Ocular morphology and visual function in relation to general growth in moderate-to-late preterm school-aged children

Foveal thickness and its association with visual acuity in adults born preterm with very low birth weight: A two-country birth cohort study

PURPOSE

To explore foveal and parafoveal thickness in adults born preterm with very low birth weight (VLBW) and its association with best-corrected visual acuity (BCVA) and gestational age (GA) compared to adults born at term.

METHODS

In a joint study of the Helsinki Study of Very Low Birth Weight Adults (Finland) and the NTNU Low Birth Weight Life study (Norway), 106 VLBW and 143 term-born controls were examined with spectral-domain optical coherence tomography and BCVA at age 31-43 years. Thickness of retinal layers was segmented in the foveal and parafoveal areas of the macula.

RESULTS

The total retinal thickness in the foveal area was thicker in VLBW adults compared with controls; mean (SD): 292.5 μm (28.2) and 272.4 μm (20.2); p < 0.001, and thinner in the parafoveal areas of the macula. These findings could be explained by a thicker inner retinal layer in the foveal area found in VLBW adults compared with controls (mean difference 20.4 μm; CI: 15.0 to 25.9), where a thicker fovea was associated with lower GA, but not BCVA.

CONCLUSION

Adults born preterm with VLBW had a thicker retina in the foveal area than controls and this was associated with GA, but not with BCVA. These changes seem to be related to a thicker inner retinal layer in VLBW adults. The findings imply that signs of macular underdevelopment are still present in adulthood, but not necessarily related to reduced visual function.

Foveal thickness and vascular variables in adolescents born moderate-to-late preterm

PURPOSE

It is well established that children born very preterm are at increased risk for ocular abnormalities including altered foveal morphology. However, little is known about how children born moderate-to-late preterm (MLP), gestational age 32 + 0-36 + 6 weeks, are affected later in life. This study investigates foveal avascular zone (FAZ) area, vascular density (VD), central foveal thickness (CFT) and ganglion cell layer thickness (GCL++) of adolescents born MLP without history of retinopathy of prematurity and compare the results with full-term controls.

METHODS

In a prospective population-based cohort study, 50 adolescents (26 girls; mean age 16.5 years) born MLP were examined with optical coherence tomography (OCT) and OCT angiography (OCT-A). FAZ and VD were obtained from OCT-A scans and adjusted for ocular magnification. CFT and GCL++ were obtained from the OCT scans. The results from the MLP individuals were compared with the results from 49 healthy full-term controls (29 girls; mean age 16.7 years).

RESULTS

The results showed statistically significant differences in FAZ area (0.22 vs 0.28 mm2; p = 0.0032) and CFT (198.1 vs 187.1 μm; p = 0.0010) between the MLP group and controls. Strong correlations between FAZ area and CFT (r = -0.773, p < 0.0001) and GCL++ (r = -0.924, p < 0.0001) were found in the MLP group. There were no differences in VD.

CONCLUSIONS

Our results show that adolescents born MLP have a smaller FAZ area and an increased CFT compared with full-term controls. These results indicate that adolescents born MLP have similar parafoveal changes as children born extreme or very preterm.

Insights into Risk: Exploring Retinopathy of Prematurity and Short-term Comorbidities in Moderate-to-Late Preterm Infants

BACKGROUND

Retinopathy of prematurity (ROP) and short-term comorbidity data moderate-to-late preterm (MLP) infants in Saudi Arabia are limited.

AIM

The present study mainly aimed to identify ROP incidence and severity in MLP infants. The secondary objective was to explore whether moderate preterm infants are more prone to systemic short-term comorbidities compared to late preterm infants.

MATERIALS AND METHODS

This retrospective study was conducted at King Abdulaziz University Hospital, a tertiary center in Jeddah, Saudi Arabia. Two-hundred and sixty-eight MLP infants born with gestational ages (GAs) of 32 to 36 + 6 weeks were included. Births were classified as moderate preterm (GA 32 to 33 + 6 weeks) and late preterm (GA 34 to 36 + 6 weeks) and the two groups were compared with an independent t-test.

RESULTS

ROP incidence was 1.5%; all cases were stage 1 and involved zone II or III. No patient had type 1 ROP requiring treatment. The short-term comorbidity incidence was high (76.1%) and included hyperbilirubinemia (n = 206, 76.7%), respiratory distress syndrome (n = 178, 66.4%), hypoglycemia (n = 32, 11.9%,), and transient tachypnea of newborn (n = 25, 9.3%). Moderate preterm infants were more likely to have lower birth weight (P < 0.001), any-stage ROP (P = 0.032), respiratory distress syndrome (P = 0.031), intraventricular hemorrhage (P = 0.038), and hyperbilirubinemia (P < 0.001) compared to the late preterm infants.

CONCLUSIONS

Any-stage ROP incidence among MLP infants was low, with no type 1 ROP cases requiring treatment. Short-term comorbidity incidence was relatively high among the moderate preterm infants. Despite the low non-type 1 ROP incidence at our center, MLP infants require proper surveillance of systemic short-term comorbidities.

Computer-assisted evaluation of retinal vessel tortuosity in moderate-to-late preterm children

PURPOSE

Since very preterm children often have increased retinal tortuosity that may indicate decisive architectural changes in the systemic microvascular network, we used a new semi-automatic software to measure retinal vessel tortuosity on fundus digital images of moderate-to-late preterm (MLP) children.

METHODS

In this observational case-control study, the global and local tortuosity parameters of retinal vessels were evaluated on fundus photographs of 36 MLP children and 36 age- and sex-matched controls. The associations between birth parameters and parameters reflecting retinal vessel tortuosity were evaluated using correlation analysis.

RESULTS

Even after incorporation of anatomical factors, the global and local tortuosity parameters were not significantly different between groups. The MLP group showed a smaller arteriolar caliber (0.53  ±  0.2) than the controls (0.56  ±  0.2; p  =  0.013). Other local tortuosity parameters, such as vessel length, distance to fovea, and distance to optic disc, were not significantly different between arteries and veins. Tortuosity in both groups was higher among vessels closer to the fovea (r  =  -0.077, p < 0.001) and the optic disc (r  =  -0.0544, p  =  0.009). Global tortuosity showed a weakly positive correlation with gestational age and a weakly negative correlation with birth weight in both groups.

CONCLUSION

MLP patients did not display increased vessel tortuosity in comparison with the controls; however, the arteriolar caliber in the MLP group was smaller than that in children born full-term. Larger studies should confirm this finding and explore associations between cardiovascular and metabolic status and retinal vessel geometry in MLP children.

Antenatal and neonatal factors and morphology of the optic nerve head in the Northern Finland birth cohort

PURPOSE

The optic nerve head (ONH) is a part of the brain that can be evaluated through the transparent medium of the eye. The purpose of this study was to explore the possible correlations among the properties of the optic nerve head, maternal factors during pregnancy and neonatal parameters in a randomized sample of a birth cohort.

METHODS

The Northern Finland 1966 Birth Cohort has been prospectively monitored since their antenatal period. Data on pregnancy and neonatal period were collected during gestation and right after birth in 1966. A randomized sample of 3070 subjects underwent an ophthalmic assessment at the age of 46-48 years. The examination protocol included scanning laser ophthalmoscopy with the Heidelberg Retina Tomograph. The ophthalmological parameters assessed were the disc area and the neuroretinal rim volume of the ONH.

RESULTS

We found that chronic pulmonary disease of the mother (p = 0.007), the number of gestational weeks (p = 0.030) and the mother's highest measured systolic blood pressure (p = 0.035) during pregnancy had a statistically significant effect on the disc area. Smaller disc size was associated with pulmonary disease and early gestation. There was a significant difference in rim volume between genders (p < 0.001). Women had larger neuroretinal rim volumes compared to men.

CONCLUSION

In this population-based study, the vast majority of antenatal and neonatal factors showed no correlation with optic disc area or rim volume. Furthermore, even the factors with statistically significant correlation with ONH morphology had limited predictive value.

Prematurity: A medical history of obligatory consideration when assessing the retinal ganglion cell complex

INTRODUCTION

Premature children birth and survival is becoming more frequent due to the improvement in obstetric and neonatal care. This makes it increasingly common to find patients with history of preterm birth in ophthalmology clinics, both in pediatric and adult ages. Premature birth can lead to ocular structural changes, being possible to affect the ganglion cell complex (GCC), among other structures, which can be studied using optical coherence tomography.

MATERIALS AND METHODS

To carry out a bibliographic review of the studies that analyze GCC in patients with a history of prematurity compared with patients born at term.

RESULTS

Several studies that analyze GCC in patients with a history of prematurity are referenced and their results are studied.

CONCLUSIONS

In our clinical practice, knowing the history of prematurity is fundamental in the assessment of GCC measured by optical coherence tomography, since this layer is different in the patients with a history of prematurity compared to patients born at term.

Retinal ganglion cell complex thickness at school-age, prematurity and neonatal stressors

PURPOSE

To investigate the association between the ganglion cell complex (GCC) thickness at early school-age and prematurity and other neonatal factors.

METHODS

Cross-sectional study. The sample included very preterm children with gestational age (GA) below 32 weeks or birthweight below 1500 g enrolled in a follow-up program (n = 101) and a comparison group of term-born children (n = 49). Ganglion cell complex (GCC) thickness was measured at 4-8 years using high-quality optical coherence tomography (OCT) images. Data on neonatal and postnatal features were extracted from clinical records; analyses included mixed linear models.

RESULTS

Ganglion cell layer (GCL) and retinal nerve fiber layer (mRNFL) were thicker in term than in preterm born children (2.9 μm and 2.4 μm respectively, p < 0.001). Within the preterm group, lower GA was associated with a decrease in total GCL (0.7 μm per week, p < 0.001). Being small for GA was associated with further thinning in both layers (1.4 and 2.8 µm). Postnatal corticosteroids therapy and severe brain lesion were associated with thinning in the total GCL of 6 µm (p < 0.001) and 4.1 µm (p = 0.002), respectively, and shock was associated with thinning in total mRNFL of 6 µm (p < 0.001).

CONCLUSIONS

Lower GA or birthweight are associated with thinning of GCC layers. When performing an OCT examination at school-age and a decrease in GCC thickness is observed, it may be relevant to ask about a history of prematurity, and further enquire about neonatal shock, postnatal corticosteroids therapy or severe brain lesion that are related to additional decrease in GCC thickness.

Ocular findings and growth in 5-year-old preterm children born to mothers with preeclampsia

PURPOSE

To evaluate growth, blood pressure and ophthalmological status in preschool children born preterm to mothers with preeclampsia.

METHODS

In a prospective cohort study, 78 children (34 girls) born preterm without retinopathy of prematurity were examined regarding length/height, weight, head circumference and insulin-like growth factor I (IGF-I) at birth and at 5 years of age. At 5 years, IGF-binding protein 3 and blood pressure were also measured. A detailed ophthalmological examination including ocular dimensions, fundus morphology, visual fields, visual evoked potentials and perceptual visual dysfunction was performed. Children born to preeclamptic mothers (n = 24) were compared to children with non-preeclamptic mothers (n = 54).

RESULTS

Children exposed to preeclampsia had lower weight (p = 0.0002, mean difference -1.46, 95% CI -2.09; -0.83), length (p = 0.013, -1.10, 95% CI -1.92; -0.23) and IGF-I levels (p = 0.0002, -26.0, 95% CI -36.0; -16.1) at birth compared to non-exposed children. At 5 years of age, the preeclamptic group had larger optic cup areas (p = 0.0006, 0.32, 95% CI 0.15; 0.46, in right eye, p = 0.049, 0.18, 95% CI 0.001; 0.35, in left eye). There was no significant difference between the groups regarding other ophthalmological findings or blood pressure. Children with reduced eye motility had lower neonatal IGF-I levels (p = 0.033, 15.5, 95% CI 1.1; 30.3).

CONCLUSION

Preeclampsia was shown to affect growth and IGF-I levels, confirming previous studies. Children exposed to preeclampsia were shown to have larger optic cup areas. Furthermore, lower neonatal IGF-I levels were seen in preterm children with reduced eye motility at 5 years of age.

Thinner retinal nerve fibre layer in young adults with foetal alcohol spectrum disorders

BACKGROUND/AIMS

Ophthalmological abnormalities such as ptosis, strabismus, refractive errors and optic nerve hypoplasia have been reported in foetal alcohol spectrum disorders (FASD). The purpose of this study was to investigate whether retinal thickness, retinal nerve fibre layer (RNFL) and optic disc area (ODA) differ between individuals with FASD and healthy controls.

METHODS

Best-corrected visual acuity (BCVA) in terms of logarithm of the minimum angle of resolution (logMAR), refraction, and fundus variables measured by optical coherence tomography were obtained from 26 young adults with FASD (12 women, median age 23 years) and 27 controls (18 women, median age 25 years).

RESULTS

The total thickness of the peripapillary RNFL was significantly lower in the FASD group than in controls; median (range) in the right/left eye was 96.5 (60-109)/96 (59-107) µm in the FASD group and 105 (95-117)/103 (91-120) µm among controls (p=0.001 and p=0.0001). Macular RNFL and retinal thickness measurements from the FASD group were also lower in most of the nine ETDRS areas, except for the central parts. Median (range) BCVA in the best eye was 0.00 (-0.1-0.3) logMAR in the FASD group and 0.00 (-0.2-0.0) logMAR in controls (p=0.001). No significant differences between the groups were found regarding ODA or refraction.

CONCLUSION

Significant differences in peripapillary and macular RNFL, retinal thickness and BCVA were found in this group of young adults with FASD compared with healthy controls. However, there were no differences in the size of the optic disc.

Evaluation of Iridocorneal Angle, Choroidal Thickness, and Retinal Nerve Fiber Layer Thickness in Children With a History of Retinopathy of Prematurity

PURPOSE

Retinopathy of prematurity (ROP) is proliferative retinopathy affecting premature infants associated with abnormal maturation of the retinal vasculature. We sought to evaluate iridocorneal angle, choroidal thickness, and retinal nerve fiber layer thickness (RNFLT) of the children that have a history of ROP using spectral-domain optical coherence tomography.

PATIENTS AND METHODS

Fifty eyes of 28 children with a history of ROP and 46 eyes of 23 healthy school-aged children were included in this study. RNFLT, choroidal thickness, and iridocorneal angle parameters [trabecular iris angle, angle opening distance (AOD500), and trabecular iris space area (TISA500) 500 μm from the scleral spur] were evaluated using spectral-domain optical coherence tomography. Student t test was used to compare the mean of the parameters. Correlations between the variables were investigated based on the Pearson or Spearman correlation coefficient.

RESULTS

Subfoveal (ROP: 253.98±42.5; control: 286.2±71.9; P=0.045), 500 µm (ROP: 242.04±41.8; control: 276.7±45.3; P=0.003), 1000 µm (ROP: 237±39.7; control: 270.15±55.93; P=0.007), and 1500 µm (ROP: 224.16±37.5; control: 259.75±55.2; P=0.003) temporal choroidal thicknesses were significantly thinner in ROP history children. None of the RNFLT parameters and ganglion cell complex thickness were different between groups. Iridocorneal angle parameters were significantly lower in children with ROP history. (trabecular iris angle: ROP=31.35±3.9 degrees, control=35.4±4.5 degrees, P<0.001; TISA500: ROP=0.167±0.05 mm, control=0.21±0.05 mm, P=0.003; AOD500: ROP=480.96±160.4 µm, control=542.95±161.2 µm, P=0.035).

CONCLUSIONS

ROP is associated with differences in the iridocorneal angle. Possible iridocorneal angle pathology should be a consideration in children with a history of ROP.

Visual Function and Fundus Morphology in Relation to Growth and Cardiovascular Status in 10-Year-Old Moderate-to-Late Preterm Children

PURPOSE

To study visual function and ocular fundus morphology in relation to growth, metabolic status, and blood pressure in moderate-to-late preterm (MLP) children at 10 years of age.

DESIGN

Prospective cohort study.

METHODS

In this population-based observational study, nonsyndromic MLP children born in Gothenburg, Sweden, were examined neonatally in the years 2002-2003 concerning length, weight, head circumference, and insulin-like growth factor I (IGF-I). At 10 years of age, 33 children (10 girls) were examined regarding previously mentioned variables, and regarding visual acuity, refraction, fundus morphology, IGF binding protein 3, leptin, adiponectin, and blood pressure. An age- and sex-matched control group consisted of 28 children (9 girls).

RESULTS

Myopia was more commonly found in MLP children than in controls (P = .004, 95% CI 1.8 to 49.8). The MLP group had smaller optic disc area (P = .01, 95% CI -0.5 to -0.1), smaller rim area (P = .001, 95% CI -0.5 to -0.2), fewer branching points (P = .0001, 95% CI -5.7 to -2.1), and higher index of tortuosity of arteries (P = .03, 95% CI 0.002 to 0.03) and veins (P = .02, 95% CI 0.003 to 0.02). Refraction correlated with IGF-I (P = .0005, r_s = 0.60 in right eye, and P = .002, r_s = 0.55 in left eye) at 10 years of age. Tortuosity of arteries at assessment correlated with neonatal IGF-I levels (P = .03, r_s = -0.39). Tortuosity of veins correlated with a leptin/adiponectin ratio at assessment (P = .04, r_s = 0.37).

CONCLUSION

The findings suggest that being born MLP is associated with myopia, smaller optic disc and rim areas, and abnormal retinal vascularization. Furthermore, metabolic status and growth factors seem to have an impact on ocular development.

The rim area of the optic nerve head, assessed with Heidelberg retina tomography, is smaller in prematurely born children than in children born at term

PURPOSE

To examine the optic nerve head with Heidelberg tomography (HRT) in prematurely born school-age children and compare them to children born at term.

METHODS

Sixty-three 5-16-year-old children born with a gestational age (GA) of ≤32 weeks were included in the study and compared to 54 children of the same age, born at term. In the preterm group, 29 children had had retinopathy of prematurity (ROP) and nine children had neurological complications. The optic nerve head was assessed with HRT. Three measurements were performed, and the different topographic parameters were noted.

RESULTS

Rim area of the optic nerve was significantly smaller in prematurely born children than in children born at term. The mean difference was 0.146 mm² (p = 0.02). No difference between the groups was found regarding disc area or cup area. In the preterm group, both disc and rim areas were reduced with increasing GA. No correlations with birthweight, ROP or neurological complications were found.

CONCLUSION

Reduced rim area of the optic nerve head was found in preterm children of school age. Previous ROP or neurological complication did not influence the result, suggesting the preterm birth per se was the reason for the reduction. Establishing whether this finding was caused by disturbed maturation of the optic nerve or by injury of the axons, or a combination of the two, will require further research.

Clinical relevance of retinal structure in children with laser-treated retinopathy of prematurity versus controls - using optical coherence tomography

PURPOSE

We aimed to assess the macular anatomy using spectral domain optical coherence tomography (SD-OCT), in children born preterm who had laser-treated retinopathy of prematurity (ROP), and to investigate the relationship between structural changes in macula and visual function.

METHODS

Thirty-seven 3-8 years old children were included in the study in two groups: 20 children born preterm [(<34 weeks of gestation, birthweight (BW) <2000 g)] who had laser-treated ROP in the Neonatology Department, Municipal Clinical Emergency Hospital of Timisoara, Romania; and 17 controls (children born at term, without eye disease, matched for age and gender). Spectral domain optical coherence tomography (SD-OCT) imaging (Spectralis OCT) was performed at central fovea and 1 mm nasally.

RESULTS

In the ROP group (total 34 eyes), we included both eyes in 14 children, and on one eye in six other children. In the control group, both eyes for all 17 children were included. Central fovea thickness (CFT) was significantly higher in children born preterm and with laser-treated ROP as compared to controls (275 ± 34.8 μm versus 224 ± 27.2 μm; p < 0.001). The laser-treated eyes with ROP had mean best-corrected visual acuity (BCVA) = 0.19 logMAR (20/31 Snellen); 35% had BCVA ≥0.3 logMAR (20/40 Snellen). In receiver operating characteristic curve (ROC) analysis, with BCVA as static variable (category 0 = BCVA ≤0.3 logMAR), the CFT cut-off was 257 μm (sensitivity: 0.917; specificity: 0.661; area under the curve: 0.810, p = 0.001).

CONCLUSION

Years after the laser intervention, central fovea was significantly thicker in ROP laser-treated children born preterm when compared to controls. Central fovea thickness (CFT) correlated strongly and inversely with BW and gestational age (GA) at birth, while a CFT value above 257 μm was suggestive for suboptimal visual acuity. The proposed cut-off value needs to be validated in future larger studies.

Pre- and Postnatal Development of the Eye: A Species Comparison

In this review paper, literature data on pre- and postnatal eye development are compared between humans and nonclinical species that are commonly used for human safety assessment, namely, mouse, rat, rabbit, dog, minipig, and nonhuman primates. Some new data on rat and minipig ocular development are also included. This compiled information can be helpful for species selection in juvenile toxicity studies or assist in the interpretation of (non)clinical data during pediatric drug development. Despite some differences in developmental windows and anatomical peculiarities, such as the lack of a fovea centralis in nonprimate species or the presence of a nictitating membrane in some nonclinical species, the functioning and development of the eye is strikingly similar between humans and other mammals. As such, all commonly used nonclinical species appear to be relatively good models for human eye development, although some practical constraints such as size may be a limiting factor. Birth Defects Research 109:1540-1567, 2017. © 2017 Wiley Periodicals, Inc.