Choroidal Circulation Research Articles

Choroidal vascular changes in silicone oil-filled eyes after vitrectomy for rhegmatogenous retinal detachments

IntroductionThe tamponade of silicone oil (SO) can affect both the structure and blood flow of the retina. However, there are few studies on the effect of SO tamponade on choroidal blood flow. Our study aimed to compare the effects of SO tamponade on the choroidal vascular index (CVI) and choroidal thickness (CT) in patients with unilateral rhegmatogenous retinal detachment (RRD) with operated eyes and fellow healthy eyes.MethodsWe retrospectively collected demographic and clinical data from 36 patients who underwent 23G pars plana vitrectomy and SO tamponade for unilateral complicated RRD. Enhanced depth imaging-optical coherence tomography (EDI-OCT) scans were performed both within 1 week before SO removal and at the last follow-up visit after SO removal. Using ImageJ software, images were binarized to segment the total choroidal area, luminal area, and stromal area, respectively. The CVI was calculated as CVI=(luminal area)/(total choroidal area), and CT was also evaluated.ResultsDuring SO tamponade, the CVI and luminal area in operated eyes were significantly lower compared to fellow eyes (57.616 ± 0.030 vs. 60.042 ± 0.019, P < 0.0001; 0.909 [0.694; 1.185] vs. 1.091 [0.785; 1.296], P = 0.007). Even after SO removal, the CVI remained lower in operated eyes than in fellow eyes (59.530 ± 0.018 vs. 60.319 ± 0.020, P = 0.031). Both CVI and luminal area were lower in operated eyes before SO removal than after SO removal (57.616 ± 0.030 vs. 59.530 ± 0.018, P = 0.0003; 0.909 [0.694; 1.185] vs. 0.994 [0.712; 1.348], P = 0.028). The duration of SO tamponade was positively correlated with the difference in CVI between fellow eyes and operated eyes during SO tamponade (P = 0.035). Total choroidal area, stromal area, and CT did not differ significantly between fellow eyes and operated eyes or between pre- and post-SO removal.ConclusionsSO tamponade reduces CVI and decreases choroidal blood circulation in patients with retinal detachments required vitrectomy combined with SO tamponade. The longer the SO tamponade time, the more CVI reduction. In future work, we will aim to reduce these side effects by shortening the duration of silicone oil filling.

An Update on Multimodal Ophthalmological Imaging of Diffuse Choroidal Hemangioma in Sturge-Weber Syndrome.

Sturge-Weber syndrome (SWS) is characterized by facial port-wine stains, leptomeningeal hemangiomas, and prominent ocular manifestations such as glaucoma and diffuse choroidal hemangiomas (DCHs). Imaging modalities are critical for diagnosing and longitudinally monitoring DCHs in SWS. Fundus photography is fundamental in assessing both eyes simultaneously, fluorescein angiography and indocyanine green angiography effectively map the retinal and choroidal circulation, and ultrasonography offers essential structural insights into the choroid and retina. NIR imaging reveals subtle retinal pigment changes, often overlooked in standard fundus examination. Enhanced depth imaging spectral domain optical coherence tomography (EDI-SDOCT) and swept-source OCT (SSOCT) improve the visualization of the choroidal-scleral boundary, essential for DCH characterization. The potential of OCT angiography (OCTA) is under exploration, particularly its role in predicting signs of disease progression or worsening, as well as potential new biomarkers such as the choroidal vascularity index (CVI). The present review aims to provide an update on multimodal imaging of DCHs in SWS.

Anatomical and Functional Evaluation of RNFL Parameters and Choroidal Thickness Changes in Patients with Chronic Renal Failure Undergoing Hemodialysis Using Spectral-Domain Optical Coherence Tomography and Visual Field

Background There is a structural analogy between the glomerular vascular network and the choroidal circulation. With hemodialysis (HD), lots of alterations occur in patients' homeostasis and metabolic parameters. These alterations affect the eye and may cause neuro-ophthalmologic complications. Aim To evaluate anatomical and functional changes of retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL), and changes in subfoveal choroidal thickness (SFCT) in patients with chronic renal failure (CRF) on HD. Methods This case control study was carried on 20 eyes of 20 CRF patients (HD group) and 20 eyes of 20 healthy individuals. 10 of the HD group were non-diabetic (NDM subgroup) and 10 were diabetic (DM subgroup). For all eyes, the thickness of peripapillary RNFL, GCL, and SFCT were measured by optical coherence tomography (OCT) (RS-3000; NIDEK, Japan) and visual field (VF) analysis using Humphrey field analyzer (Carl Zeiss, USA). Results A statistically significant decrease in peripapillary RNFL thickness in HD group when compared to the control group in most analyses, but did not amount to statistical significance in the temporal quadrant and in 5 of the studied clock hour sectors. There was also a statistically significant decrease in the macular GCL thickness of HD group when compared to the control group in both hemifields, and in all of the 8 subfields. The results of the SFCT reported in HD group were also significantly less than that reported in the control group. Analysis of results from VF demonstrated a highly significant depression in both MD and PSD of the HD group when compared to the control group. The difference between the NDM and DM subgroups was not significant in any of the studied parameters. Conclusion Our results demonstrate highly significant retinal and choroidal changes in CRF patients on HD. Thus, we recommend that CRF patients undergo regular ocular examination by OCT to prevent early ocular damage.

Choroidal circulation disturbance is an initial factor in outer retinal degeneration in rats under simulated weightlessness.

Objective: Microgravity contributes to ocular injury yet the underlying mechanism remains unclear. This study aims to elucidate the mechanism behind choroidal circulation disorder and outer retinal degeneration in rats with simulated weightlessness. Methods: Optical coherence tomography angiography (OCTA) was used to evaluate choroidal circulation and retinal morphological alterations in rats with weightlessness simulation. Electroretinogram and transmission electron microscopy were used to examine the ultrastructure and function of the choroid and outer retina. Furthermore, histological and terminal deoxynucleotidyl transferase deoxyuridine dUTP nick-end labeling (TUNEL) staining was used to monitor retinal morphology. Western blotting was performed to analyze the expressions of blood-retinal outer barrier function-related proteins (Cx43, ZO-1, and occludin). Results: The choroidal thickening was observed from the fourth week of simulated weightlessness (p < 0.05), and choroidal capillary density started to decline by the fifth week (p < 0.05). Transmission electron microscopy revealed that the choroidal vessels were open and operating well by the fourth week. However, most of the mitochondria within the vascular endothelium underwent mild swelling, and by the fifth week, the choroidal vessels had various degrees of erythrocyte aggregation, mitochondrial swelling, and apoptosis. Additionally, ERG demonstrated a decline in retinal function beginning in the fifth week (p < 0.05). TUNEL staining revealed a significantly higher apoptotic index in the outer nuclear layer of the retina (p < 0.05). At the sixth weekweeks of simulated weightlessness, OCTA and hematoxylin and eosin (HE) staining of retinal sections revealed that the outer nuclear layer of the retina started to become thin (p < 0.05). Results from western blotting revealed that Cx43, ZO-1, and occludin exhibited decreased expression (p < 0.05). Conclusion: Based on our findings in a rat model of simulated weightlessness, choroidal circulation disturbance induced by choroidal congestion is the initial cause of outer retinal degeneration. Blood-retinal barrier disruption is significant in this process.

Features of Ocular Blood Flow in Malignant Arterial Hypertension of Renal Origin

Color Doppler imaging allows a detailed non-invasive assessment of the state of blood flow in the retrobulbar vessels in patients with various vascular pathologies. Malignant hypertension (MH) is a clinical syndrome characterized by severe diastolic arterial hypertension (140 mm Hg or more), leading to ischemic damage to various organs — kidneys, heart, brain, eyes. Patients with MH often present with thrombotic microangiopathy (TMA), a rare life-threatening condition characterized by multiple systemic thromboses of the microvasculature.Purpose: to assess the state of blood flow in retrobulbar vessels by color Doppler imaging in TMA associated with MH.Methods: 10 patients (20 eyes) (age 43.5 ± 6.2 years) with TMA associated with MH underwent a study of the state of blood flow in the vessels of the retrobulbar space by color Doppler imaging. Qualitative and quantitative analyzes of retinal and choroidal circulation were assessed.Results. Analysis of the Doppler spectrum of blood flow in TMA associated with MH revealed a statistically significant increase in maximum systolic (Vsyst) and finale diastolic blood flow velocity (Vdiast) in the ophthalmic artery (OA), as well as Vsyst in the medial short posterior ciliary arteries (SPCA), compared with the control group (p &lt; 0.05). In 2 patients (20 %) of the study group, a significant bilateral decrease in the diastolic component of the spectrum was found up to the isoline (Vdiast = 0) and a maximum increase in the peripheral resistance index (RI = 1.0). Statistically significant correlations were found between some laboratory parameters of blood serum (hemoglobin, lactate dehydrogenase, creatinine), as well as the estimated glomerular filtration rate and hemodynamic parameters in the central retinal artery (CRA), lateral (SPCA) and OA (p &lt; 0.05).Conclusion. The results of the study of ocular hemodynamics using color Doppler imaging in TMA associated with MH are presented for the first time. TMA associated with MH is characterized by a statistically significant increase in the maximum systolic blood flow velocity in the OA and SPCA with the development of an ischemic state in the retinal and choroidal microcirculation in some patients. An increase in TMA activity in MH leads to a change in the microcirculation of the retina and choroid of an ischemic nature. An increase in blood creatinine in patients with TMA with MH is statistically significantly associated with a decrease in systolic blood flow velocity in the CRA.

Unexpected CT Scan Discovery of a Giant Galen Vein Aneurysm in An Infant: A Rare Case Report

Aneurysmal malformation of the Galen vein is an uncommon abnormality, comprising less than 1% of all congenital cerebral vascular malformations. However, it accounts for approximately 30% of such malformations in the pediatric population. This condition represents a cerebral arteriovenous malformation that develops prenatally, initiating prior to ten weeks of gestation. It arises from the formation of arteriovenous fistulas connecting the choroidal circulation and the median prosencephalic vein, an embryonic precursor of the Galen vein, which subsequently undergoes dilation. Here, we present an exceptional case of this malformation that was incidentally detected during a Brain CT scan.

Ex vivo ocular perfusion model to study vascular physiology in the mouse eye

Several hypotheses have been tested to understand whole organ regulation in other organs such as the brain and kidney, but no such hypothesis has yet been proposed for ocular circulations. To some extent resolve this deficit our ex vivo mouse eye perfusion model takes the first step in elucidating the mechanisms controlling the individual components of the ocular circulation. Various isolated ocular vascular preparations have been utilized in studies of ocular vascular biology, physiology, and pharmacology, including studies on both normal and pathological conditions. However, there is still significant potential for further studies to improve our understanding of ocular circulation and its regulation. The choroid specifically is inaccessible to direct visualization due to the retina's high metabolic requirement with a transparency that cannot be compromised by an overly rich vascular network on the inner retinal side hindering the visualization of the choroid. In this technical paper, we provide a detailed description of all the steps to be followed from the enucleation of mouse eyes to cannulation of the ophthalmic artery and perfusion and ex vivo confocal microscopy imaging of the dynamic nature of the choroid circulation.

Alterations of choroidal circulation and choroidal thickness before and after chemoradiotherapy in a case of metastatic choroidal tumor

BackgroundMetastatic choroidal tumors are hematogenous intraocular metastases of malignant tumors in systemic organs; however, the details of choroidal circulation and morphological changes in the choroid are unknown. The aim of this study is to present a case of metastatic choroidal tumor and examine laser speckle flowgraphy (LSFG)-based choroidal circulation and central choroidal thickness (CCT) before and after chemoradiotherapy.Case presentationA 66-year-old woman with a medical history of breast cancer 16 years ago was referred to our department struggling with blurred vision in her right eye. At the time of initial examination, her best-corrected visual acuity (BCVA) was 0.4 oculus dexter (OD) and 0.9 oculus sinister. Fundus revealed a yellowish-white choroidal elevated lesion measuring 8 papillary diameters with serous retinal detachment (SRD) in the posterior pole. Fluorescein angiography showed diffuse hyperfluorescence and fluorescent leakage due to SRD, and indocyanine green angiography demonstrated no abnormalities in the macula but hypofluorescence in the center of the tumor. Based on these clinical findings, she was diagnosed with metastatic choroidal tumor. After chemoradiotherapy, the metastatic choroidal tumor became scarred, and SRD disappeared. The rate of changes in macular blood flows assessed by mean blur rate on LSFG and CCT of her right eye were 33.8 and 32.8% decrease at 5 months after the initial visit, respectively. BCVA was 0.5 OD 27 months after the initial examination.ConclusionChemoradiotherapy resulted in regression of the metastatic choroidal tumor and disappearance of SRD, with a decrease in central choroidal blood flow and CCT. The choroidal blood flow on LSFG could reflect an increased oxygen demand by cancer cells invading the choroid and substantial blood supply.

Choroidal Circulation in 8- to 30-Year-Old Chinese, Measured by SS-OCT/OCTA: Relations to Age, Axial Length, and Choroidal Thickness.

The purpose of this study was to evaluate and explore the determinants of choroidal vascularity and choriocapillaris perfusion in a Chinese population aged 8 to 30 years old. Three hundred eighty eyes from 380 subjects aged 8 to 30 years were included in this cross-sectional study. Submacular choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), stromal area (SA), choroidal vascularity index (CVI), and choriocapillaris flow deficit (CcFD) were estimated using images obtained from optical coherence tomography (OCT). In this population, the mean ChT was 260.4 ± 63.3 µm, TCA was 1.56 ± 0.38 mm2, LA was 0.94 ± 0.25 mm2, and SA was 0.62 ± 0.15 mm2. The mean CVI was 60.25 ± 3.21% and CcFD was 11.95 ± 1.98%. Multivariable analyses showed that higher CVI and LA was associated with older age, thicker ChT, and shorter AL; and lower CcFD was associated with shorter AL. However, the associations were not uniformly rectilinear between CcFD and age. Specifically, CcFD was positively associated with age in subjects ≤19 years old and negatively associated with age in subjects >19 years old. Development of the choroidal medium- and large-sized vascular layers and choriocapillaris was different across patients aged 8 to 30 years old. Greater axial length was associated with attenuated choroidal circulation. Choroidal thickness correlated well with choroidal vascularity, but not with choriocapillaris perfusion. Further comprehensive and longitudinal assessment of choroidal vasculature and choriocapillaris perfusion will help greatly to understand the physiological and pathological mechanisms responsible for myopia.

Bilateral multifocal serous retinal detachments after multiple trauma: a case report

We present a patient with bilateral multifocal serous retinal detachments after multiple trauma in a car accident without preceding corticosteroid treatment. A 37-year-old patient was admitted to our hospital after he had suffered multiple body injuries in a car accident. After being woken from an induced coma, he complained of blurry vision in his left eye, so he underwent a complete ophthalmic examination – several serous retinal detachments were found at the posterior pole of both eyes, along with thickened choroids. As there was no intraocular inflammation, accelerated hypertension or other changes indicating other causes of serous retinal detachments, and since we observed a steady spontaneous subretinal fluid resorption, we classified our case as an atypical central serous chorioretinopathy. Alternatively, serous retinal detachments could have occurred due to transient alterations in choroidal circulation following cerebral injury. In conclusion, this case report adds new data on the occurrence of serous retinal detachments and discusses their possible aetiology in the trauma setting. Care must be taken not to miss any other underlying pathology needing treatment.

Microvascular involvement in migraine: an optical coherence tomography angiography study.

The aim of this study was to evaluate the microvasculature of the macula and the optic nerve in patients affected by migraine with aura (MA) and without aura (MO) by optical coherence tomography angiography (OCTA), comparing the findings with healthy controls (HC). We collected data from ocular and orthotic examinations, including eye motility, intraocular pressure measurement, best-corrected visual acuity (BCVA) measurement, objective refraction measurement, fundus examination, macular and optic disk OCTA examination. All subjects were imaged with solix fullrange OCT. The following OCTA parameters were recorded: macular vessel density (VD), inside disc VD, peripapillary VD, disc whole image VD, fovea choriocapillaris VD, fovea VD, parafovea VD, peripapillary thickness, fovea thickness, parafovea thickness, macular full retinal thickness, and foveal avascular zone (FAZ) parameters. Clinical and demographical data about migraine patients were collected by a neurologist. We included 56 eyes from 28 patients with a diagnosis of MO, 32 eyes from 16 patients with a diagnosis of MA, and 32 eyes from 16 HC subjects. The FAZ area was 0.230 ± 0.099 mm2 in the MO group, 0.248 ± 0.091 mm2 in the MA group and 0.184 ± 0.061 mm2 in the control group. The FAZ area was significantly larger in the MA group than in the HC group (p = 0.007). The foveal choriocapillaris VD was significantly lower in MA patients (63.6 ± 2.49%) when compared with MO patients (65.27 ± 3.29%) (p = 0.02). An impairment of retinal microcirculation can be detected in patients with MA, as demonstrated by the enlargement of FAZ. Moreover, the study of choroid circulation may reveal microvascular damage in patients with migraine with aura. OCTA is a useful non-invasive screening tool for the detection of microcirculatory disturbance in patients with migraine.

A case of choroidal melanocytosis observed by multimodal imaging with laser speckle flowgraphy

BackgroundChoroidal melanocytosis is characterized by congenital diffuse melanin pigmentation with extensive parenchymal infiltration of spindle cells in the choroid; however, little is known about the choroidal circulation and morphological changes. We herein report a case of choroidal melanocytosis observed by multimodal imaging with laser speckle flowgraphy (LSFG).Case PresentationA 56-year-old woman was referred to our hospital because of serous retinal detachment (SRD) in her left eye. At the initial examination, her best-corrected visual acuity (BCVA) was 1.5 oculus dexter (OD) and 0.8 oculus sinister (OS). An irregular, flat, brownish lesion was noted around the macula OS. Optical coherence tomography showed a choroidal structure with marked hyporeflectivity and SRD where the retinal thickness was preserved. Indocyanine green angiography demonstrated fluorescence blockade throughout. Fundus autofluorescence revealed enlarged macular hypofluorescence, suggesting chronic retinal pigment epithelium damage associated with prolonged SRD. B-mode echography showed no choroidal elevation. Based on the clinical findings, the left eye was diagnosed with choroidal melanocytosis. Four years and 10 months after the initial visit, her BCVA was 0.5 and SRD remained. During the entire period of observation, the mean blur rate (MBR) (mean ± standard deviation) of choroidal blood flow velocity on LSFG was 10.15 ± 0.72 arbitrary units (AU) OD and 1.31 ± 0.06 AU OS.ConclusionChoroidal melanocytosis presented with chronic minor circulatory disturbances due to melanocyte proliferation in the choroid, but the markedly low MBR values by LSFG were dissociated from her retinal thickness and visual function. The proliferation of melanocytes may be a cause of overestimating the cold-color signal of LSFG due to their pigmentation.

Review on imaging methods in non-infectious posterior uveitis, principles, relevance, and practical clinical applications to disease entities

The work-up and diagnosis of posterior uveitis rely heavily on multiple imaging methods that have become available beyond the mere photographic imaging and fluorescein angiography (FA) used to image uveitis in the past. Global assessment and precise follow-up of posterior uveitis were achieved with the development of indocyanine green angiography (ICGA) since the mid-1990ties that, together with FA, made it possible to perform dual FA and ICGA giving information on both the retina and the choroidal compartment. Further non-invasive imaging methods were developed subsequently that contributed to additional valuable information completing the dual FA/ICGA basic appraisal of uveitis, including (1) optical coherence tomography (OCT) giving a quasi-histological morphology of retinal structures of the posterior pole, (2) enhanced-depth imaging OCT (EDI-OCT) allowing to image the choroidal compartment and (3) blue light fundus autofluorescence (BAF) showing the integrity or damage of the retinal pigment epithelium, the photoreceptors and the outer retina. OCT-angiography (OCT-A) became available more recently and presented the advantage to image the retinal and choroidal circulations without needing dye injections, necessary for dual FA/ICGA. This review article will illustrate the principles, relevance and practical applications of these different imaging methods used in uveitis by examining the main categories of non-infectious posterior uveitis entities including (1) retinal inflammatory disorders, inflammatory diseases of the outer retina and of the choriocapillaris (choriocapillaritis) and stromal choroiditis.

Changes in Choroidal Circulation Hemodynamics Measured Using Laser Speckle Flowgraphy after a Cold Pressor Test in Young Healthy Participants

Using laser speckle flowgraphy (LSFG), we investigated the time course of changes in choroidal circulation hemodynamics after a cold pressor test in healthy eyes. This prospective study included the right eye of 19 young healthy participants. The macular mean blur rate (MBR) was measured with LSFG. The MBR, intraocular pressure (IOP), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), mean blood pressure (MBP), and ocular perfusion pressure (OPP) were evaluated at baseline; immediately after the test and 10, 20, and 30 min later. Immediately after the test (0 min), SBP, DBP, MBP, and OPP were significantly elevated compared with those at baseline. The macular MBR significantly increased by +10.3 ± 7.1% immediately after the test. However, there was no change after 10, 20, and 30 min in the above parameter. A significant positive correlation of the macular MBR with the SBP, MBP, and OPP was observed. In young healthy individuals, increased sympathetic activity induced by a cold pressor test increases choroidal hemodynamics in the macula along with an increase in systemic circulatory dynamics, which normalizes after 10 min. Therefore, LSFG may provide a novel approach for assessing sympathetic activity and intrinsic vascular responsiveness in the eye.

Molecular and Cellular Regulations in the Development of the Choroidal Circulation System.

Disorders in the development and regulation of blood vessels are involved in various ocular disorders, such as persistent hyperplastic primary vitreous, familial exudative vitreoretinopathy, and choroidal dystrophy. Thus, the appropriate regulation of vascular development is essential for healthy ocular functions. However, regulation of the developing choroidal circulation system has not been well studied compared with vascular regulation in the vitreous and the retina. The choroid is a vascular-rich and uniquely structured tissue supplying oxygen and nutrients to the retina, and hypoplasia and the degeneration of the choroid are involved in many ocular disorders. Therefore, understanding the developing choroidal circulation system expands our knowledge of ocular development and supports our understanding of ocular disorders. In this review, we examine studies on regulating the developing choroidal circulation system at the cellular and molecular levels and discuss the relevance to human diseases.

Changes in Choroidal Blood Flow by Diurnal Variation in Healthy Young Adults

Background: Little is known about the diurnal variation in choroidal circulatory dynamics in healthy eyes. Objective: This study aimed to clarify the diurnal variation in choroidal circulatory hemodynamic changes in healthy participants using laser speckle flowgraphy. Methods: This prospective study included the left eye of 14 healthy young adults (21.9 ± 4.0 years). The mean blur rate, a quantitative index of the relative blood flow velocity, was measured by laser speckle flowgraphy. The macular mean blur rate of choroidal blood flow velocity, subfoveal choroidal thickness, intraocular pressure, systolic blood pressure, diastolic blood pressure, mean blood pressure, and ocular perfusion pressure were evaluated at eight points every 3 h over a 24-h period. In addition, differences in each parameter between daytime and night were also investigated. Results: Intraocular pressure, systolic blood pressure, diastolic blood pressure, mean blood pressure, ocular perfusion pressure, and macular mean blur rate were highest at 6 PM, and subfoveal choroidal thickness was thinnest at 6 PM. There was a significant positive correlation between mean blur rate and intraocular pressure, diastolic blood pressure, and mean blood pressure. Furthermore, intraocular pressure, systolic blood pressure, diastolic blood pressure, mean blood pressure, ocular perfusion pressure, and mean blur rate were significantly higher and choroidal thickness significantly lower during daytime than at night. Conclusion: These results suggest that choroidal circulation hemodynamics change with diurnal variations in systemic circulation involving the autonomic nervous system in healthy eyes.

Ginkgo biloba extracts improve choroidal circulation leading to suppression of myopia in mice

Myopia is becoming more common across the world, necessitating the development of preventive methods. We investigated the activity of early growth response 1 (EGR-1) protein and discovered that Ginkgo biloba extracts (GBEs) activated EGR-1 in vitro. In vivo, C57BL/6 J mice were fed either normal or 0.0667% GBEs (200 mg/kg) mixed chow (n = 6 each), and myopia was induced with − 30 diopter (D) lenses from 3 to 6 weeks of age. Refraction and axial length were measured by an infrared photorefractor and an SD-OCT system, respectively. In lens-induced myopia mice, oral GBEs significantly improved refractive errors (− 9.92 ± 1.53 D vs. − 1.67 ± 3.51 D, p < 0.001) and axial elongation (0.22 ± 0.02 mm vs. 0.19 ± 0.02 mm, p < 0.05). To confirm the mechanism of GBEs in preventing myopia progression, the 3-week-old mice were divided into normally fed with either myopic-induced or non-myopic-induced groups and GBEs fed with either myopic-induced or non-myopic-induced groups (n = 10 each). Choroidal blood perfusion was measured with optical coherence tomography angiography (OCTA). In both non-myopic induced groups, compared to normal chow, oral GBEs significantly improved choroidal blood perfusion (8.48 ± 15.75%Area vs. 21.74 ± 10.54%Area, p < 0.05) and expression of Egr-1 and endothelial nitric oxide synthase (eNOS) in the choroid. In both myopic-induced groups, compared to normal chow, oral GBEs also improved choroidal blood perfusion (− 9.82 ± 9.47%Area vs. 2.29 ± 11.84%Area, p < 0.05) and was positively correlated with the change in choroidal thickness. These findings suggest that GBEs may inhibit the progression of myopia by improving choroidal blood perfusion.

Ocular blood flow evaluation by laser speckle flowgraphy in pediatric patients with anisometropia.

To determine the differences and reproducibility of blood flow among hyperopic anisometropic, fellow, and control eyes. We retrospectively studied 38 eyes of 19 patients with hyperopic anisometropia (8.2 ± 3.0 years of age) and 13 eyes of eight control patients (6.8 ± 1.9 years). We measured the optic nerve head (ONH) and choroidal circulation using laser speckle flowgraphy (LSFG) and analyzed the choroidal mean blur rate (MBR-choroid), MBR-A (mean of all values in ONH), MBR-V (vessel mean), MBR-T (tissue mean), and sample size (sample), which are thought to reflect the ONH area ratio, area ratio of the blood stream (ARBS). We then assessed the coefficient of variation (COV) and intraclass correlation coefficient (ICC) and compared the differences among amblyopic, fellow, and control eyes in MBR, sample, and ARBS. The ONH, MBR-A, MBR-T, and ARBS of amblyopic eyes were significantly higher than those of fellow eyes (P < 0.01, P < 0.05, and P < 0.05, respectively), and control eyes (MBR-A and ARBS, P < 0.05, for both comparisons). The sample-T (size of tissue component) in amblyopic eyes was significantly smaller than that in fellow and control eyes (P < 0.05). Blood flow in the choroid did not differ significantly between the eyes. The COVs of the MBR, sample, and ARBS were all ≤10%. All ICCs were ≥0.7. The COVs of pulse waveform parameter fluctuation, blowout score (BOS), blowout time (BOT), and resistivity index (RI) in the ONH and choroid were ≤10%. The MBR value of the LSFG in children exhibited reproducibility. Thus, this method can be used in clinical studies. The MBR values of the ONH in amblyopic eyes were significantly high. It has been suggested that measuring ONH blood flow using LSFG could detect the anisometropic amblyopic eyes.

Optical Coherence Tomography Angiography (OCT-A) in Uveitis: A Literature Review and a Reassessment of Its Real Role.

The global and precise follow-up of uveitis has become possible with the availability of dual fluorescein (FA) and indocyanine green angiography (ICGA) since the mid-1990s. Progressively, additional non-invasive imaging methods have emerged, bringing value-added precision to the imaging appraisal of uveitis, including, among others, optical coherence tomography (OCT), enhanced-depth imaging OCT (EDI-OCT) and blue light fundus autofluorescence (BAF). More recently, another complementary imaging method, OCT-angiography (OCT-A), further allowed retinal and choroidal circulation to be imaged without the need for dye injection. The purpose of this review was aimed at examining the evidence in published reports indicating whether OCT-A could possibly replace dye angiographic methods, as well as the real practical impact of OCT-A. A literature search in the PubMed database was performed using the terms OCT-angiography and uveitis, OCTA and uveitis and OCT-A and uveitis. Case reports were excluded. Articles were classified into technical reports, research reports and reviews. Articles in the two latter categories were analyzed in a more detailed, individual fashion. Special attention was paid to whether there were arguments in favor of an exclusive rather than complementary use of OCT-A. Furthermore, a synthesis of the main practical applications of OCT-A in the management of uveitis was attempted. Between 2016 (the year of the first articles) and 2022, 144 articles containing the search terms were identified. After excluding case report articles, 114 articles were retained: 4 in 2016, 17 in 2017, 14 in 2018, 21 in 2019, 14 in 2020, 18 in 2021 and 26 in 2022. Seven articles contained technical information or consensus-based terminology. Ninety-two articles could be considered as clinical research articles. Of those, only two hinted in their conclusions that OCT-A could hypothetically replace dye methods. The terms mostly used to qualify the contribution of the articles in this group were "complementary to dye methods", "adjunct", "supplementing" and other similar terms. Fifteen articles were reviews, none of which hinted that OCT-A could replace dye methods. The situations where OCT-A represented a significant practical contribution to the practical appraisal of uveitis were identified. To date, no evidence was found in the literature that OCT-A can replace the classic dye methods; however, it can complement them. Promoting the possibility that non-invasive OCT-A can substitute the invasive dye methods is deleterious, giving the elusive impression that dye methods are no longer inevitable for evaluating uveitis patients. Nevertheless, OCT-A is a precious tool in uveitis research.

Assessment of Retinal and Choroidal Circulation in Post COVID-19 Patients

Assessment of Retinal and Choroidal Circulation in Post COVID-19 Patients