Risk Of Severe Retinopathy Of Prematurity Research Articles

Antenatal corticosteroid administration is associated with lower risk of severe ROP in preterm twin infants

IntroductionRobust evidence revealed the impact of antenatal corticosteroid (ACS) administration on lower mortality and short-term neonatal outcomes in singleton preterm infants. We aimed to investigate the impact of ACS therapy on morbidity and mortality in preterm twin infants. MethodsWe conducted this retrospective single-center study from to the records of twin babies of 24–30 weeks of gestation admitted to the neonatal intensive care unit. The study population was grouped based on the exposure to ACS 1–7 days before birth as received or not. Groups were compared regarding in-hospital mortality and neonatal outcomes. ResultsData from 160 twin infants were analyzed. Of those, 102 (64 %) were administered ACS. The median (IQR) gestational age and birth weight of the whole cohort were 28 (27–29) weeks and 1060 (900–1240) g, respectively. ACS administration was associated with a significant decline in respiratory distress syndrome (RDS), requirement ≥2 doses of surfactant, severe intraventricular hemorrhage (IVH), early-onset sepsis (EOS), and retinopathy of prematurity (ROP) requiring treatment (p < 0.05). Logistic regression analysis revealed that gestational age (OR 0.29 95 % CI 0.14–0.62; p = 0.001), ACS administration (OR 0.14 95 % CI 0.03–0.85; p = 0.032), and time to achieve full enteral feeding (OR 1.16 95 % CI 1.03–1.31; p = 0.019) were independently associated with the risk of severe ROP. ConclusionThe reduction in the risk of severe ROP besides RDS, severe IVH, and EOS among preterm twins who received ACS was remarkable in our study similar to the trials conducted in preterm singletons. However, large-scale prospective observational studies are required to reveal the efficacy of ACS in preterm twins.

Automated oxygen delivery for preterm infants with respiratory dysfunction.

Many preterm infants require respiratory support to maintain an optimal level of oxygenation, as oxygen levels both below and above the optimal range are associated with adverse outcomes. Optimal titration of oxygen therapy for these infants presents a major challenge, especially in neonatal intensive care units (NICUs) with suboptimal staffing. Devices that offer automated oxygen delivery during respiratory support of neonates have been developed since the 1970s, and individual trials have evaluated their effectiveness. To assess the benefits and harms of automated oxygen delivery systems, embedded within a ventilator or oxygen delivery device, for preterm infants with respiratory dysfunction who require respiratory support or supplemental oxygen therapy. We searched CENTRAL, MEDLINE, CINAHL, and clinical trials databases without language or publication date restrictions on 23 January 2023. We also checked the reference lists of retrieved articles for other potentially eligible trials. We included randomised controlled trials and randomised cross-over trials that compared automated oxygen delivery versus manual oxygen delivery, or that compared different automated oxygen delivery systems head-to-head, in preterm infants (born before 37 weeks' gestation). We used standard Cochrane methods. Our main outcomes were time (%) in desired oxygen saturation (SpO2) range, all-cause in-hospital mortality by 36 weeks' postmenstrual age, severe retinopathy of prematurity (ROP), and neurodevelopmental outcomes at approximately two years' corrected age. We expressed our results using mean difference (MD), standardised mean difference (SMD), and risk ratio (RR) with 95% confidence intervals (CIs). We used GRADE to assess the certainty of evidence. We included 18 studies (27 reports, 457 infants), of which 13 (339 infants) contributed data to meta-analyses. We identified 13 ongoing studies. We evaluated three comparisons: automated oxygen delivery versus routine manual oxygen delivery (16 studies), automated oxygen delivery versus enhanced manual oxygen delivery with increased staffing (three studies), and one automated system versus another (two studies). Most studies were at low risk of bias for blinding of personnel and outcome assessment, incomplete outcome data, and selective outcome reporting; and half of studies were at low risk of bias for random sequence generation and allocation concealment. However, most were at high risk of bias in an important domain specific to cross-over trials, as only two of 16 cross-over trials provided separate outcome data for each period of the intervention (before and after cross-over). Automated oxygen delivery versus routine manual oxygen delivery Automated delivery compared with routine manual oxygen delivery probably increases time (%) in the desired SpO2 range (MD 13.54%, 95% CI 11.69 to 15.39; I2 = 80%; 11 studies, 284 infants; moderate-certainty evidence). No studies assessed in-hospital mortality. Automated oxygen delivery compared to routine manual oxygen delivery may have little or no effect on risk of severe ROP (RR 0.24, 95% CI 0.03 to 1.94; 1 study, 39 infants; low-certainty evidence). No studies assessed neurodevelopmental outcomes. Automated oxygen delivery versus enhanced manual oxygen delivery There may be no clear difference in time (%) in the desired SpO2 range between infants who receive automated oxygen delivery and infants who receive manual oxygen delivery (MD 7.28%, 95% CI -1.63 to 16.19; I2 = 0%; 2 studies, 19 infants; low-certainty evidence). No studies assessed in-hospital mortality, severe ROP, or neurodevelopmental outcomes. Revised closed-loop automatic control algorithm (CLACfast) versus original closed-loop automatic control algorithm (CLACslow) CLACfast allowed up to 120 automated adjustments per hour, whereas CLACslow allowed up to 20 automated adjustments per hour. CLACfast may result in little or no difference in time (%) in the desired SpO2 range compared to CLACslow (MD 3.00%, 95% CI -3.99 to 9.99; 1 study, 19 infants; low-certainty evidence). No studies assessed in-hospital mortality, severe ROP, or neurodevelopmental outcomes. OxyGenie compared to CLiO2 Data from a single small study were presented as medians and interquartile ranges and were not suitable for meta-analysis. Automated oxygen delivery compared to routine manual oxygen delivery probably increases time in desired SpO2 ranges in preterm infants on respiratory support. However, it is unclear whether this translates into important clinical benefits. The evidence on clinical outcomes such as severe retinopathy of prematurity are of low certainty, with little or no differences between groups. There is insufficient evidence to reach any firm conclusions on the effectiveness of automated oxygen delivery compared to enhanced manual oxygen delivery or CLACfast compared to CLACslow. Future studies should include important short- and long-term clinical outcomes such as mortality, severe ROP, bronchopulmonary dysplasia/chronic lung disease, intraventricular haemorrhage, periventricular leukomalacia, patent ductus arteriosus, necrotising enterocolitis, and long-term neurodevelopmental outcomes. The ideal study design for this evaluation is a parallel-group randomised controlled trial. Studies should clearly describe staffing levels, especially in the manual arm, to enable an assessment of reproducibility according to resources in various settings. The data of the 13 ongoing studies, when made available, may change our conclusions, including the implications for practice and research.

Incidence and Risk Factors for Retinopathy of Prematurity in a Portuguese Cohort.

To evaluate the incidence and risk factors for retinopathy of prematurity (ROP) in two Portuguese neonatal units with a sub-analysis of infants with a gestational age (GA) of 28 weeks or older. This was a retrospective case series of all infants who underwent ROP screening from 2012 to 2020. Demographic, clinical, and laboratory data were collected. Univariate logistic regression was used to examine the risk factors for ROP followed by multivariate regression. A total of 475 infants were included with a median GA of 30 weeks (range: 23 to 36 weeks) and a median birth weight of 1,229 grams (range: 408 to 2,620 grams). ROP was diagnosed in 113 infants (23.8%) and 29 (6.1%) were treated. In the multivariate analysis, GA and hyperglycemia were significantly associated with severe ROP (P < .001). In the subgroup analysis of infants with a GA of 28 weeks or older, bronchopulmonary dysplasia, late-onset sepsis, and hyperglycemia were linked to severe ROP. The incidence of ROP in the cohort falls within the range of other high-income countries. Hyperglycemia overpowered all of the other risk factors. Although rare, more mature infants are also at risk for severe ROP. Infants with older GA share the same group of risk factors, but bronchopulmonary dysplasia seems to play a greater role. [J Pediatr Ophthalmol Strabismus. 2022;59(4):254-260.].

Impact of higher oxygen saturation levels on postnatal weight gain to predict retinopathy of prematurity.

Retinopathy of prematurity (ROP) is the leading cause of vision loss in children. A well-known risk factor for the development of ROP is duration of oxygen supplementation. Other postnatal factors have also been associated with ROP risk, including poor post-natal weight gain. The weight, insulin-like growth factor, neonatal retinopathy of prematurity (WINROP) algorithm predicts severe ROP based on postnatal weight gain and has been validated in several studies,1,2 including a high sensitivity for prediction of severe ROP in our local NICU populations. However, target oxygen saturation levels were subsequently increased in many NICUs based on results from the Neonatal Oxygen Prospective Meta-analysis (NeOProM) Collaboration, which showed statistically higher death and disability rates among preterm infants randomized to a lower oxygen-saturation target range (85 - 89%) versus a higher target range (91 - 95%),3 which may affect the incidence and severity of ROP4 as well as the validity of the WINROP algorithm. In 2018, Lundgren et al reported that the WINROP algorithm was no longer able to predict ROP requiring treatment at their institution after the implementation of higher target oxygen saturation levels, with a sensitivity of only 50%.5 The objective of this review was to evaluate WINROP's ability to identify infants at risk for severe ROP at our institution after target oxygen saturation levels were increased in 2014.

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

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

Sildenafil and retinopathy of prematurity risk in very low birth weight infants.

ObjectiveTo examine the effect of sildenafil therapy on development of severe retinopathy of prematurity (ROP) requiring surgical intervention in premature infants.Study DesignWe identified premature infants who were discharged from Pediatrix Medical Group neonatal intensive care units from 2003–2012 and who received an ophthalmologic exam. We matched each infant exposed to sildenafil prior to first eye exam to three non-exposed infants using propensity scoring to control for differences in baseline infant characteristics. We evaluated the association between sildenafil exposure and development of severe ROP using conditional logistic regression.ResultOf the 57815 infants meeting inclusion criteria, 88 were exposed to sildenafil. We matched 81/88 (92%) sildenafil-exposed with 243 non-exposed infants. There was no difference in the proportion of infants who developed severe ROP in the sildenafil-exposed vs. non-exposed groups (17/81 [21%] vs. 38/243 [16%], P=0.27). On adjusted analysis, there was no difference in severe ROP in the sildenafil-exposed versus non-exposed infants (odds ratio=1.46, 95% confidence interval=0.76–2.82, P=0.26).ConclusionWe did not observe an association between risk of severe ROP and sildenafil exposure prior to first eye exam in this cohort of premature infants.

Preventing bioenergetic failure in the preterm infant

The failure to match postnatal nutritional requirements to support growth and well-being in the extremely preterm infant has been a long-standing challenge with slow progress. Several large prospective cohorts over...

Low energy intake during the first 4 weeks of life increases the risk for severe retinopathy of prematurity in extremely preterm infants

ObjectivesPoor weight gain during the first weeks of life in preterm infants is closely associated with the risk of developing the retinopathy of prematurity (ROP) and insufficient nutrition might be...

Evaluating retinopathy of prematurity screening guidelines for 24- to 27-week gestational age infants

ObjectiveTo determine if current retinopathy of prematurity screening guidelines1 adequately identify treatable ROP in a contemporary cohort of extremely low gestation infants.Study DesignData from the Surfactant, Positive Pressure, and Pulse Oximetry Randomized Trial were used. Inborn infants 24 0/7 to 27 6/7 weeks gestational age with consent prior to delivery were enrolled in 2005-2009. Severe retinopathy of prematurity (Type 1 retinopathy of prematurity or treatment with laser, cryotherapy, or bevacizumab) or death was the primary outcome for the randomized trial. Examinations followed then current American Academy of Pediatrics (AAP) screening recommendations, beginning by 31-33 weeks postmenstrual age.2,3Results1316 infants were enrolled in the trial. 997 of the 1121 who survived to first eye exam had final retinopathy of prematurity outcome determined. 137 (14% of 997) met criteria for severe retinopathy of prematurity and 128 (93%) of those had sufficient data (without missing or delayed exams) to determine age of onset of severe retinopathy of prematurity. Postmenstrual age at onset was 32.1 to 53.1 wks. In this referral center cohort, 1.4% (14/997) developed severe retinopathy of prematurity after discharge.ConclusionOur contemporary data support the 2013 AAP screening guidelines for ROP for infants 24 0/7 to 27 6/7 weeks gestational age.1 Some infants do not meet treatment criteria until after discharge home. Post-discharge follow-up of infants who are still at risk for severe ROP is crucial for timely detection and treatment.

Prenatal and postnatal factors increase risk of severe ROP

To determine that slower weight premature twins have more risk to develop severe retinopathy of prematurity (ROP) than the higher weight twins. We know that the lower weight twins had less optimal intra-uterine environments than their higher weight twins. We screened 94 consecutive premature twins for ROP. We compared the lower weight twins (n = 47) against their higher weight twins (n = 47). The risk of severe ROP (ROP stage 3 or greater) was significantly higher in the lower weight twin group (p < 0.006). In the same way, in the lower weight twin group the non-perfused area of the temporal retinal artery was higher than that of the other group (an average of 1.2 diameters of the optic nerve head), in the 4–6 postnatal weeks (p < 0.004). The lower weight twin group have an increased risk of severe ROP associated with bacteremia (p = 0.045), or a weight gain less than 7 g per day in the 4–6 postnatal weeks (p = 0.013) or a supplementary postnatal oxygen >4 days (p = 0.007) compared to the higher weight twin group. We confirm Dr. Lee's work that less optimal prenatal factors, in preterm twins, increase the risk of severe ROP.

The relationship between patterns of intermittent hypoxia and retinopathy of prematurity in preterm infants

We have previously shown an increased incidence of intermittent hypoxemia (IH) events in preterm infants with severe retinopathy of prematurity (ROP). Animal models suggest that patterns of IH events may play a role in ROP severity as well. We hypothesize that specific IH event patterns are associated with ROP in preterm infants. Variability in IH event duration, severity, and the time interval between IH events (≤80%, ≥10 s, and ≤3 min) along with the frequency spectrum of the oxygen saturation (SpO2) waveform were assessed. Severe ROP was associated with (i) an increased mean and SD of the duration of IH event (P < 0.005), (ii) more variability (histogram entropy) of the time interval between IH events (P < 0.005), (iii) a higher IH nadir (P < 0.05), (iv) a time interval between IH events of 1-20 min (P < 0.05), and (v) increased spectral power in the range of 0.002-0.008 Hz (P < 0.05), corresponding to SpO2 waveform oscillations of 2-8 min in duration. Spectral differences were detected as early as 14 d of life. Severe ROP was associated with more variable, longer, and less severe IH events. Identification of specific spectral components in the SpO2 waveform may assist in early identification of infants at risk for severe ROP.

Retinopathy of prematurity: Does race matter?

Objective: Severe Retinopathy of Prematurity (ROP) is a primary cause of visual morbidity for very low birth weight infants. Known risk factors include short gestational age, low birth weight and supplemental oxygen exposure. Some studies have shown that Black infants are less at risk for severe ROP than White infants, however this finding has not been confirmed in studies designed to look at the risk of ROP and race/ethnicity specifically. The purpose of this study is to assess the relationship between the race/ethnicity of infants and the risk of severe ROP for a sample of 1,604 infants in 1,189 hospitals located in 39 states. Patients and methods: ParadigmHealth database records for surviving infants born between 1/1/2001 and 12/31/2004 with a birth weight less than or equal to 1250 g were included in this analysis (n = 1,604). Multivariate logistic regression was used to assess the association between race/ethnicity and risk for severe ROP. Models were adjusted for birth weight, gestational age, Apgar score, race and measures of illness severity including days on oxygen and mechanical ventilation, sepsis, intraventricular hemorrhage, patent ductus arteriosus, necrotizing enterocolitis and pneumothorax. Results: In the analytic data set, the distribution of maternal race was 47.2% White, 35.3% Black, 14.9% Hispanic and 3.2% Asian. Of these infants, 9.4% developed severe ROP; 6.6% for Blacks, 9.6% for Whites, 13.8% for Hispanics and 15.7% Asians. Compared to Black neonates, the unadjusted odds ratio for ROP among White infants was 1.5 (95% CI: 1.0, 2.3), for Hispanics 2.2 (95% CI: 1.4, 3.7) and for Asians 2.6 (95% CI: 1.2, 5.9). After adjustment for gestational age, birth weight and 1 minute Apgar score, the odds ratios increased to 2.0 (CI: 1.2, 3.2) for Whites, 2.7 (CI: 1.5, 4.8) for Hispanics and 5.3 (CI 1.9, 15.1) for Asians compared to Black neonates. Adjusting for additional markers of illness severity did not alter these results. Conclusions: Results revealed lower rates of ROP among Black confirming findings from earlier studies. Interestingly, relatively high rates of ROP were also found among Hispanic and Asian neonates compared to Black infants. Controlling for possibly confounding morbidities and measures of illness severity did not alter these results. Further research in this area is warranted.

Risk Factors for Acute Retinopathy of Prematurity

We prospectively studied the risk factors and the incidence of retinopathy of prematurity (ROP) in 195 consecutive preterm infants. Birth weight and duration of mechanical ventilation were the only factors that were significantly associated with the incidence of ROP. While indomethacin increases the risk of developing ROP, maternal antenatal steroids have a protective effect against the development of severe stages of ROP. The presence of intraventricular hemorrhage increases the risk of severe ROP.

Risk Factors for Acute Retinopathy of Prematurity

We prospectively studied the risk factors and the incidence of retinopathy of prematurity (ROP) in 195 consecutive preterm infants. Birth weight and duration of mechanical ventilation were the only factors significantly associated with the incidence of ROP. While indomethacin increases the risk of developing ROP, maternal antenatal steroids have a protective effect against the development of severe stages of ROP. The presence of intraventricular hemorrhage increases the risk of severe ROP.

Adverse Neonatal Outcomes Associated With Antenatal Dexamethasone Versus Antenatal Betamethasone

For at least 25 years, the delivery of a corticosteroid-usually dexamethasone or betamethasone-has been the most important part of the management of preterm labor at 24 to 34 weeks gestation. Although antenatal corticosteroid treatment has been associated with a significant reduction in respiratory distress syndrome, intraventricular hemorrhage (IVH), and neonatal mortality, both animal and human studies suggest that one of these steroids, dexamethasone, may actually increase the risk of adverse neurologic outcomes. This historical cohort study was an attempt to compare the incidence of periventricular leukomalacia (PVL), retinopathy of prematurity (ROP), IVH, and neonatal mortality in 3600 very-low-birthweight (401-1500 g) infants born after antenatal treatment with betamethasone compared with dexamethasone. A complete course of dexamethasone consisted of 4 6-mg intramuscular doses given at 12-hour intervals and of betamethasone, 2 12-mg intramuscular doses given at a 24-hour interval. Nearly half of the infants (48%) were exposed to betamethasone and 34% to dexamethasone, whereas 18% received no antenatal steroid. The overall rate of PVL was 3.5% and was similar in all 3 groups (4.4% in the no-steroid group, 3.5% in the betamethasone group, and 2.9% in the dexamethasone group; not significant). Infants exposed to either steroid were significantly less likely to have IVH (30.7% in the no-steroid group, 24.4% in the betamethasone group, and 24.8% in the dexamethasone group; P <.05) or severe IVH (12.8% in the no-steroid group, 10.3% in the betamethasone group, and 9.4% in the dexamethasone group; P <.05) than those not exposed to either steroid. Neither steroid changed the risk of severe ROP (8.8% in the no-steroid group, 9.9% in the betamethasone group, and 10.7% in the dexamethasone group), but the overall incidence of ROP was increased in betamethasone-exposed infants (42.9% in the no-steroid group, 46.4% in the betamethasone group, and 42.2% in the dexamethasone group; P <.05). Infants given either steroid were at lower risk of death than those who did not receive antenatal steroids, but betamethasone reduced the risk significantly more than dexamethasone (11.0% in the no-steroid group, 7.4% in the betamethasone group, and 7.9% in the dexamethasone group; P <.05). Odds ratios for all these comparisons were computed by multivariate logistic regression analysis and confirmed the risk reductions. However, when multivariate logistic regression analysis was used to compare the 2 steroid-treated groups with each other, there was only one significant difference; the risk of neonatal death was lower with betamethasone than with dexamethasone (odds ratio, 0.44 for betamethasone vs 0.73 with dexamethasone, P <.05). These and other findings suggest that a randomized clinical trial should be considered to compare the fetal and neonatal effects of dexamethasone and betamethasone. At present, the best management might be to expose very-low-birthweight infants to betamethasone rather than dexamethasone when there is a choice.

Commentary on guidelines for screening for retinopathy of prematurity

I n the early 1990s one of us (W.H.) recommended to the Canadian Association of Pediatric Ophthalmologists (CAPO) that standards should be established for screening for retinopathy of prematurity (ROP) in premature infants in Canadian nurseries. From 1994 to 2000 a CAPO ad hoc committee met on numerous occasions and produced several drafts, leading to the guidelines in the preceding document. The guidelines have been approved by CAPO, the Canadian Ophthalmological Society, and the Fetus and Newborn Committee of the Canadian Paediatric Society. Screening programs should target infants at risk for severe ROP. There is no consensus regarding the minimum gestational age and birth weight of premature infants to be screened. 1 There are only a few evidencebased studies that have provided supportive data for the guidelines. The infants believed to be at highest risk for significant ROP are those born at 30 weeks' gestation or less, and those with a birth weight of 1500 g or less.2-4 Ordinarily, ROP does not appear until 4 to 6 weeks after birth, and severe ROP that would require treatment does not usually manifest before 6 weeks. However, earlier reports describe Rush disease, included as zone I plus disease in the international classification of ROP,5 occurring as early as 3 weeks but not reaching a severity requiring treatment until 6 weeks or later. 6-S This more severe variant of ROP is less amenable to treatment unless treated early. The consensus was to recommend that screening begin 4 to 6 weeks after birth. The fundamental objective of screening is to identify eyes with progressive severe stage 3 ROP that is likely to compromise vision and the eye if left untreated. Although it is not clearly defined, there is a

Missense Mutations in Norrie Disease Gene Are Not Associated with Advanced Stages of Retinopathy of Prematurity in Kuwaiti Arabs

Retinopathy of prematurity (ROP) is a disease characterized by retinal neovascularization, possibly leading to retinal detachment and finally blindness. In a proportion of ROP cases, the disease progresses to advanced stages despite rigorous intervention. Missense mutations of the Norrie disease (ND) gene have been associated with progression of the disease in ROP cases from the USA. We have investigated the presence of ND gene mutations in 102 premature newborns of Kuwaiti Arab origin to replicate this finding in a different population/racial group. 56 (55%) of these newborns had normal eyes and served as controls. In 35 (34%) cases, the ROP regressed spontaneously during stage 1–3. In 11 (11%) cases, ROP progressed to advanced stages. A PCR-RFLP method was used to detect the mutations in exon 3 of the ND gene and confirmed the DNA sequence by direct sequencing of the PCR product. The [R121W] mutation of the ND gene was not detected in the premature newborns screened from our Kuwaiti population/group. For the second mutation [L108P], a genotype (PP) was present in 98% of the premature newborns screened and only in 1 of 56 normal infants was the (LL) genotype detected. Our population is genetically homogenous in that genotype (PP) was detected at codon 108 in almost all controls and ROP cases. We did not find an association between the presence or absence of missense mutations of the ND gene and the risk of severe ROP.

Outcome-based management of retinopathy of prematurity

Purpose: A system is presented for sequentially computing the risk of progression of retinopathy of prematurity (ROP) for infants born weighing not more than 1250 gm. A personal computer program is used to monitor infants' risk of threshold ROP from first appearance of ROP, and the progression in severity is tracked with multiple logistic risk models developed from data in the Multicenter Trial of Cryotherapyfor Retinopathy of Prematurity. Methods: After entry of the infant's birth weight, gestational age, ethnicity, birth in the current hospital or elsewhere, single or multiple birth, and maturity zone of retinal vessels, risk of progression to threshold severity is calculated. New estimates of risk are computed at onset of ROP and prethreshold ROP (any zone I ROP, zone II stage 2+ or 3) according to the extent of retinal vascularization when ROP first appears, how rapidly ROP progresses, and how severe it is. When threshold ROP (8 total or 5 contiguous clock hours of stage 3+ in zone I or II) is reached,the system provides separate estimates of risk that the eye will have an unfavorable 3-month outcome if treated or not. Results: Estimates of risk of progression to threshold disease among the 4099 patients in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity natural history study varied from less than 1% to more than 70%. For eyes with threshold disease, the risk of an unfavorable outcome at 3 months without treatment varied from less than 10% to more than 90%. Conclusion: This method of tracking identifies infants at high riskforsevere ROP and poor structural outcome. It provides information about prognosis with a specificity heretofore impossible.

Home Oxygen Administration and Retinopathy of Prematurity: Survey of 1988 Practices

Sir .—Premature infants are subjected to stringent invasive and noninvasive oxygen monitoring in the pursuit of the elusive safe path between hypoxic brain damage on the one hand and increased risks of blindness from retinopathy of prematurity (ROP) on the other. For the majority of infants, this period is relatively short. In some infants, however, chronic lung disease leads to such a prolonged oxygen requirement that home oxygen administration is considered. Hudak et al 1 have recently reported a growth benefit to 30 infants receiving oxygen at home when their pulse oximetry was kept over 95% saturation. They also stressed avoidance of hyperoxia but did not relate this to the degree of retinal immaturity or ROP present in a particular infant. The risk for severe ROP appears to be proportional to the degree of retinal immaturity, ie, the amount of avascular retina. It follows from this understanding that when the