Comparison of retinochoroidal microvascular circulation in menstrual and postmenopausal periods using swept-source optical coherence tomography angiography.

PURPOSE: We aimed to examine the possible effects of the postmenopausal period on retinal and choroidal microvascular circulation using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: This cross-sectional study included 45 eyes of 45 subjects in menstrual group and 40 eyes of 40 subjects in postmenopausal group. SS-OCTA was used for the assessment of vessel density (VD), foveal avascular zone (FAZ), choroidal thickness (CT), choriocapillaris VD, central macular thickness (CMT), nerve fiber layer thickness (RNFL), and ganglion cell layer (GCL) measurements. RESULT: The VDs of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) measurements were similar in both group. FAZ area was wider in postmenopausal group (0.305 mm2 (range, 0.212-0.498 mm2)) compared to menstrual group (0.271 mm2 (range, 0.131-0.464 mm2)) (p = 0.013). Choriocapillaris VD was significantly lower in postmenopausal group (p = 0.049). CT was thicker in the postmenopausal group, but with no statistically significant difference (p = 0.066). Central macular thickness, RNFL, and GCL were similar in both groups. CONCLUSION: This is the first study in the literature to evaluate the retinochoroidal microcirculation in the menstrual and postmenopausal periods with SS-OCTA. We observed an increase in both superficial and deep FAZ area and a decrease in choroidal blood flow in the postmenopausal period. We think that this enlargement in the FAZ area may be related to the decreased amount of estrogen.

Associations between optic disc characteristics and macular choroidal microvasculature in young patients with high myopia.

BACKGROUND: This study aimed to examine changes to optic disc characteristics and macular choroidal microvasculature, and their relationships in young patients with high myopia (HM). METHODS: A total of 90 patients were enrolled in this cross-sectional study. Based on their refractive power, the patients were divided into three groups: 27 in the control group, 34 in the HM group and 29 in the extremely high myopia group. Images of each patient's macula and optic disc were taken by ocular coherence tomography angiography. The macular choroidal and retinal thickness, capillary vessel density and capillary flow area were measured using Matlab software. Parapapillary atrophy (PPA) and the ovality index (OI) obtained from the scanning laser ophthalmoscopy images and the degree of optic disc tilt obtained from the optic nerve head ocular coherence tomography B-scans were analysed by Image J and Matlab software. RESULTS: The PPA area, OI and degree of optic disc tilt were significantly different among the three groups (all p ≤ 0.001). The macular choroidal thickness and microvasculature were significantly different among the three groups (all p < 0.05). Macular choroidal thickness was significantly correlated with PPA area and the degree of optic disc tilt (r = -0.331, p = 0.003; r = -0.394, p = 0.001, respectively). Macular choroidal capillary vessel density and choriocapillaris flow area were associated with PPA area (r = -0.251, p = 0.047; r = -0.326, p = 0.009, respectively). CONCLUSIONS: PPA area, OI and the degree of optic disc tilt were increased in patients with HM, and these changes were correlated with macular choroidal thickness and choroidal microvasculature.

Associations between the retinal/choroidal microvasculature and carotid plaque in patients with CAD: An OCTA study.

Background: To investigate the associations between retinal/choroidal microvasculature and carotid plaque in patients with CAD assessed by optical coherence tomography angiography (OCTA). Methods: This study included 127 CAD patients with and 79 without carotid plaque. Each patient had both OCTA taken and digitized to determine retinal/choroidal thickness, vessel density and flow area and carotid ultrasound for carotid plaque size and stability measurement. The superficial capillary plexus (SCP), deep capillary plexus (DCP), out retina and choriocapillaris vessel density, out retina and choriocapillaris flow area, and full retina thickness were analyzed in the fovea centered 6 × 6 mm area. The association between OCTA measurements and carotid plaque characteristics in patients with CAD were evaluated. Results: The duration of hypertension and diabetes mellitus (DM) was significantly longer in CAD patients with carotid plaque than that without (p < 0.001). The mean values for vessel density SCP and DCP (except fovea zone), and choriocapillaris nasal zone were significantly lower in plaque group (p < 0.05). Negative correlations between the carotid plaque width and vessel density SCP and DCP (except fovea zone) (p < 0.05) were also found in this study. Conclusions: In patients with CAD, carotid plaque, a risk factor and marker of atherosclerosis and stenosis, is significantly and independently associated with retinal and choroidal microvascular changes by OCTA.

Parapapillary choroidal microvasculature in retrobulbar optic neuritis: An optical coherence tomography angiography study.

PURPOSE: To compare superficial and deep vascular characteristics of the optic disc in retrobulbar optic neuritis using optical coherence tomography angiography (OCT-A). METHODS: Nineteen patients with unilateral non-infectious retrobulbar neuritis were included in the study. The contralateral eyes of each patient were served as controls. OCT-A scans of the optic discs were performed in a 4.5 × 4.5 mm rectangular area, while macular OCT-A scans were performed in a 6 × 6 mm rectangular area. Various parameters, including radial peripapillary capillary (RPC) density, peripapillary retinal nerve fibre layer (pRNFL) thickness, cup volume, rim area, disc area, cup-to-disc (c/d) area ratio, and vertical and horizontal c/d ratios were automatically obtained using the instrument software. The density for superficial capillary plexus (SCP) and deep capillary plexus (DCP) were assessed using macular OCT-A. Parapapillary choroidal microvascular (PPCMv) density was calculated using MATLAB software. RESULTS: Parafoveal inferior, perifoveal total and inferior SCP densities were significantly decreased in eyes with optic neuritis when compared with contralateral control eyes in OCT-A measurements (respectively, p = 0.027, p = 0.041, p = 0.045). The axial lengths, (p = 0.72), vertical and horizontal cup-disc ratios, and disc area, cup-disc areas, cup volumes, and pRNFL thicknesses between the groups were similar (for each, p>0.05). CONCLUSIONS: This study demonstrated for the first time that patients with retrobulbar optic neuritis had decreased SCP densities, though it did not cause any changes in PPCMv density.

Automated evaluation of parapapillary choroidal microvasculature in crowded optic discs: a controlled, optical coherence tomography angiography study.

AIM: To compare superficial and deep vascular properties of optic discs between crowded discs and controls using optical coherence tomography angiography (OCT-A). METHODS: Thirty patients with crowded discs, and 47 control subjects were enrolled in the study. One eye of each individual was included and OCT-A scans of optic discs were obtained in a 4.5×4.5 mm2 rectangular area. Radial peripapillary capillary (RPC) density, peripapillary retinal nerve fiber layer (pRNFL) thickness, cup volume, rim area, disc area, cup-to-disc (c/d) area ratio, and vertical c/d ratio were obtained automatically using device software. Automated parapapillary choroidal microvasculature (PPCMv) density was calculated using MATLAB software. When the vertical c/d ratio of the optic disc was absent or small cup, it was considered as a crowded disc. RESULTS: The mean signal strength index of OCT-A images was similar between the crowded discs and control eyes (P=0.740). There was no difference in pRNFL between the two groups (P=0.102). There were no differences in RPC density in whole image (P=0.826) and peripapillary region (P=0.923), but inside disc RPC density was higher in crowded optic discs (P=0.003). The PPCMv density in the inner-hemisuperior region was also lower in crowded discs (P=0.026). The pRNFL thickness was positively correlated with peripapillary RPC density (r=0.498, P<0.001). The inside disc RPC density was negatively correlated with c/d area ratio (r=-0.341, P=0.002). CONCLUSION: The higher inside disc RPC density and lower inner-hemisuperior PPCMv density are found in eyes with crowded optic discs.

Factors Contributing to the Development of Choroidal Microvasculature Dropout in Glaucoma Suspects and Patients with Glaucoma.

We aimed to characterize and compare the occurrence of peripapillary microvasculature dropout (MvD) between glaucoma suspects and patients with glaucoma. In addition, the factors related to the development of parapapillary MvD in glaucoma suspects and patients with glaucoma were investigated. Of a total 150 eyes, 68 eyes of glaucoma suspects and 82 eyes of glaucoma patients were analyzed in this study. Univariate and multivariate logistic regression analyses were used to identify factors associated with MvD development. The classification of glaucoma patients or glaucoma suspects was not significantly associated with MvD development (beta 1.368, 95% CI, 0.718-2.608, p = 0.341). In the regression analysis of the glaucoma suspect group, greater axial length (beta 1.520, 95% CI, 1.008-2.291, p = 0.046) and baseline cup volume (beta 3.993, 95% CI, 1.292-12.345, p = 0.035) among the baseline factors and the slope of ganglion cell-inner plexiform layer (GCIPL) thickness (beta 0.027, 95% CI, 0.072-0.851, p = 0.027) and central visual field (VF) progression (beta 7.040, 95% CI, 1.781-16.306, p = 0.014) among follow-up factors were significantly associated with MvD development. In the glaucoma group, central VF progression (beta 5.985, 95% CI, 1.474-24.083, p = 0.012) and ONH depression (beta 3.765, 95% CI, 1.301-10.895, p = 0.014) among follow-up elements were observed as significant factors and the baseline factor had little relationship. MvD appears not only as a result of the progression of axonal loss of RGC in glaucoma but may also be developed due to structural changes and mechanical susceptibility of the ONH associated with baseline characteristics. Analyzing the structural susceptibility of the ONH can predict the occurrence of MvD, which can be helpful in predicting the progression of glaucoma.

Reduced Vessel Density and Enlarged Foveal Avascular Zone in the Macula as a Result of Systemic Hypoxia Caused by SARS-CoV-2 Infection.

Infection with SARS-CoV-2 can lead to various long-term consequences, including those of an ophthalmic nature. This paper reviews the results of optical coherence tomography angiography (OCTA) performed among COVID-19 patients. The review included papers evaluating short- and long-term outcomes following the SARS-CoV-2 infection. Some differentiated the obtained retinal and choroidal vascularization parameters according to gender. Following COVID-19, patients reveal changes in retinal and choroidal vascular parameters based on OCTA, such as reduced vascular density and an increased foveal avascular zone, which can persist for several months. Routine ophthalmic follow-up with OCTA should be considered in patients after SARS-CoV-2 infection to assess the effects of inflammation and systemic hypoxia in COVID-19. Further research is needed to understand whether infection with particular viral variants/subvariants may vary in the risk of effects on retinal and choroidal vascularization and whether and to what extent these risks may also differ in relation to reinfected and vaccinated individuals.

Choroidal Microvasculature Dropout in Glaucoma.

Glaucoma is a group of diseases characterized by distinctive visual field defect and optic nerve atrophy usually associated with elevated intraocular pressure (IOP). It is one of the most serious visual disorders and the leading cause of irreversible blindness worldwide. As a multifactorial disease, the pathogenesis of glaucoma is complicated and has been far from fully understood, where vascular factors are recognized to play an important role in its development and progression of glaucoma. Empirical researches have shown that parapapillary choroidal microvasculature dropout (CMvD) is closely associated with the impairment of optic nerve head (ONH) perfusion, probably accelerating the progression of glaucoma. Accordingly, it is necessary to explore the details regarding the relationship between CMvD and glaucoma progress, hoping to enhance the understanding of pathogenesis of glaucoma. In this review, we aimed to establish comprehensive understanding of the relationship between CMvD and glaucoma with generally going through relevant up-to-date literatures. Among the events that are closely associated with CMvD, we summarized the ones specifically involved in the term of glaucomatous pathological process, including thickness of retinal nerve fiber layer (RNFL) thickness, lamina cribrosa (LC) morphology, cricumpapillary vessel density (cpVD) and visual function such as visual field (VF) defect as well as the prognosis of glaucoma. Although researchers have made great advances, there are still many issues need to be addressed particularly concerning the pathogenic role of CMvD in glaucoma development and its clinical implications with respect to glaucoma prognosis.

Parapapillary Intrachoroidal Cavitation in Glaucoma: Association with Choroidal Microvasculature Dropout.

PURPOSE: To characterize the choroidal microvasculature in glaucomatous eyes with parapapillary intrachoroidal cavitation (PICC) using optical coherence tomography angiography (OCTA) and its association with parapapillary choroidal microvasculature dropout (MvD). METHODS: This study included 47 glaucomatous eyes with PICC, as identified by color fundus photography and optical coherence tomography scanning of the optic nerve head area. Peripapillary choroidal microvasculature was evaluated on en-face OCTA images. Choroidal MvD was defined as a focal sectoral capillary dropout with no visible microvascular network. RESULTS: PICC was visible as a well-demarcated area with homogeneously reduced vessel density in en-face OCTA images of the choroidal layer. MvD was detected in 42 eyes (89.4%). Although located in the juxtapapillary area adjacent to the PICC, MvD was confined to the area of parapapillary atrophy. MvD observed in OCTA en-face images was distinguished from the area of PICC by the absence of vascular signal. Of the 50 PICCs, 49 (98.0%) had hemifield visual field defects at the location corresponding to the hemispheric location of PICC. CONCLUSIONS: PICC was found to have a characteristic microvascular feature in choroidal en-face OCTA images, and to be topographically associated with glaucomatous visual field defect. PICC was frequently accompanied by MvD and was located adjacent to the area of MvD, suggesting that PICC and MvD have similar pathogenesis.

Parapapillary choroidal microvasculature dropout in nonglaucomatous healthy eyes.

PURPOSE: To determine the incidence of parapapillary choroidal microvasculature dropout (MvD) in nonglaucomatous healthy eyes using optical coherence tomography angiography (OCTA) and to characterize the MvD observed in these eyes. METHODS: Seventy-six eyes (19 eyes with an MvD and 57 age-matched eyes without an MvD) from a cohort of 297 nonglaucomatous healthy eyes that underwent OCTA were included. The peripapillary choroidal microvasculature was evaluated in en-face images obtained using swept-source OCTA. An MvD was defined as a focal sectoral capillary dropout with no visible microvascular network identified in the en-face images of the choroidal layer. The incidence of MvD and clinical characteristics associated with the presence of an MvD was determined. RESULTS: MvD was found in 19 of the 297 nonglaucomatous healthy eyes (6.4%). Compared with age-matched eyes without an MvD, eyes with an MvD had lower systolic blood pressure (p = 0.021), diastolic blood pressure (p = 0.048), mean arterial pressure (p = 0.025) and mean ocular perfusion pressure (p = 0.032). Logistic regression analyses showed that cold extremities (p = 0.046), lower mean arterial pressure (p = 0.021) and lower mean ocular perfusion pressure (p = 0.023) were associated with the presence of an MvD. CONCLUSIONS: Parapapillary choroidal MvD can be present in nonglaucomatous healthy eyes. The presence of an MvD is associated with systemic vascular dysregulation.

Choroidal thickness in patients with cardiovascular disease: A review.

The choroid is a vascular network that supplies the bulk of the retina's oxygen and nutrient supply. Prior studies have associated changes in the thickness of the choroid with the presence of various cardiovascular diseases. This is the first review that summarizes current knowledge on the relationship between choroidal thickness and cardiovascular diseases while highlighting important findings. Acute hypertension increases choroidal thickness. Chronic hypertension and heart failure may decrease choroidal thickness, but controversy exists. Both coronary artery disease and carotid artery stenosis result in decreased choroidal thickness and blood flow. Carotid endarterectomy may reverse these changes. Choroidal thickening in early stages of carotid stenosis may arise from mechanisms compensating for ischemia. Hyperlipidemia is linked to choroidal thickening, while caffeine intake is linked to choroidal thinning. The effects of smoking and exercise are mixed. Changes in choroidal thickness have been linked to cardiovascular disease. Clarity regarding these changes could lead to the use of choroidal thickness changes as a noninvasive screening or prognostic test for pathological cardiovascular changes. Future studies should also investigate the effect of cardiovascular disease treatments on the choroid.