Thinner Retinal Nerve Fiber Layer in Very Preterm Versus Term Infants and Relationship to Brain Anatomy and Neurodevelopment

Optic atrophy in prematurity: pathophysiology and clinical features

Optic atrophy is an important cause of visual impairment in children, and the aetiological profile has changed over time. Technological advancements led by neuroimaging of the visual pathway and imaging of the optic nerve with optical coherence tomography have accelerated the understanding of this condition. In the new millennium, an increasing prevalence of prematurity as a cause of optic atrophy in children has been highlighted. This new shift has been linked with increasing rates of premature births and improved neonatal survival of preterm infants. The available literature is limited to hospital and registry-based cohorts with modest sample sizes, methodological heterogeneity and selection bias limitations. Larger studies that are better designed are required to better understand the contribution of prematurity to the disease burden. In addition to considering other life-threatening aetiologies, screening for premature birth should be covered as part of a comprehensive history when evaluating a child with paediatric optic atrophy.

Early Single-Examination Optical Coherence Tomography Biomarkers for Treatment-Requiring Retinopathy of Prematurity

Purpose

Optical coherence tomography (OCT) is an emerging adjunct imaging modality to evaluate retinopathy of prematurity (ROP). From an 11-year research database, we identify early OCT biomarkers that predict treatment-requiring ROP (TR-ROP).

Methods

For preterm infants with acceptable OCT images at 32 ± 1 weeks postmenstrual age (PMA), we extracted the following measures: total retina, inner retinal layer (IRL), and outer retinal layer (ORL) thicknesses at the fovea and the parafovea, inner nuclear layer (INL) and choroidal thickness, parafovea/fovea (P/F) ratio, and presence of macular edema. Using univariable and multivariable logistic regression models, we evaluated the association between retinal and choroidal OCT measurements at 32 ± 1 weeks PMA and development of TR-ROP.

Results

Of 277 eyes (145 infants) with usable OCT images, 67 eyes had TR-ROP. Lower P/F ratio (P < 0.0001), thicker foveal IRL (P = 0.0001), and thinner choroid (P = 0.03) were associated with TR-ROP in univariable analysis, but lost significance of association when adjusted for gestational age and race. Absence of macular edema was associated with TR-ROP when adjusted for gestational age and race (P = 0.01). In 185 eyes without macular edema, P/F ratio was associated with TR-ROP in both univariable analysis (P < 0.0001) and multivariable analysis (P = 0.02) with adjustment for gestational age and race.

Conclusions

Presence of macular edema at 32 ± 1 weeks PMA in infants with lower gestational age may be protective against TR-ROP. In infants without macular edema, P/F ratio may be an early OCT biomarker for development of TR-ROP. Incorporation of early OCT biomarkers may be useful in prediction of TR-ROP.

Five degrees-of-freedom mechanical arm with remote center of motion (RCM) device for volumetric optical coherence tomography (OCT) retinal imaging

Handheld optical coherence tomography (HH-OCT) is gaining popularity for diagnosing retinal diseases in neonates (e.g. retinopathy of prematurity). Diagnosis accuracy is degraded by hand tremor and patient motion when using commercially available handheld retinal OCT probes. This work presents a low-cost arm designed to address ergonomic challenges of holding a commercial OCT probe and alleviating hand tremor. Experiments with a phantom eye show enhanced geometric uniformity and volumetric accuracy when obtaining OCT scans with our device compared to handheld imaging approaches. An in-vivo porcine volumetric image was also obtained with the mechanical arm demonstrating clinical deployability.

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.

Biphasic change in retinal nerve fibre layer thickness from 30 to 60 weeks postmenstrual age in preterm infants

BACKGROUND/AIMS

The optic nerve development during the critical postnatal weeks of preterm infants is unclear. We aimed to investigate the change of retinal nerve fibre layer (RNFL) in preterm infants.

METHODS

We used an investigational handheld optical coherence tomography (OCT) system to serially image awake preterm infants between 30 and 60 weeks postmenstrual age (PMA) at the bedside. We assessed RNFL thickness in the papillomacular bundle and nasal macular ganglion cell layer+inner plexiform layer (GCL+IPL) thickness. We applied a segmented mixed model to analyse the change in the thickness of RNFL and GCL+IPL as a function of PMA.

RESULTS

From 631 OCT imaging sessions of 101 infants (201 eyes), RNFL thickness followed a biphasic model between 30 and 60 weeks, with an estimated transition at 37.8 weeks PMA (95% CI: 37.0 to 38.6). RNFL thickness increased at 1.8 μm/week (95% CI: 1.6 to 2.1) before 37.8 weeks and decreased at -0.3 μm/week (95% CI: -0.5 to -0.2) afterwards. GCL+IPL thickness followed a similar biphasic model, in which the thickness increased at 2.9 μm/week (95% CI: 2.5 to 3.2) before 39.5 weeks PMA (95% CI: 38.8 to 40.1) and then decreased at -0.8 μm/week (95% CI: -0.9 to -0.6).

CONCLUSION

We demonstrate the feasibility of monitoring RNFL and GCL+IPL thickness from OCT during the postnatal weeks of preterm infants. Thicknesses follow a biphasic model with a transition age at 37.8 and 39.5 weeks PMA, respectively. These findings may shed light on optic nerve development in preterm infants and assist future study designs.

Peripapillary Retinal Nerve Fiber Layer Thickness Changes in Preterm Children with or without Retinopathy of Prematurity History

Purpose

To investigate peripapillary retinal nerve fiber layer (pRNFL) thickness changes in preterm children with or without retinopathy of prematurity (ROP) history compared to full-term children.

Methods

A retrospective comparative cohort study assessing pRNFL thickness was completed in children aged 4-8 years. Four groups of children were included (n = 30 each group): children with a history of ROP who were treated with intravitreal bevacizumab, children with ROP who received no treatment, and preterm children without ROP compared to age- and gender-matched full-term children.

Results

A total of 120 eyes from 120 children were enrolled in this study. Both treated and regressed ROP children showed a significantly thinner pRNFL in the nasal quadrant compared to full-term children (P = 0.017 and P = 0.008, respectively). The pRNFL in the superior quadrant of treated ROP children was thinner than the preterm and control groups (P = 0.015 and P = 0.023, respectively), whereas the inferior quadrant of treated ROP children was thinner than the preterm group alone (P = 0.008). The pRNFL thickness in the temporal quadrant was comparable between groups (P = 0.129). The average spatial distribution profile of pRNFL thickness in treated ROP children was significantly thinner than in the preterm group (P = 0.041).

Conclusion

pRNFL thickness is significantly altered in children with a prior history of treated ROP with thinning of the nasal and superior quadrants compared to full-term children.

Preterm infant retinal OCT markers of perinatal health and retinopathy of prematurity

The increasing survival of preterm infants has led to the importance of improving long-term outcomes associated with preterm birth. Antenatal and perinatal insults not only impact mortality, but also long-term disability. While in the intensive care nursery, preterm infants are also exposed to various stressors that lead to long-term cognitive deficits. It is therefore critical to identify early, low-stress, non-invasive biomarkers for preterm infant health. Optical coherence tomography (OCT) is a powerful imaging modality that has recently been adapted to the infant population and provides noninvasive, high-resolution, cross-sectional imaging of the infant eye at the bedside with low stress relative to conventional examination. In this review we delve into discussing the associations between preterm systemic health factors and OCT-based retinal findings and their potential contribution to the development of non-invasive biomarkers for infant health and for retinopathy of prematurity (ROP).

The impact of perinatal brain injury on retinal nerve fiber layer thickness and optic nerve head parameters of premature children

PURPOSE

This study aims to evaluate the impact of birth weight (BW), gestational age (GA), retinopathy of prematurity (ROP), and perinatal brain injury (PBI) on optic nerve head (ONH) parameters and nerve fiber layer thickness (RNFLT) in preterm children.

METHODS

ONH parameters and RNFLT were examined prospectively in 5-15-year-old preterm and full-term children with RTVue-100 OCT (Optovue, USA). The parameters of the two groups were compared and possible influences of BW, GA, ROP, and PBI analyzed in preterm children.

RESULTS

In total, 51 full-term and 55 preterm children were included. The mean age was 9.98 ± 3.4 years in full-term and 10.0 ± 2.5 years in preterm children. The mean GA in preterm children was 29.6 ± 3.8 weeks with a BW of 1523 ± 732 g. RNFLT was significantly lower in preterm than in full-term children in all but temporal quadrants. Cup area, volume, cup/disc area ratio, and horizontal cup/disc ratio (CDR) were significantly larger and rim area significantly thinner in preterm children. GA was positively correlated with superior, nasal, and overall RNFLT and negatively correlated with cup area, volume, and horizontal CDR. ROP stage correlated negatively with superior and nasal RNFLT. PBI was the only significant predicting factor for RNFL thinning in all but temporal quadrant in multiple regression analysis. Preterm children with PBI had a significantly larger optic cup (CDR 0.70 ± 0.33 vs. 0.37 ± 0.27) and thinner optic rim.

CONCLUSION

PBI correlated strongest with RNFL thinning, a thinner optic rim, and a larger optic cup in preterm children and should be evaluated in each patient to prevent incorrect diagnosis like glaucoma.

Ocular Pigmentation Impact on Retinal Versus Choroidal Optical Coherence Tomography Imaging in Preterm Infants

Purpose

To evaluate the association of fundus pigmentation with the visibility of retinal versus choroidal layers on optical coherence tomography (OCT) in preterm infants.

Methods

For infants enrolled in BabySTEPS, ophthalmologists recorded fundus pigmentation (blond, medium, or dark) at the first retinopathy of prematurity (ROP) examination. Bedside OCT imaging was performed at each examination, and a masked grader evaluated all OCT scans from both eyes of each infant for visibility (yes/no) of all retinal layers and of the chorio-scleral junction (CSJ). Multivariable logistic regression was used to assess associations between fundus pigmentation and visibility of all retinal layers and CSJ, controlling for potential confounders (i.e., birth weight, gestational age, sex, OCT system, pupil size, and postmenstrual age at imaging).

Results

Among 114 infants (mean birth weight, 943 grams; mean gestational age, 27.6 weeks), 43 infants (38%) had blond, 56 infants (49%) had medium, and 15 infants (13%) had dark fundus pigmentation. Of 1042 scans, all retinal layers were visible in 977 (94%) and CSJ in 895 (86%). Pigmentation was not associated with retinal layer visibility (P = 0.49), but medium and dark pigmentation were associated with decreased CSJ visibility (medium: odds ratio [OR] = 0.34, P = 0.001; dark: OR = 0.24, P = 0.009). For infants with dark pigmentation, retinal layer visibility increased (OR = 1.87 per week; P ≤ 0.001) and CSJ visibility decreased (OR = 0.78 per week; P = 0.01) with increasing age.

Conclusions

Although fundus pigmentation was not associated with the visibility of all retinal layers on OCT, darker pigmentation decreased CSJ visibility, and this effect increased with age.

Translational Relevance

The ability of bedside OCT to capture retinal layer microanatomy in preterm infants, regardless of fundus pigmentation, may represent an advantage over fundus photography for ROP telemedicine.

[Ophthalmological long-term sequelae of premature birth-Persisting into adulthood : Eye development and premature birth anamnesis]

BACKGROUND

Premature birth and the postnatal occurrence of retinopathy of prematurity (ROP) are the main risk factors for reduced visual acuity and blindness in childhood and adolescence accompanied by numerous morphological ocular changes.

OBJECTIVE

It can be assumed that these alterations persist throughout life and could represent a potential risk factor for ocular diseases, although little is known to date about the long-term effects of prematurity on ocular function and morphology in adulthood.

METHODS

The aim of the present study is to review the literature on the long-term effects of prematurity and associated factors.

RESULTS

Individuals born preterm exhibit reduced visual acuity, lower visual quality of life, and steeper corneal configuration in adulthood. Furthermore, individuals with advanced ROP and need for ROP treatment are at particularly high risk for myopic refractive error, the occurrence of strabismus, and increased lens opacities with thicker lenses. Low gestational age is associated with thinner peripapillary retinal nerve fiber layer thickness as well as thicker foveal retinal thickness and more frequent occurrence of foveal hypoplasia. In addition, data from the Gutenberg Health Study showed that low birth weight as a surrogate marker for prematurity and fetal growth restriction are associated with an increased prevalence of age-related macular degeneration as well as more frequently with diabetes and consequently diabetic retinopathy.

DISCUSSION

Premature birth and associated factors lead to life-long functional and morphological ocular changes. There is evidence that this can lead to retinal diseases later in life and thus, there appear to be fetal origins for adult eye disease. This may have implications for ophthalmic controls and its intervals in adulthood.

Retinal and peripapillary vascular deformations in prematurely born children aged 4-12 years with a history of retinopathy of prematurity

In this study, foveal, parafoveal, peripapillary anatomical, and microvascular anomalies in prematurely born children aged 4-12 years with a history of retinopathy of prematurity (ROP) were evaluated. Seventy-eight eyes of 78 prematurely born children ([tROP]: ROP with laser treatment, [srROP]: spontaneously regressed ROP) and 43 eyes of 43 healthy children were included. Foveal and peripapillary morphological parameters (including ganglion cell and inner plexiform layer (GCIPL) thickness, peripapillary retinal nerve fiber layer (pRNFL) thickness) and vasculature parameters (including foveal avascular zone area, vessel density from superficial retinal capillary plexus (SRCP), deep retinal capillary plexus (DRCP), and radial peripapillary capillary (RPC) segments) were analyzed. Foveal vessel densities in SRCP and DRCP were increased and parafoveal vessel densities in SRCP and RPC segments vessel density were decreased in both ROP groups compared with those of control eyes. The best-corrected visual acuity was negatively correlated with pRNFL thickness in the tROP group. Refractive error was negatively correlated with vessel density of RPC segments in the srROP group. In children born preterm with a history of ROP, it was found that foveal, parafoveal, and peripapillary structural and vascular anomalies and redistribution were accompanied. These retinal vascular and anatomical structure anomalies showed close relationships with visual functions.

Associations between systemic health and retinal nerve fibre layer thickness in preterm infants at 36 weeks postmenstrual age

BACKGROUND/AIMS

Neonatal insults from systemic diseases have been implicated in the pathway of impaired neurodevelopment in preterm infants. We aimed to investigate the associations between systemic health factors and retinal nerve fibre layer (RNFL) thickness in preterm infants.

METHODS

We prospectively enrolled infants and imaged both eyes at 36±1 weeks postmenstrual age (PMA) using a hand-held optical coherence tomography system at the bedside in the Duke intensive care nurseries. We evaluated associations between RNFL thickness and 29 systemic health factors using univariable and multivariable regression models.

RESULTS

83 infants with RNFL thickness measures were included in this study. Based on the multivariable model, RNFL thickness was positively associated with infant weight at imaging and was negatively associated with sepsis/necrotising enterocolitis (NEC). RNFL thickness was 10.4 µm (95% CI -15.9 to -4.9) lower in infants with than without sepsis/NEC in the univariable analysis (p<0.001). This difference remained statistically significant after adjustment for confounding variables in various combinations (birth weight, birthweight percentile, gestational age, infant weight at imaging and growth velocity). A 250 g increase in infant weight at imaging was associated with a 3.1 µm (95% CI 2.1 to 4.2) increase in RNFL thickness in the univariable analysis (p<0.001).

CONCLUSIONS

Low infant weight and sepsis/NEC were independently associated with thinner RNFL in preterm infants at 36 weeks PMA. To our knowledge, this study is the first to suggest that sepsis/NEC may affect retinal neurodevelopment. Future longitudinal studies are needed to investigate this relationship further.

Peripapillary Retinal Nerve Fiber Layer Thickness in Adults Born Extremely, Very, and Moderately Preterm With and Without Retinopathy of Prematurity: Results From the Gutenberg Prematurity Eye Study (GPES)

PURPOSE

This study investigated whether prematurity and associated factors or prenatal growth restriction have long-term effects on the peripapillary retinal nerve fiber layer (pRNFL) in adulthood.

DESIGN

Retrospective cohort study.

METHODS

The Gutenberg Prematurity Eye Study (GPES) is a retrospective cohort study with a prospective ophthalmologic examination in Germany. Selected individuals born term and preterm (age 18-52 years) were examined with spectral-domain optical coherence tomography (SD-OCT) in adulthood, and perinatal medical charts were reviewed. The pRNFL thickness was measured using SD-OCT. Univariate and multivariable linear regression analyses were conducted to investigate associations between pRNFL and gestational age (GA; categorical), birth weight percentile (categorical), retinopathy of prematurity (ROP) occurrence, and treatment and other perinatal parameters with adjustment for age, sex, and spherical equivalent.

RESULTS

In total, 766 eyes of 406 preterm and full-term individuals were included (mean age 28.4 ± 8.6 years, 228 females). After adjustment for age, sex, and spherical equivalent, global pRNFL thinning was associated with moderate (GA = 33-36 wk, β = -4.68, P < .001), very (GA = 29-32 wk, β = -5.72, P < .001), and extreme (GA ≤ 28 wk, β = -8.69, P < .001) prematurity but not with low birth weight percentile (<25th percentile, P = .9) and ROP occurrence (P = .9) in multivariable analysis. ROP treatment was associated with increased pRNFL in the temporal sector (P = .002). Maternal smoking during pregnancy showed an association with pRNFL thinning (P = .07).

CONCLUSION

Our data indicate that the more preterm individuals are born the more pRNFL thinning occurs, whereas prenatal growth restriction and postnatal occurrence of ROP show less effects on pRNFL thickness. Furthermore, individuals with severe ROP with treatment but not lower ROP stages without treatment showed an increased temporal pRNFL thickness.

Adults Born Small for Gestational Age at Term Have Thinner Peripapillary Retinal Nerve Fiber Layers Than Controls

PURPOSE

Prenatal growth restriction is associated with impaired neurodevelopment in childhood. This study investigated the effects of being born small for gestational age (SGA) on peripapillary retinal nerve fiber layer (pRNFL) thickness in adults born at term.

METHODS

A retrospective cohort study was conducted with a prospective ophthalmologic examination of participants born at full-term (gestational age ≥37 weeks) between 1969 and 2002. All participants were examined with spectral-domain optical coherence tomography and grouped according to their birth weight in correlation to gestational age as former moderate (birth weight (BW) percentile 3rd to <10th) and severe SGA (<3rd percentile), normal (10th-90th percentile, AGA), and moderately (>90th to 97th percentile) and severely (>97th percentile) large for gestational age (LGA) adults (18 to 52 years).

RESULTS

Overall, 547 eyes of 285 individuals (age 29.9±9.4 years, 151 females) born at term were included. Multivariable regression analyses revealed a strong association between a lower global pRNFL thickness in the severe SGA (B=-8.99 [95%-CI: -12.68; -5.30] µm; p<0.001) and in the moderate SGA groups (B=-6.40 [95%-CI: -10.29; -2.50] µm; p=0.001) compared to the reference AGA group.

CONCLUSION

Our results indicate that restricted fetal growth affects neurologic tissue development of the optic nerve head, particularly in individuals born severely SGA at term. This indicates that fetal growth restriction may exert disturbances in the development of neurologic tissue, which persists in adulthood.

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.

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.

Association Between Retinal Microanatomy in Preterm Infants and 9-Month Visual Acuity

Importance

Preterm infants are at risk for poor visual acuity (VA) outcomes, even without retinal problems on ophthalmoscopy. Infant retinal microanatomy may provide insight as to potential causes.

Objective

To evaluate the association between preterm infant retinal microanatomy and VA at 9 months' corrected age.

Design, Setting, and Participants

This prospective observational study took place from November 2016 and December 2019 at a single academic medical center and included preterm infants enrolled in Study of Eye Imaging in Preterm Infants (BabySTEPS). Infants were eligible for enrollment in BabySTEPS if they met criteria for retinopathy of prematurity (ROP) screening, were 35 weeks' postmenstrual age or older at the time of first OCT imaging, and a parent or guardian provided written informed consent. Of 118 infants enrolled in BabySTEPS, 61 were included in this analysis. Data were analyzed from March to April 2021.

Exposures

Bedside optical coherence tomography (OCT) imaging at a mean (SD) 39.85 (0.79) weeks' postmenstrual age and monocular grating VA measurement at 9 months' corrected age.

Main Outcomes and Measures

Presence and severity of macular edema and presence of ellipsoid zone at the fovea measured by extracting semiautomated thicknesses of inner nuclear layer, inner retina, and total retina at the foveal center; choroid across foveal 1 mm; and retinal nerve fiber layer (RNFL) across the papillomacular bundle (PMB). Pearson correlation coefficients were calculated and 95% CIs were bootstrapped for the association between retinal layer thicknesses and continuous logMAR VA. Associations were analyzed between retinal microanatomy and normal (3.70 cycles/degree or greater) vs subnormal grating VA at 9 months' corrected age using logistic regression and with logMAR VA using linear regression, adjusting for birth weight, gestational age, and ROP severity at the time of OCT imaging and accounting for intereye correlation using generalized estimating equations.

Results

The mean (SD; range) gestational age of included infants was 27.6 (2.8; 23.0-34.6) weeks, and mean (SD; range) birth weight was 958.2 (293.7; 480-1580) g. In 122 eyes of 61 infants, the correlations between retinal layer thicknesses and logMAR VA were as follows: r, 0.01 (95% CI, -0.07 to -0.27) for inner nuclear layer; r, 0.19 (95% CI, 0.01 to 0.35) for inner retina; r, 0.15 (95% CI, -0.02 to 0.31) for total retina; r, -0.22 (95% CI, -0.38 to -0.03) for choroid; and r, -0.27 (95% CI, -0.45 to 0.10) for RNFL across the PMB. In multivariable analysis, thinner RNFL across the PMB (regression coefficient, -0.05 per 10-μm increase in RNFL thickness; 95% CI, -0.10 to -0.01; P = .046) and prior ROP treatment (regression coefficient, 0.33 for ROP treatment; 95% CI, 0.11 to 0.56; P = .003) were independently associated with poorer 9-month logMAR VA.

Conclusions and Relevance

In preterm infants, RNFL thinning across the PMB was associated with poorer 9-month VA, independent of birth weight, gestational age, need for ROP treatment, and macular microanatomy. Evaluation of RNFL thickness using OCT may help identify preterm infants at risk for poor vision outcomes.

Optic Nerve Head Morphology in Adults Born Extreme, Very, and Moderate Preterm With and Without Retinopathy of Prematurity: Results From the Gutenberg Prematurity Eye Study

PURPOSE

This study aimed to investigate associations of prematurity and associated factors with optic disc morphology in adulthood as long-term effects.

DESIGN

Retrospective cohort study.

METHODS

The Gutenberg Prematurity Eye Study (GPES) is a retrospective cohort study with a prospective ophthalmologic examination of adults (age 18-52 years) in Germany. In every participant, photography of optic discs was performed with a nonmydriatic fundus camera, and optic disc measurements were done manually. The vertical cup-to-disc ratio (VCDR), optic disc area, and torted and tilted discs were assessed and exploratively compared between individuals with retinopathy of prematurity (ROP) with treatment, an ROP group without treatment and groups of individuals of different gestational ages (GAs) without ROP (GA ≤ 28 weeks, GA 29-32 weeks, GA 33-36 weeks, and GA ≥ 37 weeks [control group]).

RESULTS

The present analysis included 743 eyes of 393 individuals born preterm and full-term (aged 28.4 ± 8.6 years, 223 females). The VCDR was significantly larger in subjects with a GA ≤28 weeks without ROP compared to the full-term control group (GA ≥37 weeks) (P = .002). Subjects with ROP without treatment also had a larger VCDR (P = .001), whereas those with ROP treatment showed a smaller VCDR than the full-term control group (P = .02). In addition, individuals with ROP treatment were more likely to have a torted disc than the full-term control group (P = .006).

CONCLUSION

The present study provides evidence that individuals born extremely preterm have increased VCDR in adulthood. Furthermore, these results indicate that fetal origins affect optic disc morphology until adulthood, which might predispose the affected individual to degenerative optic nerve head diseases or being incorrectly diagnosed to glaucoma.

Integrated Visualization Highlighting Retinal Changes in Retinopathy of Prematurity From 3-Dimensional Optical Coherence Tomography Data

Importance

Early diagnosis of plus disease is critical in the management of retinopathy of prematurity (ROP). However, there is substantial interexpert disagreement in the diagnosis of plus disease based on vascular changes alone. Information derived from optical coherence tomography (OCT) may help characterize the severity of vascular and structural abnormalities in ROP.

Objective

To describe integrated visualization of 3-dimensional (3-D) data from investigational swept-source OCT optimized to delineate retinal vascular and microanatomical features in eyes with and without ROP.

Design, Setting, and Participants

This cross-sectional, observational report of OCT was captured in the prospective Study of Eye Imaging in Preterm Infants (BabySTEPS) designed in July 2016 at the Duke Health Intensive Care Nursery. Between December 2018 and August 2019, 2 preterm infants born at 24 and 30 weeks' gestation were enrolled, underwent ROP screening, and were imaged at those screening visits. Data at 36 weeks' postmenstrual age were analyzed via this visualization developed between September 2020 and May 2021.

Main Outcomes and Measures

Superimposed en face retinal vascular shadow view (RVSV) montages and thickness maps were used along with OCT B-scans to evaluate retinal vasculature and cross-section in eyes with and without ROP.

Results

In the right eyes of 2 infants, 3-D data were integrated and visualized from investigational bedside OCT imaging at the posterior pole. In the infant who developed type 1 ROP, RVSV-OCT confirmed presence of dilated and tortuous posterior pole vessels, shunting, and incomplete perifoveal vascular development, resulting in a temporal notch of avascular retina in zone 1. The thickness map revealed irregular pockets of thickening and thinning, and integrated visualization outlined the demarcation between thicker vascularized retina and thinner avascular fovea and presence of extraretinal neovascularization overlying elevated vessels in the superior arcades. In the infant without ROP (stage 0), RVSV-OCT revealed no abnormal vascular findings at the posterior pole. The integrated visualization showed a dome-shaped retinal thickening at the fovea, which was confirmed as macular edema.

Conclusions and Relevance

In 2 preterm infants in BabySTEPS, 3-D visualization of OCT findings during the ongoing ROP disease process demonstrated supplemental information about the retinal vasculature and microanatomy that can be useful to clinicians. These additional details provided by OCT could be integrated into future ROP screening methods with artificial intelligence-based analytics.

Evaluation of Ocular Biometric and Optical Coherence Tomography Parameters in Preterm Children Without Retinopathy of Prematurity

Purpose

To evaluate and compare biometric and optical coherence tomography parameters of ocular structures in preterm children without retinopathy of prematurity with term children.

Methods

A cross-sectional, comparative study was carried out from 2018 to 2019. In this study, 124 eyes of 62 preterm children were compared with 132 eyes of 66 term children aged between 7 and 9 years. Preterm children were born at 28 to 32 weeks with a birth weight of less than 2 kg with no ocular abnormalities, and term children were delivered at 37 or greater weeks and had a birth weight of 2 kg or more. All children had standardized eye examinations, and ocular measurements using the anterior and posterior segment optical coherence tomography and laser interferometry.

Results

Significant differences were found between the term and preterm children for horizontal corneal diameter: median, 12.2 mm (interquartile range [IQR], 0.4) versus median, 12.1 mm (IQR, 0.6; P < 0.005); axial length median, 23.03 mm (IQR, 1.10 mm) versus median, 22.88 mm (IQR, 1.35 mm; P = 0.017); global retinal nerve fiber layer thickness: mean ± standard deviation, 106.54 ± 10.23 µm versus mean ± standard deviation, 103.65 ± 10.178 µm (P = 0.024); temporal retinal nerve fiber layer thickness: median, 76 µm (IQR, 16 µm) vs median, 74 µm (IQR, 14 µm; P = 0.012); and the angle opening distance at 750 µm nasal: mean ± standard deviation, 0.815 ± 0.23 mm vs mean ± standard deviation, 0.749 ± 0.21 mm (P = 0.016). No significant differences were found for other anterior segment and angle parameters.

Conclusions

Preterm children with no retinopathy of prematurity have smaller eyes and thinner retinal nerve fiber layers than their term counterparts. The long-term effects of interrupted ocular growth in preterm children should be further studied into adulthood.

Translational Relevance

Preterm children maybe more predisposed to certain eye conditions because they have smaller eyes, and thus should be further monitored clinically.

[Modern possibilities of diagnosing lesions of the visual analyzer in perinatal lesions of the central nervous system in full-term and premature infants]

The article provides an overview of current neuro-ophthalmological diagnostic capabilities in patients with perinatal lesions. The main attention is paid to the diagnosis of patients with periventricular leukomalacia and peri- and intraventricular hemorrhages. The most relevant methods of neuro-ophthalmological diagnosis in hypoxic-ischemic CNS lesions are covered. The functions and peculiarities of blood supply of the germinal matrix are described. The importance of the use of optical coherence tomography and visual evoked potential recording in full-term and premature infants with visual pathway and/or visual cortex lesions in brain lesions is discussed. The conclusion emphasizes the need for an interdisciplinary approach in the examination of children with perinatal CNS lesions.

Visuopathy of prematurity: is retinopathy just the tip of the iceberg?

Research on retinopathy of prematurity (ROP) focuses mainly on the abnormal vascularization patterns that are directly visible for ophthalmologists. However, recent findings indicate that children born prematurely also exhibit changes in the retinal cellular architecture and along the dorsal visual stream, such as structural changes between and within cortical areas. Moreover, perinatal sustained systemic inflammation (SSI) is associated with an increased risk for ROP and the visual deficits that follow. In this paper, we propose that ROP might just be the tip of an iceberg we call visuopathy of prematurity (VOP). The VOP paradigm comprises abnormal vascularization of the retina, alterations in retinal cellular architecture, choroidal degeneration, and abnormalities in the visual pathway, including cortical areas. Furthermore, VOP itself might influence the developmental trajectories of cerebral structures and functions deemed responsible for visual processing, thereby explaining visual deficits among children born preterm.

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.

Systemic Factors Associated with a Thinner Choroid in Preterm Infants

Purpose

To identify systemic health factors associated with a thinner choroid, which has been hypothesized as a cause of poor visual outcomes in low–birth weight infants.

Design

The prospective, observational Study of Eye Imaging in Preterm Infants (BabySTEPS) enrolled infants recommended for retinopathy of prematurity screening based on the American Association of Pediatrics guidelines.

Participants

Infants who underwent imaging with investigational handheld OCT at 36 ± 1 weeks’ postmenstrual age (PMA) as part of BabySTEPS.

Methods

Average choroidal thickness was measured across the central subfoveal 1 mm. We concurrently collected maternal and infant clinical health data. Univariate and multivariate linear regression analyses were performed to evaluate factors associated with choroidal thickness. The left and right eyes showed similar thicknesses, so their average was used for analysis.

Main Outcomes Measures

Association between infant health factors and subfoveal choroidal thickness.

Results

Subfoveal choroidal thickness was measurable in 82 of 85 infants and 94% of eyes. Mean choroidal thickness was 231 ± 78 μm. In the univariate analysis, a thinner choroid was associated with decreased growth velocity (P < 0.001), lower birth weight (P < 0.001), smaller head circumference (P < 0.001), younger gestational age (P = 0.01), the presence of patent ductus arteriosus (P = 0.05), sepsis or necrotizing enterocolitis (P = 0.03), bronchopulmonary dysplasia (P = 0.03), pulmonary interstitial emphysema (P = 0.002), more days on oxygen support (P < 0.001), and being on oxygen support at 36 weeks (P < 0.001) and at the time of imaging (P < 0.001). In the multivariate analysis, growth velocity (P = 0.002) and oxygen support at the time of OCT imaging (P = 0.004) remained associated with a thinner choroid.

Conclusions

A thinner choroid is associated independently with growth velocity and receiving oxygen support at 36 ± 1 weeks PMA. This suggests that choroidal development in preterm infants may be related to growth rate in the first weeks of life and the prolonged use of supplemental oxygen. Longitudinal studies are needed to assess differences in choroidal thickness before 36 weeks PMA and to assess their impact on visual outcomes.

[Impact of prematurity on the optic nerve]

INTRODUCTION

Thanks to the progress made in the past few years in pediatric intensive care as well as the increased survival of preterm infants, the consequences of premature birth are increasingly well documented. With regard to ophthalmologic complications, retinopathy of prematurity is well described, but the optic nerve may also be affected. The goal of this study is to compare the optic nerves of preterm infants as a function of their gestational period with a control group of the same age.

MATERIALS AND METHODS

We conducted a case-control study pairing a full-term infant with each preterm infant. Inclusion criteria were: any child from 5- to 10-years-old, separated into three sub-groups according to their degree of prematurity. Variables were: cup/disc ratio, ocular biometry, intraocular pressure and RNFL thickness.

RESULTS

Thirty-seven preterm infants and 37 controls were included in the study. The mean age at the time of inclusion was 7.05 years for the preterm group and 7.19 years for the control group. No significant difference was observed in axial length or spherical equivalent (P=0.31 and P=0.98, respectively). No significant difference was observed in pachymetry or intraocular pressure (P=0.28 and P=0.22, respectively). We observed a significant increase of 0.1 in the cup/disc ratio of the preterm group compared to the control group (P<0.05). The preterm group cup/disc ratio was 0.36 versus 0.27 for the control group. No significant difference was observed in the 7 quadrants of RNFL between the two groups. However, when comparing infants born before 28 weeks gestation with the control group, we observed a mean decrease of 14.5 microns in the superior temporal sector (P=0.04), a 9 micron decrease in the global thickness G (P=0.03) and a 12.7 micron decrease in the nasal sector (P=0.01).

CONCLUSIONS

In the case of the studied children (aged 5 to 10), the reduced RNFL fiber thickness is a phenomenon dependent essentially on the stage of prematurity. It would be useful to follow these preterm populations over the long term and to compare them to a matched control group to be able to obtain functional results.

Birth Weight Is a Significant Predictor of Retinal Nerve Fiber Layer Thickness at 36 Weeks Postmenstrual Age in Preterm Infants

PURPOSE

To assess retinal nerve fiber layer (RNFL) thickness in preterm infants.

DESIGN

Prospective observational study.

METHODS

We imaged 83 awake infants (159 eyes) at 36 ± 1 weeks postmenstrual age (defined as the time elapsed between the first day of the last maternal menstrual period and the time at imaging) using a handheld optical coherence tomography (OCT) system at the bedside. Blinded graders semi-automatically segmented RNFL in the papillomacular bundle (-15 to +15° relative to the fovea-optic nerve axis). We correlated RNFL thickness and 7 characteristics of interest (sex, race, ethnicity, gestational age, birth weight, stage of retinopathy at prematurity, and presence of pre-plus or plus disease) via univariable and multivariable regressions.

RESULTS

RNFL was 3.4 μm thicker in the right eyes than in the left eyes (P < .001). Among 7 characteristics, birth weight was the only independent predictor of RNFL thickness (P < .001). A 250-g increase in birth weight was associated with 5.2 μm (95% confidence interval: 3.3-7.0) increase in RNFL thickness. Compared with very preterm infants, extremely preterm infants had thinner RNFL (58.0 ± 10.7 μm vs 63.4 ± 10.7 μm, P = .03), but the statistical significance disappeared after adjustment for birth weight (P = .25). RNFL thickness was 11.2 μm thinner in extremely low birth weight infants than in very low birth weight infants (55.5 ± 8.3 μm vs. 66.7 ± 10.2 μm; P < .001). The difference remained statistically significant after adjustment for gestational age.

CONCLUSION

Birth weight is a significant independent predictor of RNFL thickness near birth, implying that the retinal ganglion cells reserve is affected by intrauterine processes that affect birth weight.

Macular OCT Characteristics at 36 Weeks' Postmenstrual Age in Infants Examined for Retinopathy of Prematurity

PURPOSE

To report our ability to capture,-grade reliably, and analyze bedside macular OCT images from preterm infants and relate OCT findings to biological factors and retinopathy of prematurity (ROP) status at a single time window in the Study of Eye Imaging in Preterm Infants (BabySTEPS).

DESIGN

Prospective, observational study.

PARTICIPANTS

Preterm infants eligible for ROP screening with parental consent for research and a 36 ± 1 weeks' postmenstrual age (PMA) visit.

METHODS

We imaged both eyes of preterm infants with an investigational noncontact, handheld swept-source (SS) OCT at the time of clinical ROP examinations. Macular OCT features and layer thicknesses for untreated eyes of infants at 36 ± 1 weeks' PMA were compared with demographic data and clinical ROP examination performed by experts. Statistical analyses accounted for the use of both eyes of infants.

MAIN OUTCOME MEASURES

Macular OCT features and layer thicknesses, gender, race or ethnicity, gestational age, birth weight, ROP stage, and plus disease.

RESULTS

We captured macular OCT from 169 eyes (1 eye excluded because of prior ROP treatment) at 36 ± 1 weeks' PMA. The quality of OCT volumes was excellent in 33 eyes (19%), acceptable in 112 eyes (67%), poor in 24 eyes (14%), and unusable in 0 eyes (0%). Macular edema was present in 60% of eyes and was bilateral in 82% of infants with edema. At the fovea, retinal and inner nuclear layer thickness increased with edema severity: 183 ± 36 μm and 51 ± 27 μm in mild (16% of eyes), 308 ± 57 μm and 163 ± 53 μm in moderate (25%), and 460 ± 76 μm and 280 ± 83 μm in severe edema (12%), respectively. With an increase in ROP stage from 0 to 2, the mean ± standard deviation retinal thickness at the fovea increased from 227± 124 μm to 297 ± 99 μm (P < 0.001). The choroid was thinner, 155 ± 72 μm, with preplus or plus disease versus without, 236 ± 79 μm (P = 0.04), whereas retinal thickness did not vary.

CONCLUSIONS

We demonstrated the reliability of methods and the prevalence of OCT findings in preterm infants enrolled in BabySTEPS at a single time point of 36 ± 1 weeks' PMA. Variations in layer thicknesses in infants at this time point may reflect abnormalities resulting from delay in foveal development that may be impacted by macular edema, ROP, or both.

Decreased retinal thickness in preschool offspring of maternal gestational hypertension: the Nanjing Eye Study

PURPOSE

To evaluate the influence of maternal gestational hypertension (GH) on retinal thickness of 5-6-year-old children, including macular thickness, ganglion cell-inner plexiform layer (GC-IPL) thickness and peripapillary retinal nerve fibre layer (RNFL) thickness.

METHODS

As part of Nanjing Eye Study, comprehensive ocular examinations were conducted in children aged 61-72 months, including noncycloplegic refraction, ocular biometric parameters and retinal parameters. Retinal thickness was measured by Spectral Domain-Optical Coherence Tomography. Data on pregnancy and birth history were obtained from a detailed questionnaire completed by parents.

RESULTS

Among 1062 children [mean age (standard deviation): 66.9 (3.4) months] with complete from eye examination and questionnaire, 30 (2.8%) children were born with maternal GH. In generalized linear models (adjusted for sex, age, spherical equivalent, axial length, body mass index, birth weight and premature history), children born with maternal GH had thinner average RNFL thickness (100.5 versus 104.4 μm, p = 0.035), superior RNFL thickness (123.7 versus 132.0 μm, p = 0.007), superior GC-IPL thickness (83.7 versus 86.4 μm, p = 0.005), superior-nasal GC-IPL thickness (86.3 versus 88.4 μm, p = 0.029) and superior outer macular thickness (278.0 versus 283.0 μm, p = 0.034) than children born with normal pregnancy.

CONCLUSION

Children exposed to maternal GH tended to have thinner macular, RNFL and GC-IPL thickness. These findings suggest that maternal GH may affect the development of retina in children thus hinders the development of the offspring's nervous system.

Association of Birth Weight with Peripapillary Retinal Nerve Fiber Layer Thickness in Adulthood—Results from a Population-Based Study

Purpose

Low birth weight is associated with altered retinal development in childhood, including reduced peripapillary retinal nerve fiber layer (pRNFL) thickness. However, to the best of our knowledge, no population-based study has analyzed the relationship of low birth weight to pRNFL thickness in adulthood. The purpose of this study was to investigate whether birth weight has a long-term effect on pRNFL thickness in adulthood.

Methods

In the German population-based Gutenberg Health Study (GHS), participants were examined with spectral-domain optical coherence tomography using a peripapillary scan and automated measurement of pRNFL thickness as a global parameter and in six sectors. The association between self-reported birth weight and the different pRNFL sectors were analyzed with multivariable linear regression, adjusted for potential confounders including sex, age, axial length, self-reported age-related macular degeneration, and glaucoma.

Results

In 3,028 participants, self-reported birth weight was documented and pRNFL measurements were successfully performed (1632 females, ages 54.9 ± 10.0 years). After adjustment for several confounders in the multivariable model, a positive association was observed between birth weight and pRNFL thickness in the global sector (β = 0.13 µm/100 g; 95% CI, 0.08–0.18; P < 0.001; R² = 0.007) and especially in the inferotemporal sector (β = 0.22 µm/100 g; 95% CI, 0.15–0.29; P < 0.001; R² = 0.008) and inferonasal sector (β = 0.28 µm/100 g; 95% CI, 0.17–0.39; P < 0.001; R² = 0.005).

Conclusions

Our data show that there is a weak relationship between birth weight and pRNFL thickness in adulthood. This weak association is particularly present in the inferior part of the optic nerve head. Therefore, low birth weight may have an impact on optic nerve head development and potentially on ocular disease development.

Reliability and Recommended Settings for Pediatric Circumpapillary Retinal Nerve Fiber Layer Imaging Using Hand-Held Optical Coherence Tomography

Purpose

To investigate feasibility and reliability of 3-dimensional full circumpapillary retinal nerve fiber layer (cpRNFL) analysis in children, with and without glaucoma, without the use of sedation and to recommend a protocol for hand-held optical coherence tomography use.

Methods

A cohort of pediatric glaucoma patients and normal children were imaged with hand-held optical coherence tomography to assess the feasibility of obtaining full cpRNFL. Two consecutive scans were acquired in a smaller sample to investigate test–retest repeatability and interassessor reproducibility. The cpRNFL thickness was assessed in four quadrants, at several visual angles from the optic nerve center.

Results

Scanning was attempted in both eyes of 90 children with pediatric glaucoma and 180 controls to investigate feasibility (mean age, 6.98 ± 4.42 years). Scanning was not possible in 68 eyes of glaucoma children mainly owing to nystagmus, unclear optical media, or high refractive errors. Where three-dimensional imaging was possible, success at obtaining full cpRNFL was 67% in children with glaucoma and 89% for controls. Seventeen children with pediatric glaucoma and 34 controls contributed to reliability analysis (mean age, 6.3 ± 3.63 years). For repeatability intraclass correlation coefficients across quadrants ranged from 0.63 to 0.82 at 4° and improved to 0.88 to 0.94 at 6°. Intraclass correlation coefficients for reproducibility were also highest at 6° (>0.97 across all quadrants).

Conclusions

We demonstrate that acquisition and measurement of cpRNFL thickness values using 3-dimensional hand-held optical coherence tomography volumes in awake children is both feasible and reliable and is optimal at 6° from optic nerve center.

Translational Relevance

Our recommended protocol provides guidance on how pediatric optic nerve pathologies are managed by clinicians.

Subclinical Retinal versus Brain Findings in Infants with Hypoxic Ischemic Encephalopathy

PURPOSE

To detect retinal features and abnormalities on optical coherence tomography (OCT) without pupil dilation and relate these to brain injury in infants with a clinical diagnosis of hypoxic ischemic encephalopathy (HIE).

METHODS

Under an institutional review board-approved protocol, we imaged eight infants without pharmacologic mydriasis, using handheld, non-contact spectral-domain (Leica Microsystems, IL) or investigational swept-source OCT at the bedside in an intensive care nursery, after birth (depending on primary clinical care team permission based on health status) and weekly until discharge. The newborn infant with HIE is neurologically unstable; therefore, pharmacologic mydriasis and stimulation with visible light for retinal examination are usually avoided. We analyzed images for retinal pathologies, central foveal thickness, and retinal nerve fiber layer (RNFL) thickness at the papillomacular bundle and compared them to historical controls and published normative data, HIE clinical assessment, and abnormalities on brain magnetic resonance imaging (MRI).

RESULTS

On OCT, three of eight infants had bilateral multiple small macular and perimacular cystoid spaces; two of these three infants also had pronounced retinal ganglion cell layer thinning and severe brain injury on MRI and the third had bilateral paracentral acute middle maculopathy and mild brain injury on MRI. Other findings in HIE infant eyes included abnormally thin fovea and thin RNFL and markers of retinal immaturity such as the absence of sub-foveal photoreceptor development and sub-foveal fluid.

CONCLUSIONS

Bedside handheld OCT imaging within the first 2 weeks of life revealed retinal injury in infants with HIE-related brain injury. Future studies may determine the relationship between acute/subacute retinal abnormalities and brain injury severity and neurodevelopmental outcomes in HIE.

Periventricular Leukomalacia in Patients With Pseudo-glaucomatous Cupping

PURPOSE

Periventricular leukomalacia (PVL) is a structural loss of white matter pathways that carry visual information from the lateral geniculate bodies to the visual cortex. It is observed radiologically in patients with a history of prematurity and is associated with visual field (VF) defects and optic disc cupping. Advances in perinatal care have improved survival for premature babies, so many now present as adolescents and adults to comprehensive eye doctors who are unaware of the relationship of cupping, field defects, and prematurity and who may diagnose manifest or suspected normal tension glaucoma. We describe 2 such patients to raise awareness of this entity.

DESIGN

Case series.

METHODS

Review of clinical information of 2 patients identified during clinical practice. Charts were reviewed for gestational age, optic nerve appearance, intraocular pressure (IOP), and sequelae of prematurity. Magnetic resonance imaging (MRI), optical coherence tomography (OCT), VF, and optic disc photographs were reviewed.

RESULTS

Two young patients with a history of prematurity presented with enlarged cup-to-disc ratio and normal IOP. OCT thinning was most prominent superiorly, with VF defects more notable inferior and homonymous. No progression on VF or OCT was noted in the index case over almost 4 years.

CONCLUSIONS

Periventricular leukomalacia should be added to the differential diagnosis of normal tension glaucoma (NTG) when there is a history of prematurity. Careful examination of the optic nerve will assist in differentiating from NTG. Specifically, horizontal cupping with minimal or no nasal displacement of vessels, and superior optic nerve thinning with inferior VF defects, suggest PVL.

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.

Retinopathy of prematurity, visual and neurodevelopmental outcome, and imaging of the central nervous system

Recent findings indicate that retinopathy of prematurity (ROP), presently classified by clinical examinations of retinal vascular tissue, is associated with structural alterations of the central nervous system. Such alterations may be the correlate of the association between ROP and impaired long-term neurocognitive and visual development. The advent of imaging techniques such as structural and diffusion tensor magnetic resonance imaging of the brain, and optical coherence tomography of the retina, will allow the complete visual system to be characterized in greater detail. It has been suggested that ROP may be not only a vascular, but a neurovascular disease, being part of a spectrum that includes pathological development in both the retinal and cerebral neurovascular interphase. We review the present knowledge in the field and point to future directions for research to tackle these questions.

Mercury in the retina and optic nerve following prenatal exposure to mercury vapor

Damage to the retina and optic nerve is found in some neurodegenerative disorders, but it is unclear whether the optic pathway and central nervous system (CNS) are affected by the same injurious agent, or whether optic pathway damage is due to retrograde degeneration following the CNS damage. Finding an environmental agent that could be responsible for the optic pathway damage would support the hypothesis that this environmental toxicant also triggers the CNS lesions. Toxic metals have been implicated in neurodegenerative disorders, and mercury has been found in the retina and optic nerve of experimentally-exposed animals. Therefore, to see if mercury exposure in the prenatal period could be one link between optic pathway damage and human CNS disorders of later life, we examined the retina and optic nerve of neonatal mice that had been exposed prenatally to mercury vapor, using a technique, autometallography, that detects the presence of mercury within cells. Pregnant mice were exposed to a non-toxic dose of mercury vapor for four hours a day for five days in late gestation, when the mouse placenta most closely resembles the human placenta. The neonatal offspring were sacrificed one day after birth and gapless serial sections of formalin-fixed paraffin-embedded blocks containing the eyes were stained with silver nitrate autometallography to detect inorganic mercury. Mercury was seen in the nuclear membranes of retinal ganglion cells and endothelial cells. A smaller amount of mercury was present in the retinal inner plexiform and inner nuclear layers. Mercury was conspicuous in the peripapillary retinal pigment epithelium. In the optic nerve, mercury was seen in the nuclear membranes and processes of glia and in endothelial cells. Optic pathway and CNS endothelial cells contained mercury. In conclusion, mercury is taken up preferentially by fetal retinal ganglion cells, optic nerve glial cells, the retinal pigment epithelium, and endothelial cells. Mercury induces free radical formation, autoimmunity, and genetic and epigenetic changes, so these findings raise the possibility that mercury plays a part in the pathogenesis of degenerative CNS disorders that also affect the retina and optic nerve.

Correlation of morphological parameters and visual acuity with neurological development in former preterm children aged 4-10 years

PURPOSE

The objective of this study was to investigate the relationship between visual acuity, peripapillary retinal nerve fibre layer (pRNFL), retinal thickness at the fovea and other factors with the neurologic status of former preterm children.

METHODS

In this cross-sectional hospital based study in a maximum care tertiary centre, detailed anthropometric and ophthalmological data of former preterm children ranging from 4 to 10 years of age with a gestational age (GA) ≤32 weeks were assessed. Analyses of the correlation between pRNFL and foveal thickness, as well as visual acuity (VA) parameters at 4-10 years of age, with neurological development were evaluated at 2 years of age by Bayley Scales II of Infant Development, including Psychomotor Developmental Index (PDI) and Mental Developmental Index (MDI).

RESULTS

Data were available for 106 former preterm children. Univariate analysis revealed a correlation between PDI with pRNFL thickness (B = 0.43; p = 0.013), VA (B = -29.2; p < 0.001), GA (B = 2.7; p = 0.002), retinopathy of prematurity (ROP; B = -16.3; p < 0.001) and intraventricular haemorrhages (IVH; B = -22.9; p < 0.001) but not with strabismus or foveal thickness. In the multivariable analysis, the association remained for visual acuity and IVH, but not for pRNFL thickness or ROP. Mental Developmental Index (MDI) was associated with visual acuity (B = -34.3; p = 0.001), GA (B = 2.53; p = 0.02) and IVH (B = -15.4; p = 0.02), the latter also in the multivariable analysis.

CONCLUSION

This study revealed an association between PDI at 2 years of age and lower visual acuity later in childhood. However, there was no correlation between retinal morphology and neurologic outcome in former preterm children after adjusting for several potential confounders.

HANDHELD SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY IMAGING THROUGH THE UNDILATED PUPIL IN INFANTS BORN PRETERM OR WITH HYPOXIC INJURY OR HYDROCEPHALUS

PURPOSE

The authors investigated feasibility of undilated handheld spectral domain optical coherence tomography (SDOCT) retinal imaging in preterm infants and children with neurologic abnormalities.

METHODS

Under an institutional review board-approved protocol, the authors attempted handheld SDOCT imaging of the retina, choroid, and optic nerve in infants and young children without pupil dilation. Scans were analyzed for quality and successful capture of foveal, optic nerve, and retinal structural parameters and abnormalities.

RESULTS

The authors obtained images through an undilated pupil of 11 infants/children over 28 eye imaging sessions, 27 at the bedside without sedation, and one under anesthesia. Infants had retinopathy of prematurity (n = 8), hypoxic ischemic encephalopathy (n = 2), or obstructive hydrocephalus (n = 1 child). Pupil sizes ranged from 1.0 mm to 3.5 mm. The authors captured fovea and optic nerve scans in 25/28 eye imaging sessions, with scans of adequate quality to discern prespecified foveal and optic nerve morphology, and of the 25 sessions, the choroidal-scleral junction was visible in all but 6 sessions.

CONCLUSION

Undilated, handheld SDOCT imaging is a potential alternative method to evaluate the retina and optic nerve in patients with relative contraindication to pharmacological pupil dilation. This approach will enable the study of the eye-brain connection and ocular manifestations of neurologic diseases.

Retinal Parameters as Compared with Head Circumference, Height, Weight, and Body Mass Index in Children in Kenya and Bhutan

The retina shares embryological derivation with the brain and may provide a new measurement of overall growth status, especially useful in resource-limited settings. Optical coherence tomography (OCT) provides detailed quantification of retinal structures. We enrolled community-dwelling children ages 3–11 years old in Siaya, Kenya and Thimphu, Bhutan in 2016. We measured head circumference (age < 5 years only), height, and weight, and standardized these by age and gender. Research staff performed OCT (iScan; Optovue, Inc., Fremont, CA), measuring the peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) thicknesses. A neuro-ophthalmologist performed quality control for centration, motion artifact, and algorithm-derived quality scores. Generalized estimating equations were used to determine the relationship between anthropometric and retinal measurements. Two hundred and fifty-eight children (139 females, average age 6.4 years) successfully completed at least one retinal scan, totaling 1,048 scans. Nine hundred and twenty-two scans (88.0%) were deemed usable. Fifty-three of the 258 children (20.5%) were able to complete all six scans. Kenyan children had a thinner average GCC (P < 0.001) than Bhutanese children after adjustment for age and gender, but not RNFL (P = 0.70). In models adjusting for age, gender, and study location, none of standardized height, weight, and body mass index (BMI) were statistically significantly associated with RNFL or GCC. We determined that OCT is feasible in some children in resource-limited settings, particularly those > 4 years old, using the iScan device. We found no evidence for GCC or RNFL as a proxy for height-, weight-, or BMI-for-age. The variation in mean GCC thickness in Asian versus African children warrants further investigation.

Injuries to the Immature Optic Radiation Show Correlated Thinning of the Macular Ganglion Cell Layer

Injuries to the immature optic radiation (OR) are associated with thinning of the retinal nerve fiber layer and corresponding visual field (VF) defects. The aim of the current study was to seek evidence for causal retrograde trans-synaptic degeneration by exploring the correspondence between the localization and extension of the injury to the OR and the structure of the macular ganglion cell complex, and the relation to VF function. Seven adults (age range 18–35) with visual dysfunction secondary to white-matter damage of immaturity and six healthy adults (age range 22–33) underwent magnetic resonance imaging (MRI). Fiber tractography was used to generate the geniculate projections to the dorsal and ventral striate cortex, delineated by retinotopic functional MRI mapping. The structure of the macular ganglion cell complex was measured with optical coherence tomography. The tractography showed overlaps between the dorsal and ventral geniculo-striate projections. However, in four patients with inferior VF defects, the dorsal projections were to a large extent traversing the space normally solely occupied by ventral projections. This is consistent with structural changes to the OR and suggests of re-organization upon injury. Diffusion parameters were significantly different between patients and controls, and most pronounced in the dorsal geniculo-striate projections, with a pattern indicating primary injury. The macular ganglion cell complex was significantly thinner in the patients and most pronounced in the superior sectors; a pattern particularly evident in the four patients with inferior VF defects. The ratio of the mean thickness of the macular ganglion cell complex in the superior and inferior sectors significantly correlated with the axial and mean diffusivities in the contra- and ipsilateral dorsal striate projections. The results suggest a causal link between injuries to the superior portion of the immature OR and secondary thinning in the macular ganglion cell complex, resulting in inferior VF defects.

Relation of Retinopathy of Prematurity to Brain Volumes at Term Equivalent Age and Developmental Outcome at 2 Years of Corrected Age in Very Preterm Infants

BACKGROUND

Retinopathy of prematurity (ROP) is a major complication of preterm birth and has been associated with later visual and nonvisual impairments.

OBJECTIVES

To evaluate relationships between any stage of ROP, brain volumes, and developmental outcomes.

METHODS

This study included 52 very preterm infants (gestational age [mean ± SD]: 26.4 ± 1.9 weeks). Total brain, gray matter, unmyelinated white matter (UWMV), and cerebellar volumes were estimated in 51 out of 52 infants by magnetic resonance imaging at term-equivalent age. Bayley Scales of Infant Development were used to assess developmental outcomes in 49 out of 52 infants at a mean corrected age of 24.6 months.

RESULTS

Nineteen out of 52 infants developed any stage of ROP. Infants with ROP had a lower median (IQR) UWMV (173 [156-181] vs. 204 [186-216] mL, p < 0.001) and cerebellar volume (18.3 [16.5-20] vs. 22.3 [20.3-24.7] mL, p < 0.001) than infants without ROP. They also had a lower median (IQR) mental developmental index (72 [56-83] vs. 100 [88-104], p < 0.001) and a lower psychomotor developmental index (80 [60-85] vs. 92 [81-103], p = 0.002). Brain volumes and developmental outcomes did not differ among infants with different stages of ROP.

CONCLUSION

Any stage of ROP in preterm infants was associated with a reduced brain volume and an impaired developmental outcome. These results suggest that common pathways may lead to impaired neural and neurovascular development in the brain and retina and that all stages of ROP may be considered in future studies on ROP and development.

Severe retinopathy of prematurity predicts delayed white matter maturation and poorer neurodevelopment

OBJECTIVE

To determine whether severe retinopathy of prematurity (ROP) is associated with (1) abnormal white matter maturation and (2) neurodevelopmental outcomes at 18 months' corrected age (CA) compared with neonates without severe ROP.

DESIGN

We conducted a prospective longitudinal cohort of extremely preterm neonates born 24-28 weeks' gestational age recruited between 2006 and 2013 with brain MRIs obtained both early in life and at term-equivalent age. Severe ROP was defined as ROP treated with retinal laser photocoagulation. Using diffusion tensor imaging and tract-based spatial statistics (TBSS), white matter maturation was assessed by mean fractional anisotropy (FA) in seven predefined regions of interest. Neurodevelopmental outcomes were assessed with Bayley Scales of Infant and Toddler Development-III (Bayley-III) composite scores at 18 months' CA. Subjects were compared using Fisher's exact, Kruskal-Wallis and generalised estimating equations.

SETTING

Families were recruited from the neonatal intensive care unit at BC Women's Hospital.

PATIENTS

Of 98 extremely preterm neonates (median: 26.0 weeks) assessed locally for ROP, 19 (19%) had severe ROP and 83 (85%) were assessed at 18 months' CA.

RESULTS

Severe ROP was associated with lower FA in the posterior white matter, and with decreased measures of brain maturation in the optic radiations, posterior limb of the internal capsule (PLIC) and external capsule on TBSS. Bayley-III cognitive and motor scores were lower in infants with severe ROP.

CONCLUSIONS

Severe ROP is associated with maturational delay in the optic radiations, PLIC, external capsule and posterior white matter, housing the primary visual and motor pathways, and is associated with poorer cognitive and motor outcomes at 18 months' CA.

The inner retinal structures of the eyes of children with a history of retinopathy of prematurity

PurposeTo investigate the microstructural differences of the inner retina in the peripapillary and macular areas in children with or without retinopathy of prematurity (ROP).MethodsThis prospective cohort study included school-age children with a history of ROP and age-matched healthy, full-term children. The macular ganglion cell complex (mGCC), peripapillary retinal nerve fiber layer (RNFL), refractive status, and ocular biometry were measured. The metrics of the mGCC and associated anatomical changes were the primary outcomes. Mann-Whitney U tests and chi-squared tests were used to compare variables between the two groups.ResultsA total of 41 eyes from 21 preterm children with ROP and 34 eyes from 17 full-term children were enrolled. ROP eyes had significantly thicker mGCC (P<0.001) with uneven distribution compared with full-term eyes. The RNFLs of ROP eyes were thicker in the temporal quadrants but thinner in the nasal quadrants (P=0.01 and.04, respectively). In addition, the ROP eyes had shallower anterior chamber depths (ACDs), thicker lenses, and higher degrees of refractive errors (all P<0.05) but similar axial lengths (ALs) (P=0.58) compared with full-term eyes.ConclusionsThe mGCC was thicker in children with ROP, and their inner retinal structures had a different distribution pattern than those in full-term children. The myopia of children with ROP was associated with the abnormal development of the anterior segment rather than long ALs. These alterations in inner retinal anatomy and optic components emphasize the importance of careful examinations to monitor the development of glaucoma or visual decline in children with ROP.

Macular morphology in former preterm and full-term infants aged 4 to 10 years

OBJECTIVE

To analyse macular retinal and choroidal layer thickness in former preterm and full-term infants and to assess associated perinatal influence factors and functional correlation.

METHODS

This prospective controlled, cross-sectional, hospital-based study in a tertiary center of maximum care examined former preterm infants with a gestational age (GA) ≤ 32 weeks and full-term neonates currently aged 4 to 10 years. We investigated data from 397 infants, analysing total foveal retinal thickness and six distinct macular retinal layer and choroidal layer measurements via spectral-domain optical coherence tomography. Multivariable linear regression analysis was performed to investigate associations of layer thickness with GA and retinopathy of prematurity (ROP).

RESULTS

Total retinal thickness in the fovea was thicker in former preterm infants with GA ≤ 28 weeks and in those with GA between 29-32 weeks compared to full-term infants independently of ROP. Occurrence of ROP was also associated with increased foveal thickness. Ganglion cell layer together with inner plexiform layer (GCL+IPL) was thinner in infants with GA ≤ 28 weeks than in full-term infants at 1000 and 2000μm distance from the fovea, but no association with ROP was present. Similar results were found for the photoreceptor layer. Total foveal retinal thickness was associated with low visual function.

CONCLUSION

This study identified low gestational age and ROP occurrence as main determinants for foveal thickening. Furthermore, thinned GCL+IPL measurements were associated with lower gestational age. This study highlights the prognostic value of these maturity parameters influencing retinal morphology, which may affect visual function.

IGF-1 in retinopathy of prematurity, a CNS neurovascular disease

The retina is part of the central nervous system and both the retina as well as the brain can suffer from severe damage after very preterm birth. Retinopathy of prematurity is one of the major causes of blindness in these children and brain neuronal impairments including cognitive defects, cerebral palsy and intraventricular hemorrhage (IVH) are also complications of very preterm birth. Insulin-like growth factor 1 (IGF-1) acts to promote proliferation, maturation, growth and survival of neural cells. Low levels of circulating IGF-1 are associated with ROP and defects in the IGF-1 gene are associated with CNS disorders including learning deficits and brain growth restriction. Treatment of preterm infants with recombinant IGF-1 may potentially prevent ROP and CNS disorders. This review compares the role of IGF-1 in ROP and CNS disorders. A recent phase 2 study showed a positive effect of IGF-1 on the severity of IVH but no effect on ROP. A phase 3 trial is planned.

Optical coherence tomography of the preterm eye: from retinopathy of prematurity to brain development

Preterm infants with retinopathy of prematurity are at increased risk of poor neurodevelopmental outcomes. Because the neurosensory retina is an extension of the central nervous system, anatomic abnormalities in the anterior visual pathway often relate to system and central nervous system health. We describe optical coherence tomography as a powerful imaging modality that has recently been adapted to the infant population and provides noninvasive, high-resolution, cross-sectional imaging of the infant eye at the bedside. Optical coherence tomography has increased understanding of normal eye development and has identified several potential biomarkers of brain abnormalities and poorer neurodevelopment.