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Investigative Ophthalmology & Visual... May 2017Improved understanding of the mechanisms underlying inherited retinal degenerations has created the possibility of developing much needed treatments for these... (Review)
Review
Improved understanding of the mechanisms underlying inherited retinal degenerations has created the possibility of developing much needed treatments for these relentless, blinding diseases. However, standard clinical indicators of retinal health (such as visual acuity and visual field sensitivity) are insensitive measures of photoreceptor survival. In many retinal degenerations, significant photoreceptor loss must occur before measurable differences in visual function are observed. Thus, there is a recognized need for more sensitive outcome measures to assess therapeutic efficacy as numerous clinical trials are getting underway. Adaptive optics (AO) retinal imaging techniques correct for the monochromatic aberrations of the eye and can be used to provide nearly diffraction-limited images of the retina. Many groups routinely are using AO imaging tools to obtain in vivo images of the rod and cone photoreceptor mosaic, and it now is possible to monitor photoreceptor structure over time with single cell resolution. Highlighting recent work using AO scanning light ophthalmoscopy (AOSLO) across a range of patient populations, we review the development of photoreceptor-based metrics (e.g., density/geometry, reflectivity, and size) as candidate biomarkers. Going forward, there is a need for further development of automated tools and normative databases, with the latter facilitating the comparison of data sets across research groups and devices. Ongoing and future clinical trials for inherited retinal diseases will benefit from the improved resolution and sensitivity that multimodal AO retinal imaging affords to evaluate safety and efficacy of emerging therapies.
Topics: Biomarkers; Diagnostic Imaging; Humans; Ophthalmoscopy; Photoreceptor Cells, Vertebrate; Retina; Retinal Degeneration
PubMed: 28873135
DOI: 10.1167/iovs.17-21868 -
Ophthalmologica. Journal International... 2016To assess the clinical application of multicolor imaging by confocal scanning laser ophthalmoscopy (cSLO). (Review)
Review
PURPOSE
To assess the clinical application of multicolor imaging by confocal scanning laser ophthalmoscopy (cSLO).
METHODS
Retinal imaging was performed in 76 patients including cSLO multicolor imaging (SPECTRALIS SD-OCT, Heidelberg Engineering, Heidelberg, Germany) and color fundus photography (CFP).
RESULTS
The use of confocal optics, reduced light scatter and automated eye tracking enable high-resolution cSLO reflectance images. Compared to CFP, the appearance of pigment alterations and hemorrhages were some of the differences observed. Various artifacts including those derived from optical media alterations need to be considered when interpreting images. Specific pathological findings including epiretinal membranes, fibrovascular proliferations, and reticular pseudodrusen may be better visualized on multicolor images.
CONCLUSIONS
When using multicolor imaging, ophthalmologists need to be mindful about differences in the appearance of pathological changes and artifacts. Multicolor imaging may offer information over and above conventional CFP; it can be performed through undilated pupils and is less affected by media opacities.
Topics: Diagnostic Imaging; Fluorescein Angiography; Fundus Oculi; Humans; Ophthalmoscopy; Optics and Photonics; Photography; Retina; Retinal Drusen; Retinal Pigment Epithelium; Tomography, Optical Coherence
PubMed: 27404384
DOI: 10.1159/000446857 -
Survey of Ophthalmology 2022Retinal vascular diseases are a leading cause for blindness and partial sight certifications. By applying adaptive optics (AO) to conventional imaging modalities, the... (Meta-Analysis)
Meta-Analysis Review
Retinal vascular diseases are a leading cause for blindness and partial sight certifications. By applying adaptive optics (AO) to conventional imaging modalities, the microstructures of the retinal vasculature can be observed with high spatial resolution, hence offering a unique opportunity for the exploration of the human microcirculation. The objective of this systematic review is to describe the current state of retinal vascular biomarkers imaged by AO flood illumination ophthalmoscopy (FIO) and AO scanning laser ophthalmoscopy (SLO). A literature research was conducted in the PubMed and Scopus databases on July 9, 2020. From 217 screened studies, 42 were eligible for this review. All studies underwent a quality check regarding their content. A meta-analysis was performed for the biomarkers reported for the same pathology in at least three studies using the same modality. The most frequently studied vascular biomarkers were the inner diameter (ID), outer diameter (OD), parietal thickness (PT), wall cross-sectional area (WCSA), and wall-to-lumen ratio (WLR). The applicability of AO vascular biomarkers has been mostly explored in systemic hypertension using AO FIO and in diabetes using AO SLO. The result of the meta-analysis for hypertensive patients showed that WLR, PT, and ID were significantly different when compared to healthy controls, while WCSA was not (P < 0.001, P = 0.002, P < 0.001, and P = 0.070, respectively). The presented review shows that, although a substantial number of retinal vascular biomarkers have been explored in AO en face imaging, further clinical research and standardization of procedures is needed to validate such biomarkers for the longitudinal monitoring of arterial hypertension and other diseases.
Topics: Biomarkers; Humans; Ophthalmoscopy; Optics and Photonics; Retinal Diseases; Retinal Vessels
PubMed: 34090882
DOI: 10.1016/j.survophthal.2021.05.012 -
Progress in Retinal and Eye Research Jan 2019Adaptive Optics (AO) retinal imaging has provided revolutionary tools to scientists and clinicians for studying retinal structure and function in the living eye. From... (Review)
Review
Adaptive Optics (AO) retinal imaging has provided revolutionary tools to scientists and clinicians for studying retinal structure and function in the living eye. From animal models to clinical patients, AO imaging is changing the way scientists are approaching the study of the retina. By providing cellular and subcellular details without the need for histology, it is now possible to perform large scale studies as well as to understand how an individual retina changes over time. Because AO retinal imaging is non-invasive and when performed with near-IR wavelengths both safe and easily tolerated by patients, it holds promise for being incorporated into clinical trials providing cell specific approaches to monitoring diseases and therapeutic interventions. AO is being used to enhance the ability of OCT, fluorescence imaging, and reflectance imaging. By incorporating imaging that is sensitive to differences in the scattering properties of retinal tissue, it is especially sensitive to disease, which can drastically impact retinal tissue properties. This review examines human AO retinal imaging with a concentration on the use of the Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO). It first covers the background and the overall approaches to human AO retinal imaging, and the technology involved, and then concentrates on using AO retinal imaging to study the structure and function of the retina.
Topics: Humans; Ophthalmoscopes; Ophthalmoscopy; Optics and Photonics; Peripheral Vascular Diseases; Retinal Diseases; Tomography, Optical Coherence
PubMed: 30165239
DOI: 10.1016/j.preteyeres.2018.08.002 -
Investigative Ophthalmology & Visual... Sep 2020Because preterm birth and retinopathy of prematurity (ROP) are associated with poor visual acuity (VA) and altered foveal development, we evaluated relationships among...
PURPOSE
Because preterm birth and retinopathy of prematurity (ROP) are associated with poor visual acuity (VA) and altered foveal development, we evaluated relationships among the central retinal photoreceptors, postreceptor retinal neurons, overlying fovea, and VA in ROP.
METHODS
We obtained optical coherence tomograms (OCTs) in preterm born subjects with no history of ROP (none; n = 61), ROP that resolved spontaneously without treatment (mild; n = 51), and ROP that required treatment by laser ablation of the avascular peripheral retina (severe; n = 22), as well as in term born control subjects (term; n = 111). We obtained foveal shape descriptors, measured central retinal layer thicknesses, and demarcated the anatomic parafovea using automated routines. In subsets of these subjects, we obtained OCTs eccentrically through the pupil (n = 46) to reveal the fiber layer of Henle (FLH) and obtained adaptive optics scanning light ophthalmograms (AO-SLOs) of the parafoveal cones (n = 34) and measured their spacing and distribution.
RESULTS
Both VA and foveal depth decreased with increasing ROP severity (term, none, mild, severe). In severe subjects, foveae were broader than normal and the parafovea was significantly enlarged compared to every other group. The FLH was thinner than normal in mild (but not severe) subjects. VA was associated with foveal depth more than group. Density of parafoveal cones did not differ significantly among groups.
CONCLUSIONS
Foveal structure is associated with loss of VA in ROP. The preserved FLH in severe (relative to mild) eyes suggests treatment may help cone axon development. The significantly larger parafovea and increased outer nuclear layer (ONL) thickness in ROP hint that some developmental process affecting the photoreceptors is not arrested in ROP but rather is supranormal.
Topics: Adolescent; Adult; Child; Female; Fovea Centralis; Humans; Male; Ophthalmoscopy; Retinopathy of Prematurity; Tomography, Optical Coherence; Visual Acuity; Young Adult
PubMed: 32936301
DOI: 10.1167/iovs.61.11.28 -
PloS One 2021This study aimed to describe and determine the prevalence of ocular abnormalities in Polish Hunting Dogs. The study was conducted with 193 Polish Hunting Dogs: 101...
This study aimed to describe and determine the prevalence of ocular abnormalities in Polish Hunting Dogs. The study was conducted with 193 Polish Hunting Dogs: 101 female and 92 male animals, aged between 3 months and 12 years. Ophthalmic examinations were performed using slit lamp biomicroscopy, ophthalmoscopy, and tonometry based on the ophthalmological protocol for the examination of hereditary eye diseases. Spectral-domain optical coherence tomography (SD-OCT) was performed for dogs with sudden acquired retinal degeneration syndrome (SARDS) and progressive retinal atrophy (PRA), while electroretinography was also performed in dogs with SARDS. Five dogs (2.6%) were diagnosed with cataract, iris coloboma in 3 dogs (1.6%), ocular dermoid in 1 dog (0.5%), and retinal dysplasia, distichiasis and entropion in 1 dog (1%). Three dogs (1.6%) were diagnosed with PRA and SARDS occurred in 1 dog. Retinal lesions was observed in 16 dogs (8.3%). The clinical signs of retinopathy observed in Polish Hunting Dogs included discoloration of the tapetal fundus, patchy increased reflectivity in the region of discoloration, focus of hyperpigmentation and an area of tapetal hyper-reflectivity with a pigmented center. SD-OCT performed in the 3 dogs with PRA revealed alteration in the retinal layers, which was most advanced in the non-tapetal fundus. Although SD-OCT revealed retinal layers with normal architecture only in some parts of the dorsal, nasal and temporal regions in dogs with SARDS, areas of disorganized external limiting membrane, myeloid zone, ellipsoid zone, outer photoreceptor segment and interdigitation zone were also observed. Polish Hunting Dogs should undergo periodic ophthalmological examination for the evaluation of other hereditary eye diseases. The prevalence of retinal lesions in Polish Hunting Dogs requires further research.
Topics: Animals; Dogs; Electroretinography; Female; Fundus Oculi; Male; Ophthalmoscopy; Pedigree; Prevalence; Retina; Retinal Degeneration; Syndrome; Tomography, Optical Coherence
PubMed: 34739488
DOI: 10.1371/journal.pone.0258636 -
Indian Journal of Ophthalmology Feb 2019
Topics: Diagnosis, Differential; Fluorescein Angiography; Fundus Oculi; Humans; Macula Lutea; Male; Ophthalmoscopy; Retinal Diseases; Retinal Pigment Epithelium; Tomography, Optical Coherence; Young Adult
PubMed: 30672487
DOI: 10.4103/ijo.IJO_886_18 -
Optometry and Vision Science : Official... Feb 2017: Fundus autofluorescence (FAF) provides detailed insight into the health of the retinal pigment epithelium (RPE). This is highly valuable in age-related macular... (Review)
Review
: Fundus autofluorescence (FAF) provides detailed insight into the health of the retinal pigment epithelium (RPE). This is highly valuable in age-related macular degeneration (AMD) as RPE damage is a hallmark of the disease. The purpose of this paper is to critically appraise current clinical descriptions regarding the appearance of AMD using FAF and to integrate these findings into a chair-side reference. A wide variety of FAF patterns have been described in AMD, which is consistent with the clinical heterogeneity of the disease. In particular, FAF imaging in early to intermediate AMD has the capacity to reveal RPE alterations in areas that appear normal on funduscopy, which aids in the stratification of cases and may have visually significant prognostic implications. It can assist in differential diagnoses and also represents a reliable, sensitive method for distinguishing reticular pseudodrusen. FAF is especially valuable in the detection, evaluation, and monitoring of geographic atrophy and has been used as an endpoint in clinical trials. In neovascular AMD, FAF reveals distinct patterns of classic choroidal neovascularization noninvasively and may be especially useful for determining which eyes are likely to benefit from therapeutic intervention. FAF represents a rapid, effective, noninvasive imaging method that has been underutilized, and incorporation into the routine assessment of AMD cases should be considered. However, the practicing clinician should also be aware of the limitations of the modality, such as in the detection of foveal involvement and in the distinction of phenotypes (hypo-autofluorescent drusen from small areas of geographic atrophy).
Topics: Choroidal Neovascularization; Fluorescein Angiography; Fundus Oculi; Humans; Ophthalmoscopy; Phenotype; Retinal Pigment Epithelium; Wet Macular Degeneration
PubMed: 27668639
DOI: 10.1097/OPX.0000000000000997 -
Asia-Pacific Journal of Ophthalmology... 2018This article explores the development of retinal imaging, with particular emphasis on ultra-widefield imaging and the key concept of field of view. Two ultra-widefield... (Review)
Review
This article explores the development of retinal imaging, with particular emphasis on ultra-widefield imaging and the key concept of field of view. Two ultra-widefield imaging platforms are examined in detail-Optomap and Spectralis-noncontact imaging systems that include protocols for performing angiography in infants. Applications of ultra-widefield imaging are illustrated using case studies, including diagnosis, monitoring, and screening.
Topics: Fluorescein Angiography; Humans; Ophthalmoscopy; Optical Imaging; Pediatrics; Retina; Retinal Diseases
PubMed: 29888558
DOI: 10.22608/APO.2018100 -
Middle East African Journal of... 2015While the primary method for evaluating diabetic retinopathy involves direct and indirect ophthalmoscopy, various imaging modalities are of significant utility in the... (Review)
Review
While the primary method for evaluating diabetic retinopathy involves direct and indirect ophthalmoscopy, various imaging modalities are of significant utility in the screening, evaluation, diagnosis, and treatment of different presentations and manifestations of this disease. This manuscript is a review of the important imaging modalities that are used in diabetic retinopathy, including color fundus photography, fluorescein angiography, B-scan ultrasonography, and optical coherence tomography. The article will provide an overview of these different imaging techniques and how they can be most effectively used in current practice.
Topics: Diabetic Retinopathy; Diagnostic Techniques, Ophthalmological; Fluorescein Angiography; Humans; Ophthalmoscopy; Photography; Tomography, Optical Coherence
PubMed: 25949070
DOI: 10.4103/0974-9233.151887