Relationship between Retinal Thickness Profiles and Visual Outcomes in Young Adults Born Extremely Preterm

Ophthalmic sequelae of prematurity in late childhood and adulthood: A review

Advances in the care of premature infants have resulted in unprecedented rates of survival of these infants into adulthood, including those born at very low gestational ages. Ophthalmologists have historically followed premature infants to assess for the presence of and potential need for treatment of retinopathy of prematurity. However, a growing body of literature suggests that the ophthalmic consequences of prematurity extended beyond retinopathy of prematurity and that ophthalmic sequelae of prematurity can endure through adulthood even among formerly preterm adults who were never diagnosed with retinopathy of prematurity. These abnormalities can include a range of both anterior segment and posterior segment sequelae, including higher rates of corneal aberrations, ocular hypertension, strabismus, foveal anomalies, and retinal tears and detachments. This review aims to summarise this literature, underscoring the importance of lifelong examinations and regular monitoring for these complications among adults who were born prematurely.

Visual outcomes and their association with grey and white matter microstructure in adults born preterm with very low birth weight

Individuals born with very low birth weight (VLBW; < 1500 g) have a higher risk of reduced visual function and brain alterations. In a longitudinal cohort study, we assessed differences in visual outcomes and diffusion metrics from diffusion tensor imaging (DTI) at 3 tesla in the visual white matter pathway and primary visual cortex at age 26 in VLBW adults versus controls and explored whether DTI metrics at 26 years was associated with visual outcomes at 32 years. Thirty-three VLBW adults and 50 term-born controls was included in the study. Visual outcomes included best corrected visual acuity, contrast sensitivity, P100 latency, and retinal nerve fibre layer thickness. Mean diffusivity, axial diffusivity, radial diffusivity, and fractional anisotropy was extracted from seven regions of interest in the visual pathway: splenium, genu, and body of corpus callosum, optic radiations, lateral geniculate nucleus, inferior-fronto occipital fasciculus, and primary visual cortex. On average the VLBW group had lower contrast sensitivity, a thicker retinal nerve fibre layer and higher axial diffusivity and radial diffusivity in genu of corpus callosum and higher radial diffusivity in optic radiations than the control group. Higher fractional anisotropy in corpus callosum areas were associated with better visual function in the VLBW group but not the control group.

Central macular morphology and optic nerve fibre layer thickness in young adults born premature and screened for retinopathy of prematurity

PURPOSE

To investigate central retinal morphology and optic retinal nerve fibre layer (RNFL) in prematurely born young adults and compare to term born controls.

MATERIALS AND METHODS

The participants were 59 prematurely born individuals, with a birthweight ≤1.500 g, and 44 term born controls, all 25-29 years of age. Visual acuity (VA) and contrast sensitivity (CS) were assessed. The retinal macular thickness, ganglion cell-inner plexiform layer (GC-IPL) thickness and RNFL thickness were assessed with Cirrus optical coherence tomography (OCT).

RESULTS

Central macular thickness was increased (mean 26.7 μm) in prematurely born individuals compared to controls. The macular GC-IPL was thinner (mean 3.84 μm), also when excluding those with previous retinopathy of prematurity (ROP) and those with neurological complications. Gestational age at birth and previous treatment of ROP were risk factors for a thicker macula, however, not for reduced GC-IPL. The average peripapillary RNFL was thinner (mean 4.61 μm) in the prematurely born individuals, also when excluding those with previous ROP and/or neurological complications. Within the prematurely born group, treated ROP was correlated with increased average RNFL. Further, both better VA and CS were associated with thinner optic nerve RNFL and thicker average GC-IPL.

CONCLUSION

Macular and optic nerve morphology were influenced by premature birth as assessed with OCT in adult individuals. Gestational age at birth and treatment for ROP seemed to affect central macular thickness, and treated ROP affected the peripapillary RNFL. Thus, retinal sequelae remained in adulthood.

Semi-Automated Analysis of Foveal Maturity in Premature and Full-Term Infants Using Handheld Swept-Source Optical Coherence Tomography

Purpose

To develop a semi-automated method of measuring foveal maturity using investigational handheld swept source-optical coherence tomography (SS-OCT).

Methods

In this prospective, observational study, full-term newborns and preterm infants undergoing routine retinopathy of prematurity screening were imaged. Semi-automated analysis measured foveal angle and chorioretinal thicknesses at the central fovea and average two-sided parafovea by three-grader consensus, correlating with OCT features and demographics.

Results

One hundred ninety-four imaging sessions from 70 infants were included (47.8% girls, 37.6 ± 3.4 weeks postmenstrual age, 26 preterm infants with birth weight 1057 ± 325.0, gestational age 29.0 ± 3.0 weeks). Foveal angle (96.1 ± 22.0 degrees) steepened with increasing birth weight (P = 0.003), decreasing inner retinal layer thickness, and increasing gestational age, postmenstrual age, and foveal and parafoveal choroidal thickness (all P < 0.001). Inner retinal fovea/parafovea ratio (0.4 ± 0.2) correlated with increasing inner foveal layers, decreasing postmenstrual age, gestational age, and birth weight (all P < 0.001). Outer retinal F/P ratio (0.7 ± 0.2) correlated with ellipsoid zone presence (P < 0.001), increased gestational age (P = 0.002), and birth weight (P = 0.003). Foveal (447.8 ± 120.6 microns) and parafoveal (420.9 ± 109.2) choroidal thicknesses correlated with foveal ellipsoid zone presence (P = 0.007 and P = 0.01, respectively), postmenstrual age, birth weight, gestational age, and decreasing inner retinal layers (all P < 0.001).

Conclusions

Foveal development is dynamic and partially observed through semi-automated analysis of handheld SS-OCT imaging.

Translational Relevance

Semi-automated analysis of SS-OCT images can identify measures of foveal maturity.

Macular thickness variation and interocular symmetry by gestational age in preterm school-age children

PURPOSE

To determine changes in macular thickness profile according to gestational age (GA) and to assess interocular symmetry in the macula of children born very preterm.

METHODS

In this cross-sectional study of preterm (n = 106) and term-born (n = 49) children 5-8 years of age at time of examination, optical coherence tomography was used to measure macula thickness as described in the ETDRS study. Statistical analyses included stratified and multivariable analyses.

RESULTS

Foveal minimum thickness increased with decreasing GA (P for trend, <0.001; 254.7 ± 32.8 μm for children born at 24-25 weeks and 193.2 ± 32.8 μm in term-born children). Inner and outer area thickness differed for term and preterm children, but did not vary with the degree of prematurity (inner area, 267.0 ± 11.0 μm for 24-25 weeks' GA and 305.4 ± 11.8 μm for term children [P < 0.01]; outer ring, 305.5 ± 10.4 μm in extreme preterm and 271.0 ± 10.4 μm in term children [P < 0.01]). Interocular asymmetry in preterm children was not significant for most areas; the largest interocular difference was found in the central zone (16.3 ±16.6 μm).

CONCLUSIONS

In our study cohort, children born very preterm examined at school age compared to term born children had greater central thickness with decreased foveal pit, decreased inner ring, and increased thickness of the outer ring. They did not show greater interocular asymmetry.

Peripapillary retinal nerve fibre layer thickness and macular ganglion cell layer volume in association with motor and cognitive outcomes in 11-year-old children born very preterm

PURPOSE

The purpose of the study was to study the association between retinal parameters and motor and cognitive outcomes in children born very preterm.

METHODS

This study is part of a prospective cohort study of very preterm infants (birth weight ≤ 1500 grams/gestational age < 32 weeks). At 11 years of age, the ophthalmological assessment included a retinal optical coherence tomography (OCT) examination of the peripapillary retinal nerve fibre layer (PRNFL) and the macular ganglion cell layer (GCL). The motor performance was assessed with the Movement Assessment Battery for Children-Second Edition (Movement ABC-2), and the cognitive outcome with the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV).

RESULTS

A total of 141 children were included. The mean (SD) average PRNFL was 95 μm (10.2 μm). The mean (SD) macular GCL volume was 0.34 mm³ (0.03 mm³ ). Higher PRNFL thickness associated with higher percentiles for total scores in the motor assessment (b = 0.5, 95% CI 0.1-0.8, p = 0.01) and higher macular GCL volume with higher scores in the cognitive assessment (b = 1.4, 95% CI 0.5-2.3, p = 0.002), also when adjusted for gender, birth weight z-score (birth weight in relation to gestational age) and major brain pathology at term.

CONCLUSION

The associations between higher average PRNFL thickness and better motor performance as well as higher macular GCL volume and better cognitive performance refer to more generalized changes in the brain of 11-year-old children born very preterm. Retinal OCT examinations might provide a deeper insight than mere eyesight in long-term neurodevelopmental follow-up of children born very preterm.

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.

Structural impact of arrested foveal development in children born extremely preterm without ROP at 6.5 years of age

Objectives

To characterize changes of foveal topography and microstructure of persisting foveal immaturity at 6.5 years of age in children born extremely preterm without retinopathy of prematurity (EPT-NoROP).

Methods

Images from previous optical coherence tomography examinations of 37 EPT-NoROP and 92 control eyes were selected from a regional cohort of the EXPRESS (Extremely Preterm Infants in Sweden) study. Thickness of ganglion cell + inner plexiform layer (GCL+), outer nuclear layer (ONL), retinal thickness (RT) at the foveal centre (FC), foveal depth (FD) and RT at the foveal rim were evaluated.

Results

Layer thickness of GCL+, ONL and RT was increased at FC in the EPT-NoROP group. More than two-thirds had thickness values above the control limit (control mean +2 SD) at FC (GCL + 68%, ONL 76%, and RT 68%), and 50% had reduced FD compared to controls. All parameters showed a high correlation within the EPT-NoROP group, whereas no or weaker correlation was seen in control eyes. The EPT-NoROP sub-groups, divided based on the control limit, did not differ in terms of associated factors such as gestational age, birth weight, visual acuity, and refraction.

Conclusions

Extreme prematurity without impact of ROP is associated with increased GCL + , ONL, and RT thickness at FC as well as reduced FD compared to full-term controls at age 6.5. This indicates that prematurity per se may have a profound effect on foveal anatomical maturation during the first months after birth. Our results suggest RT at FC to be a simple and useful measure of foveal anatomical immaturity.

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.

Insights into the developing fovea revealed by imaging

Early development of the fovea has been documented by histological studies over the past few decades. However, structural distortion due to sample processing and the paucity of high-quality post-mortem tissue has limited the effectiveness of this approach. With the continuous progress in high-resolution non-invasive imaging technology, most notably optical coherence tomography (OCT) and OCT angiography (OCT-A), in vivo visualization of the developing retina has become possible. Combining the information from histologic studies with this novel imaging information has provided a more complete and accurate picture of retinal development, and in particular the developing fovea. Advances in neonatal care have increased the survival rate of extremely premature infants. However, with enhanced survival there has been an attendant increase in retinal developmental complications. Several key abnormalities, including a thickening of the inner retina at the foveal center, a shallower foveal pit, a smaller foveal avascular zone, and delayed development of the photoreceptors have been described in preterm infants when compared to full-term infants. Notably these abnormalities, which are consistent with a partial arrest of foveal development, appear to persist into later childhood and adulthood in these eyes of individuals born prematurely. Understanding normal foveal development is vital to interpreting these pathologic findings associated with prematurity. In this review, we first discuss the various advanced imaging technologies that have been adapted for imaging the infant eye. We then review the key events and steps in the development of the normal structure of the fovea and contrast structural features in normal and preterm retina from infancy to childhood. Finally, we discuss the development of the perifoveal retinal microvasculature and highlight future opportunities to expand our understanding of the developing fovea.

RETINAL THICKNESS AND FOVEAL HYPOPLASIA IN ADULTS BORN PRETERM WITH AND WITHOUT RETINOPATHY OF PREMATURITY: The Gutenberg Prematurity Eye Study

PURPOSE

This study analyses whether prematurity, retinopathy of prematurity (ROP), and associated factors lead to altered foveal shape in adulthood and whether these alterations are associated with visual acuity.

METHODS

The Gutenberg Prematurity Eye Study is a German cohort study with a prospective ophthalmologic examination (participants aged 18-52 years) of individuals born preterm and full-term that were examined with spectral domain optical coherence tomography. Participants were grouped according to gestational age (GA) and postnatal ROP status. Multivariable linear regression analyses for foveolar retinal thickness, foveal hypoplasia, and posterior vitreous status were performed.

RESULTS

A total of 755 eyes of 414 preterm and full-term individuals were included (aged 28.6 ± 8.6 years, 233 female individuals). Central foveal retinal thickness increased as GA decreased. The prevalence of foveal hypoplasia was 2% (control group), 9% (GA 33-36), 18% (GA 29-32), 48% (GA ≤28), 50% (ROP without treatment), and 82% of eyes (with ROP requiring treatment). In multivariable analyses, central foveal thickness was independently associated with GA and advanced stages of ROP requiring treatment while foveal hypoplasia was only associated with GA. Posterior vitreous was more frequently visible as partially detached in full-term than in preterm individuals. Lower distant-corrected visual acuity correlated with increased foveolar thickness (rho = 0.08; P = 0.03) and with foveal hypoplasia (rho = 0.15, P < 0.001).

CONCLUSION

Our findings indicate that there are fetal origins affecting foveal shape, resulting in foveal hypoplasia potentially affecting the visual acuity in adulthood.

Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

Retinopathy of prematurity (ROP) is one of the main blinding diseases affecting preterm newborns and is classically considered a vascular disorder. The premature exposure to the extrauterine environment, which is hyperoxic in respect to the intrauterine environment, triggers a cascade of events leading to retinal ischemia which, in turn, makes the retina hypoxic thus setting off angiogenic processes. However, many children with a history of ROP show persistent vision impairment, and there is evidence of an association between ROP and neurosensory disabilities. This is not surprising given the strict relationship between neuronal function and an adequate blood supply. In the present work, we revised literature data evidencing to what extent ROP can be considered a neurodegenerative disease, also taking advantage from data obtained in preclinical models of ROP. The involvement of different retinal cell populations in triggering the neuronal damage in ROP was described along with the neurological outcomes associated to ROP. The situation of ROP in Italy was assessed as well.

Characterization of Foveal Development in Treatment-Naïve Extremely Preterm Infants

Objective

To characterize and quantify foveal development in treatment-naïve extremely preterm infants using optical coherence tomography.

Methods

In this cross-sectional study, eyes treated for retinopathy of prematurity before imaging were excluded. Inner retinal thickness and outer retina thickness at foveal center and foveal rim were assessed. Extremely preterm (EPT, <28 weeks gestational age) eyes were compared with infants more than 28 weeks of gestation using a multivariable dimension reduction analysis (principal component analysis) and a bilinear factor mode analysis (partial least square discriminant analysis) to determine group intervariability. Further analyses were performed to investigate the effects of gestation on foveal development.

Results

Twenty-six infants born at gestational ages ranging from 22 to 39 weeks were imaged between 32 and 80 weeks postmenstrual age. A principal component analysis and partial least squares discriminant analysis revealed that the foveal inner retina thickness was the main difference between EPT infants and non-EPT infants. This difference was reflected by comparing their inner retinal thickness over time (32-80 weeks postmenstrual age), which revealed a sustained thicker foveal inner retina for EPT infants when compared with non-EPT infants. The foveal pit seemed to be shallower in EPT infants when compared with non-EPT infants.

Conclusions

Twenty-eight weeks of gestation seems to be a critical timepoint for foveal development; EPT infants had altered foveal inner retinal development throughout early postnatal development, which led to a thicker foveal inner retina and a shallower foveal pit soon after birth.

Translational Relevance

Measuring untreated foveal parameters informs about the effects of prematurity on the fovea and provides a baseline when comparing with post-treatment foveal development.

Functional Ophthalmic Factors Associated With Extreme Prematurity in Young Adults

IMPORTANCE

Children born preterm (<37 weeks' gestation) have a higher risk of visual impairment and ocular morbidities compared peers born at full term. However, the long-term ocular sequelae in adulthood for those born extremely preterm (EP), who have the highest risk of neonatal retinopathy, are unknown.

OBJECTIVE

To evaluate visual function and ocular morbidity in young adults born EP compared with controls born full term.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study of a geographically based birth cohort in the UK and Ireland born from March 1 through December 31, 1995, included 128 participants aged 19 years (born at 22-25 weeks' gestation) and 65 age-matched controls born at full term. Statistical analysis was performed from March 1, 2020, to November 26, 2021.

EXPOSURES

Participants underwent eye examinations as part of a comprehensive outcome evaluation.

MAIN OUTCOMES AND MEASURES

Best-corrected visual acuity, refractive status, contrast sensitivity, color vision, prevalence of strabismus and nystagmus, and patient-reported visual function, measured using the Health Utilities Index Mark 3.

RESULTS

The study comprised 128 participants (256 eyes; 68 female participants [53%]; mean [SD] age, 19.3 [0.5] years) and 65 age-matched controls born at full term (130 eyes; 40 female participants [62%]; mean [SD] age, 19.2 [0.5] years). Compared with control eyes, the mean (SD) best-corrected visual acuity among eyes in the EP group was significantly worse (monocular vision: -0.06 [0.14] logMAR in the control group vs 0.14 [0.38] logMAR in the EP group; P < .001; binocular vision: -0.14 [0.15] logMAR in the control group vs 0.06 [0.37] logMAR in the EP group; P < .001). Participants in the EP group had a significantly higher prevalence of strabismus (36% [46 of 127] vs 0%; P < .001), abnormal ocular motility (15% [19 of 125] vs 0%; P < .001), and nystagmus (13% [16 of 127] vs 0%; P < .001) than the control group. No significant differences between participants in the EP group and controls were observed for refractive error, contrast sensitivity, color vision, or patient-reported visual function. Among the participants in the EP group, 48% of eyes (120 of 250) had no retinopathy of prematurity (ROP), 39% (98 of 250) had ROP not requiring neonatal treatment, and 13% (32 of 250) received cryotherapy or laser ablation for ROP. Within the EP group, there was no significant difference in binocular visual function parameters, prevalence of ocular morbidity, and patient-reported visual function by neonatal ROP status.

CONCLUSIONS AND RELEVANCE

Extreme prematurity is associated with an increased prevalence of visual and ocular deficits in young adulthood; this study suggests that, for individuals born EP, visual and ocular deficits appear to be partially independent of ROP status in the neonatal period but reports similar overall visual function.

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.

Association of Birth Weight With Foveolar Thickness in Adulthood: Results From a Population-Based Study

Purpose

Low birth weight (BW) is associated with alterations of foveal shape development in childhood-leading to an increased retinal thickness of the fovea. The aim of the present study was to assess whether BW has a long-term effect on foveal retinal thickness (RT) and is still present in adulthood.

Methods

In the German population-based Gutenberg Health Study (GHS), participants were examined with spectral-domain optical coherence tomography. The association between self-reported BW and RT in the foveolar and perifoveal locations was assessed. Multivariable linear regression analyses with adjustment for potential confounders and grading of foveal hypoplasia were performed.

Results

Overall, RT measurements and self-reported BW were available for 2,539 participants (1300 female, mean age 54.5 ± 9.7 years). The absolute foveolar RT was 239.6 ± 25.8 µm, 232.2 ± 20.1 µm and 234.8 ± 21.0 µm, respectively, in the low (<2500 g), normal (2500-4000 g) and high (>4000 g) BW groups (P < 0.001). After adjustment for confounders, an association was observed between lower BW and increased foveolar thickness (B = -0.35 [95% confidence interval {CI}: -0.49; -0.20] µm/100 g; P < 0.001), whereas only a weak association with RT was observed with the nasal (P = 0.010), temporal (P = 0.011), and inferior (P = 0.021) quadrants in the 1 mm distance, with no association in the 2 mm distance to the fovea. Foveal hypoplasia grade 1 was more frequent in the low BW group (6.8%) compared to the normal (0.9%) and high BW group (1.2%).

Conclusions

This study provides evidence of an association between lower BW and increased foveolar thickness and foveal hypoplasia, indicating that prenatal growth may affect macular morphology, which in turn may persist until adulthood and predispose to retinal disease later in life.

Foveal Differentiation and Inner Retinal Displacement Are Arrested in Extremely Premature Infants

Purpose

Children with a history of prematurity often have poorly developed foveae but when during development foveal differences arise. We hypothesize that the course of foveal development is altered from the time of preterm birth.

Methods

Eyes of 102 preterm infants undergoing retinopathy of prematurity screening examinations in the STudy of Eye imaging in Premature infantS (BabySTEPS) (NCT02887157) were serially imaged between 30 and 42 weeks postmenstrual age (PMA) using handheld optical coherence tomography systems. Total retinal thickness, inner retinal layer (IRL) thickness, and outer retinal layer (ORL) thickness were measured at the foveal center and parafovea. Foveal put depth, IRL thickness, and ORL thickness were compared between infants born at different gestational ages using mixed effects models.

Results

Foveal pit depth and IRL thickness were inversely related to gestational age; on average, the most premature infants had the thickest IRL and shallowest pits at all PMAs. Differences were evident by 30 weeks PMA and persisted through 42 weeks PMA. The foveal pits of the most premature infants did not progressively deepen, and the IRLs did not continue to thin with increasing chronological age.

Conclusions

Foveation in extremely preterm infants is arrested from the earliest observed ages and fails to progress through term equivalent age. The developmental displacement of the IRL from the foveal center into the parafovea does not occur normally after preterm birth. These observations suggest that foveal hypoplasia seen in children with history of prematurity is due to disturbances in foveal development that manifest within weeks of birth.

Comparison of foveal thickness in preschool children with a history of retinopathy of prematurity and laser photocoagulation or anti-vascular endothelial growth factor treatment: a prospective, longitudinal study

AIMS

To determine longitudinal differences in foveal thickness in preschool-aged patients with or without a history of type I retinopathy of prematurity (ROP).

METHODS

A study of 201 eyes, including 32 laser±intravitreal bevacizumab (IVB)-treated eyes, 37 IVB-treated eyes, 14 spontaneously regressed ROP eyes, and 118 age-matched controls were enrolled in this study. The retinal thicknesses (full, inner and outer) were measured in the foveal area at 6-month intervals four consecutive times by optical coherence tomography.

RESULTS

The foveal thicknesses among the four groups were similar at all four visits (all p>0.05) after gestational age (GA) adjustment and remained similar with no differences after the full retinal thickness was divided into inner and outer thicknesses (all p>0.05). The full and outer foveal thicknesses of premature children increased over time (0.17 μm/month and 0.17 μm/month; p=0.0001 and 0.0003, respectively), but the inner foveal thickness remained unchanged with time (0.002 μm/month; p=0.09). Moreover, the positive correlation with best-corrected visual acuity was stronger for outer foveal thickness than for inner foveal thickness (γ=0.281, p<0.0001 and γ=0.181, p<0.0001, respectively).

CONCLUSION

The thickness of fovea in laser±IVB-treated, IVB-treated, regressed ROP and preterm eyes showed no difference after GA adjustment. The whole and outer foveal thicknesses increased with time in preschool-aged children over a 1.5-year follow-up period, but the inner foveal thickness remained unchanged with time.

Cohort protocol: Guangzhou High-Risk Infant Cohort study

INTRODUCTION

Despite the increase in the survival rate of high-risk infants (HRIs) worldwide, the prevalence of motor and neurodevelopmental sequelae in such newborns has not shown concomitant improvement. Meanwhile, there are few cohorts that explore factors related to the development of HRIs in China. Therefore, the Guangzhou High-Risk Infant Cohort (GHRIC) has been designed to examine the complex relationships among a myriad of factors influencing growth and development in such children.

METHODS AND ANALYSIS

The GHRIC study is a prospective cohort study that by the year 2023 will enrol an estimated total of 3000 HRIs from Guangzhou Women and Children's Medical Center (GWCMC) in Guangzhou, China. This study is designed to assess the growth and cognitive characteristics of HRIs and the risk factors affecting their development and prognoses. Data on risk factors, neurodevelopmental and cognitive-function evaluations, laboratory results, and specimens will be collected and analysed. Information on perinatal and clinical interventions for these infants will also be recorded during regular follow-up visits until age 6.

ETHICS AND DISSEMINATION

The protocol for this study has been approved by the Research Ethics Committee of GWCMC, which accepted responsibility for supervising all of the aspects of the study (No. 2017102712). Study outcomes will be disseminated through conference presentations, peer-reviewed publications, the Internet and social media.

TRIAL REGISTRATION NUMBER

ChiCTR-EOC-17013236.

Foveal structure, function and microvascular morphology in school-age children with laser-treated retinopathy of prematurity

PURPOSE

The purpose of this retrospective case-control study was to evaluate the relationship between foveal structure, function, microvascular morphology and visual acuity in school-age children with laser-treated retinopathy of prematurity (ROP).

METHODS

Foveal structural parameters, including the central foveal thickness (CFT), inner retinal thickness (IRT) and outer retinal thickness (ORT), were measured on B-scans using an Optovue XR Avanti optical coherence tomography device. Foveal microvascular parameters, including the foveal avascular zone (FAZ), superficial capillary plexus-vessel density (SCP-VD) and deep capillary plexus-vessel density (DCP-VD), were measured on optical coherence tomography angiography with a scan size of 3 × 3. The P1 amplitudes and P1 implicit times were recorded by a multifocal electroretinogram with 61 elements.

RESULTS

Fifty-five eyes (26 eyes of school-age ROP children and 29 eyes of full-term controls) were analysed. The ROP children manifested a significantly smaller FAZ, higher SCP-VD and higher DCP-VD than the controls (p < 0.001). The CFT (p < 0.001), IRT (p < 0.001) and ORT (p = 0.001) were significantly increased in the ROP group. The P1 amplitudes in all five-ring retinal regions were significantly smaller in the ROP group (p < 0.001). Multivariable analysis indicated that best-corrected visual acuity was positively correlated with post-menstrual age (PMA) and negatively correlated with SCP-VD and CFT (R² = 0.529, p < 0.001, 0.043 and 0.020, respectively).

CONCLUSION

The foveal structure, function and microvascular morphology are affected in school-age children with laser-treated ROP. PMA, foveal structural anomalies and microvascular changes in ROP children were associated with impaired visual function.

POTENTIAL UTILITY OF FOVEAL MORPHOLOGY IN PRETERM INFANTS MEASURED USING HAND-HELD OPTICAL COHERENCE TOMOGRAPHY IN RETINOPATHY OF PREMATURITY SCREENING

PURPOSE

To investigate dynamic foveal morphology with postmenstrual age, in preterm infants with and without retinopathy of prematurity using hand-held optical coherence tomography, adjusting for gestational age (GA) and birthweight (BW).

METHODS

Prospective mixed cross-sectional/longitudinal observational study of 87 participants (23-36 weeks GA; n = 30 with, n = 57 without retinopathy of prematurity) using hand-held optical coherence tomography images (n = 278) acquired between 31 weeks and 44 weeks postmenstrual age excluding treated retinopathy of prematurity. Measurements included foveal width, area, depth, central foveal thickness, maximum slope, and parafoveal retinal thickness at 1,000 µm nasal and temporal to the central fovea.

RESULTS

Retinopathy of prematurity was significantly correlated with only foveal width in either GA or BW adjusted statistical models. In contrast, severity of prematurity (GA, BW) correlated with foveal area (P < 0.005), depth (P ≤ 0.001), and slope (P < 0.01), although central foveal thickness (P = 0.007) and parafoveal retinal thickness (P < 0.001) correlated with GA, but not with BW.

CONCLUSION

Foveal width is independent of GA and BW with potential in retinopathy of prematurity screening assessment using hand-held optical coherence tomography. Foveal morphology could be graded in prematurity during development, with possible implications for future management of preterm infants.

Macular thickness in children aged 3-6 years born preterm

PURPOSE

To determine macular thickness in 3- to 6-year-old children who were born preterm compared with age-matched controls born at term.

METHODS

Children 36-72 months of age born ≤34 weeks and age-matched control children born at term were included in this prospective case-control study. Macular thickness measurements obtained using spectral domain optical coherence tomography were compared between groups and correlations of macular thickness were investigated in the preterm group.

RESULTS

A total of 45 preterm children (median age, 57.7 months) and 44 controls (median, 56.1 months) were included. Central macula thickness (CMT) was significantly higher (P = 0.010) and perifoveal thickness was significantly lower (P = 0.029) in the preterm group compared with the control group. Moderate negative correlations of CMT with gestational age and birth weight were found in the preterm group. Best-corrected visual acuity was similar between groups and was not correlated with CMT in the preterm group. No significant difference in macular thickness was found between subjects who had retinopathy of prematurity and those who did not.

CONCLUSIONS

Compared with controls, children in the preterm group had thicker retinas at the central macula and thinner perifoveal retinas. These subtle alterations were not correlated with visual acuity and may be considered a reflection of prematurity.

Macular Ganglion Cell-Inner Plexiform Layer, Ganglion Cell Complex, and Outer Retinal Layer Thicknesses in a Large Cohort of Chinese Children

Purpose

The purpose of this study was to describe the normative values, distribution patterns, and correlated factors of macular ganglion cell-inner plexiform layer (GCIPL), ganglion cell complex (GCC), and outer retinal layer (ORL) thicknesses in Chinese children.

Methods

A sample of 3000 healthy children with different refractive status aged 6 to 19 years was consecutively examined. Demographics were recorded, and a comprehensive ophthalmic examination including refractive error and axial length (AL) was taken from all participants. The GCIPL, GCC, and ORL thicknesses were measured using swept source-optical coherence tomography (OCT), and multiple linear regression was used to determine which factors were associated with the thickness of each layer.

Results

The average thickness was 77.00 ± 4.78 μm (95% confidence interval [CI]: 69.56-84.56 μm) in the GCIPL, 107.68 ± 5.95 μm (95% CI: 98.45-117.21 μm) in the GCC, and 178.57 ± 9.02 μm (95% CI: 164.33-192.56 μm) in the ORL. Multiple regression analysis indicated that GCIPL thickness was associated with sex (β = 0.168, P < 0.001), age (β = 0.126, P < 0.001), axial length (β = -0.181, P < 0.001), and refractive error (β = 0.233, P < 0.001). Age (β = 0.154, P < 0.001), sex (β = 0.102, P < 0.001), and refractive error (β = 0.149, P < 0.001) were associated independently with GCC thickness after adjusting for the other factors. Furthermore, age (β = 0.100, P < 0.001), sex (β = 0.163, P < 0.001), AL (β = -0.283, P < 0.001), and refractive error (β = 0.207, P < 0.001) were the independent factors associated with ORL thickness.

Conclusions

The present study established a normative pediatric database for macular layer thicknesses in healthy Chinese children, advancing the ability of OCT in diseases diagnosis and monitoring among children.