Objective: To demonstrate optical coherence tomography for high-resolution, noninvasive imaging of the human retina. Optical coherence tomography is a new imaging technique analogous to ultrasound B scan that can provide cross-sectional images of the retina with micrometer-scale resolution. Design: Survey optical coherence tomographic examination of the retina, including the macula and optic nerve head in normal human subjects. Settings Research laboratory. Participants: Convenience sample of normal human subjects. Main Outcome Measures: Correlation of optical coherence retinal tomographs with known normal retinal anatomy. Results: Optical coherence tomographs can discriminate the cross-sectional morphologic features of the fovea and optic disc, the layered structure of the retina, and normal anatomic variations in retinal and retinal nerve fiber layer thicknesses with 10- μm depth resolution. Conclusion: Optical coherence tomography is a potentially useful technique for high depth resolution, cross-sectional examination of the fundus.

Optical Coherence Tomography of the Human Retina

State-of-the-art retinal optical coherence tomography

In the past two decades, optical coherence tomography (OCT) has been established as an adjunct diagnostic technique for noninvasive, high-resolution, cross-sectional imaging in a variety of medical fields. The rapid development of ultrabroad bandwidth light sources has recently enabled a significant improvement in OCT imaging resolution, demonstrating the potential of OCT to accomplish its original goal of performing noninvasive optical biopsies, i.e., the in vivo visualization of microstructural morphology in situ, which had previously only been possible with histopathology. In addition, these novel light sources might also enable the use of spectroscopic OCT, an extension of ultrahigh-resolution OCT, for enhancing image contrast as well as detecting spatially resolved functional, biochemical tissue information. State-of-the-art-light sources that now permit ultrahigh-resolution OCT covering the whole wavelength region from 500 to 1600 nm are reviewed and fundamental limitations of OCT image resolution are discussed. Ex vivo ultrahigh-resolution OCT tomograms are compared with histological results; first clinical in vivo ultrahigh-resolution OCT and preliminary spectroscopic OCT results are presented and their impact for future clinical and research applications is discussed.

Ultrahigh Resolution Optical Coherence Tomography

Objectives To demonstrate a new generation of ophthalmic optical coherence tomography(OCT) technology with unprecedented axial resolution for enhanced imaging of intraretinal microstructures and to investigate its clinical feasibility to visualize intraretinal morphology of macular pathology. Methods A clinically viable ultrahigh-resolution ophthalmic OCT system was developed and used in clinical imaging for the first time. Fifty-six eyes of 40 selected patients with different macular diseases including macular hole, macular edema, age-related macular degeneration, central serous chorioretinopathy, epiretinal membranes, and detachment of pigment epithelium and sensory retina were included. Outcome Measures Ultrahigh-resolution tomograms visualizing intraretinal morphologic features in different retinal diseases. Results An axial image resolution of approximately 3 µm was achieved in the eyes examined, nearly 2 orders of magnitude better than conventional ophthalmic ultrasound. Ultrahigh-resolution OCT images provided additional diagnostically important information on intraretinal morphologic features that could not have been obtained by standard techniques. Conclusions Ultrahigh-resolution ophthalmic OCT enables unprecedented visualization of intraretinal morphologic features and therefore has the potential to contribute to a better understanding of ocular pathogenesis, as well as to enhance the sensitivity and specificity for early ophthalmic diagnosis and to monitor the efficacy of therapy. This study establishes a baseline for the interpretation of ultrahigh-resolution ophthalmic OCT imaging of macular diseases.

https://jamanetwork.com/journals/OPHTH/articlepdf/415327/eni20007.pdf

Enhanced visualization of macular pathology with the use of ultrahigh-resolution optical coherence tomography.

Since its introduction, optical coherence tomography OCT technology has advanced from the laboratory bench to the clinic and back again. Arising from the fields of low coherence inter- ferometry and optical time- and frequency-domain reflectometry, OCT was initially demonstrated for retinal imaging and followed a unique path to commercialization for clinical use. Concurrently, sig- nificant technological advances were brought about from within the research community, including improved laser sources, beam delivery instruments, and detection schemes. While many of these technolo- gies improved retinal imaging, they also allowed for the application of OCT to many new clinical areas. As a result, OCT has been clinically demonstrated in a diverse set of medical and surgical specialties, in- cluding gastroenterology, dermatology, cardiology, and oncology, among others. The lessons learned in the clinic are currently spurring a new set of advances in the laboratory that will again expand the clinical use of OCT by adding molecular sensitivity, improving image quality, and increasing acquisition speeds. This continuous cycle of laboratory development and clinical application has allowed the OCT technology to grow at a rapid rate and represents a unique model for the translation of biomedical optics to the patient bedside. This work presents a brief history of OCT development, reviews current clinical applications, discusses some clinical translation challenges, and re- views laboratory developments poised for future clinical application.

/pdf/optical-coherence-tomography-a-review-of-clinical-3q2jethpbe.pdf

Optical coherence tomography: a review of clinical development from bench to bedside

Optical coherence tomography of idiopathic macular epiretinal membranes before and after surgery

BACKGROUND: Retinal detachment often leads to a severe and permanent loss of vision and its therapeutic management remains to this day exclusively surgical. We have used surgical specimens to perform a differential analysis of the transcriptome of human retinal tissues following detachment in order to identify new potential pharmacological targets that could be used in combination with surgery to further improve final outcome. METHODOLOGY/PRINCIPAL FINDINGS: Statistical analysis reveals major involvement of the immune response in the disease. Interestingly, using a novel approach relying on coordinated expression, the interindividual variation was monitored to unravel a second crucial aspect of the pathological process: the death of photoreceptor cells. Within the genes identified, the expression of the major histocompatibility complex I gene HLA-C enables diagnosis of the disease, while PKD2L1 and SLCO4A1 -which are both down-regulated- act synergistically to provide an estimate of the duration of the retinal detachment process. Our analysis thus reveals the two complementary cellular and molecular aspects linked to retinal detachment: an immune response and the degeneration of photoreceptor cells. We also reveal that the human specimens have a higher clinical value as compared to artificial models that point to IL6 and oxidative stress, not implicated in the surgical specimens studied here. CONCLUSIONS/SIGNIFICANCE: This systematic analysis confirmed the occurrence of both neurodegeneration and inflammation during retinal detachment, and further identifies precisely the modification of expression of the different genes implicated in these two phenomena. Our data henceforth give a new insight into the disease process and provide a rationale for therapeutic strategies aimed at limiting inflammation and photoreceptor damage associated with retinal detachment and, in turn, improving visual prognosis after retinal surgery.

/pdf/transcriptomic-analysis-of-human-retinal-detachment-reveals-4gpwup1s3z.pdf

Transcriptomic analysis of human retinal detachment reveals both inflammatory response and photoreceptor death.

BACKGROUND: Ocular lesions known to occur after shaken baby syndrome (SBS) are epiretinal, intraretinal, and subretinal hemorrhages, which are present in up to 100% of patients. Retinoschisis and retinal folds have also been described. We describe three patients with SBS who presented with tractional retinal detachments secondary to neovascular proliferation and discuss the role of ischemia at the retinal level. PATIENTS: Three patients (two 4-month-old babies and one 4-year-old child) with a history of SBS in the first year of life presented with tractional retinal detachment due to severe preretinal fibrovascular proliferation. Peripheral retinal ischemia and vascular disorganization were noted during clinical examination. CONCLUSION: Although physiopathology of SBS remains disputed, ischemia has been accepted as the main feature of cerebral lesions. Ischemia could also be present at the retinal level as suggested by our patients' presentation. It could be induced by direct vitreous shearing of the capillary network or more probably by vascular leak due to brain edema and hypoxic damage of capillaries. Long-term ocular follow-up is necessary in SBS to treat these patients preventively. Language: en

Ischemic retinopathy and neovascular proliferation secondary to shaken baby syndrome.

But de l'etude Analyse des resultats anatomiques et fonctionnels de la retinectomie dans le traitement des decollements de retine complexes. Materiel et methode Notre etude a porte sur 48 patients chez lesquels une retinectomie de 90° ou plus a ete realisee pour traiter une decollement de retine complique de proliferation vitreo-retinienne avec retraction anterieure de stade A1 (6 cas), A2 (23 cas), A3 (11 cas), ou A4 (8 cas). La retinotomie a ete realisee quand, malgre une dissection soigneuse de la retraction peripherique, on n'obtenait pas une reapplication complete de la retine en arriere du cerclage, sous perfluorodecaline. Elle a ete completee par une retinectomie peripherique. Une retinopexie au laser sous perfluorocarbone liquide, et un tamponnement interne par huile de silicone ont ete pratiques. Resultats L'ablation de l'huile de silicone a ete realisee dans 46 cas. Un succes anatomique a ete obtenu dans 37 cas (77 %), avec une acuite visuelle superieure ou egale a 1/20 dans 19 cas. Le resultat fonctionnel n'etait pas correle a l'etendue de la retinectomie. La principale complication observee a ete la retraction des bords de la retinectomie et la recidive de la proliferation vitreo-retinienne, responsable de 9 echecs sur 11. Une hypotonie (pression intraoculaire inferieure ou egale a 5 mmHg) est survenue dans seulement 6 des 37 cas operes avec succes. Conclusion La retinectomie represente une solution chirurgicale utile pour des yeux presentant une proliferation vitreo-retinienne anterieure severe, et apparaissant difficilement traitable par une dissection-indentation pendant l'intervention. Elle procure un taux de succes satisfaisant pour des cas aussi graves et relativement peu de complications.

Retinectomies in the treatment of retinal detachments with vitreoretinal proliferation

Purpose: To describe the clinical characteristics of epiretinal membranes (ERMs) secondary to nonprogressive diseases in very young children and to assess their surgical outcome. Methods: Retrospective interventional case series study of 13 pediatric patients (aged less than 12 years) operated on for ERM more than a 6-year period. Visual acuity measurement, ophthalmic examination, and optical coherence tomography imaging were assessed preoperatively and postoperatively. Results: Mean age was 6.5 years (3–12 years). Mean follow-up duration was of 28.5 months (12–69 months). Among the 13 patients, there were 7 cases of idiopathic ERM, 4 cases of combined hamartoma of the retina and retinal pigment epithelium, and 2 cases of posttraumatic ERM. The diagnosis of ERM was fortuitous in 10 cases (77%). Twelve children (92%) experienced a functional improvement. All patients received adjuvant treatment of amblyopia. Best-corrected visual acuity improved significantly after surgery from 20/160 to 20/40 (P = 0.001). Conclusion: Even in very young children, surgery resulted in a significant long-term improvement. Children screening was essential for diagnosis and treatment in most cases.

F. Metge

Papers

Optical coherence tomography of idiopathic macular epiretinal membranes before and after surgery

Transcriptomic analysis of human retinal detachment reveals both inflammatory response and photoreceptor death.

Ischemic retinopathy and neovascular proliferation secondary to shaken baby syndrome.

Retinectomies in the treatment of retinal detachments with vitreoretinal proliferation

Long-term outcome of epiretinal membrane surgery in young children.