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

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.

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.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Translational Relevance

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

The Development and Clinical Application of Innovative Optical Ophthalmic Imaging Techniques

The field of ophthalmic imaging has grown substantially over the last years. Massive improvements in image processing and computer hardware have allowed the emergence of multiple imaging techniques of the eye that can transform patient care. The purpose of this review is to describe the most recent advances in eye imaging and explain how new technologies and imaging methods can be utilized in a clinical setting. The introduction of optical coherence tomography (OCT) was a revolution in eye imaging and has since become the standard of care for a plethora of conditions. Its most recent iterations, OCT angiography, and visible light OCT, as well as imaging modalities, such as fluorescent lifetime imaging ophthalmoscopy, would allow a more thorough evaluation of patients and provide additional information on disease processes. Toward that goal, the application of adaptive optics (AO) and full-field scanning to a variety of eye imaging techniques has further allowed the histologic study of single cells in the retina and anterior segment. Toward the goal of remote eye care and more accessible eye imaging, methods such as handheld OCT devices and imaging through smartphones, have emerged. Finally, incorporating artificial intelligence (AI) in eye images has the potential to become a new milestone for eye imaging while also contributing in social aspects of eye care.