Three-dimensional assessment of vascular and perivascular characteristics in subjects with retinopathy of prematurity

Implementation of optical coherence tomography in retinopathy of prematurity screening

PURPOSE OF REVIEW

In this review, we explore the investigational applications of optical coherence tomography (OCT) in retinopathy of prematurity (ROP), the insights they have delivered thus far, and key milestones for its integration into the standard of care.

RECENT FINDINGS

While OCT has been widely integrated into clinical management of common retinal diseases, its use in pediatric contexts has been undermined by limitations in ergonomics, image acquisition time, and field of view. Recently, investigational handheld OCT devices have been reported with advancements including ultra-widefield view, noncontact use, and high-speed image capture permitting real-time en face visualization. These developments are compelling for OCT as a more objective alternative with reduced neonatal stress compared to indirect ophthalmoscopy and/or fundus photography as a means of classifying and monitoring ROP.

SUMMARY

OCT may become a viable modality in management of ROP. Ongoing innovation surrounding handheld devices should aim to optimize patient comfort and image resolution in the retinal periphery. Future clinical investigations may seek to objectively characterize features of peripheral stage and explore novel biomarkers of disease activity.

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.

USE OF HAND-HELD OPTICAL COHERENCE TOMOGRAPHY DURING RETINOPATHY OF PREMATURITY SCREENING DEMONSTRATES AN INCREASED OUTER RETINA FROM EARLY POSTMENSTRUAL AGE IN PRETERM INFANTS WITH RETINOPATHY OF PREMATURITY

PURPOSE

To identify structural markers of active retinopathy of prematurity (ROP) in foveal and parafoveal retinal layers using hand-held optical coherence tomography.

METHODS

Hand-held optical coherence tomography images (n = 278) were acquired from a prospective mixed cross-sectional longitudinal observational study of 87 participants (23-36 weeks gestational age; n = 30 with ROP, n = 57 without ROP) between 31 and 44 weeks postmenstrual age excluding treated ROP and features of cystoid macular edema. Six retinal layer thicknesses from the fovea to the parafovea were analyzed at five locations up to 1,000 µ m, temporally and nasally.

RESULTS

The mean outer retinal thickness during active ROP increased at the fovea and parafovea from postmenstrual age 33 weeks to 39 weeks ( P < 0.001), whereas the parafoveal inner nuclear layer and retinal nerve fiber layer reduced ( P < 0.001). Outer retinal thickness at the fovea from 33 weeks to 39 weeks postmenstrual age was consistently thicker in infants with ROP across all levels of prematurity (gestational age).

CONCLUSION

Increased foveal and parafoveal outer retina measured using hand-held optical coherence tomography shows potential as a marker for ROP screening.

Identification of novel biomarkers for retinopathy of prematurity in preterm infants by use of innovative technologies and artificial intelligence

Retinopathy of prematurity (ROP) is a leading cause of preventable vision loss in preterm infants. While appropriate screening is crucial for early identification and treatment of ROP, current screening guidelines remain limited by inter-examiner variability in screening modalities, absence of local protocol for ROP screening in some settings, a paucity of resources and an increased survival of younger and smaller infants. This review summarizes the advancements and challenges of current innovative technologies, artificial intelligence (AI), and predictive biomarkers for the diagnosis and management of ROP. We provide a contemporary overview of AI-based models for detection of ROP, its severity, progression, and response to treatment. To address the transition from experimental settings to real-world clinical practice, challenges to the clinical implementation of AI for ROP are reviewed and potential solutions are proposed. The use of optical coherence tomography (OCT) and OCT angiography (OCTA) technology is also explored, providing evaluation of subclinical ROP characteristics that are often imperceptible on fundus examination. Furthermore, we explore several potential biomarkers to reduce the need for invasive procedures, to enhance diagnostic accuracy and treatment efficacy. Finally, we emphasize the need of a symbiotic integration of biologic and imaging biomarkers and AI in ROP screening, where the robustness of biomarkers in early disease detection is complemented by the predictive precision of AI algorithms.

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).

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.

Vitreoretinal biomarkers of retinopathy of prematurity using handheld optical coherence tomography: a review

Retinopathy of prematurity (ROP) is caused by abnormal retinal vascularization in premature infants that has the potential for severe long-term vision impairment. Recent advancements in handheld optical coherence tomography (OCT) have enabled noninvasive, high-resolution, cross-sectional imaging of the infant eye at the bedside. The use of handheld OCT devices in the diagnosis of ROP in premature infants has furthered our understanding of disease state and progression. This review discusses the known and novel biomarkers of ROP severity in premature infants identified through handheld OCT and potential for future directions.

Multivariate Models to Diagnose Early Referral-Warranted Retinopathy of Prematurity With Handheld Optical Coherence Tomography

Purpose

The purpose of this study was to create multivariate models predicting early referral-warranted retinopathy of prematurity (ROP) using non-contact handheld spectral-domain optical coherence tomography (OCT) and demographic data.

Methods

Between July 2015 and February 2018, infants ≤1500 grams birth weight or ≤30 weeks gestational age from 2 academic neonatal intensive care units were eligible for this study. Infants were excluded if they were too unstable to participate in ophthalmologic examination (2), had inadequate image quality (20), or received prior ROP treatment (2). Multivariate models were created using demographic variables and imaging findings to identify early referral-warranted ROP (referral-warranted ROP and/or pre-plus disease) by routine indirect ophthalmoscopy.

Results

A total of 167 imaging sessions of 71 infants (45% male infants, gestational age 28.2+/-2.8 weeks, and birth weight 995.6+/-292.0 grams) were included. Twelve of 71 infants (17%) developed early referral-warranted ROP. The area under the receiver operating characteristic curve (AUC) was 0.94 for the generalized linear mixed model (sensitivity = 95.5% and specificity = 80.7%) and 0.83 for the machine learning model (sensitivity = 91.7% and specificity = 77.8%). The strongest variables in both models were birth weight, image-based Vitreous Opacity Ratio (an estimate of opacity density), vessel elevation, and hyporeflective vessels. A model using only birth weight and gestational age yielded an AUC of 0.68 (sensitivity = 77.3% and specificity = 63.4%), and a model using only imaging biomarkers yielded 0.88 (sensitivity = 81.8% and specificity = 84.8%).

Conclusions

A generalized linear mixed model containing handheld OCT biomarkers can identify early referral-warranted ROP. Machine learning produced a less optimal model.

Translational Relevance

With further validation, this work may lead to a better-tolerated ROP screening tool.

Optical Coherence Tomography and Optical Coherence Tomography Angiography in Pediatric Retinal Diseases

Indirect ophthalmoscopy and handheld retinal imaging are the most common and traditional modalities for the evaluation and documentation of the pediatric fundus, especially for pre-verbal children. Optical coherence tomography (OCT) allows for in vivo visualization that resembles histology, and optical coherence tomography angiography (OCTA) allows for non-invasive depth-resolved imaging of the retinal vasculature. Both OCT and OCTA were extensively used and studied in adults, but not in children. The advent of prototype handheld OCT and OCTA have allowed for detailed imaging in younger infants and even neonates in the neonatal care intensive unit with retinopathy of prematurity (ROP). In this review, we discuss the use of OCTA and OCTA in various pediatric retinal diseases, including ROP, familial exudative vitreoretinopathy (FEVR), Coats disease and other less common diseases. For example, handheld portable OCT was shown to detect subclinical macular edema and incomplete foveal development in ROP, as well as subretinal exudation and fibrosis in Coats disease. Some challenges in the pediatric age group include the lack of a normative database and the difficulty in image registration for longitudinal comparison. We believe that technological improvements in the use of OCT and OCTA will improve our understanding and care of pediatric retina patients in the future.

Multimodal Imaging, Tele-Education, and Telemedicine in Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a disease that affects retinal vasculature in premature infants and remains one of the leading causes of blindness in childhood worldwide. ROP screening can encounter some difficulties such as the lack of specialists and services in rural areas. The evolution of technology has helped address these issues and led to the emergence of state-of-the-art multimodal digital imaging devices such fundus cameras with its variable properties, optical coherence tomography (OCT), OCT angiography, and fluorescein angiography which has helped immensely in the process of improving ROP care and understanding the disease pathophysiology. Computer-based imaging analysis and deep learning have recently been demonstrating promising outcomes in regard to ROP diagnosis. Telemedicine is considered an acceptable alternative to clinical examination when optimal circumstances for ROP screening in certain areas are lacking, and the expansion of these programs has been reported. Tele-education programs in ROP have the potential to improve the quality of training to physicians to optimize ROP care.

Advances in retinopathy of prematurity imaging

Retinopathy of prematurity (ROP) remains the leading cause of childhood blindness worldwide. Recent advances in ROP imaging have significantly improved our understanding of the pathogenesis and pathophysiological course of ROP including the acute phase, regression, reactivation, and late complications, known as adult ROP. Recent progress includes various contact and noncontact wide-field imaging devices for fundus imaging, smartphone-based fundus photography, wide-field fluorescein angiography, handheld optical coherence tomography (OCT) devices for wide-field en face OCT images, and OCT angiography. Images taken by those devices were incorporated in the recently updated guidelines of ROP, the International Classification of Retinopathy of Prematurity, Third Edition (ICROP3). ROP imaging has also allowed the real-world adoption of telemedicine- and artificial intelligence (AI)-based screening. Recent study demonstrated proof of concept that AI has a high diagnostic performance for the detection of ROP in a real-world screening. Here, we summarize the recent advances in ROP imaging and their application for screening, diagnosis, and management of ROP.

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.

Peripheral OCT Assisted by Scleral Depression in Retinopathy of Prematurity

OBJECTIVE

To determine whether handheld widefield optical coherence tomography (OCT) can be used to document retinopathy of prematurity (ROP) stage while using scleral depression to improve peripheral views.

DESIGN

Prospective observational study.

PARTICIPANTS

Consecutive neonates admitted to the neonatal intensive care unit (NICU) in a single academic medical center who also met criteria for ROP screening and consented for research imaging.

METHODS

Scleral depression was combined with widefield OCT using an investigational 400-kHz, 55-degree field of view handheld OCT during routine ROP screening from October 28, 2020 to March 03, 2021.

MAIN OUTCOME MEASURES

Acquisition of en face and B-scan imaging of the peripheral retina to objectively assess early vitreoretinal pathology, including the demarcation between vascularized and anterior avascular retina, the presence of early ridge formation, and small neovascular tufts.

RESULTS

Various stages of ROP were detected using a rapid acquisition OCT system. In one neonate, serial OCT imaging over a five-week period demonstrated accumulation of neovascular tufts with progression to stage 3 ROP with extraretinal fibrovascular proliferation along the ridge. Videography of this technique is included in this report for instructional purposes.

CONCLUSIONS

Serial examinations using widefield OCT and scleral depression is feasible and may improve detection and documentation of ROP disease progression. Earlier detection of ROP-related proliferation may prevent vitreoretinal traction, retinal detachment, and blindness.

Vitreous opacities in infants born full-term and preterm by handheld swept-source optical coherence tomography

PURPOSE

To compare vitreous opacity density in infants born at term and in infants born prematurely using an investigational handheld swept-source optical coherence tomography (SS-OCT).

METHODS

Infants born at term underwent imaging once between 12 and 48 hours after birth; infants born prematurely were imaged at each routine retinopathy of prematurity (ROP) examination. Three masked, trained graders analyzed images. Semiautomated methods were used to quantify vitreous opacity density, which was correlated with ROP severity based on indirect ophthalmoscopy, other SS-OCT findings, and medical comorbidities.

RESULTS

Between April 2018 and June 2019, 251 SS-OCT imaging sessions were performed on 78 infants (49% female; 36% preterm, with mean birth weight of 1018 ± 338 g and gestational age of 28.6 ± 3.2 weeks). All SS-OCT sessions produced images of adequate quality. Punctate vitreous opacities were present in 25 of 28 term infants (89%) and 41 of 50 premature infants (82%). Dice coefficient and F1 scores for intergrader agreement were 0.99 ± 0.03 and 0.77 ± 0.31, respectively. Vitreous opacity density was 0.118 ± 0.187 in prematurely born infants and 0.031 ± 0.118 in infants born at term (P = 0.009). In the former, vitreous opacity density was associated with ROP zone (P = 0.044) and stage (P = 0.031), intraventricular hemorrhage (P = 0.028), subchorionic hemorrhage (P = 0.026), and African American race (P = 0.023). In the latter, vitreous opacity density was associated with maternal diabetes (P = 0.049).

CONCLUSIONS

Our investigational handheld SS-OCT achieved high-quality vitreoretinal images. In our study cohort, punctate vitreous opacities were a frequent finding in infants born at term and those born prematurely, with increased density in those born prematurely, particularly those with severe ROP.

Advantages of Widefield Optical Coherence Tomography in the Diagnosis of Retinopathy of Prematurity

Recent advances in portable optical coherence tomography (OCT) and OCT angiography (OCTA) have resulted in wider fields of view (FOV) and shorter capture times, further expanding the potential clinical role of OCT technology in the diagnosis and management of retinopathy of prematurity (ROP). Using a prototype, handheld OCT device, retinal imaging was obtained in non-sedated infants in the neonatal intensive care unit (NICU) as well as sedated infants in the operating room of Oregon Health & Science University (OHSU) Hospital. In this observational study, we provide an overview of potential advantages of OCT-based disease assessment in ROP. We observed that next-generation OCT imaging (a) may be sufficient for objective diagnosis and zone/stage/plus disease categorization, (b) allows for minimally-invasive longitudinal monitoring of disease progression and post-treatment course, (c) provides three-dimensional mapping of the vitreoretinal interface, and (d) with OCTA, enables dye-free visualization of normal and pathologic vascular development.

OCT Imaging in Infants

Optical coherence tomography (OCT) is widely applied in diagnosis and management of retina diseases particularly macular diseases in adult retina practices. However, it has been under-utilized in pediatric retinal diseases especially in neonates and infants. Utilization of OCT in primary macular diseases in this age group is also uncommon and is less reported. Challenges involved in image acquisition and limitations with available devices technique can explain the limited research and accurate data availability in the literature in this field. Purpose of this review article is to summarize the use of OCT and its importance in various infantile retinal pathologies such as vascular diseases, tumors, retinal dystrophies, and optic nerve pathologies with primary focus on neonates and infants, along with infant choroid. In addition, we also discuss about future directions including OCT angiography for infants.

Dome-shaped macula in premature infants visualized by handheld spectral-domain optical coherence tomography

PURPOSE

To describe dome-shaped macula and associated clinical findings in premature infants.

METHODS

This prospective, observational cohort study included a consecutive sample of premature infants screened for retinopathy of prematurity (ROP) with 9-month follow-up. Handheld spectral domain optical coherence tomography (SD-OCT) was performed at the time of ROP screening. Images were assessed for dome-shaped macula, cystoid macular edema, epiretinal membrane, vitreous bands, and punctate hyperreflective vitreous opacities. Dome height measurements were performed in a subset of images. Teller visual acuity and cycloplegic refraction were performed at an adjusted age of 8-10 months.

RESULTS

Of 37 infants (74 eyes; 49% male; mean gestational age 27.8 ± 3.2 weeks; mean birth weight 949 ± 284 g), 24/37 (65%) demonstrated dome-shaped macula in at least one eye (13 both eyes, 5 right eye only, and 6 left eye only). Of the 74 eyes, 26 (35%) could be reliably measured, with a mean dome height of 139.0 ± 72.3 μm (range, 54-369 μm). Presence of dome-shaped macula was associated with a diagnosis of ROP (P = 0.02; OR, 3.03; 95% CI, 1.18-7.82) and pre-plus or plus disease (P = 0.02; OR, 4.20; 95% CI, 1.05-16.78). Infants with dome-shaped macula had lower birth weight compared with those without (877 vs 1081 g; P = 0.04). No associations with other demographics, OCT findings, and 9-month refractive outcomes were found.

CONCLUSIONS

Dome-shaped macula was frequently identified by handheld SD-OCT in premature infants, especially those with lower birth weight and severe ROP. The long-term clinical significance of this finding is unknown.

Imaging the pediatric retina: An overview

Recent decade has seen a shift in the causes of childhood blinding diseases from anterior segment to retinal disease in both developed and developing countries. The common retinal disorders are retinopathy of prematurity and vitreoretinal infections in neonates, congenital anomalies in infants, and vascular retinopathies including type 1 diabetes, tumors, and inherited retinal diseases in children (up to 12 years). Retinal imaging helps in diagnosis, management, follow up and prognostication in all these disorders. These imaging modalities include fundus photography, fluorescein angiography, ultrasonography, retinal vascular and structural studies, and electrodiagnosis. Over the decades there has been tremendous advances both in design (compact, multifunctional, tele-consult capable) and technology (wide- and ultra-wide field and noninvasive retinal angiography). These new advances have application in most of the pediatric retinal diseases though at most times the designs of new devices have remained confined to use in adults. Poor patient cooperation and insufficient attention span in children demand careful crafting of the devices. The newer attempts of hand-held retinal diagnostic devices are welcome additions in this direction. While much has been done, there is still much to do in the coming years. One of the compelling and immediate needs is the pediatric version of optical coherence tomography angiography. These needs and demands would increase many folds in future. A sound policy could be the simultaneous development of adult and pediatric version of all ophthalmic diagnostic devices, coupled with capacity building of trained medical personnel.

Choroidal Thickness by Handheld Swept-Source Optical Coherence Tomography in Term Newborns

Purpose

To describe normative values for choroidal thickness in newborns and characterize their relationship to vitreoretinal features.

Methods

Term newborns underwent awake, handheld swept-source optical coherence tomography (SS-OCT) in this prospective cohort study. An automated segmentation algorithm followed by manual adjustments measured choroidal thickness at the fovea and five perifoveal locations. Two masked, trained graders, with a third mediating disagreements, analyzed scans for vitreoretinal findings. OCT vitreoretinal findings, including dome-shaped macula, subretinal fluid, punctate hyperreflective vitreous opacities, persistent inner retinal layers, foveal ellipsoid zone, tractional and non-tractional vitreous bands, epiretinal membrane, cystoid macular edema, vessel elevation, scalloped retinal layers, hyporeflective vessels, and retinal spaces, were assessed and correlated with foveal choroidal thickness using a generalized linear mixed model.

Results

Fifty-nine eyes of 39 infants (mean gestational age, 39.5 weeks; 18 male, 46%) were included. Mean foveal choroidal thickness was 455.5 ± 93.9 µm. Choroid was thinner inferonasally (343.6 ± 106.2 µm) compared to superonasally (368.4 ± 92.9 µm; P = 0.03) and superotemporally (369.6 ± 100.6 µm; P = 0.02). Thinner foveal choroidal thickness was associated with absence of a foveal ellipsoid zone (437.1 ± 78.5 µm vs. 553.7 ± 93.9 µm; P = 0.02). Choroidal thickness was not significantly associated with other OCT findings.

Conclusions

We identified an association between thinner choroid and foveal immaturity. Additional study is needed to determine whether choroidal development impacts visual outcomes.

Translational Relevance

Handheld SS-OCT achieved normative measurements for choroidal thickness across the macula in term newborns, providing a foundation for future investigations into the role of choroidal development in infancy.

Retinal imaging in infants

Digital retinal imaging is at the core of a revolution that is continually improving the screening, diagnosis, documentation, monitoring, and treatment of infant retinal diseases. Historically, imaging the retina of infants had been limited and difficult to obtain. Recent advances in photographic instrumentation have significantly improved the ability to obtain high quality multimodal images of the infant retina. These include color fundus photography with different camera angles, ultrasonography, fundus fluorescein angiography, optical coherence tomography, and optical coherence tomography angiography. We provide a summary of the current literature on retinal imaging in infants and highlight areas where further research is required.

Quantitative Handheld Swept-Source Optical Coherence Tomography Angiography in Awake Preterm and Full-Term Infants

Purpose

To compare retinal vascular parameters acquired by handheld swept-source optical coherence tomography angiography (SS-OCTA) between nonsedated preterm and full-term infants.

Methods

Preterm and full-term infants at the University of Washington Medical Center were enrolled. Retinal angiograms (nominal size ∼7 × 7 mm²) were obtained at each routine retinopathy of prematurity (ROP) screening session for preterms and once during the first 72 hours of life for full-terms. Macular vessel area density and nonperfusion area were evaluated on the binarized vasculature map in both small (1.5 × 1.5 mm) and large (3 × 3 mm) quadrants. Average vessel diameter and tortuosity values were obtained from each large vessel branch (length >200 µm). All vascular analyses used previously published algorithms.

Results

Handheld SS-OCTA captured 31 of 55 (56%) high-quality volumes on 8 awake preterm infants (gestational age 28 ± 4 weeks, birth weight 891 ± 314 g, postmenstrual age at first imaging session 37 ± 2 weeks) and 48 of 54 (89%) volumes on 12 awake full-term infants (gestational age 39 ± 1 weeks, birth weight 3405 ± 329 g). Signal-to-noise ratio was 5.08 ± 1.52 dB in preterm and 4.90 ± 1.12 dB in full-term infants. Preterm infants had higher mean large vessel tortuosity compared to full-term infants (P = 0.004). The large nasal quadrant vessel area density of infants with stage 3 and/or pre-plus or worse ROP was higher than other preterm infants (P = 0.007).

Conclusions

Although inadequate image quality limited usable imaging sessions, handheld SS-OCTA achieved adequate signal-to-noise ratio in nonsedated infants for quantitative retinal vascular parameter analysis.

Translational Relevance

Large- and small-vessel parameters were associated with prematurity and ROP severity, respectively.

Vitreous Findings by Handheld Spectral-Domain OCT Correlate with Retinopathy of Prematurity Severity

PURPOSE

To evaluate the association between retinopathy of prematurity (ROP) and vitreous findings in premature infants detected by handheld spectral-domain (SD) OCT.

DESIGN

Prospective, observational cohort study.

PARTICIPANTS

Consecutive sample of 92 premature infants requiring ROP screening at 2 academic neonatal intensive care units between July 2015 and March 2018.

METHODS

Infants underwent handheld SD OCT at the time of routine ROP examinations. Two masked, trained graders analyzed right-eye vitreoretinal findings, including semiautomated quantification of punctate hyperreflective vitreous opacities within 5 foveal or parafoveal B-scans (vitreous opacity ratio).

MAIN OUTCOME MEASURES

Excluding posttreatment data, vitreous findings were compared with clinical ROP diagnoses.

RESULTS

Agreement between image graders for all vitreoretinal findings was 91% (κ = 0.86; 95% confidence interval, 0.82-0.90; P < 0.001). Among 92 infants undergoing 280 imaging sessions (52% male; mean gestational age, 28.3 ± 2.8 weeks; mean birthweight, 1014.5 ± 285.0 g), 36 of 92 (39%) demonstrated ROP. Punctate hyperreflective vitreous opacities were identified in 61 of 92 infants (66%). The presence of punctate hyperreflective vitreous opacities at least once was associated with a diagnosis of ROP (62% vs. 29% without opacities; P = 0.003), maximum ROP stage (P = 0.001), preplus or plus disease (24% vs. 5%; P = 0.005), and type 1 disease (14% vs. 2%; P = 0.03). Among 29 infants (45 imaging sessions) with right-eye punctate hyperreflective vitreous opacities, the vitreous opacity ratio from 2 graders (F1 score, 0.82 ± 0.36; Dice coefficient, 0.97 ± 0.04) correlated with ROP stage (P = 0.02). Tractional vitreous bands on imaging correlated with plus disease status (29% vs. 5% without bands; P = 0.05).

CONCLUSIONS

Punctate hyperreflective vitreous opacities and tractional vitreous bands predict the presence and severity of ROP. Further studies should explore handheld OCT as a noninvasive ROP screening tool.

Auto-Processed Retinal Vessel Shadow View Images From Bedside Optical Coherence Tomography to Evaluate Plus Disease in Retinopathy of Prematurity

Purpose

To describe the creation of en face retinal vessel shadow view (RVSV) optical coherence tomography (OCT) images and assess the feasibility of using these for evaluating vascular disease in preterm infants at risk for retinopathy of prematurity (ROP).

Methods

In this exploratory study, we selected images from eyes with a range of ROP vascular disease, prospectively acquired from preterm infants using an investigational, noncontact, handheld, bedside swept-source OCT. We autosegmented OCT volumes using custom infant-specific software, extracted RVSV-OCT images from volumetric data bracketed around the retinal pigment epithelium, and automontaged the resulting RVSV-OCT images. Three masked ophthalmologists graded the RVSV-OCT montages as plus, pre-plus, or neither and ranked them by relative vascular disease severity.

Results

We selected images from 17 imaging sessions (7 plus, 4 pre-plus, 6 neither on clinical examination). On review, 15/17 (88%) RVSV-OCT montages were gradable for plus, pre-plus, or neither and all 17 montages were rankable for relative severity. Intergrader agreement for plus, pre-plus, or neither grading was good (κ, 0.67; 95% confidence interval, 0.42–0.86) and for relative severity ranking was excellent (intraclass correlation coefficient, 0.98; 95% confidence interval, 0.96–0.99).

Conclusions

Our novel automatic processing method can create RVSV-OCT montages optimized for retinal vessel visualization for ROP screening. Although our data support the feasibility of using RVSV-OCT montages for ranking relative vascular disease severity, there is room for improved OCT image capture and processing methods in preterm infants screened for ROP.

Translational Relevance

Creation and grading of RVSV-OCT images could eventually be integrated into an alternative method for ROP screening.

Development of a Retinopathy of Prematurity Activity Scale and Clinical Outcome Measures for Use in Clinical Trials

Importance

To facilitate drug and device development for neonates, the International Neonatal Consortium brings together key stakeholders, including pharmaceutical companies, practitioners, regulators, funding agencies, scientists, and families, to address the need for objective, standardized clinical trial outcome measurements to fulfill regulatory requirements. Retinopathy of prematurity (ROP) is a disease that affects preterm neonates. The current International Classification of Retinopathy of Prematurity does not take into account all of the characteristics of ROP and does not adequately discriminate small changes in disease after treatment. These factors are critical for evaluating outcomes in clinical trials.

Observations

There is need for an updated ROP acute disease activity and structure scale as well as end-stage structure and ophthalmologic outcome measures designed for use at different ages. The scale and measures, based on current diagnostic methods and treatments, could be used as a guideline for clinical intervention trials. The scale is intended to be validated against retrospective data and revised for use in future trials. An iterative revision process can be accomplished if new measures are added to clinical trials and evaluated at the end of each trial for prognostic value. The new measures would then be incorporated into a new version of the activity scale and the outcome measures revised.

Conclusions and Relevance

An ROP activity scale and outcome measures to obtain the most robust and discriminatory data for clinical trials are needed. The scales should be dynamic and modified as knowledge and imaging modalities improve and then validated using data from well-documented clinical trials. This approach is relevant to improving clinical trial data quality.

Handheld swept-source optical coherence tomography with angiography in awake premature neonates

Background

Retinopathy of prematurity (ROP) can lead to retinal detachment and severe vision loss and is a common cause of childhood blindness. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality that can be used to detect potential abnormalities in the microvasculature in this population. The objective of this study is to assess the feasibility of a newly developed handheld swept source OCT (SS-OCT) device to successfully acquire structural vitreoretinal and retinal microvascular images in awake premature infants.

Methods

OCT and OCTA images were acquired at the time of routine ROP examinations from awake, unsedated preterm infants in the Neonatal Intensive Care Unit using a clinical research prototype handheld probe integrated with an SS-OCT system working at 1,060 nm wavelength and an imaging speed of 200,000 A-scans per second (200 kHz), enabling volume OCT and OCTA scans. Each volume was acquired with approximately 36˚ field of view (~6.3×6.3 mm in infants) in 4.8 s. Quality of acquired OCT and OCTA volume images, microvascular information, and vitreoretinal features were determined by 3-masked grader consensus.

Results

Twelve infants (5 females, mean gestational age 28.3 weeks, median birth weight 901 g, stages 0 to 3 ROP) underwent a total of 73 individual eye imaging sessions. High-quality OCT images of the fovea and the optic nerve were present in 69/73 (94.5%) and 56/73 (76.7%) scans, respectively. Vitreous bands were observed in 10/73 (13.7%); punctate hyperreflective vitreous opacities in 47/73 (64.4%); epiretinal membrane (ERM) in 6/73 (8.2%); and cystoid macular edema (CME) in 12/73 (16.4%) scans. Mild vessel elevation was noted in 3/73 (4.1%) images, and severe vessel elevation in 4/73 (5.5%) scans. OCTA images obtained in 8 awake infants revealed good quality images of the foveal microvasculature in 11/19 (58%) eye imaging sessions for 6/8 (75%) infants; and peripapillary microvasculature in 14/19 (74%) eye imaging sessions for 5/8 (63%) infants.

Conclusions

The SS-OCTA handheld device can capture important vitreoretinal characteristics such as peripapillary and foveal microvasculature, as well as hyperreflective punctate vitreous opacities and tractional vitreous bands, which may predict ROP severity. These images were captured in awake, premature infants without the use of direct ocular contact, an eyelid speculum, or sedation.

Experimental Evidence Behind Clinical Trial Outcomes in Retinopathy of Prematurity

Treatment of severe retinopathy of prematurity (ROP) has evolved over the last decade. This article reviews recent clinical trials and experimental evidence that supports clinical outcomes and observations, including the efficacy of anti-vascular endothelial growth factor (VEGF) agents in reducing the vascular activity of severe ROP, and the mechanisms behind recurrent stage 3 ROP and plus disease in some infants treated with anti-VEGF agents. Also discussed will be current imaging modalities that link experimental models of ROP with longitudinal human studies and which provide exciting future opportunities to enhance the understanding of pathophysiology of ROP and improve treatments. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:228-234.].

Imaging in Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a leading cause of preventable childhood blindness worldwide. Barriers to ROP screening and difficulties with subsequent evaluation and management include poor access to care, lack of physicians trained in ROP, and issues with objective documentation. Digital retinal imaging can help address these barriers and improve our knowledge of the pathophysiology of the disease. Advancements in technology have led to new, non-mydriatic and mydriatic cameras with wider fields of view as well as devices that can simultaneously incorporate fluorescein angiography, optical coherence tomography (OCT), and OCT angiography. Image analysis in ROP is also being employed through smartphones and computer-based software. Telemedicine programs in the United States and worldwide have utilized imaging to extend ROP screening to infants in remote areas and have shown that digital retinal imaging can be reliable, accurate, and cost-effective. In addition, tele-education programs are also using digital retinal images to increase the number of healthcare providers trained in ROP. Although indirect ophthalmoscopy is still an important skill for screening, digital retinal imaging holds promise for more widespread screening and management of ROP.

Three-dimensional pattern of extraretinal neovascular development in retinopathy of prematurity

BACKGROUND

The application of three-dimensional (3D) visualization techniques to evaluate the earliest visible onset of abnormal retinal vascular development in preterm infants with retinopathy of prematurity (ROP), using bedside non-contact optical coherence tomography (OCT) imaging to characterize morphology and sequential structural changes of abnormal extraretinal neovascularization.

METHODS

Thirty-one preterm infants undergoing routine ROP screening with written informed consent for research imaging were enrolled in this prospective observational study. We imaged the macula and temporal periphery of preterm infants using a handheld OCT system (Envisu 2300 or handheld swept-source research system). The scans obtained were segmented and, using enhanced ray casting, were converted to 3D volumes to which color filter was applied.

RESULTS

Using colorized 3D visualization, we defined extraretinal neovascular structures as buds, bridging networks, and placoid lesions. We could longitudinally follow progression and regression of extraretinal neovascularization in stage 3 ROP after treatment in one infant over 12 weeks and document the appearance of early buds, and formation of florid neovascularization. From stages 2 to 3 ROP, we observed progression from sessile buds to a complex plaque that corresponded to stage 3 ROP on clinical examination. We demonstrated regression of neovascular complexes to small pre-retinal tufts after treatment with anti-VEGF.

CONCLUSIONS

The extension of OCT processing to include surface flattening and colorization that further improved structural analysis rendered better understanding of extraretinal tissue. Our ability to image similar areas in the same infant over multiple visits enabled us to study the evolution of these structural components and follow pathological vascular events longitudinally in development and regression after treatment. These methods can be applied to further study which are likely contribute to our understanding of the pathophysiology of neovascularization in ROP.

Plus Disease in Retinopathy of Prematurity: More Than Meets the ICROP?

Retinopathy of prematurity (ROP), a vasoproliferative retinal disease affecting premature infants, is a leading cause of childhood blindness throughout the world. Plus disease, defined as venous dilatation and arteriolar tortuosity within the posterior retinal vessels greater than or equal to that of a standard published photograph, is the most critical finding in identifying treatment-requiring ROP. Despite an internationally accepted definition of plus disease, there is significant variability in diagnostic process and outcome, producing variable levels of reported intra- and interexpert agreement. Several potential explanations for poor agreement have been proposed, including attention to undefined vascular features such as venous tortuosity, focus on narrower or wider field of view, unfamiliarity with digital images, the magnification and apparent severity of the standard photograph, and cut-off point differences among experts as to the level of tortuosity and dilation sufficient for "plus disease" along a continuum. Moreover, differences in diagnostic consistency among groups of experts separated both geographically and chronologically have been reported. These findings have implications for clinical care, research, and education, and highlight the need for a more precise definition of plus disease and objective diagnostic methods for ROP.

The role of intraoperative optical coherence tomography in pediatric hyphema: a case report

PURPOSE

Intraoperative optical coherence tomography (iOCT) is a valuable tool during vitreoretinal surgery, helping the decision-making process. It is particularly useful in pediatric cases to evaluate the macular anatomy intraoperatively, avoiding further potentially dangerous surgery in children. The aim of this report is to describe the role of integrated iOCT in the management of traumatic hyphema in a pediatric patient.

CASE REPORT

A 5-year-old girl was referred to our department with a history of recent domestic trauma in her right eye. Massive bleeding in the anterior chamber without visualization of the posterior segment was evident. Surgery was planned for the next day under general anesthesia. A 25-G irrigation cannula and 25-G vitrectome were inserted at the limbus into the anterior chamber for removal of the anterior chamber clot. Careful inspection of the posterior pole and retinal periphery to exclude pathologic findings was carried out. A real-time OCT integrated system was used to assess the macular anatomy and the corneal state. The postoperative course was uneventful and full visual recovery was achieved.

CONCLUSIONS

The objective confirmation of macular integrity by means of iOCT after anterior chamber clearing had great prognostic value, excluding the need for surgical revision with a second general anesthesia in this young patient.

Characterization of Long Working Distance Optical Coherence Tomography for Imaging of Pediatric Retinal Pathology

PURPOSE

We determined the feasibility of fovea and optic nerve head imaging with a long working distance (LWD) swept source optical coherence tomography (OCT) prototype in adults, teenagers, and young children.

METHODS

A prototype swept source OCT system with a LWD (defined as distance from the last optical element of the imaging system to the eye) of 350 mm with custom fixation targets was developed to facilitate imaging of children. Imaging was performed in 49 participants from three age groups: 26 adults, 16 children 13 to 18 years old (teenagers), and seven children under 6 years old (young children) under an approved institutional review board protocol. The imaging goal was to acquire high quality scans of the fovea and optic nerve in each eye in the shortest time possible. OCT B-scans and volumes of the fovea and optic nerve head of each eligible eye were captured and graded based on four categories (lateral and axial centration, contrast, and resolution) and on ability to determine presence or absence of pathology.

RESULTS

LWD-OCT imaging was successful in 88 of 94 eligible eyes, including seven of 10 eyes of young children. Of the successfully acquired OCT images, 83% of B-scan and volumetric images, including 86% from young children, were graded as high-quality scans. Pathology was observed in high-quality OCT images.

CONCLUSIONS

The prototype LWD-OCT system achieved high quality retinal imaging of adults, teenagers, and some young children with and without pathology with reasonable alignment time.

TRANSLATIONAL RELEVANCE

The LWD-OCT system can facilitate imaging in children.

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.

FUNCTIONAL OUTCOMES OF YOUNG INFANTS WITH AND WITHOUT MACULAR EDEMA

PURPOSE

The authors relate posterior segment microanatomy from perinatal spectral domain optical coherence tomography to visual acuity, brain abnormalities, and neurodevelopment.

METHODS

Thirteen infants (11 preterm and 2 term birth), imaged in the nursery with portable spectral domain optical coherence tomography, had visual acuity and sensorimotor testing at age 9 months to 15 months (grating acuity) or 4 years to 5 years (optotype), and medical records reviewed for brain magnetic resonance imaging reports and Bayley scales testing at age 18 months to 24 months.

RESULTS

Eight children with age-appropriate macular microanatomy without edema on perinatal spectral domain optical coherence tomography had optimal (≥ 20/40) or within normal limits (grating acuity) visual acuity. Five children with perinatal macular edema had suboptimal visual acuity (in 9/10 eyes) and sensorimotor deficits, magnetic resonance imaging abnormalities, or poor neurodevelopment. Macular edema persisted in 1 infant through 9-month corrected age.

CONCLUSION

Maturation of the visual system and evolution of retinal anomalies can be monitored with posterior segment spectral domain optical coherence tomography. Retinal microanatomy observed in infancy might relate to subsequent vision and other central nervous system events, but additional studies are needed to determine the range of normal microanatomy in infants and how this relates to vision and neurodevelopment.

Retinal Imaging of Infants on Spectral Domain Optical Coherence Tomography

Spectral domain coherence tomography (SD OCT) has become an important tool in the management of pediatric retinal diseases. It is a noncontact imaging device that provides detailed assessment of the microanatomy and pathology of the infant retina with a short acquisition time allowing office examination without the requirement of anesthesia. Our understanding of the development and maturation of the infant fovea has been enhanced by SD OCT allowing an in vivo assessment that correlates with histopathology. This has helped us understand the critical correlation of foveal development with visual potential in the first year of life and beyond. In this review, we summarize the recent literature on the clinical applications of SD OCT in studying the pathoanatomy of the infant macula, its ability to detect subclinical features, and its correlation with disease and vision. Retinopathy of prematurity and macular edema have been discussed in detail. The review also summarizes the current status of SD OCT in other infant retinal conditions, imaging the optic nerve, the choroid, and the retinal nerve fibre in infants and children, and suggests future areas of research.

Spectral-Domain OCT Analyses of Macular Changes After Ranibizumab Therapy for Type 1 Retinopathy of Prematurity

PURPOSE

To investigate the clinical and macular spectral-domain optical coherence tomography (SD-OCT) findings after intravitreal ranibizumab treatment for type 1 retinopathy of prematurity (ROP).

METHODS

Eighteen eyes of 10 premature infants with type 1 ROP were retrospectively studied. All eyes were treated with intravitreal ranibizumab as monotherapy. Macular SD-OCT was performed before and after intravitreal ranibizumab therapy using a portable SD-OCT machine; the follow-up images were taken 1 day, 1 week, 1 month, and 2 months after therapy.

RESULTS

Among the 10 infants, there were six males and four females. Mean central foveal thickness before and 2 months after intravitreal ranibizumab was 292.5 ± 61.4 and 171.6 ± 21.7 µm, respectively. Differences were statistically significant (P = .01). Sixteen eyes of eight patients had macular edema before treatment. Two eyes of two patients developed a crack in the outer hyperreflective line on SD-OCT corresponding with retinal pigment epithelium with serous retinal detachment 1 day after treatment. Macular edema regressed in all patients 2 months after intravitreal ranibizumab therapy. Mean follow-up time was 11.4 ± 1.5 months. No recurrence was seen except in both eyes of one patient treated with intravitreal ranibizumab monotherapy.

CONCLUSIONS

Intravitreal ranibizumab injection is effective for the treatment of type 1 ROP as a monotherapy agent; however, macular changes not seen with indirect ophthalmoscope may develop.

Assessment of retinal nerve fiber layer thickness in healthy, full-term neonates

PURPOSE

To measure average retinal nerve fiber layer (RNFL) thicknesses in healthy, full-term neonates.

DESIGN

Descriptive research to develop normative data.

METHODS

Healthy infants born between 37 and 42 weeks postmenstrual age were imaged with hand-held spectral-domain optical coherence tomography. A custom script segmented the RNFL; the fovea and optic nerve center were manually selected. A second script measured the average RNFL thickness along the papillomacular bundle, defined as the arc from -15 degrees to +15 degrees on the axis from the optic nerve to fovea, with radii of 1.1, 1.3, 1.5, and 1.7 mm from the center of the optic disc. Shapiro-Wilk W tests assessed these measurements for normality to determine the age-appropriate radial distance for subsequent analyses. Average RNFL thicknesses for four temporal 45-degree sectors (superior temporal, temporal superior, temporal inferior, and inferior temporal) and the temporal quadrant were calculated and compared to demographic parameters for all infants.

RESULTS

Fifty full-term infants were adequately imaged for RNFL analysis. RNFL thicknesses at 1.5 mm radial distance from the optic nerve were the most normally distributed. While there was a trend toward greater mean superior temporal RNFL thickness for both black and Hispanic vs white infants (128 ± 27 μm, 124 ± 30 μm, and 100 ± 19 μm, respectively, P = .04 for both comparisons), there were no other significant differences noted in RNFL thicknesses by race, sex, gestational age, or birth weight.

CONCLUSIONS

We present RNFL thickness measurements for healthy, full-term infants that may serve as normative data for future analyses.

Poorer neurodevelopmental outcomes associated with cystoid macular edema identified in preterm infants in the intensive care nursery

PURPOSE

To evaluate the association between cystoid macular edema (CME) observed in very preterm infants and developmental outcomes at 18 to 24 months corrected age.

DESIGN

Cohort study.

PARTICIPANTS

Infants born at or less than 1500 g or at or less than 30 weeks postmenstrual age who underwent screening for retinopathy of prematurity (ROP) in an intensive care nursery.

METHODS

Bedside handheld spectral-domain optical coherence tomography (SD OCT; Envisu, Bioptigen, Inc, Research Triangle Park, NC) imaging was obtained from preterm infants who were being screened for ROP and graded for presence of CME, central foveal thickness (CFT), inner nuclear layer thickness, and foveal-to-parafoveal thickness ratio. At 18 to 24 months corrected age, the children were assessed with the Bayley Scales of Infant and Toddler Development, Third Edition.

MAIN OUTCOME MEASURES

Scores on the Bayley cognitive, language, and motor subscales.

RESULTS

Among 77 children with SD OCT imaging, 53 were evaluated with the Bayley Scales. Compared with children who did not have CME as infants (n=22), the mean score for children who had CME (n=31) was 7.3 points (95% confidence interval [CI], -15.5 to 0.9; P=0.08) lower on the cognitive subscale, 14.1 points (95% CI, -22.7 to -5.5; P=0.002) lower for the language subscale, and 11.5 points (95% CI, -21.6 to -1.3; P=0.03) lower for the motor subscale. Differences were maintained after adjusting for gestational age and birth weight. Severity of CME, as assessed by foveal-to-parafoveal thickness ratio, within the CME group correlated with poorer cognitive (R2=0.16, P=0.03) and motor (R2=0.15, P=0.03) development.

CONCLUSIONS

Cystoid macular edema observed on SD OCT in very preterm infants screened for ROP is associated with poorer language and motor skills at 18 to 24 months corrected age. Evaluation of the retina with SD-OCT may serve as an indicator of neurodevelopmental health for very preterm infants in the intensive care nursery.

Evaluation of optic nerve development in preterm and term infants using handheld spectral-domain optical coherence tomography

PURPOSE

To evaluate effects of prematurity on early optic nerve (ON) development and the usefulness of ON parameters as indicators of central nervous system (CNS) development and pathology.

DESIGN

Prospective, cross-sectional, longitudinal study.

PARTICIPANTS

Forty-four preterm infants undergoing retinopathy of prematurity (ROP) screening and 52 term infants.

METHODS

We analyzed ON from portable handheld spectral-domain optical coherence tomography (SD-OCT) images (Bioptigen, Inc, Research Triangle Park, NC) of 44 preterm and 52 term infants. The highest-quality ON scan from either eye was selected for quantitative analysis. Longitudinal analysis was performed at 31-36 weeks and 37-42 weeks postmenstrual age (PMA). Preterm ON parameters also were assessed for correlation with indicators of cognitive, language, and motor development and CNS pathology.

MAIN OUTCOME MEASURES

Vertical cup diameter (vCD), vertical disc diameter (vDD), vertical cup-to-disc ratio (vCDR), cup depth, and indicators of neurocognitive development and CNS pathology.

RESULTS

At 37-42 weeks PMA, preterm infants had larger vCD and vCDR than term infants (908 vs. 700 μm [P<0.001] and 0.68 vs. 0.53 μm [P<0.001], respectively), whereas cup depth and vDD were not significantly different. Longitudinal changes (n = 26 preterm eyes; mean interval, 4.7 weeks) in vDD and in vCDR were an increase of 74 μm (P = 0.008) and decrease of 0.05 (P = 0.015), respectively. In preterm infants (n = 44), periventricular leukomalacia was associated with larger vCD (1084 vs. 828 μm; P = 0.005) and vCDR (0.85 vs. 0.63; P<0.001), posthemorrhagic hydrocephalus was associated with shallower cup (331 vs. 456 μm; P = 0.030), and clinical magnetic resonance imaging was associated with larger vCDR (0.73 vs. 0.64; P = 0.023). In 23 preterm infants with Bayley Scales of Infant Development scores, larger vCDR was associated with lower cognitive scores (P = 0.049).

CONCLUSIONS

This is the first analysis of ON parameters in premature infants using SD-OCT. It demonstrated that by age of term birth, vCD and vCDR are larger in preterm infants who were screened for ROP than in term infants. In this prospective pilot study, ON parameters in these preterm infants associate weakly with CNS pathology and future cognitive development. Future prospective studies with larger numbers are necessary before further conclusions can be made.

Modern technologies for retinal scanning and imaging: an introduction for the biomedical engineer

This review article is meant to help biomedical engineers and nonphysical scientists better understand the principles of, and the main trends in modern scanning and imaging modalities used in ophthalmology. It is intended to ease the communication between physicists, medical doctors and engineers, and hopefully encourage “classical” biomedical engineers to generate new ideas and to initiate projects in an area which has traditionally been dominated by optical physics. Most of the methods involved are applicable to other areas of biomedical optics and optoelectronics, such as microscopic imaging, spectroscopy, spectral imaging, opto-acoustic tomography, fluorescence imaging etc., all of which are with potential biomedical application. Although all described methods are novel and important, the emphasis of this review has been placed on three technologies introduced in the 1990’s and still undergoing vigorous development: Confocal Scanning Laser Ophthalmoscopy, Optical Coherence Tomography, and polarization-sensitive retinal scanning.