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Progress in Retinal and Eye Research Mar 2010The choroid of the eye is primarily a vascular structure supplying the outer retina. It has several unusual features: It contains large membrane-lined lacunae, which, at... (Review)
Review
The choroid of the eye is primarily a vascular structure supplying the outer retina. It has several unusual features: It contains large membrane-lined lacunae, which, at least in birds, function as part of the lymphatic drainage of the eye and which can change their volume dramatically, thereby changing the thickness of the choroid as much as four-fold over a few days (much less in primates). It contains non-vascular smooth muscle cells, especially behind the fovea, the contraction of which may thin the choroid, thereby opposing the thickening caused by expansion of the lacunae. It has intrinsic choroidal neurons, also mostly behind the central retina, which may control these muscles and may modulate choroidal blood flow as well. These neurons receive sympathetic, parasympathetic and nitrergic innervation. The choroid has several functions: Its vasculature is the major supply for the outer retina; impairment of the flow of oxygen from choroid to retina may cause Age-Related Macular Degeneration. The choroidal blood flow, which is as great as in any other organ, may also cool and warm the retina. In addition to its vascular functions, the choroid contains secretory cells, probably involved in modulation of vascularization and in growth of the sclera. Finally, the dramatic changes in choroidal thickness move the retina forward and back, bringing the photoreceptors into the plane of focus, a function demonstrated by the thinning of the choroid that occurs when the focal plane is moved back by the wearing of negative lenses, and, conversely, by the thickening that occurs when positive lenses are worn. In addition to focusing the eye, more slowly than accommodation and more quickly than emmetropization, we argue that the choroidal thickness changes also are correlated with changes in the growth of the sclera, and hence of the eye. Because transient increases in choroidal thickness are followed by a prolonged decrease in synthesis of extracellular matrix molecules and a slowing of ocular elongation, and attempts to decouple the choroidal and scleral changes have largely failed, it seems that the thickening of the choroid may be mechanistically linked to the scleral synthesis of macromolecules, and thus may play an important role in the homeostatic control of eye growth, and, consequently, in the etiology of myopia and hyperopia.
Topics: Animals; Choroid; Humans; Muscle, Smooth; Myopia
PubMed: 20044062
DOI: 10.1016/j.preteyeres.2009.12.002 -
Proceedings of the National Academy of... Nov 2019The human retinal pigment epithelium (RPE) and choroid are complex tissues that provide crucial support to the retina. Disease affecting either of these supportive...
The human retinal pigment epithelium (RPE) and choroid are complex tissues that provide crucial support to the retina. Disease affecting either of these supportive tissues can lead to irreversible blindness in the setting of age-related macular degeneration. In this study, single-cell RNA sequencing was performed on macular and peripheral regions of RPE-choroid from 7 human donor eyes in 2 independent experiments. In the first experiment, total RPE/choroid preparations were evaluated and expression profiles specific to RPE and major choroidal cell populations were identified. As choroidal endothelial cells represent a minority of the total RPE/choroidal cell population but are strongly implicated in age-related macular degeneration (AMD) pathogenesis, a second single-cell RNA-sequencing experiment was performed using endothelial cells enriched by magnetic separation. In this second study, we identified gene expression signatures along the choroidal vascular tree, classifying the transcriptome of human choriocapillaris, arterial, and venous endothelial cells. We found that the choriocapillaris highly and specifically expresses the regulator of cell cycle gene (), a gene that responds to complement activation and induces apoptosis in endothelial cells. In addition, was the most up-regulated choriocapillaris gene in a donor diagnosed with AMD. These results provide a characterization of the human RPE and choriocapillaris transcriptome, offering potential insight into the mechanisms of choriocapillaris response to complement injury and choroidal vascular disease in age-related macular degeneration.
Topics: Choroid; Epithelial Cells; Epithelium; Humans; Macular Degeneration; Retina; Single-Cell Analysis; Transcriptome
PubMed: 31712411
DOI: 10.1073/pnas.1914143116 -
Investigative Ophthalmology & Visual... May 2023The choroid is the richly vascular layer of the eye located between the sclera and Bruch's membrane. Early studies in animals, as well as more recent studies in humans,... (Review)
Review
The choroid is the richly vascular layer of the eye located between the sclera and Bruch's membrane. Early studies in animals, as well as more recent studies in humans, have demonstrated that the choroid is a dynamic, multifunctional structure, with its thickness directly and indirectly subject to modulation by a variety of physiologic and visual stimuli. In this review, the anatomy and function of the choroid are summarized and links between the choroid, eye growth regulation, and myopia, as demonstrated in animal models, discussed. Methods for quantifying choroidal thickness in the human eye and associated challenges are described, the literature examining choroidal changes in response to various visual stimuli and refractive error-related differences are summarized, and the potential implications of the latter for myopia are considered. This review also allowed for the reexamination of the hypothesis that short-term changes in choroidal thickness induced by pharmacologic, optical, or environmental stimuli are predictive of future long-term changes in axial elongation, and the speculation that short-term choroidal thickening can be used as a biomarker of treatment efficacy for myopia control therapies, with the general conclusion that current evidence is not sufficient.
Topics: Animals; Humans; Axial Length, Eye; Choroid; Bruch Membrane; Myopia; Models, Animal; Tomography, Optical Coherence
PubMed: 37126359
DOI: 10.1167/iovs.64.6.4 -
Acta Ophthalmologica Nov 2021Myopia is the most common type of refractive errors characterized by excessive elongation of the ocular globe. With the increasing prevalence of myopia, improved... (Review)
Review
Myopia is the most common type of refractive errors characterized by excessive elongation of the ocular globe. With the increasing prevalence of myopia, improved knowledge of factors involved in myopia development is of particular importance. There are growing evidence suggesting that the choroid plays an important role in the regulation of eye growth and the development of myopia. Studies have demonstrated that thinning choroid is a structural feature of myopia, with a negative correlation between choroidal thickness and axial length, suggesting that the change in choroidal thickness may be a predictive biomarker for long-term changes in ocular elongation. Given the fact that the choroid is primarily a vascular structure capable of rapidly changing blood flow, variations of choroidal thickness might be primarily caused by changes in choroidal blood flow. Considering that hypoxia is associated with myopia and choroidal blood flow is the main source of oxygen and nourishment supply, apart from the effect on myopia possibly by changing choroidal thickness, decreasing choroidal blood flow may contribute to scleral ischaemia and hypoxia, resulting in alterations in the scleral structure and thus leading to myopia. This review aims to provide an overview of recent work exploring the influence of the choroid on myopia from perspectives of choroidal thickness and blood flow, which may present new predictive indicators for the onset of myopia and new targets for the development of novel therapeutic approaches for myopia.
Topics: Choroid; Disease Progression; Humans; Myopia; Regional Blood Flow; Tomography, Optical Coherence
PubMed: 33550704
DOI: 10.1111/aos.14773 -
JAMA Ophthalmology Feb 2021Noninvasive retinal imaging may detect structural changes associated with Parkinson disease (PD) and may represent a novel biomarker for disease detection.
IMPORTANCE
Noninvasive retinal imaging may detect structural changes associated with Parkinson disease (PD) and may represent a novel biomarker for disease detection.
OBJECTIVE
To characterize alterations in the structure and microvasculature of the retina and choroid in eyes of individuals with PD and compare them with eyes of age- and sex-matched cognitively healthy control individuals using optical coherence tomography (OCT) and OCT angiography (OCTA).
DESIGN, SETTING, AND PARTICIPANTS
This cross-sectional study was conducted at the Duke Neurological Disorders Clinic in Durham, North Carolina. Individuals aged 50 years or older with a diagnosis of PD were eligible for inclusion and underwent an evaluation and diagnosis confirmation before enrollment. Control individuals aged 50 years or older and without subjective cognitive dysfunction, a history of tremor, or evidence of motor dysfunction consistent with parkinsonism were solicited from the clinic or the Duke Alzheimer's Disease Prevention Registry. Individuals with diabetes, glaucoma, retinal pathology, other dementias, and corrected Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity worse than 20/40 Snellen were excluded. Data were analyzed between January 1, 2020, and March 30, 2020.
EXPOSURES
All participants underwent OCT and OCTA imaging.
MAIN OUTCOMES AND MEASURES
Generalized estimating equation analysis was used to characterize the association between imaging parameters and PD diagnosis. Superficial capillary plexus vessel density (VD) and perfusion density (PFD) were assessed within the ETDRS 6 × 6-mm circle, 6 × 6-mm inner ring, and 6 × 6-mm outer ring, as was the foveal avascular zone area. Peripapillary retinal nerve fiber layer thickness, macular ganglion cell-inner plexiform layer thickness, central subfield thickness, subfoveal choroidal thickness, total choroidal area, luminal area, and choroidal vascularity index (CVI) were measured.
RESULTS
A total of 124 eyes of 69 participants with PD (39 men [56.5%]; mean [SD] age, 71.7 [7.0] years) and 248 eyes of 137 control participants (77 men [56.2%]; mean [SD] age, 70.9 [6.7] years) were analyzed. In the 6 × 6-mm ETDRS circle, VD (β coefficient = 0.37; 95% CI, 0.04-0.71; P = .03) and PFD (β coefficient = 0.009; 95% CI, 0.0003-0.018; P = .04) were lower in eyes of participants with PD. In the inner ring of the 6 × 6-mm ETDRS circle, VD (β coefficient = 0.61; 95% CI, 0.20-1.02; P = .003) and PFD (β coefficient = 0.015; 95% CI, 0.005-0.026; P = .004) were lower in eyes of participants with PD. Total choroidal area (β coefficient = -1.74 units2; 95% CI, -3.12 to -0.37 units2; P = .01) and luminal area (β coefficient = -1.02 units2; 95% CI, -1.86 to -0.18 units2; P = .02) were greater, but CVI was lower (β coefficient = 0.5%; 95% CI, 0.2%-0.8%; P < .001) in eyes of individuals with PD.
CONCLUSIONS AND RELEVANCE
This study found that individuals with PD had decreased retinal VD and PFD as well as choroidal structural changes compared with age- and sex-matched control participants. Given the observed population differences in these noninvasive retinal biomarkers, further research into their clinical utility in PD is needed.
Topics: Aged; Angiography; Case-Control Studies; Choroid; Cross-Sectional Studies; Female; Humans; Male; Microvascular Density; Microvessels; Middle Aged; North Carolina; Parkinson Disease; Predictive Value of Tests; Prospective Studies; Regional Blood Flow; Retinal Vessels; Tomography, Optical Coherence
PubMed: 33355613
DOI: 10.1001/jamaophthalmol.2020.5730 -
Investigative Ophthalmology & Visual... Jan 2021To explore the association of choroidal vascularity and choriocapillaris blood perfusion with myopic severity in anisomyopes.
PURPOSE
To explore the association of choroidal vascularity and choriocapillaris blood perfusion with myopic severity in anisomyopes.
METHODS
Refractive error, axial length (AL), and other biometric parameters were measured in 34 anisomyopic young adults. Macular choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI), were determined from swept-source optical coherence tomography (SS-OCT) vertical and horizontal B-scans. The percentage of choriocapillaris flow voids (FV%) was obtained from en face SS-OCT-angiography.
RESULTS
The spherical equivalent refraction (SER) was -3.35 ± 1.25 diopters in the more myopic eyes and -1.25 ± 1.17 diopters in the less myopic eyes (P < 0.001). The interocular difference in SER was highly correlated with that in AL (P < 0.001). The macular ChT, TCA, LA, and SA were smaller in the more myopic eyes than in the less myopic eyes in both vertical and horizontal scans (all P < 0.001). Importantly, the CVIs in vertical and horizontal scans were smaller and the FV% was greater in the more myopic eyes (P < 0.05). In vertical scans, the interocular difference in CVIs was correlated with that in the SER, AL, and ChT (all P < 0.05). The interocular difference in FV% was correlated with that in SER, AL, and vertical and horizontal ChTs (all P < 0.05).
CONCLUSIONS
Choroidal vascularity and choriocapillaris blood perfusion were lower in the more myopic eyes of anisomyopic adults. These changes were correlated with the severity of myopia and choroidal thinning, indicating that choroidal blood flow is disturbed in human myopia.
Topics: Adult; Anisometropia; Biometry; Blood Physiological Phenomena; Choroid; Female; Fluorescein Angiography; Humans; Male; Myopia; Refraction, Ocular; Regional Blood Flow; Tomography, Optical Coherence; Young Adult
PubMed: 33393974
DOI: 10.1167/iovs.62.1.8 -
Journal of Investigative Medicine High... 2019Coccidioidomycosis is an invasive fungus found primarily in the soil of Southwestern United States, Mexico, and Central America. Primary disease mostly presents as a...
Coccidioidomycosis is an invasive fungus found primarily in the soil of Southwestern United States, Mexico, and Central America. Primary disease mostly presents as a pulmonary disease although multiple organ systems can be affected through lymphohematogenous dissemination, with ocular seeding extremely rare. When present, the anterior segment structures are most commonly affected. Isolated choroid and/or vitreal disease has been reported infrequently. This is a case of chorioretinitis with vitreal involvement.
Topics: Adult; Chorioretinitis; Coccidioides; Coccidioidomycosis; Eye Infections, Fungal; Humans; Male; Tomography, Optical Coherence; Tomography, X-Ray Computed; Vitreous Body
PubMed: 31597500
DOI: 10.1177/2324709619881561 -
Vision Research Oct 2017Early histopathological studies of diabetic choroids demonstrated loss of choriocapillaris (CC), tortuous blood vessels, microaneurysms, drusenoid deposits on Bruchs... (Review)
Review
Early histopathological studies of diabetic choroids demonstrated loss of choriocapillaris (CC), tortuous blood vessels, microaneurysms, drusenoid deposits on Bruchs membrane, and choroidal neovascularization. The preponderance of histopathological changes were at and beyond equator. Studies from my lab suggest that diabetic choroidopathy is an inflammatory disease in that leukocyte adhesion molecules are elevated in the choroidal vasculature and polymorphonuclear neutrophils are often associated with sites of vascular loss. Modern imaging techniques demonstrate that blood flow is reduced in subfoveal choroidal vasculature. Angiography has shown areas of hypofluorescence and late filling that probably represent areas of vascular loss and/or compromise. Perhaps, as a result of vascular insufficiency, the choroid appears to thin in DC unless macular edema is present. Enhanced depth imaging (EDI-SD) OCT and swept source (SS) OCT have documented the tortuosity and loss in intermediate and large blood vessels in Sattler's and Haller's layer seen previously with histological techniques. The risk factors for DC include diabetic retinopathy, degree of diabetic control, and the treatment regimen. In the future, OCT angiography could be used to document loss of CC. Because most of the measurement and imaging are in the posterior pole, the severity of DC may be underappreciated in the published accounts of DC assessed with imaging techniques. However, it is now possible to document DC and quantify these changes clinically. This suggests that DC should be evaluated in future clinical trials of drugs targeting DR because vascular changes similar to those in DR are occurring in DC.
Topics: Choroid; Choroid Diseases; Diabetes Complications; Humans; Neutrophils; Tomography, Optical Coherence
PubMed: 28535994
DOI: 10.1016/j.visres.2017.04.011 -
Indian Journal of Ophthalmology Mar 2019Serpiginous choroiditis (SC) is an asymmetrically bilateral inflammation of the choroid that leads to loss of choriocapillaris atrophy or loss of overlying retinal... (Review)
Review
Serpiginous choroiditis (SC) is an asymmetrically bilateral inflammation of the choroid that leads to loss of choriocapillaris atrophy or loss of overlying retinal pigment epithelium. Over the last few decades, SC has passed through a long evolution of nomenclature, etiologies and morphological variations. Initially diagnosed in patients with tuberculosis and syphilis, SC was predominantly considered as autoimmune process. With the advancement of molecular diagnosis, a new aspect of infectious subtypes of SC has emerged out. The terminologies such as serpiginous-like choroiditis (SLC) and multifocal serpiginoid choroiditis are now used to denote the subtypes of SC which are associated with infectious etiologies especially tuberculosis. In a country endemic for tuberculosis such as India, it is very important to differentiate between classic SC and SLC before initiating aggressive immunomodulatory therapy. Also, management of paradoxical worsening of the clinical condition with antitubercular treatment is another challenge in SLC and ophthalmologists should be aware of such situations. With advent of newer imaging modalities, monitoring the patient with choroiditis and identification of complications such as choroidal neovascular membrane have become much easier. This article aims to review the existing literature on SC with a special emphasis on management of SC and SLC.
Topics: Choroid; Choroiditis; Diagnosis, Differential; Fluorescein Angiography; Fundus Oculi; Humans; Multifocal Choroiditis; Retinal Pigment Epithelium; Tomography, Optical Coherence
PubMed: 30777946
DOI: 10.4103/ijo.IJO_822_18 -
Revista de La Facultad de Ciencias... Mar 2022To provide a complete picture and to improve understanding of the serpiginous-like choroiditis caused by Mycobacterium Tuberculosis. (Review)
Review
OBJECTIVE
To provide a complete picture and to improve understanding of the serpiginous-like choroiditis caused by Mycobacterium Tuberculosis.
MATERIALS AND METHODS
Literature review of serpiginous-like choroiditis. A number of scientific search engines were searched including Medline (PubMed), Scielo, and Cochrane Library. Using MeSH and DeCS terms.
RESULTS
107 articles were obtained, of which 44 met inclusion criteria.
DISCUSSION
serpiginous-like choroiditis is described as its etiology, pathogenesis, ocular findings, diagnosis, differential diagnosis and treatment.
CONCLUSIONS
Modern studies are needed to understand the pathophysiology, new diagnostic strategies, and future treatments of serpiginous-like choroiditis
Topics: Choroiditis; Diagnosis, Differential; Humans
PubMed: 35312256
DOI: 10.31053/1853.0605.v79.n1.32223