants with detached retinas, one was a 25 week gestation infant weighing 840 g, two were 27 weeks' gestation weighing 960 and 980 g and one infant was a 28 week gestation infant weighing 620 g. No infant developed Stage 5 ROP.

CONCLUSION

In the more mature infants 29-31 weeks' gestation, the rate of ROP is low, although severe ROP still occurs. However, only 65.1% of these infants were examined for ROP and we should be diligent in screening for ROP in the sicker infants in this group. The incidence of severe ROP as well as the rate of cryo/laser therapy in premature infants 23-26 weeks' in NSW has not changed since the increases seen in the early 1990s. Retinal detachment also occurs in the infants 27-28 weeks' gestation and it is important that all these infants are screened for ROP.

Results of screening low-birth-weight infants for retinopathy of prematurity

Retinopathy of prematurity (ROP) continues to be an important cause of potentially preventable blindness worldwide. The pattern of visual impairment from ROP in some middle-income countries--high rates affecting larger and more mature infants--resembles that seen in more developed countries two decades ago and has been called a "third epidemic" of the disease. Expert bodies in the United Kingdom and the United States have recently issued new guidelines for screening for ROP that utilize both birth weight and gestational age criteria. Studies in both countries suggest these criteria might be further revised to decrease time spent on screening without missing any significant disease. Population-based follow-up studies of extremely preterm infants suggest that although more preterm infants are surviving, with adequate screening and treatment, rates of blindness from ROP may be declining. Further information on the longer-term impact of ROP comes from a number of studies and particularly the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study. The risk of both myopia and strabismus is increased with any and each higher stage of ROP. Evidence is emerging that laser therapy for threshold disease may be associated with better visual outcome than cryotherapy, although complications following the former remain a concern. The fight against ROP may be enhanced by new information on the pathogenesis, including possible genetic predisposition and the role of vascular endothelial growth factor.

Role of endothelial cell survival and death signals in angiogenesis

Angiogenesis, the process of new microvessel development, is encountered in a select number of physiological processes and is central to the pathogenesis of a wide variety of diseases. There is now convincing evidence that regulated patterns of endothelial cell survival and death, a process known as apoptosis, play a central role in the periodic remodeling of the vasculature, and in the timely evolution and regression of angiogenic responses. In this review we discuss the current evidence suggesting a role for inducers and inhibitors of angiogenesis as well as other mediators that modify endothelial cells functions in the survival and death of endothelial cells. We also discuss how dysregulation of apoptosis can lead to aberrant angiogenesis as demonstrated in the pathogenesis of retinopathy of prematurity and cancer.