The use of handheld spectral domain optical coherence tomography in pediatric ophthalmology practice: Our experience of 975 infants and children

Artificial Intelligence, Digital Imaging, and Robotics Technologies for Surgical Vitreoretinal Diseases

OBJECTIVE

To review recent technological advancement in imaging, surgical visualization, robotics technology, and the use of artificial intelligence in surgical vitreoretinal (VR) diseases.

BACKGROUND

Technological advancements in imaging enhance both preoperative and intraoperative management of surgical VR diseases. Widefield imaging in fundal photography and OCT can improve assessment of peripheral retinal disorders such as retinal detachments, degeneration, and tumors. OCT angiography provides a rapid and noninvasive imaging of the retinal and choroidal vasculature. Surgical visualization has also improved with intraoperative OCT providing a detailed real-time assessment of retinal layers to guide surgical decisions. Heads-up display and head-mounted display utilize 3-dimensional technology to provide surgeons with enhanced visual guidance and improved ergonomics during surgery. Intraocular robotics technology allows for greater surgical precision and is shown to be useful in retinal vein cannulation and subretinal drug delivery. In addition, deep learning techniques leverage on diverse data including widefield retinal photography and OCT for better predictive accuracy in classification, segmentation, and prognostication of many surgical VR diseases.

CONCLUSION

This review article summarized the latest updates in these areas and highlights the importance of continuous innovation and improvement in technology within the field. These advancements have the potential to reshape management of surgical VR diseases in the very near future and to ultimately improve patient care.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Handheld contact-type OCT and color fundus system for retinal imaging

We present proof of concept for a handheld contact-type system capable of simultaneous optical coherence tomography (OCT) imaging of the retina and wide-field digital fundus color photography. The study focuses on demonstrating the feasibility of the proposed approach, particularly for eventual use in pediatric patients during examination under anesthesia in the operating room and in the neonatal intensive care unit. Direct contact of the probe with the cornea allows the photographer to maintain a stable position during imaging, reducing motion artifacts in the OCT images. Additionally, it simplifies the alignment process and increases the field of view of the optics. By integrating OCT and fundus imaging into a single device, the proposed compact modular design eliminates the need for separate, space-consuming systems dedicated to each imaging modality.

Diagnostic Imaging for Retinoblastoma Cancer Staging: Guide for Providing Essential Insights for Ophthalmologists and Oncologists

Retinoblastoma is the most common cause of all intraocular pediatric malignancies. It is caused by the loss of RB1 tumor suppressor gene function, although some tumors occur due to MYCN oncogene amplification with normal RB1 genes. Nearly half of all retinoblastomas occur due to a hereditary germline RB1 pathogenic variant, most of which manifest with bilateral tumors. This germline RB1 mutation also predisposes to intracranial midline embryonal tumors. Accurate staging of retinoblastoma is crucial in providing optimal vision-, eye-, and life-saving treatment. The AJCC Cancer Staging Manual has undergone significant changes, resulting in a universally accepted system with a multidisciplinary approach for managing retinoblastoma. The authors discuss the role of MRI and other diagnostic imaging techniques in the pretreatment assessment and staging of retinoblastoma. A thorough overview of the prevailing imaging standards and evidence-based perspectives on the benefits and drawbacks of these techniques is provided. Published under a CC BY 4.0 license. Test Your Knowledge questions for this article are available in the supplemental material.

Ophthalmic imaging in abusive head trauma

BACKGROUND

Ophthalmic imaging plays an increasingly important role the evaluation of abusive head trauma, however these imaging modalities may be unfamiliar to non-ophthalmologists.

OBJECTIVE

To provide pediatricians and child abuse pediatric professionals with background on ophthalmic imaging techniques in the context of suspected abuse, as well as information on commercial options and costs for those interested in augmenting their ophthalmic imaging capabilities.

METHODS

We performed a review of the ophthalmic imaging literature for fundus photography, ocular coherence tomography, fluorescein angiography, ocular ultrasound, computed tomography, magnetic resonance imaging and postmortem imaging. We also contacted individual vendors for equipment pricing information.

RESULTS

For each ophthalmic imaging modality, we demonstrate its role in the evaluation of abusive head trauma including indications, potential findings, sensitivity and specificity of findings for abuse, and commercial options.

CONCLUSIONS

Ophthalmic imaging is an important supportive component of the evaluation for abusive head trauma. When used in conjunction with clinical examination, ophthalmic imaging can improve diagnostic accuracy, support documentation, and possibly improve communication in medicolegal contexts.

Intraoperative OCT for Lamellar Corneal Surgery: A User Guide

Intraoperative OCT is an innovative and promising technology which allows anterior and posterior segment ocular surgeons to obtain a near-histologic cross-sectional and tomographic image of the tissues. Intraoperative OCT has several applications in ocular surgery which are particularly interesting in the context of corneal transplantation. Indeed, iOCT images provide a direct and meticulous visualization of the anatomy, which could guide surgical decisions. In particular, during both big-bubble and manual DALK, the visualization of the relationship between the corneal layers and instruments allows the surgeon to obtain a more desirable depth of the trephination, thus achieving more type 1 bubbles, better regularity of the plane, and a reduced risk of DM perforation. During EK procedures, iOCT supplies information about proper descemetorhexis, graft orientation, and interface quality in order to optimize the postoperative adhesion and reduce the need for re-bubbling. Finally, mushroom PK, a challenging technique for many surgeons, can be aided through the use of iOCT since it guides the correct apposition of the lamellae and their centration. The technology of iOCT is still evolving: a larger field of view could allow for the visualization of all surgical fields, and automated tracking and iOCT autofocusing guarantee the continued centration of the image.

Posterior Segment Optical Coherence Tomography in Uncooperative Paediatric Patients Using Exo-Illumination and Microscope-Integrated Optical Coherence Tomography

BACKGROUND AND OBJECTIVE

To describe a non-invasive technique for the acquisition of retinal optical coherence tomography (OCT) scans in paediatric patients undergoing examination under general anaesthesia (EUA) using microscope-integrated OCT (MIOCT).

STUDY DESIGN

Prospective observational study Methods and Material: The study included 10 paediatric patients undergoing EUA for posterior segment pathology. These patients underwent OCT using MIOCT. No sclerotomy was made during imaging. The fundus was externally illuminated with a 25 gauge endoilluminator probe placed at the limbus and directed towards the posterior pole to aid in image acquisition by MIOCT (exo-illumination). Imaging for all patients was done by two trained vitreoretinal surgeons independently. Acquisition time was recorded for each surgeon. Interobserver variability in acquisition time and image quality was assessed to estimate the reliability of the novel imaging technique.

RESULTS

In nine cases (90%), MIOCT successfully imaged the posterior segment pathology while in one case (10%) of X-linked retinoschisis, it failed to detect an inner retinal break located anteriorly at the equator. The mean acquisition time for surgeons one and two was 211.75 ± 26.00 and 212.58 ± 23.47 seconds, respectively. There was no significant difference in total image acquisition time between the two surgeons (P = 1.0) and the findings of both surgeons were comparable for structural morphology. 4x4 mm-sized scans provided the best delineation in macular pathology, while a 16x16 mm scan size was best suited for localising the area of interest and post-equatorial pathology.

CONCLUSION

Using this technique acquisition of posterior segment OCT scans can be achieved non-invasively, using exo-illumination and MIOCT in paediatric patients undergoing EUA.

Ophthalmological Manifestations of Oculocutaneous and Ocular Albinism: Current Perspectives

Albinism describes a heterogeneous group of genetically determined disorders characterized by disrupted synthesis of melanin and a range of developmental ocular abnormalities. The main ocular features common to both oculocutaneous albinism (OCA), and ocular albinism (OA) include reduced visual acuity, refractive errors, foveal hypoplasia, congenital nystagmus, iris and fundus hypopigmentation and visual pathway misrouting, but clinical signs vary and there is phenotypic overlap with other pathologies. This study reviews the prevalence, genetics and ocular manifestations of OCA and OA, including abnormal development of the optic chiasm. The role of visual electrophysiology in the detection of chiasmal dysfunction and visual pathway misrouting is emphasized, highlighting how age-associated changes in visual evoked potential (VEP) test results must be considered to enable accurate diagnosis, and illustrated further by the inclusion of novel VEP data in genetically confirmed cases. Differential diagnosis is considered in the context of suspected retinal and other disorders, including rare syndromes that may masquerade as albinism.

Portable boom-type ultrahigh-resolution OCT with an integrated imaging probe for supine position retinal imaging

To expand the clinical applications and improve the ease of use of ultrahigh-resolution optical coherence tomography (UHR-OCT), we developed a portable boom-type ophthalmic UHR-OCT operating in supine position that can be used for pediatric subjects, bedridden patients and perioperative conditions. By integrating the OCT sample arm probe with real-time iris display and automatic focusing electric lens for easy alignment, coupling the probe on a self-locking multi-directional manipulator to reduce motion artifacts and operator fatigue, and installing the OCT module on a moveable cart for system mobility, our customized portable boom-type UHR-OCT enables non-contact, high-resolution and high-stability retinal examinations to be performed on subjects in supine position. The spectral-domain UHR-OCT operates at a wavelength of 845 nm with 130 nm FWHM (full width at half maximum) bandwidth, achieving an axial resolution of ≈2.3µm in tissue with an A-line acquisition rate up to 128 kHz. A high-definition two-dimensional (2D) raster protocol was used for high-quality cross-sectional imaging while a cube volume three-dimensional (3D) scan was used for three-dimensional imaging and en-face reconstruction, resolving major layer structures of the retina. The feasibility of the system was demonstrated by performing supine position 2D/3D retinal imaging on healthy human subjects, sedated infants, and non-sedated awake neonates.

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.

Management of nystagmus in children: a review of the literature and current practice in UK specialist services

Nystagmus is an eye movement disorder characterised by abnormal, involuntary rhythmic oscillations of one or both eyes, initiated by a slow phase. It is not uncommon in the UK and regularly seen in paediatric ophthalmology and adult general/strabismus clinics. In some cases, it occurs in isolation, and in others, it occurs as part of a multisystem disorder, severe visual impairment or neurological disorder. Similarly, in some cases, visual acuity can be normal and in others can be severely degraded. Furthermore, the impact on vision goes well beyond static acuity alone, is rarely measured and may vary on a minute-to-minute, day-to-day or month-to-month basis. For these reasons, management of children with nystagmus in the UK is varied, and patients report hugely different experiences and investigations. In this review, we hope to shine a light on the current management of children with nystagmus across five specialist centres in the UK in order to present, for the first time, a consensus on investigation and clinical management.

Intraoperative optical coherence tomography in anterior segment surgery

Intraoperative optical coherence tomography (iOCT) enables real-time visualization of ocular structures during surgery and enhances our understanding of intraoperative dynamics. iOCT aids in decision-making during various anterior segment surgeries, and its efficacy and feasibility in anterior lamellar keratoplasty and endothelial keratoplasty is well established. The landmark DISCOVER study observed that iOCT altered the surgeon decision in 38% of cases undergoing lamellar keratoplasty and provided guidance regarding the need for secondary surgical intervention. iOCT also finds an application in phacoemulsification wherein it helps to assess corneal incisions, intralenticular pressure, and posterior capsule integrity during nuclear emulsification. iOCT aids in the visualization of angle structures during placement of tubes and shunts in glaucoma surgeries and allows precise creation of partial thickness scleral flaps. In addition, iOCT helps in establishing a diagnosis, as well as provide intraoperative guidance, in pediatric patients who are not cooperative for examination. The role of iOCT in refractive surgeries and ocular surface disorders is increasingly being evaluated. The limitations of present-day iOCT systems are related to instrument compatibility, automated tracking of the surgical field, and on-table volumetric analysis of the real-time images. Technological advances may facilitate complete integration of OCT in the surgical microscopes for all surgical procedures.

Swept-source optical coherence tomography features of regressed macular retinoblastoma

Purpose:

To describe the swept-source optical coherence tomography (SS-OCT) features of regressed macular retinoblastoma (RB).

Methods:

A cross-sectional observational study was carried out in 13 patients with regressed macular RB with good fixation in at least one eye. Fundus photography and SS-OCT were documented. High-resolution scans with good signal strength were selected. The types of clinical regression and SS-OCT characteristics of the regressed lesions (presence of vitreous detachment, intratumor schisis/cavitation, calcification, foveal dip, and OCT pattern) were noted.

Results:

Of the 13 eyes, 7 (53%) were group B, 4 (30%) were group C, and 2 (17%) were group D. Lesion involving fovea was seen in seven eyes (53%). On SS-OCT, the lesion was isodense to hyperdense in all cases. Three patterns of regressed RB were noted on OCT. Intralesion calcification was noted in eight cases. Subretinal fluid was not detected in any of the cases.

Conclusion:

SS-OCT is a useful technology to image and analyze cases of regressed macular RB including large lesions. SS-OCT system helps in successful imaging even in smaller children.

Optical coherence tomography (OCT) to image active and inactive retinoblastomas as well as retinomas

PURPOSE

To illustrate Optical Coherence Tomography (OCT) images of active and inactive retinoblastoma (Rb) tumours.

METHODS

Current observational study included patients diagnosed with retinoblastoma and retinoma who were presented at Amsterdam UMC and Jules-Gonin Eye Hospital, between November 2010 and October 2017. Patients aged between 0 and 4 years were imaged under general anaesthesia with handheld OCT in supine position. Patients older than 4 years were imaged with the conventional OCT (Heidelberg Engineering, Heidelberg Spectralis, Germany). All patients included were divided into two groups: active and inactive tumours (retinoma and regression patterns). Patients' medical records and OCT images were analysed during meetings via discussions by ophthalmologists and physicists.

RESULTS

Twelve Dutch and 8 Swiss patients were divided into two groups: 2 patients with active tumour versus 18 patients with inactive tumour. Subsequently, inactive group could be divided in two groups, which consisted of 10 patients with retinoma and 8 patients with different regression pattern types. Of all included patients, 15 were male (75%). Median age at diagnosis was 18.0 months (range 0.19-715.2 months). A total of 12 retinoblastoma (active and inactive) and 8 retinoma foci were investigated by OCT. No distinction could be made between active and inactive tumours using only OCT.

CONCLUSION

Optical coherence tomography alone cannot distinguish between active and inactive Rbs. However, handheld OCT adds useful information to the established imaging techniques in the monitoring and follow-up of retinoblastoma patients. With this study, we provide an overview of OCT images of active and inactive Rbs.

HAND-HELD OPTICAL COHERENCE TOMOGRAPHY MONITORING OF CHEMORESISTANT RETINOBLASTOMA

PURPOSE

Retinoblastoma (Rb) is a potentially fatal intraocular malignancy in children, and hand-held optical coherence tomography (HH-OCT) can assist in submillimeter detection and monitoring after treatment of Rb. Retinoblastoma located in the macula, or those with chemoresistance, can be among the most difficult to manage. We describe HH-OCT features in a case of chemoresistant macular Rb that eventually responded to plaque radiotherapy after failing intravenous chemotherapy and intraarterial chemotherapy.

METHODS

Observational case report.

RESULTS

A 15-month-old girl with leukocoria was found to have Group D Rb in the right eye of 6-mm thickness and macular Group B Rb in the left eye of 4-mm thickness. She was treated with 6-monthly cycles of systemic intravenous chemotherapy and focal consolidation therapies to both eyes, with tumor regression in both eyes. However, macular tumor in the left eye demonstrated subsequent recurrence, from regressed thickness of 792 μm on HH-OCT to a dome-shaped hyperreflective retinal mass of >2000 μm thickness. Three cycles of intraarterial chemotherapy were sufficient for tumor regression down to 977 μm thickness on HH-OCT. Six months later, macular tumor in the left eye recurred again to >2000 μm thickness and necessitated plaque radiotherapy using apex dose of 35 Gy over 95.25 hours. Hand-held OCT confirmed rapid tumor regression to 722 μm after plaque treatment and regression remained stable at 6-month follow-up.

CONCLUSION

Hand-held OCT was critical in assessment of Rb after failed intravenous chemotherapy and intraarterial chemotherapy and later documenting regression after plaque radiotherapy. Hand-held OCT is vital in providing cross-sectional imaging and measurements of small macular and paramacular Rbs.

Optical coherence tomography (OCT) in unconscious and systemically unwell patients using a mobile OCT device: a pilot study

OBJECTIVE

This study aims to evaluate the feasibility of retinal imaging in critical care using a novel mobile optical coherence tomography (OCT) device. The Heidelberg SPECTRALIS FLEX module (Heidelberg Engineering, Heidelberg, Germany) is an OCT unit with a boom arm, enabling ocular OCT assessment in less mobile patients.

DESIGN

We undertook an evaluation of the feasibility of using the SPECTRALIS FLEX for undertaking ocular OCT images in unconscious and critically ill patients.

SETTING

This study was conducted in the critical care unit of a large tertiary referral unit in the United Kingdom.

PARTICIPANTS

13 systemically unwell patients admitted to the critical care unit were purposively sampled to enable evaluation in patients with a range of clinical states.

OUTCOME MEASURES

The primary outcome was the feasibility of acquiring clinically interpretable OCT scans on a consecutive series of patients. The standardised scanning protocol included macula-focused OCT, OCT optic nerve head (ONH), OCT angiography (OCTA) of the macula and ONH OCTA.

RESULTS

OCT images from 13 patients were attempted. The success rates of each scan type are 84% for OCT macula, 76% for OCT ONH, 56% for OCTA macula and 36% for OCTA ONH. The overall mean success rate of scans per patient was 64% (95% CI 46% to 81%). Clinicians reported clinical value in 100% scans which were successfully obtained, including both ruling in and ruling out relevant ocular complications such as corneal thinning, macular oedema and optic disc swelling. The most common causes of failure to achieve clinically interpretable scans were inadequately sustained OCT alignment in delirious patients and a compromised ocular surface due to corneal exposure.

CONCLUSIONS

This prospective evaluation indicates the feasibility and potential clinical value of the SPECTRALIS FLEX OCT system on the critical care unit. Portable OCT systems have the potential to bring instrument-based ophthalmic assessment to critically ill patients, enabling detection and micron-level monitoring of ocular complications.

Handheld spectrally encoded coherence tomography and reflectometry for motion-corrected ophthalmic optical coherence tomography and optical coherence tomography angiography

Optical coherence tomography (OCT) is the gold standard for quantitative ophthalmic imaging. The majority of commercial and research systems require patients to fixate and be imaged in a seated upright position, which limits the ability to perform ophthalmic imaging in bedridden or pediatric patients. Handheld OCT devices overcome this limitation, but image quality often suffers due to a lack of real-time aiming and patient eye and photographer motion. We describe a handheld spectrally encoded coherence tomography and reflectometry (SECTR) system that enables simultaneous en face reflectance and cross-sectional OCT imaging. The handheld probe utilizes a custom double-pass scan lens for fully telecentric OCT scanning with a compact optomechanical design and a rapid-prototyped enclosure to reduce the overall system size and weight. We also introduce a variable velocity scan waveform that allows for simultaneous acquisition of densely sampled OCT angiography (OCTA) volumes and widefield reflectance images, which enables high-resolution vascular imaging with precision motion-tracking for volumetric motion correction and multivolumetric mosaicking. Finally, we demonstrate in vivo human retinal OCT and OCT angiography (OCTA) imaging using handheld SECTR on a healthy volunteer. Clinical translation of handheld SECTR will allow for high-speed, motion-corrected widefield OCT and OCTA imaging in bedridden and pediatric patients who may benefit ophthalmic disease diagnosis and monitoring.

Ergonomic handheld OCT angiography probe optimized for pediatric and supine imaging

OCT angiography is a functional extension of OCT that allows for non-invasive imaging of retinal microvasculature. However, most current OCT angiography systems are tabletop systems that are typically used for imaging compliant, seated subjects. These systems cannot be readily applied for imaging important patient populations such as bedridden patients, patients undergoing surgery in the operating room, young children in the clinic, and infants in the intensive care nursery. In this manuscript, we describe the design and development of a non-contact, handheld probe optimized for OCT angiography that features a novel diverging light on the scanner optical design that provides improved optical performance over traditional OCT scanner designs. Unlike most handheld OCT probes, which are designed to be held by the side of the case or by a handle, the new probe was optimized for ergonomics of supine imaging where imagers prefer to hold the probe by the lens tube. The probe's design also includes an adjustable brace that gives the operator a point of contact closer to the center of mass of the probe, reducing the moment of inertia around the operator's fingers, facilitating stabilization, and reducing operator fatigue. The probe supports high-speed imaging using a 200 kHz swept source OCT engine, has a motorized stage that provides + 10 to -10 D refractive error correction and weighs 700g. We present initial handheld OCT angiography images from healthy adult volunteers, young children during exams under anesthesia, and non-sedated infants in the intensive care nursery. To the best of our knowledge, this represents the first reported use of handheld OCT angiography in non-sedated infants, and the first handheld OCT angiography images which show the clear delineation of key features of the retinal capillary complex including the foveal avascular zone, peripapillary vasculature, the superficial vascular complex, and the deep vascular complex.

Optical coherence tomography in paediatric clinical practice

Optical coherence tomography is a non-invasive ocular imaging technique that is frequently used in the diagnosis and monitoring of optic nerve or retinal disease. Advances in optical coherence tomography speed and image processing capability allow increased use of the modality in clinical practice, especially in younger children. This review outlines the challenges involved in imaging children, highlights the technological progress, the importance of acquiring normative data and, finally, focuses on the clinical applicability of optical coherence tomography in our paediatric population with various ocular conditions.

Development of a clinical prototype of a miniature hand-held optical coherence tomography probe for prematurity and pediatric ophthalmic imaging

We report a novel design and operation of a highly integrated miniature handheld OCT probe, with high-speed angiography function that can be used in clinical settings for young children and infants, providing rapid, non-invasive structural and angiographic imaging of the retina and choroid. The imaging system is operated at 200 kHz, with 3D OCT and OCTA scan time of 0.8 and 3.2 seconds, respectively, and the scanning angle on the pupil is ± 36°, covering the full perifoveal region. Operator assisting features of the direct-view iris camera and on-probe display are integrated into the hand-held probe, and the fixation target can display animations to attract the attention of young subjects. Compared to conventional OCT systems, the high-speed hand-held OCT system significantly improves the operator's experience and scanning efficiency, which is important for imaging infants. Imaging results indicate a significant reduction in total time consumption in pediatric ophthalmic imaging sessions, as well as the image quality of OCT angiography.

Long term follow-up of a family with GUCY2D dominant cone dystrophy

AIM

To describe long term follow-up in a family with GUCY2D dominant cone dystrophy.

METHODS

Optical coherence tomography scans and fundus autofluorescence images were obtained. Flash and pattern electroretinograms (ERGs) and occipital pattern reversal visual evoked potentials were recorded.

RESULTS

Two members of the same family (father and son) were identified to have the heterozygous R838C mutation in the GUCY2D gene. The father presented at the age of 45 with bilateral bull's eye maculopathy and temporal disc pallor. Over 13y of serial follow up visits, the bull's eye maculopathy progressed gradually into macular atrophy. Electrophysiological tests were significantly degraded suggesting poor macular function. Spectral-domain optical coherence tomography (SD-OCT) scans showed progressive loss and disruption of the ellipsoid layer at the foveal level. His son presented at the age of 16 with bilateral granular retinal pigment epithelial changes in both maculae. Electrophysiological testing was initially borderline normal but has gradually deteriorated to show reduced cone ERGs and macula function. SD-OCT demonstrated gradual macular thinning and atrophy bilaterally. Unlike his father, there was no disruption of the ellipsoid layer.

CONCLUSION

Both family members exhibited gradual changes in their fundi, electrophysiological testing and multimodal imaging. Changes were milder than those observed in other mutations of the same gene.

Detection of Candida Endophthalmitis in a Newborn Using Handheld Spectral-Domain Optical Coherence Tomography

In a newborn with candidemia, two retinal lesions were seen without external inflammatory signs or reaction in the anterior chamber or vitreous. However, handheld spectral domain-optical coherence tomography (HH SD-OCT) images show that one of the retinal lesions had a “firework display” projecting to the vitreous that was not identified in indirect ophthalmoscopy. This finding suggested a Candida endophthalmitis. HH SD-OCT findings allowed us to make an accurate diagnosis and, therefore, modified the decision-making process in the treatment of the pathology.

Hand-held Optical Coherence Tomography Monitoring of Submillimeter Retinoblastoma Treated with Indocyanine Green-enhanced Transpupillary Therapy

Over recent years, hand-held optical coherence tomography (HH-OCT) has become critical for retinoblastoma diagnosis and management. We report precise HH-OCT findings in a case of sub-millimeter retinoblastoma treated with foveal-sparing indocyanine green-enhanced transpupillary thermotherapy (ICG-TTT). A 2-month-old Caucasian female with bilateral Group B retinoblastoma showed two recurrent macular tumors in the right eye, demonstrating 88 μm and 37 μm of growth to 344 μm and 413 μm in thickness, respectively, on HH-OCT. Each was treated with additional intravenous chemotherapy and foveal-sparing ICG-TTT. Tumor regression to 154 μm and 224 μm was documented on HH-OCT and maintained on follow-up. HH-OCT is vital in confirming clinical findings and influencing management decisions in retinoblastoma. In this case, HH-OCT precisely documented submillimeter retinoblastoma recurrence and treatment response.

Parafoveolar retinoblastoma regression with foveal preservation following intra-arterial chemotherapy documented on hand-held optical coherence tomography in a newborn

Background

Optical coherence tomography (OCT) has become an invaluable tool in retinoblastoma management, providing submillimeter visualization of tumor control following treatment. Herein, we document OCT-detection of a subtle tumor recurrence, allowing early intervention and achieving foveal microanatomy preservation.

Case presentation

A 3-week-old girl was diagnosed with bilateral familial retinoblastoma, classified as group D in the right eye (OD) and group B in the left eye (OS), and treated with intravenous chemoreduction. At 6-months follow-up, the right eye was under control, but the left eye revealed a subtle juxtafoveal tumor recurrence, documented on handheld OCT (HH-OCT) and measuring 2750 µm in diameter and 792 µm in thickness. Treatment with intraarterial chemotherapy (IAC) using 1 cycle of melphalan 5 mg was performed and complete tumor control was achieved, leaving a flat, concave scar 663 µm from the intact foveola and measuring 2750 µm in diameter and 120 µm in thickness. Foveal microanatomy OS was preserved on HH-OCT. The findings remained stable at 2 years following IAC.

Conclusions

HH-OCT is an important tool in retinoblastoma management. In this case, HH-OCT allowed for early detection of retinoblastoma recurrence, before foveal invasion. Following treatment with IAC, complete tumor regression was noted and foveal microanatomy remained intact.

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.

Retinoblastoma: Update on Current Management

Retinoblastoma is a rare cancer in children, where in less than a century of dire mortality there has been a cure in industrialized countries. Unfortunately, mortality remains high in emerging countries. The evolution of treatment makes it possible to go further by preserving the eyeball but this must not be done at the cost of the reappearance of metastases. Herein we outline the evolution of treatment from the beginning of the 20th century until the last recent evolutions, trying to imagine what could be the future treatments. In this pathology, the ophthalmologist is a doctor who must cure his patient and enucleation is considered a failure. This situation should not lead to shizophrenic situations where to keep an eye one would take risks with the life of the child. New international classifications, international prospective multicentric studies, and the search for blood biomarkers that can predict the risk of micrometastases could allow for better stratification of patients.

Optical Coherence Tomography-Guided Decisions in Retinoblastoma Management

PURPOSE

Assess the role of handheld optical coherence tomography (OCT) in guiding management decisions during diagnosis, treatment, and follow-up of eyes affected by retinoblastoma.

DESIGN

Retrospective, noncomparative, single-institution case series.

PARTICIPANTS

All children newly diagnosed with retinoblastoma from January 2011 to December 2015 who had an OCT session during their active treatment at The Hospital for Sick Children (SickKids) in Toronto, Canada. The OCT sessions for fellow eyes of unilateral retinoblastoma without any suspicious lesion and those performed more than 6 months after the last treatment were excluded.

METHODS

Data collected included age at presentation, sex, family history, RB1 mutation status, 8th edition TNMH cancer staging and International Intraocular Retinoblastoma Classification (IIRC), and number of OCT sessions per eye. Details of each session were scored for indication-related details (informative or not) and assessed for guidance (directive or not), diagnosis (staging changed, new tumors found or excluded), treatment (modified, stopped, or modality shifted), or follow-up modified.

MAIN OUTCOME MEASURES

Frequency of OCT-guided management decisions, stratified by indication and type of guidance (confirmatory vs. influential).

RESULTS

Sixty-three eyes of 44 children had 339 OCT sessions over the course of clinical management (median number of OCT scans per eye, 5; range, 1-15). The age at presentation and presence of a heritable RB1 mutation significantly correlated with an increased number of OCT sessions. Indications included evaluation of post-treatment scar (55%) or fovea (16%), and posterior pole scanning for new tumors (11%). Of all sessions, 92% (312/339) were informative; 19 of 27 noninformative sessions had large, elevated lesions; of these, 14 of 19 were T2a or T2b (IIRC group C or D) eyes. In 94% (293/312) of the informative sessions, OCT directed treatment decisions (58%), diagnosis (16%), and follow-up (26%). Optical coherence tomography influenced and changed management from pre-OCT clinical plans in 15% of all OCT sessions and 17% of directive sessions.

CONCLUSIONS

Optical coherence tomography improves the accuracy of clinical evaluation in retinoblastoma management.

Establishment of a novel retinoblastoma (Rb) nude mouse model by intravitreal injection of human Rb Y79 cells - comparison of in vivo analysis versus histological follow up

Retinoblastoma (Rb) is the most frequent primary intraocular tumour in children and, if left untreated, can cause death. Preclinical animal models that mimic molecular, genetic, and cellular features of cancers are essential for studying cancer and searching for promising diagnosis and treatment modalities. There are several models described for Rb, but none of them fully meet our requirements. The aim of this study was to create a novel xenograft-nude mouse-model with broad application possibilities, which closely resembles the clinical observations of Rb patients and which could be used to investigate the development and spread of the tumour by using scanning laser ophthalmoscopy/optical coherence tomography (SLO/OCT) as well as histology methods. We injected human retinoblastoma Y79 cells intravitreally in both eyes of immune-deficient nude mice. The incidences of retinoblastoma as well as growth velocity were analysed 3, 6, 9 and 12 weeks after cell injection in vivo by SLO/OCT as well as ex vivo by electron microscopy (EM) and hematoxylin/eosin (HE) staining. Moreover, internal organs were histologically screened for potentially occurring metastases. Three weeks post-injection, animals developed a retinoblastoma, and after five weeks tumour growth resulted in swelling of the eyes in individual animals, showing a similar phenotype to that of untreated Rb patients at advanced stages of tumour-development. After 12 weeks, 67.5% of all analysed eyes (29 of 42) contained a retinoblastoma. At early stages of Rb development, the SLO/OCT analysis correlated with the histology results. If the tumours were too large, only histological investigations were feasible. The ultrastructural characteristics of the xenograft-tumours were very similar to those described for patient's tumours. In one mouse, brain metastases were observed. Our retinoblastoma mouse model closely resembles the human disease. SLO/OCT can be used for the detection of Rb at early stages of development and could be used for monitoring the success of future therapies.

Summary: We present a novel retinoblastoma nude xenograft mouse model which closely resembles the human disease and allows broad application possibilities and a comparison of in vivo and histological analysis.