Update on retinopathy of prematurity: treatment options and outcomes

Misalignment of center of foveal avascular zone and center of photoreceptors in eyes with history of retinopathy of prematurity

To determine the relationship between the center of the foveal avascular zone (FAZ) and the center of the foveal photoreceptors in eyes with a history of retinopathy of prematurity (ROP). To accomplish this, we reviewed the medical records of patients with ROP who were examined at the ROP Clinic of the Tokyo Women's Medical University Hospital. We studied 43 eyes of 23 children with ROP and 67 eyes of 36 control children without any fundus abnormalities. The optical coherence tomography angiographic (OCTA) en face images were used to measure the size and location of the foveal avascular zone (FAZ), and cross-sectional OCT images to measure the central retinal thickness (CRT). Our results showed that the size of the FAZ was significantly smaller in the ROP group (0.200 ± 0.142 mm2) than in the control group (0.319 ± 0.085 mm2; P < 0.01). The CRT was significantly thicker in the ROP group (228 ± 30 µm) than in the control group (189 ± 13 µm; P < 0.01). The mean length of the foveal bulge was not significantly different between the two groups. The actual distance of the misalignment between the center of the FAZ and the center of the photoreceptors was significantly greater in the ROP group (50.4 ± 29.5 µm) than in the control group (39.6 ± 21.9 µm; P = 0.001). The correlations between the actual distance of misalignment and the size of the FAZ, CRT, and length of the foveal bulge in both groups were not significant. Despite the significant misalignment in eyes with a history of ROP, the center of the foveal photoreceptors was consistently located within the narrow FAZ which indicates that the development of the FAZ and photoreceptor formation are interrelated.

Effect of foveal morphology on visual acuity in 4-6-year-old children with retinopathy of prematurity: a J-CREST study

Laser therapy is the most effective treatment considered for retinopathy of prematurity (ROP). We compared the foveal morphology of the retina in eyes with a history of ROP to that of full-term children. This cross-sectional comparative study included 74 patients with a history of ROP, aged 4–6 years. Among them, 41 underwent laser treatment for ROP. The clinical findings and retinal morphology in these patients were compared to that of 33 patients who had spontaneous ROP regression and 30 age-matched full-term controls. All the patients with ROP had 20/40 or better best-corrected visual acuity (BCVA). The foveal thickness was significantly thicker in laser-treated ROP eyes than in regressed ROP eyes and controls. The outer nuclear layer was significantly thicker, and the inner segment (IS) of the photoreceptors and the inner retinal layer were significantly thicker in the laser-treated ROP eyes than that in the control eyes. In the patients with ROP and controls, better BCVA was associated positively with deeper foveal depression, which was associated with a later gestational age. Our results suggest that prematurity and laser treatment affect the foveal morphology and BCVA.

Functional and Structural Findings in Infants Treated for Retinopathy of Prematurity Using Optical Coherence Tomography Angiography

BACKGROUND AND OBJECTIVE

To assess the foveal microvascular structure of children with retinopathy of prematurity (ROP) treated with diode laser photocoagulation using optical coherence tomography angiography (OCTA).

PATIENTS AND METHODS

OCTA was performed at a tertiary medical center in 17 children (27 eyes) aged 4 to 16 years with a history of diode laser photocoagulation treated ROP. OCTA parameters were compared with those of 12 healthy age-matched controls (23 eyes) attending the orthoptics clinic and correlated with clinical factors.

RESULTS

Compared with controls, the ROP group had a smaller foveal avascular zone area (P < .001), lower deep vascular plexus density (P < .001), lower flow density (P = .025), and greater central macular thickness (P < .001). High intraventricular hemorrhage grade correlated with smaller foveal avascular zone area (P = .008) and greater inner macular thickness (P = .047). There was no impact of gestational age, birth weight, or refractive status.

CONCLUSION

OCTA can identify significant quantifiable long-term macular microvascular and structural changes in this patient population. [Ophthalmic Surg Lasers Imaging Retina. 2022;53(4):194-201.].

Impairment of endothelium-dependent vasodilator function of retinal blood vessels in adult rats with a history of retinopathy of prematurity

Retinopathy of prematurity (ROP) is a proliferative retinal vascular disease, initiated by delayed retinal vascular growth after premature birth. In the majority of cases, ROP resolves spontaneously; however, a history of ROP may increase the risk of long-term visual problems. In this study, we evaluated the endothelial function of retinal blood vessels in adult rats with a history of ROP. ROP was induced in rats by subcutaneous injection of a vascular endothelial growth factor receptor tyrosine kinase inhibitor (KRN633) on postnatal day (P) 7 and P8. On P56, vasodilator responses to acetylcholine, GSK1016790A (an activator of transient receptor potential vanilloid 4 channels), NOR3 (a nitric oxide [NO] donor), and salbutamol (a β2-adrenoceptor agonist) were assessed. Compared to age-matched controls, retinal vasodilator responses to acetylcholine and GSK1016790A were attenuated in P56 rats with a history of ROP. No attenuation of acetylcholine-induced retinal vasodilator response was observed under inhibition of NO synthase. Retinal vasodilator responses to NOR3 and salbutamol were unaffected. These results suggest that the production of and/or release of NO is impaired in retinal blood vessels in adult rats with a history of ROP. A history of ROP might increase the risk of impaired retinal circulation in adulthood.

Retinal vessel architecture in retinopathy of prematurity and healthy controls using swept-source optical coherence tomography angiography

PURPOSE

To determine microvascular changes in children with a history of retinopathy of prematurity (ROP) and in a control group of full-term children.

METHODS

In a cross-sectional study, 30 eyes of 15 children aged 6-8 years with a history of ROP were evaluated with swept-source optical coherence tomography angiography (SS-OCTA). Twenty-eight eyes of 22 age-matched full-term children served as a healthy control group. The foveal avascular zone (FAZ), vessel density (VD) and choroidal vascular flow area (VFA) were evaluated on OCTA and correlated with central retinal thickness (CRT), visual acuity (VA), birth weight (BW), gestational age (GA) and ROP stages.

RESULTS

Twenty-two eyes of 14 children with a history of ROP (stage 1-3) and 25 eyes of 19 full-term children were available for evaluation. In the ROP group, the gestational age was 27 ± 2 weeks and birth weight was 781 ± 164 g. In the ROP group, CRT was higher in the central ETDRS segment (mean difference [95% CI]: 32.8 µm [18.7; 47.0], p = 0.0002) compared to the controls. Smaller mean FAZ area (-0.12 [-0.19; -0.04], p = 0.004) and perimeter (-662 [-1228; -96], p = 0.03) was found in comparison to the control group. An oval shape of the FAZ was observed among patients with a history of ROP. The mean central VD of the superficial plexus was 28 ± 8/23 ± 8% and of the deep plexus 7 ± 7/3 ± 5% (ROP group/control group; p > 0.05). No statistically significant difference was found regarding the choroidal VFA. Only weak correlation of FAZ and VD with function was observed.

CONCLUSIONS

Swept-source optical coherence tomography angiography imaging revealed significant microvascular anomalies in children with a history of ROP indicating disturbance of early morphological development of the central retina.

VISUAL FUNCTION AND OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FEATURES IN CHILDREN BORN PRETERM

PURPOSE

Preterm children have an increased risk of impaired vision from retinopathy, strabismus, and high refractive error. The aim of this study was to investigate the relationship between foveal parameters generated by optical coherence tomography angiography and visual function in preterm children.

METHODS

Eighty eyes (32 eyes of former preterm infants and 48 age-matched full-term control eyes) were analyzed. Subjects underwent complete eye examinations including best-corrected visual acuity and retinal imaging with the Optovue XR Avanti optical coherence tomography angiography device. Foveal morphologic parameters including foveal depth, central foveal thickness, inner retinal area, and outer retinal area were measured on a central horizontal B-scan. Foveal vasculature parameters including foveal avascular zone, superficial capillary plexus-vessel density, and deep capillary plexus-vessel density were measured on optical coherence tomography angiography.

RESULTS

The best-corrected visual acuity was significantly affected in preterm children compared with controls (P < 0.0001). The central foveal thickness (P < 0.0001), inner retinal area (P = 0.01), and outer retinal area (P = 0.03) were significantly increased in preterm compared with control eyes. Foveal depth (P < 0.001) and foveal avascular zone (P < 0.001) were significantly decreased in preterm compared with control eyes. The superficial capillary plexus-vessel density (P = 0.01) and deep capillary plexus-vessel density (P = 0.003) at the fovea (1 mm) were significantly increased in preterm compared with control eyes. The best-corrected visual acuity was negatively correlated with foveal depth (r = -0.42, P = 0.001) and foveal avascular zone (r = -0.53, P < 0.001), and positively correlated with central foveal thickness (r = 0.32, P = 0.01) and inner retinal area (r = 0.32, P = 0.01), indicating that worse visual acuity was associated with a smaller foveal avascular zone, shallower foveal depth, increased central foveal thickness, and larger inner retinal area.

CONCLUSION

Foveal morphology and vasculature changes in preterm children were associated with impaired visual function. Further longitudinal studies are required to evaluate these changes over time.

Changes in the Incidence of Retinopathy of Prematurity in Extremely Low Birth Weight Infants in South China From 2004 to 2018

PURPOSE

To report the changes in incidence and risk factors of retinopathy of prematurity (ROP) in extremely low birth weight (ELBW) infants over a 15-year period in South China.

METHODS

The medical records of ELBW infants were retrospectively reviewed through established database of Shenzhen Screening for ROP Cooperative Group. The incidence and severity of ROP were compared among three successive 5-year periods (P1: 2004-2008, P2: 2009-2013, P3: 2014-2018). Gestational age, birth weight, plurality, mode of delivery and gender were analyzed as risk factors for ROP in ELBW infants.

RESULTS

Among the 1099 included ELBW infants, 557 (50.7%) had ROP, and 328 (29.9%) had severe ROP. The highest incidence of ROP (87.5%) and severe ROP (82.5%) were seen in P1. From P2 to P3, the incidence of ROP and severe ROP increased from 45.9% to 50.3% for ROP (P < .05) and from 26.4% to 28.3% for severe ROP (P < .05), respectively. Multivariate logistic regression analysis found only gestational age has a significant effect on the incidence of ROP and severe ROP.

CONCLUSIONS

From 2004 to 2018, the incidence of ROP and severe ROP in ELBW infants in South China was 50.7% and 29.9%, respectively. Controlling for the other risk factors, only gestational age was statistically associated with ROP in ELBW infants.

Choroidal structural changes in preterm children with and without retinopathy of prematurity

PURPOSE

Evaluate choroidal structural changes in preterm children with and without retinopathy of prematurity (ROP) using image binarization technique on swept-source optical coherence tomography (SS-OCT) scans.

METHODS

Prospective case-control study. Forty-one (79 eyes) children aged 5-15 years with a history of preterm birth and 33 (63 eyes) age-matched full-term children were recruited. Demographics including gestational age at birth, birth weight and history of ROP were documented. All subjects had undergone complete eye examinations, including best-corrected visual acuity and SS-OCT imaging. Subfoveal choroidal thickness (SFCT) was calculated, and images were binarized to obtain stromal and luminal areas (LA). The choroidal vascularity index (CVI) was derived from the proportion of LA to the total subfoveal choroidal area.

RESULTS

There were no significant differences in SFCT between the preterm children with (286.63 ± 83.98 μm) or without (306.59 ± 77.29 μm) ROP and the full-term children (311.82 ± 42.87; p = 0.20 and 0.67, respectively). The CVI was significantly reduced in the preterm children with ROP (68.66 ± 3.24%; p = 0.005) compared with the CVI in the full-term control group (71.37 ± 3.63%); however, the CVI in the preterm children without ROP (71.68 ± 3.09%; p = 0.93) was not significantly affected.

CONCLUSION

The reduced CVI in preterm children with ROP may indicate compromised choroidal vascularity. The CVI was found to be a more sensitive OCT biomarker than the SFCT and may be helpful in evaluating associated choroidal structural changes in preterm children, especially those with a history of ROP.

Foveal abnormalities determined by optical coherence tomography angiography in children with history of retinopathy of prematurity

PURPOSE

To describe the foveal characteristics of children with a history of retinopathy of prematurity (ROP) using optical coherence tomography angiography (OCTA).

METHODS

All eyes were examined by OCTA (RTVue AVANTI, Optovue Inc, Fremont, CA) with a scan of 3 × 3 mm cantered on the fovea. The size of the foveal avascular zone (FAZ), central retinal thickness (CRT), and foveal bulge were measured.

RESULTS

Forty-eight eyes of 26 children with a history of ROP and a mean age of 8.8 years with a range of 4-16 years (ROP group) were studied. Sixty-six eyes of 36 children without any fundus abnormalities and with an average age of 10.5 years and a range of 3-17 years (control group) were studied as controls. The mean FAZ area in the ROP group was 0.18 mm² which was significantly smaller than the 0.32 mm² in the control group (p < 0.01). The mean CRT was significantly thicker in the ROP group (228 µm) compared to the control group (189 µm; p < 0.01). The size of FAZ was not measurable in 5 eyes (10.4%) of 3 children in the ROP group. The correlation between the FAZ area and CRT was significant in both the ROP and control groups (r = -0.53 in ROP; r = -0.57 in control; both p < 0.01). There was no significant difference in the height of the foveal bulge between two groups (p = 0.64).

CONCLUSIONS

The FAZ is smaller in ex-preterm children with a history of ROP (including laser treatment for ROP) than in children who were not premature.

Optical Coherence Tomography Angiography of the Macula in Adults With a History of Preterm Birth

BACKGROUND AND OBJECTIVE

To evaluate the fovea microvasculature in adult subjects with history of preterm birth using optical coherence angiography (OCTA).

PATIENTS AND METHODS

In this retrospective study, macular OCTA images were obtained from adult subjects with a history of preterm birth. The presence of the foveal avascular zone (FAZ) and its size was determined.

RESULTS

Ten eyes from six subjects with ages ranging from 26 years old to 65 years old were evaluated. A distinct FAZ was not observed in three eyes (30%). The FAZ was small in other eyes, ranging from 0.07 mm² to 0.18 mm².

CONCLUSION

Adult subjects with a history of preterm birth may have persistent foveal vasculature in the FAZ. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:122-125.].

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF THE FOVEA IN CHILDREN BORN PRETERM

PURPOSE

To compare the foveal avascular zone (FAZ) area measured by optical coherence tomography angiography in children who had been born preterm with age-matched controls.

METHODS

In this cross-sectional observational comparative case series, 43 eyes of 26 children (28 eyes of 15 former preterm infants and 15 eyes of 11 former term infants) between the ages of 4 and 12 years old were included. Optical coherence tomography angiography with a scan size of 3 × 3 was performed for all eyes. Foveal avascular zone area was measured using the Optovue RTVue AVANTI instrument (Optovue Inc, Fremont, CA) software. Inner and outer retinal thicknesses were measured with the instrument caliper.

RESULTS

A distinct FAZ was absent in 12 eyes (42.8%) of children with a history of preterm birth, however, it was present in all (100%) control eyes. The FAZ area was significantly correlated with gestational age (r = 0.82, P < 0.001) and birth weight (r = 0.80, P < 0.001). The gestational age was less than 29 weeks and birth weight was less than 1,480 grams in eyes with no distinct FAZ. Mean central foveal vessel density in the superficial capillary plexus was 41.8 ± 4.4% in the preterm group and 32.8 ± 5.8% in the control group (P < 0.001). In all eyes, a significant negative correlation was found between the central foveal vessel density and gestational age (r = -0.63, P = 0.001) and birth weight (r = -0.59, P = 0.002). On spectral domain optical coherence tomography examination, the foveal depression was absent and the inner retinal layers were preserved in all eyes with absent FAZ. In all eyes, a significant negative correlation was found between the inner retinal thickness and gestational age (r = -0.68, P < 0.001) and birth weight (r = -0.61, P = 0.001). Ten eyes of 6 preterm children had a history of laser therapy for retinopathy of prematurity. A distinct FAZ was absent in six eyes (60%) with retinopathy of prematurity with history of laser therapy, and six eyes (33.3%) with preterm birth without laser therapy. Eyes with history of laser therapy had a statistically significantly higher inner retinal thickness and central foveal vessel density and smaller FAZ compared with the eyes with preterm birth without laser therapy (P < 0.001, P = 0.04 and P = 0.03, respectively).

CONCLUSION

Optical coherence tomography angiography is a novel modality for noninvasive visualization of the retinal vasculature in pediatric patients and expands our knowledge of foveal abnormalities in retinopathy of prematurity. A small or absent FAZ seems to be a distinct sign of prematurity.

Trends in the incidence and causes of severe visual impairment and blindness in children from Israel

PURPOSE

To describe trends in the incidence and causes of legal childhood blindness in Israel, one of the few countries worldwide that maintain a national registry of the blind.

METHODS

We performed a historical cohort study of annual reports of the National Registry of the Blind (NRB) between 1999 and 2013. All data regarding demographic information, year of registration and cause of blindness of children 0-18 years of age registered for blind certification were obtained from the annual reports of the NRB. Causes of legal blindness analyzed were optic atrophy, retinitis pigmentosa, retinopathy of prematurity (ROP), albinism, other retinal disorders, cataract, and glaucoma. The main outcome measure was the incidence of new cases of certified legal blindness.

RESULTS

The incidence of newly registered legally blind children in Israel almost halved from 7.7 per 100,000 in 1999 to 3.1 per 100,000 in 2013. The decline was mainly attributable to a decreased incidence of blindness resulting from retinitis pigmentosa and ROP. The incidence of registered cases due to cerebral visual impairment increased.

CONCLUSIONS

During the past decade the incidence of severe childhood visual impairment and blindness declined in Israel. A continuous decline in consanguineous marriages among the Jewish and Arab populations in Israel may have contributed to the decrease in the rate of vision loss due to retinitis pigmentosa in children.

Activation of the endothelin system mediates pathological angiogenesis during ischemic retinopathy

Retinopathy of prematurity adversely affects premature infants because of oxygen-induced damage of the immature retinal vasculature, resulting in pathological neovascularization (NV). Our pilot studies using the mouse model of oxygen-induced retinopathy (OIR) showed marked increases in angiogenic mediators, including endothelins and endothelin receptor (EDNR) A. We hypothesized that activation of the endothelin system via EDNRA plays a causal role in pathological angiogenesis and up-regulation of angiogenic mediators, including vascular endothelial growth factor A (VEGFA) in OIR. Mice were exposed to 75% oxygen from post-natal day P7 to P12, treated with either vehicle or EDNRA antagonist BQ-123 or EDNRB antagonist BQ-788 on P12, and kept at room air from P12 to P17 (ischemic phase). RT-PCR analysis revealed increased levels of EDN2 and EDNRA mRNA, and Western blot analysis revealed increased EDN2 expression during the ischemic phase. EDNRA inhibition significantly increased vessel sprouting, resulting in enhanced physiological angiogenesis and decreased pathological NV, whereas EDNRB inhibition modestly improved vascular repair. OIR triggered significant increases in VEGFA protein and mRNA for delta-like ligand 4, apelin, angiopoietin-2, and monocyte chemoattractant protein-1. BQ-123 treatment significantly reduced these alterations. EDN2 expression was localized to retinal glia and pathological NV tufts of the OIR retinas. EDN2 also induced VEGFA protein expression in cultured astrocytes. In conclusion, inhibition of the EDNRA during OIR suppresses pathological NV and promotes physiological angiogenesis.

Correlation between periventricular leukomalacia and retinopathy of prematurity

PURPOSE

To investigate the correlation between periventricular leukomalacia (PVL) and retinopathy of prematurity (ROP), which are complications of perinatal and postnatal hypoxic-ischemic insults in premature infants.

METHODS

In this retrospective case series study, from 1996 to 2008, after excluding cases with follow-up of less than 3 months, we reviewed medical charts of babies who had gestational age (GA) less than 30 weeks or birthweight (BW) less than 2000 g. A total of 195 patients were diagnosed with ROP and/or PVL and were enrolled in this analysis. We investigated the correlation between ROP and PVL with Pearson chi-square test and evaluated BW, GA, and Apgar scores at 1 minute and 5 minutes after birth as risk factors by independent t test.

RESULTS

There were no significant differences in the prevalence of PVL between patients who received ROP treatment and those who did not receive ROP treatment. The BW was significantly lower in patients with PVL than in patients without PVL. Gestational age, BW, and Apgar scores significantly differed between patients who did and did not receive retinal treatment for ROP.

CONCLUSIONS

Periventricular leukomalacia did not increase the severity of ROP or requirement of ROP treatment. Birthweight, GA, and Apgar scores were the principal factors that determined the necessity of ROP treatment.

Perinatal infection, inflammation, and retinopathy of prematurity

The major known risk factors for retinopathy of prematurity (ROP) are extremely low gestational age, exposure to high levels of oxygen early after birth (phase I) and relatively lower oxygen levels later (phase II). In this review, we summarize recent data suggesting that exposure to perinatal infection/inflammation is associated with an increased risk for ROP. Part of this effect might be due to direct exposure of the developing retina to circulating products of infection and/or inflammation. Another potential mechanism that deserves exploration is that inflammation and/or oxidative stress can modify the known increased risk of oxygen-associated ROP. Taken together, accumulating evidence suggests that prenatal, perinatal, and postnatal systemic inflammation contribute to a 'pre-phase', sensitizing the pre-ROP retina for subsequent insults, setting the stage for what are now called phase I and phase II of ROP pathogenesis. Strategies targeting inflammatory responses might help reduce the risk for ROP in extremely low gestational age newborns.

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.

Current update on retinopathy of prematurity: screening and treatment

PURPOSE OF REVIEW

Despite current treatments, retinopathy of prematurity (ROP) remains a major cause of blindness in premature infants and the incidence is increasing with increased survival of infants born at very early gestational ages. This review summarizes the recent literature on ROP with a special focus on recent advances in treatment options as well as newly developed methods for disease screening.

RECENT FINDINGS

Genetic studies find a genetic predisposition to ROP-linking genes in the Wnt pathway with development of severe ROP. With regard to diagnosis, a new screening method has been developed that allows prediction of ROP risk based on postnatal body weight gain alone. Formerly weight gain postnatally in combination with insulin-like growth factor levels was found to predict treatable ROP. New treatment options for severe cases of ROP have been proposed targeting vascular endothelial growth factor (VEGF). Whether anti-VEGF treatment is well tolerated in preterm infants, however, has to be further evaluated in controlled clinical trials. Finally, new reports from the early treatment ROP group suggest that early laser treatment for type 1 but not type 2 high-risk prethreshold ROP improves visual acuity outcomes at 6 years of age.

SUMMARY

With the increasing survival of premature infants and increased incidence of ROP, it is important to screen for ROP risk and treat at-risk patients in a timely manner to preserve their visual function and reduce complications.