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Purpose: To assess the changes in optic nerve head and macular microvascular networks after acute intraocular pressure (IOP) rise in healthy eyes versus the eyes of diabetic patients. Methods: In this prospective, interventional, comparative study, 24 eyes of 24 adults including 12 eyes of healthy nondiabetic subjects and 12 eyes with mild or moderate non-proliferative diabetic retinopathy (NPDR) were enrolled. IOP elevation was induced by a suction cup attached to the conjunctiva. IOP and optical coherence tomography angiographic (OCTA) images of the optic disc and macula were obtained before and immediately after the IOP rise. Results: Baseline and post-suction IOPs were not significantly different between the two groups (all P > 0.05). The mean IOP elevation was 13.93 ± 3.41 mmHg among all eyes and was statistically significant as compared to the baseline in both groups (both P < 0.05). After IOP elevation, healthy eyes demonstrated a reduction in the vessel density in the whole image deep and superficial capillary plexuses and parafoveal deep capillary plexus (DCP) (all P < 0.05). In diabetic retinopathy, foveal vessel density at DCP decreased significantly following IOP rise (P = 0.003). In both groups, inside disc vessel density decreased significantly after IOP rise (both P < 0.05), however, no significant change was observed in peripapillary vessel density (both P >0.05). Conclusion: Acute rise of IOP may induce different levels of microvascular changes in healthy and diabetic eyes. Optic disc microvasculature originating from the posterior ciliary artery may be more susceptible to IOP elevation than that of retinal microvasculature. [ABSTRACT FROM AUTHOR]

To evaluate short-term retinal and choroidal vascularity changes in the healthcare professionals after four hours of use filtering facepiece respirators (FFR). This prospective study included 20 healthcare professionals. Oxygen saturation, pulse rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), mean ocular perfusion pressure (MOPP), and spectral domain optical coherence tomography (OCT) imaging were evaluated at baseline and after four hours wearing of FFP3 FFRs without an exhalation valve. Superior temporal artery (STA), inferior temporal artery (ITA), superior temporal vein (STV), and inferior temporal vein (ITV) diameter were measured from OCT images. The total subfoveal choroidal area (TCA), luminal area (LA), stromal area (SA) choroidal vascularity index [(CVI), the ratio of LA to TCA] were determined after binarization of enhanced depth imaging OCT (EDI-OCT) images of the choroid. The mean age of the participants was 27.35 ± 2.80 years (range, 25–34). Eight of them were female and 12 were male. After wearing the FFR for four hours, a significant decrease was observed in the mean DBP (p = 0.018), MAP (p = 0.016), and MOPP (p = 0.007) when compared to base-line values. STV diameter (p = 0.019) and ITV diameter (p = 0.046) measurements were found significantly higher than baseline measurements. A significant increase in the choroidal vascularity was observed in the LA (p = 0.004) and TCA values (p = 0.043) after wearing the FFR for four hours. The current study shows that after four hours usage of FFR, in addition to systemic changes, retinal and choroidal vascularity might be affected significantly. With further studies, long-term effects and clinical significance of these short-term changes should be investigated on healthcare professionals. [ABSTRACT FROM AUTHOR]

Background: The purpose of this pilot study was to investigate the differences in neurovascular coupling between Caucasian patients with normal tension glaucoma (NTG) and healthy subjects (HS) with laser speckle flowgraphy (LSFG). Methods: Measurement of optic nerve head blood flow was performed with LSFG. The mean blur rate of the whole optic nerve head (MA), of the big retinal vessels (MV) and of the microvasculature (MT) was analysed during continuous flicker light stimulation for four minutes. Results: We included 12 eyes from 12 Caucasian patients with a diagnosis of normal tension glaucoma and 12 eyes from 12 age- and sex-matched healthy individuals. MA, MV and MT all increased significantly in both groups during the observation period with no difference between the groups. Conclusion: Neurovascular coupling is detectable in NTG patients. Flicker light stimulation leads to a comparable increase in ocular blood flow in glaucoma patients and healthy individuals. [ABSTRACT FROM AUTHOR]

Patients with glaucoma demonstrate disturbed ocular blood flow that is induced by oxidative stress, endothelial dysfunction and impaired autonomic nervous system activity. It has not yet been clarified whether the reduced blood flow in glaucoma is secondary (to tissue loss or a decrease in perfusion pressure with disturbed autoregulation) or is itself the primary cause of optic neuropathy. Due to the complex system of blood supply to the optic disc and retina there is no single diagnostic method that allows the measurement of all vascular beds in the eye important for glaucoma. The article, based on a review of the literature, discusses current and previous techniques for assessing retinal, choroidal and retrobulbar circulation in glaucoma, with particular attention to color Doppler ultrasonography and optical coherence tomography angiography. Advantages and limitations of each technology are presented and the results of the most important research with their use are listed. In the light of the latest research, optical coherence tomography angiography is an imaging modality that has great scientific and clinical potential to enhance the knowledge of glaucoma pathogenesis and to improve the ability to detect glaucomatous damage. [ABSTRACT FROM AUTHOR]

Purpose: Intravitreal injection of anti‐vascular endothelial growth factor (anti‐VEGF) is the standard treatment for neovascular age‐related macular degeneration (AMD). As VEGF is a physiological key player for regulating retinal vascular tone, questions have been raised whether the application of anti‐VEGF could induce alterations in ocular perfusion. Methods: The study included 20 eyes from 20 Caucasian patients with unilateral neovascular AMD and 20 fellow eyes. All eyes were treated with standard intravitreal injection of aflibercept (IVA). Measurements of blood flow at the optic nerve head (ONH) and the choroid were performed with laser speckle flowgraphy (LSFG). The intraocular pressure (IOP), systolic and diastolic blood pressure, heart rate, mean arterial pressure (MAP) and ocular perfusion pressure (OPP) were analysed. Measurements were performed at baseline and repeated immediately after the injection and 30 and 45 min later. Results: Mean time between injection of aflibercept and first follow‐up was 8:56 ± 4:25 min. The injection led to significant rise in IOP. In the injected eyes, mean blur rate (MBR, i.e. a relative measure of perfusion and the main outcome parameter of LSFG) within the major vessels of the ONH as well as at the entire ONH region decreased significantly (p < 0.001). No change in MBR was observed in the fellow eye. Choroidal blood flow was maintained stable in both eyes. Conclusion: Intravitreal injection of aflibercept (IVA) led to a short‐term reduction in perfusion only in the treated eye. This was independent from IOP, indicating a direct pharmacological effect. No changes in choroidal perfusion were observed during the first 45 min after the injection. [ABSTRACT FROM AUTHOR]

Purpose: To provide the reader with information on the principal techniques of optical coherence tomography angiography (OCTA); the current literature on OCTA reproducibility; its applications to glaucoma detection and monitoring of progression; and the role of OCTA in the assessment of the vascular component in glaucoma pathogenesis.Methods: A literature review of the pertinent publications for the OCTA in relation to the development, techniques, and its use in glaucoma was carried out.Results: Rapid improvements in optical coherence tomography (OCT) technology have allowed for enhancement of both image resolution and scanning speed, and the development of vascular assessment modality. OCTA is the non-invasive in vivo imaging of the vasculature located within the retina and optic nerve head area. The principle of OCTA is to use the variations in OCT signals caused by moving particles as the contrast mechanism for imaging of flow. Several algorithms which aim to maximize the contrast signal and minimize the noise have been developed including the phase-based techniques, intensity-based techniques (e.g., split-spectrum amplitude decorrelation angiography (SSADA)), and complex-based techniques (e.g., optical microangiography (OMAG)). With its reliable technique, high image resolution, and current availability, OCTA has been widely used in the assessment of posterior segment diseases including glaucoma in which ocular perfusion dysfunction has been proposed as a pathophysiological mechanism.Conclusion: OCTA may enhance our knowledge of glaucoma pathogenesis and offer an improvement in our ability to detect glaucomatous change. [ABSTRACT FROM AUTHOR]

The benefits of physical exercise on health and well‐being have been studied in a wide range of systemic and ocular diseases, including glaucoma, a progressive optic neuropathy characterized by accelerated apoptosis of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) and insufficient ocular perfusion have been postulated to be the two main theories in glaucoma development and progression. The effects of exercise in these two aspects have been demonstrated by numerous researches. A review in 2009 focusing on these two theories concluded that exercise results in transient IOP reduction but an inconsistent elevation in ocular perfusion. However, the majority of the studies had been conducted in healthy subjects. Over the past decade, technological advancement has brought forth new and more detailed evidence regarding the effects of exercise. Moreover, the neuroprotective effect of exercise by upregulation of neurotrophin and enhancement of mitochondrial function has been a focus of interest. Apart from visual impairment, the mental health issues in patients with glaucoma, which include anxiety and depression, should also be addressed. In this review, we mainly focus on publications from the recent years, so as to provide a comprehensive review on the impact of physical exercise on IOP, ocular perfusion, neuroprotection and mental health in patients with glaucoma. [ABSTRACT FROM AUTHOR]

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Reactive oxygen species (ROS) play an important role in the pathogenesis of various ocular diseases. ROS can induce vasodilation or vasoconstriction depending on the species, the tested vessel bed, and the condition of the vessel. This study investigates the effect of different dosages of ROS on the tone of rat ophthalmic arteries. Methods: Freshly dissected rat ophthalmic arteries were pressurized in a perfusion setup in steps of 10 mmHg to 180 mmHg in three consecutive cycles. The first cycle was run under mostly physiological conditions, the second cycle was run after ROS treatment, and the third cycle as passive dilation after all Ca was removed from the solution. ROS-induced dilation or constriction was calculated in relation to the passive dilation. All experiments were performed with or without endothelium. Results: For vessels with endothelium, dilation in control experiments was 20.0 ± 0.1 %; after 5 s of ROS dilation was 74.4 ± 0.6 %, and after 20 s 87.4 ± 0.3 %. ANOVA revealed significant differences between these groups ( P = 0.048). For vessels without endothelium, a slight dilation was seen in control experiments (14.5 ± 0.4 %), which was also present after 5 s of ROS treatment (15.4 ± 0.4 %). Treatment with ROS for 20 s led to a constriction of the vessel preparations (−16.6 ± 0.5 %; P = 0.831). Conclusions: ROS led to a vasodilation in vessels with endothelium that was not seen in vessels without endothelium. Endothelial function seems to determine the effect of ROS on the vessel tone in isolated rat ophthalmic arteries. [ABSTRACT FROM AUTHOR]

. Purpose: Little information is available about the relationship between glaucomatous visual field defects, morphological changes of the optic disc and ocular blood flow. In this study, ocular blood flow parameters were correlated with parameters of optic nerve head (ONH) morphology and visual field performance in a cross-sectional study. Methods: A total of 103 patients with primary open angle glaucoma were included. Choroidal and ONH blood flow was assessed using laser Doppler flowmetry. Retinal blood velocities and retinal vessel diameters were measured with laser Doppler velocimetry and a Retinal Vessel Analyzer, respectively. To evaluate the ONH morphology, fundus photographs were taken and confocal laser scanning tomography was performed. Results: Among all measured ocular hemodynamic parameters, the ONH blood flow was most strongly correlated to structural parameters of ONH damage and visual field loss. Reduced retinal vessel diameters were only slightly correlated with the degree of glaucomatous damage. Conclusion: Reduced blood flow in the ONH was associated with increasing amount of visual field defect and morphological changes of the ONH. Retinal vessel diameters were only marginally associated with glaucomatous optic nerve damage. Based on retinal vessel diameter determination alone, it is not possible to assess whether reduced retinal blood flow is causative or secondary in glaucoma. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of combined intravitreal triamcinolone and ocular photodynamic therapy on retinal and choroidal hemodynamics in age-related macular degeneration. Methods: Intravitreal triamcinolone (4 mg, 0.1 cc) and photodynamic therapy with verteporfin were applied to 48 eyes of 33 subjects (25 male and 8 female; mean age: 68.9 years) with subfoveal choroidal neovascular membrane secondary to age-related macular degeneration. Patients were assessed for ocular hemodynamic parameters with color Doppler imaging 24 hr before and 1 week, 1 month, and 3 months after a single-dose administration of combined intravitreal triamcinolone and photodynamic therapy. Results: Throughout the study period, no significant difference in resistance index, peak systolic velocity, or end diastolic velocity existed in the ophthalmic artery ( P == 0.58, P == 0.18, and P == 0.19, respectively), the posterior ciliary arteries ( P == 0.73, P == 0.19, and P == 0.34, respectively), or the central retinal artery ( P == 0.09, P == 0.32, and P == 0.47, respectively). Conclusion: Combined intravitreal triamcinolone and photodynamic therapy was not associated with any alteration in ocular blood flow or flow velocity over 3 months in eyes with age-related macular degeneration. [ABSTRACT FROM AUTHOR]

PurposeTo evaluate the effect of latanoprost 0.005% on the optic nerve head (ONH) and retinal circulation of newly diagnosed and previously untreated primary open-angle glaucoma (POAG) patients.MethodsTwenty-two newly diagnosed and previously untreated POAG patients (mean age±SD: 68.38±11.92 years) were included in this longitudinal open-label study. Patients were treated with latanoprost 0.005% once a day. Intraocular pressure (IOP), systemic blood pressure (BP), mean ocular perfusion pressure (MOPP), and ocular perfusion parameters ‘volume’, ‘velocity’, and ‘flow’ measured at the optic nerve head (ONH) and retina by means of Heidelberg Retina Flowmeter system were evaluated during a 6-month follow-up period.ResultsTreatment with latanoprost 0.005% resulted in a significant decrease in IOP (P<0.0001) and increase in MOPP (P<0.0001). After correcting for changes in MOPP, the blood velocity measured at the ONH level was significantly higher after 6 months of treatment than at baseline (P=0.0310). In addition, blood volume and flow measured at the peripapillary retina level improved after 3 and 6 months of treatment (P=0.0170; P=0.0260, and P=0.0170; P=0.0240 respectively).ConclusionPreviously untreated POAG patients exhibit reduced IOP, increased MOPP and improved ocular perfusion at the ONH and retina levels when treated with Latanoprost 0.005%. These effects could be beneficial for glaucoma patients suffering from ocular vascular dysregulation.Eye (2008) 22, 363–369; doi:10.1038/sj.eye.6702639; published online 17 November 2006 [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of sildenafil on ocular hemodynamics by color Doppler ultrasonography (CDU). In all, 38 patients with erectile dysfunction diagnosed by International Index of Erectile Function (IIEF) and Sexual Health Inventory of Men (SHIM) scores were included into the study. After taking 100?mg of oral sildenafil citrate, all patients underwent CDU examination of central retinal artery at 60 and 75?min and CDU examination of cavernosal artery at 20, 60 and 75?min. All of the side effects during and after the test were also recorded. The mean cavernous artery peak systolic flow velocity increased significantly after sildenafil. However, no significant change was determined in central retinal artery flow parameters including peak systolic flow velocity, end-diastolic flow velocity, resistive index, pulsatility index, volume and diameter. Five patients experienced ocular side effects. No significant change was observed in retinal artery CDU measurements of patients having ocular side effects. Sildenafil has no effect on ocular hemodynamics on the basis of CDU. Ocular side effects may be the result of other changes in retinal photoreceptors rather than the ocular circulation.International Journal of Impotence Research (2004) 16, 244-248. doi:10.1038/sj.ijir.3901189 Published online 19 February 2004 [ABSTRACT FROM AUTHOR]

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We describe an elderly gentleman with a ten-year history of transient monocular blindness of the right eye. Ten years previously he had suffered a stroke affecting his left side, carotid duplex showed total occlusion of the right internal carotid artery. It was postulated that his symptoms were due to hypoperfusion of the optic nerve head (ONH). His antihypertensive medication was stopped and his ocular symptoms improved, however his blood pressure became dangerously high. Consequently he was started on latanoprost eye drops to reduce his intraocular pressure and improve ONH perfusion. This led to a dramatic improvement in his symptoms, which worsened again when he ran out of drops. To our knowledge management of transient visual loss due to reduced ocular perfusion by lowering of intraocular pressure has not been described previously. [ABSTRACT FROM AUTHOR]