Ocular Blood Flow In Patients Research Articles

Effects of switching from intravitreal injection of aflibercept to faricimab on ocular blood flow in patients with diabetic macular edema

We assessed the short-term effects of switching from intravitreal aflibercept (IVA) to intravitreal faricimab (IVF) on ocular blood flow in patients with treatment-resistant diabetic macular edema (DME). The medical records of 15 patients with DME who had received IVA injection ≥ 3 months before were retrospectively reviewed. The best-corrected visual acuity, central macular thickness (CMT) on optical coherence tomography, and mean blur rate (MBR) of all disc areas on laser speckle flowgraphy were measured before, 1 week after, and 4 weeks after IVA and IVF, respectively. The changes in visual acuity showed no significant difference after switching from IVA to IVF (P = 0.732). The mean CMT decreased significantly during the follow-up period (both P < 0.001). MBR showed no significant difference during the follow-up period (P = 0.26). However, it decreased significantly 4 weeks after IVF (P = 0.01) compared with the baseline value, but not 4 weeks after IVA (P = 0.074). A significant association was observed between decreased MBR and decreased CMT in patients who received IVF (correlation coefficient: 0.501, P = 0.005) but not in those who received IVA (P = 0.735). Thus, IVF maintained ocular blood flow reduction, although no significant differences in visual acuity and CMT changes were observed compared to IVA.

High-intensity interval training in patients with glaucoma (HIT-GLAUCOMA): protocol for a multicenter randomized controlled exercise trial.

Glaucoma stands as a prominent global cause of irreversible blindness and the primary treatment approach involves reducing intraocular pressure (IOP). However, around one-third of patients exhibit disease progression despite effective IOP reduction. Microvascular endothelial function, chronic inflammation, and oxidative stress are known to affect retinal neuronal networks and have been associated with disease severity and progression. Exercise training has the potential to counteract these mechanisms as add-on treatment to usual care. The HIT-GLAUCOMA study will investigate the effects of a 6-month high-intensity interval training (HIIT) on intermediate endpoints such as local retinal microvascular and systemic large artery function, inflammation, and oxidative stress as well as clinical endpoints such as visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology. The study is a multi-center randomized controlled clinical trial in patients with both normal tension and high-tension primary open angle glaucoma. Across two study centers, 128 patients will be enrolled and randomized on a 1:1 basis into an exercise intervention group and a usual care control group. The primary microvascular endpoints are retinal arteriolar and venular flicker light-induced dilation at 6months. The primary endpoint in the systemic circulation is brachial artery flow-mediated dilation at 6months. We hypothesize that exercise therapy will improve retinal microvascular function and thus ocular blood flow in patients with glaucoma. As clinical outcomes, we will investigate the effect of exercise on visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology. HIT-GLAUCOMA is a blueprint trial design to study the effect of exercise training on neurodegenerative and cardiovascular diseases. Importantly, patients are also expected to benefit from improvements in general health and cardiovascular co-morbidities. If proven effective, exercise may offer a new add-on treatment strategy to slow glaucoma progression. The trial is registered at Clinicaltrials.gov under the identifier NCT06058598 and is currently in the recruitment stage.

Changes in ocular blood flow in patients with neovascular age-related macular degeneration after intravitreal injection of ranibizumab biosimilar and brolucizumab.

To assess ocular blood flow (OBF) changes in patients with neovascular age-related macular degeneration (nAMD) treated with intravitreal injections of ranibizumab biosimilar (IVRbs) or brolucizumab (IVBr). This retrospective longitudinal study included 43 eyes of 43 patients (74.5 ± 9.8 years old, male to female ratio 31:12) with nAMD treated with IVBr (29 eyes) or IVRbs (14 eyes). OBF in the optic nerve head (ONH) and choroid (Ch) was measured with laser speckle flowgraphy (Softcare Co., Ltd., Fukutsu, Japan) before and one month after treatment. Changes in mean blur rate (MBR) before and after each treatment were tested using Wilcoxon's signed-rank tests and mixed-effect models for repeated measures. In the IVBr group, MBR was significantly reduced in both the ONH and Ch (p < 0.01). In contrast, the IVRbs group showed no significant change in MBR in either the ONH or Ch (p = 0.56, p = 1). The linear mixed effect model showed a significant interaction between time and anti-VEGF drugs for MBR in both the ONH and Ch (ONH: p = 0.04; Ch: p = 0.002). A post hoc pairwise comparison of estimated marginal means showed that MBR decreased significantly only after IVBr (p < 0.001). Our findings suggest that the short-term impact on OBF varies depending on the drug used for nAMD.

OCTA evaluation of posterior ocular blood flow in patients after COVID-19 infection without pneumonia

We aimed to demonstrate the changes in optic nerve and retinal microvascular structures with Optical Coherence Tomography Angiography (OCTA) in patients who had COVID-19 infection. Prospective study. Retina, choroid and optic nerve head microvascular flow and vascular densities of both groups were measured by OCTA. OCTA measurements of 122 right eyes of a total of 122 patients, including 72 patients in the COVID-19 group and 50 patients in the control group, were included in the study. The Deep Capillary Plexus (DCP) Flow Area (FA) in the COVID-19 group was 1.42±0.23mm2, in the control group was 1.50±0.15mm2, Choriocapillary Plexus FA was 1.89±0.04mm2 in the COVID-19 group, was 1.91±0.05mm2 in the control group, and a statistically significant difference was found between the two groups (respectively; P=0.03; P=0.02). DCP Whole Vascular density (VD) values were 56.76±4.16% in the COVID-19 group, 58.28±3.88% in the control group; difference between the values was statistically significant (P=0.04). There was no statistically significant difference between the two groups in terms of optic nerve head flow areas and other parameters examined according to quadrants. Results show that the retinal microcirculation in subjects with mild disease is affected. Even if the disease is mild, patients may need to be followed up for retinal changes that may develop in the future.

Study of the Orbital Vessels by Color Doppler in Known Diabetic Patients for Evaluation of Diabetic Retinopathy

Introduction: Diabetic retinopathy is a vascular disorder affecting the microvasculature of retina. It is caused bychanges in the blood vessels of retina. If untreated, it may lead to blindness which is usually preventable if retinopathyis diagnosed early and treated promptly. As the prevalence of diabetes is rising, the systemic complications thatinclude retinopathy, nephropathy , neuropathy and involvement of cardiovascular system are also increasing.Diabetic retinopathy is the leading cause of blindness in the world. Prevention of retinopathy needs early diagnosis.(1) In ophthalmology, Color Doppler imaging is a new method that enables us to assess the orbital vasculature. Itallows for simultaneous two dimensional anatomical and Doppler evaluations of retinal artery.Objective and Aim: Aim of the study is to evaluate the ocular blood flow in patients with diabetes mellitus withno ocular symptoms.Materials and Methods: Color Doppler evaluation of 50 diabetic patients (100 eyes) was done with SIEMENSSONOLINE G- 50 machine with High frequency probe (5-7.5 Mega Hertz). Doppler spectral analysis of ophthalmicarteries (OA) and central retinal arteries (CRA) were done. The peak systolic velocity (PSV), end diastolic velocity(EDV), resistive index (RI) and S/D ratio were calculated. PSV, EDV, RI were measured in all patients in both the eyes.Results: The PSV of CRA in diabetics was significantly reduced (p=&lt;0.05). The EDV of CRA in diabetics wasalso significantly reduced (p=&lt;0.05). The RI of CRA is significantly increased (p=&lt;0.05) in diabetics. The 95%confidence interval is observed in PSV, EDV, RI of CRA in diabetics.Conclusion: There was statistical significant difference between the PSV, EDV and RI of CRA in diabetics. Thissignificant difference could be due to the circulatory changes in blood vessels in diabetics. No significant differencewas made in OA in diabetics. This study concludes that retinal hemodynamic changes were present even beforethe clinical manifestations of retinopathy in diabetics.

Efficacy of dorzolamide in improving ocular blood flow in patients with open-angle glaucoma: The Indian carbonic anhydrase inhibitor trial.

Impaired ocular blood flow is an important risk factor in the pathogenesis of open-angle glaucoma (OAG). Studies have reported that dorzolamide 2% may be effective in improving ocular blood flow (OBF) in OAG patients. The objective of this study was to determine the efficacy of dorzolamide 2% (DORZOX, Cipla Ltd.) in improving retrobulbar blood flow in an Indian setting. The study was conducted as an interventional pilot project in 24 healthy subjects and 19 OAG patients. Baseline OBF measurements were done for all glaucoma patients with color Doppler imaging (CDI). Baseline ocular perfusion pressure (OPP) was calculated for all participants. Glaucoma patients were given dorzolamide 2% thrice daily for 12 weeks. The primary efficacy endpoints were mean changes in the CDI parameters of the retrobulbar vessels and OPP posttreatment. The secondary endpoint was mean change in the intraocular pressure (IOP) and adverse events, if any. In comparison to healthy subjects, glaucoma patients displayed significantly reduced baseline OPP (P = 0.002). Treatment with dorzolamide 2% for 12 weeks led to a significant increase in OPP (P < 0.001) and a significant increase in end diastolic velocity (EDV) in all major ophthalmic arteries like ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary artery (SPCA) (P < 0.001, P = 0.04, and P = 0.0075, respectively). A significant reduction in the intraocular pressure (IOP; P = 0.007) was observed posttreatment, with no adverse events reported. Dorzolamide 2% significantly improved parameters such as the EDV and OPP in major ophthalmic arteries. This pilot study shows promising results on using dorzolamide for treating Indian patients with OAG.

Changes in ocular hemodynamics in patients recovered from COVID-19

To evaluate the severity of hemodynamic changes in the ocular vessels of patients recovered from COVID-19. The study included 44 patients (88 eyes) aged 28-60 years, among them 24 (54.5%) women and 20 (45.4%) men, with SARS-CoV-2 infection confirmed by PCR no more than 2 months prior to enrollment and with no ophthalmological complaints within 2 months before the disease, as well as 20 healthy volunteers (40 eyes). At the time of the study all patients had a negative PCR result for SARS-CoV-2. The patients were divided into 2 groups. The first group comprised 24 patients who did not take any anticoagulants during the treatment. The second group consisted of 20 patients who received anticoagulants (Rivaroxaban (Xarelto)) at a dosage of 10 mg per day for 1-1.5 months. The maximum systolic (Vs), end-diastolic (Vd) blood flow velocity, as well as resistance index (RI) in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were measured in all study patients with the ultrasound imaging system VOLUSON E8 Expert («Kretz», USA). Additionally, the flowmetry method was used to assess the volumetric ocular blood flow (VOBF) on Ocular Blood Flow Analyzer system («Paradigm Medical Industries, Inc.», USA). In the first group, a decrease in Vs and Vd was noted amid a significant increase of RI in CRA and SPCA, as well as an increase of RI in OA compared with the age-normal values (p<0.05). In the second group, a decrease in Vs and Vd was noted amid a significant increase of RI in CRA, as well as a decrease in Vs in SPCA and an increase of RI in OA relative to the age-normal values (p<0.05). A decrease in VOBF was noted in the first group in comparison to the second group and the age norm (p<0.05). Blood flow velocity parameters in the ocular vessels are reduced in patients recovered from COVID-19 compared to the age-normal values. There was a significant decrease in volumetric ocular blood flow parameters in COVID-19 patients who did not take any anticoagulants compared to the age-normal values. Anticoagulants intake has a positive impact on hemodynamic characteristics in the ocular vessels and volumetric ocular blood flow in patients with COVID-19.

Ocular microcirculation after revascularization of the internal carotid artery in the early postoperative period

To study the impact of CEA and CAS interventions on ocular blood flow in patients with clinically significant ICA stenosis in the early postoperative period. Thirty-two patients with hemodynamically significant stenosis (≥75%) of the left or right ICA were examined using optical coherence tomography angiography (OCT-A) and flowmetry before and after CEA or CAS in order to assess the changes in ocular blood flow parameters. There were no significant differences in hemodynamic parameters in the eyes on the side of the stenotic and non-stenotic ICA before revascularization. In the early postoperative period (3-7 days) in the ipsilateral eyes, there was an increase in blood flow density and vascular density at the level of the superficial and deep plexuses in the macular area (p≤0.05), as well as an increase in the ocular blood flow volume, the level of tolerated intraocular pressure (p≤0.05) and a decrease in intraocular pressure (p≤0.05) bilaterally. In the contralateral eyes, after ICA revascularization there was a partial improvement in microcirculation parameters according to OCT-A (p≤0.05). Peripapillary blood flow density and peripapillary vessel density did not change significantly either on the ipsilateral or the contralateral side. In patients with clinically significant ICA stenosis, ICA revascularization by stenting or endarterectomy contributed to an improvement in retinal microcirculation and retrobulbar blood flow in both eyes. OCT-A and flowmetry allow non-invasive assessment of retinal microvessels and retrobulbar blood flow, and the measurements provided by these methods can serve as valuable biomarkers for predicting and monitoring hemodynamic changes in patients who undergo CEA and CAS surgeries.

Evaluation of ocular blood flow by Doppler ultrasound in patients with essential blepharospasm.

Benign essential blepharospasm (EB) is a focal facial dyskinesia that occurs with the involuntary contraction of muscles around the eyes. In the literature, studies on blepharospasm focus on elucidating the pathophysiology of this condition in the brain. To the best of our knowledge, there is no research evaluating the orbital imaging findings of patients with EB. Therefore, the current study aimed to determine whether there was any change in the blood supply of muscles around the eye or ocular blood flow in patients with blepharospasm and investigate flow changes that may be caused by spasm. Thirty patients with EB and 30 controls were included in the study. Orbital Doppler ultrasound was performed in all cases to measure ophthalmic and temporal artery peak systolic velocity and end diastolic velocity and calculate resistive index values. Superior ophthalmic vein blood flow velocity (SOVBFV) was also measured. There was no significant difference between the groups in terms of age and gender distribution (P = 0.345 and 0.870, respectively). SOVBFV was found to be significantly higher in the EB group (P = 0.001). No significant difference was observed in the remaining investigated parameters. In conclusion, our study suggested that ocular spasm in patients with EB had no effect on blood flow other than SOVBFV. When SOVBFV was compared between the EB and control groups, it was found to be increased in the EB group. We consider that this statistical difference may be clinically and pathophysiologically significant.

A Study to Assess the Effect of a 3-month Folate Supplementation on Systemic Homocysteine Plasma Concentration and Ocular Blood Flow in Patients With Diabetes

A Study to Assess the Effect of a 3-month Folate Supplementation on Systemic Homocysteine Plasma Concentration and Ocular Blood Flow in Patients With Diabetes

Evaluation of the effect of prostaglandin analogues and a carbonic anhydrase inhibitor/β-blocker combination on the ocular blood flow in patients with primary open-angle glaucoma

To assess the effect of latanoprost and fixed combination of dorzolamide/timolol on ocular hemodynamics in patients with primary open-angle glaucoma (POAG). The study examined 34 patients (56 eyes) aged 51 to 69 years (average - 62.4±9.7 years) diagnosed with POAG in the initial (31 eyes) or advanced stage (25 eyes). Patients of the first group (20 patients, 36 eyes) were receiving latanoprost (Glauprost, Rompharm Company, Romania). The second group (14 patients, 20 eyes) was assigned to receive a fixed combination of dorzolamide/timolol (Dorzopt plus, Rompharm Company, Romania). Patient examination before and at 6 and 12 months included tonometry (ICare PRO), perimetry (Heidelberg Edge Perimeter), HRT and OCT of the optic nerve (Heidelberg Retina Tomograph 3 and Spectralis OCT2), as well as measurement of the density of surface (SVL) and deep (DVL) vascular plexus, and the Bruch's membrane opening minimum rim width (BMO-MRW). Additionally, we evaluated microcirculation in the choroid (MC) according to our original technique that uses Spectralis OCT2, and calculated rheographic index (RI) and stroke volume using transpalpebral rheoophthalmography. The decrease in IOP in the Latanoprost group was on average 27% and in the control group receiving timolol and dorzolamide - on average 22% and remained stable until the end of the study. The value of the area and volume of the disc rim band, BMO-MRW did not exhibit statistically significant changes in both groups by the 12th month of observation. A tendency to increase the RI from 51.5±24.5 to 62.2±19 (p=0.084) and the median of the index of microcirculation of the choroid (MC) from 16476 up to 23767 (p=0.062) in 1st group was observed. The study confirms the feasibility of using latanoprost and a fixed combination of dorzolamide and timolol in ocular hypotensive therapy of glaucoma thanks to their pronounced hypotensive effect. Patients were noted to have a tendency for improvement of ocular hemodynamics when using latanoprost.

Association between mitochondrial DNA damage and ocular blood flow in patients with glaucoma

Background/AimsWe determined the relationship between tissue mean blur rate (MT) and mitochondrial dysfunction, represented by the mitochondrial/nuclear DNA (mtDNA/nDNA) ratio. We also investigated the usefulness of these biomarkers.MethodsWe assessed ocular...

The effects of antioxidants on ocular blood flow in patients with glaucoma.

To investigate the effects of an antioxidant dietary supplement that includes Ginkgo biloba, on retinal and retrobulbar blood flow in patients with open-angle glaucoma (OAG). Forty-five patients with confirmed OAG were enroled in a randomized, double blinded, placebo-controlled cross-over study. Baseline and postadministration measurements of intraocular pressure (IOP), ocular perfusion pressure (OPP), retrobulbar blood flow, and retinal capillary blood flow were non-invasively measured (ultrasound and laser Doppler modalities, respectively) before and one month after antioxidant nutraceuticals and placebo administration. Changes in measurements between the active supplement and placebo arms were evaluated using paired t-tests, with p<0.05 considered statistically significant. Antioxidant supplementation produced a statistically significant increase in peak systolic and/or end diastolic blood flow velocities in all retrobulbar blood vessels compared to placebo. Vascular resistance was also reduced in central retinal and nasal short posterior ciliary arteries following antioxidant administration. Additionally, antioxidant supplementation increased superior and inferior temporal retinal capillary mean blood flow and the ratio of active to non-active retina capillaries compared to placebo. One-month oral administration of antioxidants produced increases in biomarkers of ocular blood flow within retinal and retrobulbar vascular beds in patients with OAG.

Effects of photocoagulation on ocular blood flow in patients with severe non-proliferative diabetic retinopathy.

PurposeTo investigate ocular blood flow and correlations between ocular blood flow and variables in patients with severe non-proliferative diabetic retinopathy (S-NPDR) following panretinal photocoagulation (PRP).MethodsIn this retrospective, cross-sectional study, the blood flow on the optic nerve head (ONH) and choroid was assessed with laser speckle flowgraphy (LSFG) using the mean blur rate (MBR) in 76 eyes of 76 patients with S-NPDR who underwent PRP, 39 eyes of 39 patients with S-NPDR who did not undergo PRP, and 71 eyes of 71 normal subjects. The correlation between MBR and variables, including visual acuity (VA) and choroidal area determined by binarization method, was analyzed.ResultsThe mean age was 62.9 ± 11.9 years in the S-NPDR with PRP eyes, 55.6 ± 11.4 years in the S-NPDR without PRP eyes, and 60.3 ± 11.1 years in the normal subject eyes. The ONH MBR in vessel and tissue areas and the choroidal MBR were significantly lower in the S-NDR with PRP group than in the other groups (p < 0.001, p < 0.001, and p < 0.001, respectively). The luminal and the stromal areas were significantly smaller in the S-NDR with PRP group than in the other groups (p < 0.001 and p < 0.001, respectively). LogMAR best corrected visual acuity (BCVA) exhibited significant negative correlation with the ONH MBR in vessel (r = −0.386, p < 0.001), tissue (r = −0.348, p < 0.001), and the choroid MBR (r = −0.339, p = 0.002) in the S-NDR with PRP group. Stepwise multiple regression analysis demonstrated that BCVA was a common independent factor associated with the ONH MBR in vessel, tissue, and the choroidal MBR in the S-NDR with PRP group.ConclusionsONH and choroid MBR in addition to choroidal component, including the luminal area, were significantly lower in eyes of patients with S-NPDR after PRP compared with no PRP and normal subjects group. This could suggest that the significantly reduced ocular blood flow in PRP-treated S-NPDR eyes correlated with long-term decreased post-PRP luminal area and visual acuity.

Oral Administration of Cilostazol Increases Ocular Blood Flow in Patients with Diabetic Retinopathy

PurposeTo investigate the effect of cilostazol on ocular hemodynamics and to determine whether the administration of cilostazol increases the ocular blood flow in patients with diabetic retinopathy.MethodsThis prospective observational study investigated the effect of orally administered cilostazol on diabetic retinopathy. Before and after administration for 1 week, pulsatile ocular blood flow (POBF) and retrobulbar hemodynamics were measured using a POBF analyzer and transcranial Doppler imaging, respectively. Visual acuity, intraocular pressure, and blood pressure were also evaluated before and after treatment.ResultsTwenty-five eyes of 25 patients were included in this study. POBF increased significantly (16.8 ± 4.6 µL/sec vs. 19.6 ± 6.2 µL/sec, p < 0.001) after administration of cilostazol, while no significant change was identified in visual acuity, intraocular pressure, and blood pressure. Mean flow velocity in the ophthalmic artery as measured with transcranial Doppler imaging also increased significantly after medication (23.5 ± 5.6 cm/sec vs. 26.0 ± 6.9 cm/sec, p = 0.001). The change in POBF directly correlated with the change in mean flow velocity (r = 0.419, p = 0.007).ConclusionsCilostazol was effective in increasing ocular blood flow in patients with diabetic retinopathy, possibly by modulating retrobulbar circulation.

The association between systemic oxidative stress and ocular blood flow in patients with normal-tension glaucoma.

To evaluate the association between ocular blood flow and biomarkers of systemic oxidative stress, as well as the potential of these biomarkers to assess normal-tension glaucoma (NTG). This study included 73 eyes of 73 patients with NTG. We assessed ocular blood flow by measuring mean blur rate (MBR) in the optic nerve head using laser speckle flowgraphy, both overall and separately in the vessel and tissue areas. We also measured urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and skin autofluorescence (SAF), and lastly, determined correlations between these measurements and with other clinical parameters. SAF was correlated with age, circumpapillary retinal nerve fiber layer thickness (cpRNFLT), mean deviation (MD), and overall MBR (P = 0.003, P = 0.013, P = 0.015 and P = 0.006, respectively). SAF and 8-OHdG were both correlated with tissue-area MBR (P = 0.006 and P = 0.010, respectively). Visual acuity, cpRNFLT, mean deviation and tissue-area MBR had a significant tendency to change with NTG severity (P = 0.014, P < 0.001, P < 0.001 and P = 0.006, respectively). Multiple regression analysis revealed that cpRNFLT and 8-OHdG were independent contributing factors to MD (P < 0.001 and P = 0.040, respectively), and that cpRNFLT and 8-OHdG were independent contributing factors to tissue-area MBR (P = 0.005 and P = 0.028, respectively). We found a close relationship between cpRNFLT, MD, tissue MBR, SAF and 8-OHdG, suggesting that systemic oxidative stress is associated with decreased ocular blood flow and may be involved in the pathogenesis of NTG.

Changes of ocular blood flow in patients with subclinical atherosclerosis

Changes of ocular blood flow in patients with subclinical atherosclerosis

Doppler evaluation of ocular vessels in patients with primary open angle glaucoma.

To assess ocular blood flow in patients with primary open angle glaucoma (POAG) with or without progressive visual field loss in comparison with controls. Color Doppler imaging was performed on 78 eyes with established POAG (25 with progressive visual field loss and 53 with stable visual field) and 78 control eyes. Peak systolic velocity, end diastolic velocity (EDV), and resistance index (RI) were measured in the ophthalmic (OA), central-retinal, and medial and lateral posterior ciliary arteries. Peak systolic velocity and EDV were lower and RI was higher in the ocular vessels of eyes with POAG (p < .01). The OA and medial posterior ciliary arteries RI was higher, and the OA EDV was lower in glaucomatous eyes with progressive than with stable visual field loss. The receiver operating characteristic curve showed the optimal cutoff RI to be 0.847. Ocular blood flow appears compromised in eyes with POAG, particularly in those with progressive visual field loss.

A Double-Masked Randomized Crossover Study Comparing the Effect of Latanoprost/Timolol and Brimonidine/Timolol Fixed Combination on Intraocular Pressure and Ocular Blood Flow in Patients with Primary Open-Angle Glaucoma or Ocular Hypertension

Ocular blood flow dysregulation has been implicated in the pathogenesis of glaucoma. Whereas the effect of single antiglaucoma substances on ocular blood flow has been addressed in various experiments, evidence for fixed combinations is sparse. In the present study, we set out to compare the effects of latanoprost 0.005%/timolol 0.5% (LT) fixed combination and brimonidine 0.2%/timolol 0.5% (BT) fixed combination on intraocular pressure (IOP) and ocular blood flow. In the present study, which followed a randomized, double-masked 2-way crossover design, 16 patients with primary open-angle glaucoma and 2 patients with ocular hypertension were included. The patients underwent a 6-week treatment with LT and a 6-week treatment with BT after a washout for previous antiglaucoma medication. Optic nerve head blood flow (ONHBF) was measured using laser Doppler flowmetry; retrobulbar flow velocities were measured using color Doppler imaging in the ophthalmic artery, the central retinal artery, and the posterior ciliary arteries. IOP was measured at 8 AM, 12 PM, and 4 PM. The mean baseline IOP was 25.3±2.8 mmHg. Both drugs were equally effective in reducing IOP (LT: -35.0%±10.0%; BT: -33.6%±8.8%, P=0.463 between groups). In addition, no difference in ocular perfusion pressure was observed between the 2 treatment groups (P=0.1, between groups). Neither LT nor BT altered ONHBF (P=0.4, baseline vs. treatment) and no effect on flow velocities in the retrobulbar vessels was seen with either of the 2 treatments. In the present study, a 6-week treatment with LT or BT was equally effective in reducing IOP. In addition, none of the administered drugs induced a significant effect on ocular blood flow parameters.

Visual outcomes after carotid reconstructive surgery for ocular ischemia

This study aimed to determine the influence of carotid artery surgery on ocular functions and ocular blood flow in patients with ocular ischaemic syndrome (OIS) in the late postoperative period. One hundred and eighty patients with OIS were operated on; 104 of them suffered from acute forms of the ischaemic disease and 76 patients had chronic forms of ocular ischaemia. Before surgery and in the course of 6 months and 12 months afterwards, all the patients were examined. Visual acuity, electrophysiological investigations (the threshold of electrical sensitivity (TES) and the level of liability of optic nerve (LON)) and blood flow in orbital vessels were assessed. After surgery visual acuity increased in patients with the acute forms of OIS (P<0.05). TES and LON also improved (P<0.01). Mean indices of blood-flow velocities in the ophthalmic artery, the central retinal artery and the posterior ciliary arteries increased at 6 and 12 months after surgery (P<0.05). There was ocular blood flow acceleration and decrease of vasoresistance in orbital arteries in both groups of patients. Carotid artery surgery effectively improved ocular blood flow in patients with acute and chronic forms of OIS in the late post operative period.