OBJECTIVETo review articles aiming to present an overview of the principles, progress, uses and limitations of laser speckle flowgraphy (LSFG) in posterior fundus circulation research.

DATA SOURCESThe data used in this review was obtained mainly from the studies reported in PubMed using the key terms "laser speckle", "ocular blood flowmetry" and "retinal imaging".

STUDY SELECTIONRelevant literatures on studies of LSFG were selected.

RESULTSLSFG is a unique, noninvasive imaging instrument to quantitatively visualize posterior fundus circulation in vivo. This review delineates the LSFG principles and development, demonstrates its extensive applicability for measurement of retina, choroid and optic nerve head circulation, compares it with other retinal imaging technologies and discusses unresolved issues.

CONCLUSIONSLSFG is a noninvasive, two-dimensional objective diagnostic technique that has become a powerful method for the clinical and scientific assessment of posterior fundus circulation. Further studies may help to develop a more comprehensive evidence-based measurement and facilitate the correlation with other methods for chorioretinal circulation assessment.

Eye ; blood supply ; Fundus Oculi ; Humans ; Laser-Doppler Flowmetry ; methods ; Optic Disk ; blood supply

Neovascularization at the disc (NVD) is the most serious complication in diabetic retinopathy, and leads to vitreous hemorrhage and tractional retinal detachment. We report two cases of spontaneous regression of NVD in proliferative diabetic retinopathy. Two men (31 and 46 years old) with diabetes had NVD in both eyes. They were treated with panretinal photocoagulation on the left eye first, but their right eyes went untreated, because they did not revisit our clinic for several months. Fortunately, on revisit, their neovascularization had disappeared a few months later in both eyes, including their untreated right eyes. We could not find any specific causes for the spontaneous regression of the new vessels.
Adult ; Diabetic Retinopathy/*physiopathology ; Fluorescein Angiography ; Humans ; Male ; Middle Aged ; Optic Disk/*blood supply ; Remission, Spontaneous ; Retinal Neovascularization/*physiopathology

BACKGROUNDOptical coherence tomography (OCT) angiography is a novel technique by which we can detect the local perfusion of fundus directly. The aim of this study was to evaluate the reproducibility of optic disc and macular flow perfusion parameters in rhesus monkeys using OCT angiography.

METHODSEighteen healthy monkeys (18 eyes) were subjected to optic disc and macula flow index measurements via a high-speed and high-resolution spectral-domain OCT XR Avanti with a split-spectrum amplitude de-correlation angiography algorithm. Right eye was imaged 3 times during the first examination and once during each of the two following examinations. The intra-visit and inter-visit intraclass correlation coefficients (ICCs) were both determined.

RESULTSThe average flow indices of the four optic disc area layers were 0.171 ± 0.009 (optic nerve head), 0.015 ± 0.004 (vitreous), 0.052 ± 0.009 (radial peripapillary capillary), and 0.167 ± 0.011 (choroid). Average flow indices of the four macula area layers were 0.044 ± 0.011 (superficial retina), 0.036 ± 0.011 (deep retina), 0.016 ± 0.009 (outer retina), and 0.155 ± 0.013 (choroid). Intra-visit (ICC value: 0.821-0.954) and inter-visit (ICC value: 0.844-0.899) repeatability were both high.

CONCLUSIONSThe study is about the reproducibility of optic disc and macular perfusion parameters as measured by OCT angiography in healthy rhesus monkeys. Flow index measurement reproducibility is high for both the optic disc and macula of normal monkey eyes. OCT angiography might be a useful technique to assess changes when examining monkeys with experimental ocular diseases.

Angiography ; Animals ; Macaca mulatta ; Macula Lutea ; blood supply ; diagnostic imaging ; Male ; Optic Disk ; blood supply ; diagnostic imaging ; Reproducibility of Results ; Tomography, Optical Coherence ; methods

PURPOSE: We evaluated fundus and fluorescein angiography (FAG) findings and characteristics that can help distinguish nonarteritic anterior ischemic optic neuropathy (NAION) from optic neuritis (ON). METHODS: Twenty-three NAION patients and 17 ON with disc swelling patients were enrolled in this study. We performed fundus photography and FAG. The disc-swelling pattern, hyperemia grade, presence of splinter hemorrhages, cotton-wool spots, artery/vein ratio and degree of focal telangiectasia were investigated. The FAG findings for each patient were compared with respect to the following features: the pattern of disc leakage in the early phase, arteriovenous (artery/vein) transit time (second), and the presence and pattern of the filling delay. RESULTS: Cotton-wool spots, focal telangiectasia, and venous congestion were more common in the affected eyes of NAION patients. Upon FAG, 76.5% of the patients in the ON group exhibited normal choroidal circulation. However, 56.5% of patients in the NAION group demonstrated abnormal filling defects, such as peripapillary, generalized, or watershed zone filling delays. CONCLUSIONS: Fundus findings, including cotton-wool spots, focal telangiectasia, and venous congestion in the affected eye, may be clues that can be used to diagnose NAION. In addition, choroidal insufficiencies on FAG could be also helpful in differentiating NAION from ON.
Choroid/blood supply/*diagnostic imaging ; Female ; Fluorescein Angiography/*methods ; Fundus Oculi ; Humans ; Male ; Middle Aged ; Optic Disk/blood supply/*diagnostic imaging ; Optic Neuritis/*diagnosis ; Optic Neuropathy, Ischemic/*diagnosis ; Photography/*methods ; Retrospective Studies

PURPOSE: Goggles are frequently worn in the sport of swimming and are designed to form a seal around the periorbital tissue orbit. The resultant pressure on the eye may have the potential to affect intraocular pressure and blood flow of the optic nerve head. This study evaluates the influence of wearing swimming goggles on intraocular pressure (IOP) and blood flow of the ocular nerve head (ONH) in normal subjects. MATERIALS AND METHODS: Thirty healthy participants took part in this study. The IOP of each participant was measured using a Goldmann tonometer. Measurements were taken immediately before putting on swimming goggles, at 5, 10, 30, and 60 minutes after putting on swimming goggles, and then immediately after taking off the goggles. Blood flow of the ONH was measured using the Heidelberg retinal flowmeter. RESULTS: The average IOP before, during and after wearing the swimming goggles were 11.88 +/- 2.82mmHg, 14.20 +/- 2.81 mmHg and 11.78 +/- 2.89mmHg, respectively. The IOP increased immediately after putting on the goggles (p < 0.05) and then returned to normal values immediately after removal (p > 0.05). Blood flow of the ONH was 336.60 +/- 89.07 Arbitrary Units (AU) before and 319.18 +/- 96.02 AU after the goggles were worn (p < 0.05). CONCLUSION: A small but significant IOP elevation was observed immediately after the swimming goggles were put on. This elevated IOP was maintained while the goggles were kept on, and then returned to normal levels as soon as they were taken off. Blood flow of the ONH did not change significantly throughout the experiment. These facts should be considered for safety concerns, especially in advanced glaucoma patients.
Adult ; Eye Protective Devices/*adverse effects ; Female ; Humans ; *Intraocular Pressure ; Male ; Optic Disk/*blood supply ; Regional Blood Flow ; *Swimming ; Time Factors

BACKGROUNDMorphological changes of the vasculature system in patients with myopia have been observed by Doppler ultrasound and fundus fluorescein angiography (FFA); however, these studies have limitations. Doppler ultrasound provides low-resolution images which are mainly obtained from visualized large vessels, and FFA is an invasive examination. Optic coherence tomography (OCT) angiography is a noninvasive, high-resolution measurement for vascular density. The purpose of this study was to investigate the change of vascular density in myopic eyes using OCT angiography.

METHODSThis cross-sectional study includes a total of 91 eyes from 47 participants including control, moderate, and high myopia that were evaluated by OCT angiography. Patients with myopia were recruited from the Refractive Department, Shenzhen Aier Eye Hospital, from August 5, 2015 to April 1, 2016. Emmetropic eyes were from healthy volunteers. The vascular density at macula and optic disc regions, ganglion cell complex (GCC) thickness, and retinal nerve fiber layer (RNFL) thickness were measured. Their relationships with axial length (AL) and refractive error were analyzed. One-way analysis of variance (ANOVA), Pearson's correlation, and generalized estimating equation were used for statistical analysis.

RESULTSBoth superficial and deep macular vascular density were highest in control (25.64% ± 3.76% and 37.12% ± 3.66%, respectively), then in moderate myopia (21.15% ± 5.33% and 35.35% ± 5.50%, respectively), and lowest in high myopia group (19.64% ± 3.87% and 32.81% ± 6.29%, respectively) (F = 13.74 and 4.57, respectively; both P < 0.001). Both superficial (β = -0.850 and 0.460, respectively) and deep (β = -0.766 and 0.396, respectively) macular vascular density were associated with AL and spherical equivalent (all P < 0.001). Superficial macular vascular density was associated with GCC thickness (β = 0.244, P = 0.040), independent of spherical equivalent. The vascular density in optic disc region had no difference among the three groups, and it was not associated with AL, spherical equivalent, or RNFL thickness.

CONCLUSIONOur results suggested that with the increase of myopia, the vascular density decreased in macular region, but not in optic disc region.

Adult ; Cross-Sectional Studies ; Eye ; blood supply ; Female ; Fluorescein Angiography ; Humans ; Macula Lutea ; pathology ; physiopathology ; Male ; Middle Aged ; Myopia ; pathology ; physiopathology ; Optic Disk ; pathology ; physiopathology ; Prospective Studies ; Retina ; pathology ; physiopathology ; Retinal Ganglion Cells ; pathology ; Tomography, Optical Coherence ; Young Adult

PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG). METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed. RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area. CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.
Aged ; Double-Blind Method ; Female ; *Ginkgo biloba ; Humans ; Laser-Doppler Flowmetry ; Low Tension Glaucoma/*drug therapy/physiopathology ; Male ; Optic Disk/blood supply ; Phytotherapy/*methods ; Plant Extracts/*therapeutic use ; Regional Blood Flow/*drug effects ; Retina/*physiopathology ; Retrospective Studies ; Time Factors ; Visual Fields

PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG). METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed. RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area. CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.
Aged ; Double-Blind Method ; Female ; *Ginkgo biloba ; Humans ; Laser-Doppler Flowmetry ; Low Tension Glaucoma/*drug therapy/physiopathology ; Male ; Optic Disk/blood supply ; Phytotherapy/*methods ; Plant Extracts/*therapeutic use ; Regional Blood Flow/*drug effects ; Retina/*physiopathology ; Retrospective Studies ; Time Factors ; Visual Fields

PURPOSE: To compare clinical, angiographic, and optical coherence tomographic characteristics between eyes with acute Vogt-Koyanagi-Harada (VKH) disease and eyes with acute bilateral central serous chorioretinopathy (CSC), and to demonstrate distinguishing features between the two diseases in confusing cases. METHODS: The medical records of 35 patients with VKH disease and 25 patients with bilateral CSC were retrospectively reviewed. Characteristics according to slit-lamp biomicroscopy, ophthalmoscopy, fundus photography, fluorescein angiography, indocyanine green angiography, and spectral-domain optical coherence tomography were compared between the two diseases. RESULTS: Five of 35 patients (10 of 70 eyes, 14.3%) with VKH disease were initially misdiagnosed as CSC patients, and six of 25 patients (12 of 50 eyes, 24%) with bilateral CSC were initially misdiagnosed as patients with VKH disease. Pigment epithelial detachment in CSC and optic disc hyperemia in VKH disease show the highest positive predictive values of 100% for each disease. CONCLUSIONS: Optic disc hyperemia in VKH disease and pigment epithelial detachment in bilateral CSC are the most specific clinical manifestations of each disease at initial patient presentation.
Acute Disease ; Adult ; Aged ; Aged, 80 and over ; Central Serous Chorioretinopathy/*diagnostic imaging ; Female ; Fluorescein Angiography ; Humans ; Hyperemia/diagnosis ; Indocyanine Green/administration & dosage ; Male ; Middle Aged ; Multimodal Imaging ; Ophthalmoscopy ; Optic Disk/blood supply ; Photography ; Retinal Detachment/diagnosis ; Retinal Pigment Epithelium/pathology ; Retrospective Studies ; Slit Lamp Microscopy ; Tomography, Optical Coherence ; Uveomeningoencephalitic Syndrome/*diagnostic imaging ; Young Adult