Posterior Ciliary Arteries Research Articles

Super-Resolution Ultrasound Localization Microscopy for Visualization of the Ocular Blood Flow.

The ocular vascular system plays an important role in preserving the visual function. Alterations in either anatomy or hemodynamics of the eye may have adverse effects on vision. Thus, an imaging approach that can monitor alterations of ocular blood flow of the deep eye vasculature ranging from capillary-level vessels to large supporting vessels would be advantageous for detection of early stage retinal and optic nerve diseases. We propose a super-resolution ultrasound localization microscopy (ULM) technique that can assess both the microvessel and flow velocity of the deep eye with high resolution. Ultrafast plane wave imaging was acquired using an L22-14v linear array on a high frequency Verasonics Vantage system. A robust microbubble localization and tracking technique was applied to reconstruct ULM images. The experiment was first performed on pre-designed flow phantoms in vitro and then tested on a New Zealand white rabbit eye in vivo calibrated to various intraocular pressures (IOP) - 10 mmHg, 30 mmHg and 50 mmHg. We demonstrated that retinal/choroidal vessels, central retinal artery, posterior ciliary artery, and vortex vein were all visible at high resolution. In addition, reduction of vascular density and flow velocity were observed with elevated IOPs. These results indicate that super-resolution ULM is able to image the deep ocular tissue while maintaining high resolution that is comparable with optical coherence tomography angiography. Capability to detect subtle changes of blood flow may be clinically important in detecting and monitoring eye diseases such as glaucoma.

Evaluation of Hemodynamic Changes in Retrobulbar Blood Vessels Using Color Doppler Imaging in Diabetic Patients.

Background—Diabetic retinopathy is a common complication of long-standing hyperglycemia. Microangiopathy-induced retinal changes are well-visualized on ophthalmoscopic examination. However, certain hemodynamic alterations have also been documented in the diabetic population, which have not been completely understood. Aim—To study the hemodynamic changes in retrobulbar circulation in diabetic patients with and without retinopathy, and to compare these changes with non-diabetic controls. Materials and Methods—This hospital-based prospective study included 50 diabetic and 50 non-diabetic patients. The diabetic groups consisted of 25 patients without retinopathy and 25 patients with retinopathy, and were labeled as Groups I and II, respectively. All subjects underwent orbital color Doppler ultrasonography using a linear high-frequency probe. The color Doppler parameters (peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI)) were measured and recorded using the spectral waveform of the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCA). Comparison of obtained values was carried out using appropriate tests of significance. Results—The resistive indices of the ophthalmic, central retinal, and short posterior ciliary arteries were significantly higher in diabetic patients compared to controls (p < 0.001). The difference was also significant between Group I and Group II. Comparison of PSV and EDV of CRA and SPCAs among three groups using one-way ANOVA revealed a significant difference, with the highest blood flow velocities in the control group and the lowest in diabetics with retinopathy. The ophthalmic artery showed no significant change in blood flow velocity. Analysis using the Pearson correlation coefficient provided a positive correlation between the RI values of OA, CRA, and SPCA and the presence of diabetic retinopathy (OA = r 0.417, p < 0.001; CRA = r 0.466, p < 0.001; SPCA = r 0.438; p < 0.001). Conclusions—The resistive index of OA, CRA, and SPCA is a reliable indicator to assess diabetic-associated hemodynamic changes. The use of orbital color Doppler ultrasonography in diabetic patients can help in the identification of patients who are at risk of developing retinopathy.

Quantitative evaluation of retinal and choroidal vascularity and retrobulbar blood flow in patients with myopic anisometropia by CDI and OCTA

AimsTo investigate the association between the myopic severity and retinal microvascular density, choroidal vascularity and retrobulbar blood flow in adult anisomyopes.MethodsThis study comprised 90 eyes of 45 myopic anisomyopes who...

The Anatomy, Physiology, and Histology of Optic Nerve

The optic nerve (Nervus opticus) is the second of the 12 cranial nerves and is considered to be a part of the central nervous system. It carries visual information from the neurosensory retina to the occipital cortex. The nerve consists of the axons of retinal ganglion cells (RGCs). These axons extend in an organized pattern from the RGC soma to the lateral geniculate nucleus where the neuron's synapse. The nerve is subdivided into fascicles by connective tissue and glial septa, and it is surrounded by cerebrospinal fluid. The optic nerve has intraocular, intraorbital, intracanalicular, and intracranial parts and a length of approximately 50 mm. The central retinal artery, the Zinn-Haller circle formed by the short posterior ciliary artery extensions, and pial vessels take part in the blood supply of the nerve.

Retrobulbar blood flow velocity in systemic lupus erythematosus assessed by color Doppler imaging.

To analyze the blood flow in retrobulbar vessels in systemic lupus erythematosus (SLE) by color Doppler imaging (CDI) and to investigate the associations between immunological markers, retinal abnormalities, disease activity, and vascular parameters. We examined 30 patients with SLE who were aged 32.1 ± 11.6years with a disease duration of 68.0 ± 55.6months and 30 participants in a control group. The peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI), and resistive index (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary arteries (PCAs) were determined. Physical and ophthalmic examinations with assessments of immunological markers were performed. All parameters were compared between SLE patients and normal controls while the correlations among parameters were analyzed. In the SLE group, CDI confirmed blood flow abnormalities in the CRA and PCAs, with significantly lower blood flow velocities and increased RI and PI (p < 0.05). There was a significantly negative correlation between disease duration and EDV in the CRA, PCA, and OA (p = 0.0423, 0.0453, 0.0448). There was also a significant relationship between the SLE Disease Activity Index and the PI of the OA (p = 0.0367). The patients who had received biological agents (Rituximab) had lower EDV in the CRA and PCA (p = 0.0026, 0.028). SLE patients with kidney or CNS involvement had a significant increase in the PI in the OA (p = 0.0287). The PSV and EDV in the CRA were significantly related to creatinine (p = 0.0007 and 0.0418). We also noted a significant decreased EDV in the CRA and an increased RI in the OA among participants positive for anti-dsDNA antibodies (p = 0.0331 and 0.0228). Retrobulbar circulatory disturbances were detected in SLE patients by CDI. These findings seem likely to affect smaller vessels like the CRA and PCA. However, the presence of measurable changes in the OA is generally indicative of a coexistent nephropathy or central nervous system (CNS) vasculitis. Creatinine, the disease activity index, being positive for anti-dsDNA, and receiving biological agents were associated with measurable changes on the retrobulbar blood flow.

The effect of increased preset intraocular pressure level on choroidal blood flow during phacoemulsification

Purpose: to evaluate blood flow velocity in the posterior short ciliary arteries during phacoemulsification (PE) at different levels of intraocular pressure (IOP).Material and methods. The study included 29 patients aged 62–83 (average 71.2 ± 6.0) with initial-stage age-related cataract. PE was performed using the Alcon Centurion vision system at a preset IOP level of 60 mm Hg. Blood flow velocity was determined three times using an expert-class ultrasound scanner (GE Logiq S8): immediately before surgery (before opening the eyeball), intraoperatively at an IOP level of 58.77 ± 8.28 mm Hg, and after surgery and IOP normalization. Additionally, the IOP level was measured three times (by Icare PRO tonometer). The blood pressure level was monitored by the standard method on the brachial artery using the Dr ger Vista 120 system. The measurement results were compared with the control group which included 20 healthy fellow eyes.Results. A decrease in blood flow velocity was established upon reaching the IOP level of 58.77 ± 8.28 mm Hg. The maximum systolic blood flow velocity in the posterior short ciliary lateral artery decreased from 14.46 ± 2.92 to 11.22 ± 2.55 cm/s, while the final diastolic blood flow fell from 5.11 ± 1.83 to 2.97 ± 1.27 cm/s. The maximum systolic blood flow velocity on the medial side also fell from 12.37 ± 2.74 to 9.50 ± 1.68 cm/s, and the final diastolic velocity fell from 4.54 ± 1.35 to 2.73 ± 0.91 cm/s (p &lt; 0.05).Conclusion. During PE, the IOP level exceeding certain values leads to a decrease in blood flow velocity in the posterior short ciliary arteries. It is important to realize, however, that autoregulatory mechanisms for maintaining stable hemodynamics are limited if IOP levels are increased.

Investigation into the ophthalmic artery and its branches by superselective angiography.

The vascular anatomy of orbit is highly complex, and the main blood supply to the orbit is via the ophthalmic artery, which is a branch of the internal carotid artery. The purpose of this study was to determine the morphometry of the ophthalmic artery and its branches by superselective angiography in a large series of pediatric patients. We evaluated 134 angiographies performed on children with intraocular retinoblastoma undergoing intra-arterial chemotherapy. The origin, diameter, and angiographic visibility percentages of the ophthalmic artery and its branches were examined according to age group and sex. The ophthalmic artery originated 97.8% from the internal carotid artery and 2.2% from the middle meningeal artery. The mean diameter of ophthalmic artery was measured 0.76 ± 0.14 mm in girls, 0.80 ± 0.15 mm in boys and 0.79 ± 0.15 mm in general. The posterior ciliary, lacrimal, inferior muscular, and anterior ethmoidal arteries had a higher angiographic visibility percentages (> 85%) than the other OA branches. Only the diameter of the dorsal nasal artery showed a significant correlation with age. The supratrochlear and posterior ciliary arteries showed statistically significant relationship with sex. Present study will make a substantial contribution to the pediatric literature about the ophthalmic artery and its branches. A better understanding of ophthalmic artery morphology can help surgeons and neurointerventional radiologists to avoid possible severe complications during embolization, intra-arterial chemotherapy, cosmetic procedures, endonasal and orbital surgeries.

Micro-balloon-assisted embolization of anterior cranial fossa dural arteriovenous fistula via a trans-ophthalmic approach — a technical report and case series

PurposeDural arteriovenous fistulas (dAVF) account for approximately 10–15% of all intracranial arteriovenous abnormalities. dAVFs carry a significant risk of mortality, particularly in cases of acute hemorrhage, of up to 10%. A small proportion of these dAVFs are found in the anterior cranial fossa (ACF), of which the rate of hemorrhage can be as high as up to 91%. The Scepter Mini (SM) is the smallest dual-lumen micro-balloon (MB) available for neurointerventional practice. It consists of a 2.8 French outer diameter, with a 2.2 mm × 9 mm semi-compliant balloon providing a working length of 165 cm. The SM is navigated with a 0.008-inch wire making it a particularly attractive tool accessible to the pedicles normally reached with liquid embolization micro-catheters.MethodsFive consecutive patients over a 1-year period between 2020 and 2021 were evaluated and treated for ACF dAVF using a liquid embolization approach using the SM balloon. All patients were treated using ethylene–vinyl alcohol copolymer (EVOH), of which Squid 18 and/or Squid 12 were the chosen viscosities. Control angiograms were performed for all patients post-embolization.ResultsAll patients demonstrated complete occlusion of the ACF dAVF on immediate post-treatment angiography. No immediate complications were encountered; particularly, there were no reports of visual field deficit in any of the patients.ConclusionThe MB is a valuable adjunctive tool that can enhance the safety and efficacy of trans-ophthalmic embolization of ACF dAVFs, providing additional protection to the retinal and posterior ciliary arteries against unwanted reflux of liquid embolic agent.

Evaluation of the impact of childhood obesity on retrobulbar hemodynamics and retinal microvasculature.

To evaluate changes in retrobulbar ocular blood flow parameters by using Colour Doppler Imaging (CDI) and changes in foveal microvasculature by using Optical Coherence Tomography Angiography (OCTA) in pediatric obese patients and to compare them with a group of healthy children. Children diagnosed with obesity without hypertension and diabetes (39 subjects, obese group) and age-matched healthy controls (26 subjects, control group) underwent CDI and OCTA imaging. Peak systolic velocity, end-diastolic velocity and resistivity index from ophthalmic, central retinal and posterior ciliary arteries on CDI; superficial and deep capillary plexus vascular density and foveal avascular zone area on OCTA imaging were obtained in each group. Central foveal and subfoveal choroidal thicknesses were also measured. CDI and OCTA parameters were compared between two groups. Peak systolic and end-diastolic velocities were found to be significantly lower in obese children than in controls in all three examined arteries (p < 0.05). Resistivity index values were similar between the groups. OCTA imaging did not reveal significant changes in superficial and deep capillary plexus vascular densities and foveal avascular zone area across analysed retinal regions between the groups. Subfoveal choroid was thicker in obese group than in control group (325.89 ± 52.77 µm vs. 304.52 ± 21.76 µm, p = 0.04). An apparent decrease was present in retrobulbar hemodynamics in obese children. This arises the possibility of early ocular macrovascular compromise rather than retinal microvascular impairment in childhood obesity.

Retinal vascular morphology and blood flow characteristics of patients with various degrees of intracranial internal carotid artery stenosis

To explore the retinal vascular morphology and blood flow characteristics of patients with varying degrees of intracranial internal carotid artery (IICA) stenosis. A total of 280 eligible patients were divided into non-stenosis (n=39), mild stenosis (n=80), moderate stenosis (n=83) and severe stenosis groups (n=49). Hemodynamic indices of the posterior ophthalmic artery (OA), central retinal artery (CRA) and posterior ciliary artery (PCA) in the dark zone of optic nerve were detected using color Doppler ultrasonography. CRA equivalent (CRAE), central retinal vein equivalent (CRVE) and arteriole-to-venule ratio (AVR) within 0.5-1.0 PD from the optic disc rim to the center of the fundus image were measured using IVAN software. The diagnostic values of PCA peak systolic velocity (PSV) and end-diastolic velocity (EDV) for severe IICA stenosis were evaluated by receiver operating characteristic (ROC) curves. The blood flow parameters (PSV and EDV) of the OA, CRA and PCA in the severe stenosis group were the lowest (P<0.05). The PSV and EDV of the OA, CRA and PCA had significant negative correlations with severe IICA stenosis, and PCA PSV was more sensitive in the presence of the same index. The areas under the ROC curves for PCA PSV and EDV were 0.722 and 0.761, respectively, indicating that PCA PSV and EDV had high diagnostic values. There is no correlation between retinal vascular morphology and IICA stenosis. Severe IICA stenosis has significant negative correlations with ocular the blood flow parameters PSV and EDV, and PCA PSV is most sensitive with the same index, thus being a potential predictive index.

Ocular Complications Post-Cosmetic Periocular Hyaluronic Acid Injections: A Systematic Review

With the global rise in the use of hyaluronic acid (HA) fillers as a minimally invasive cosmetic procedure, significant adverse effects such as vascular compromise and blindness have become common. Hence, we present the first systematic review aimed to investigate ocular complications secondary to a facial HA injection and to understand the presentation, cause, management, and outcome of these complications. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used to report this review. A systematic search was performed in July 2021 for published literature using the PubMed, MEDLINE, and Cochrane databases. The following terms were used: facial fillers, facial injections, hyaluronic acid, blindness, ophthalmoplegia, diplopia, ptosis, ophthalmic artery occlusion, posterior ciliary artery occlusion, and ocular ischemic syndrome. A total of 2496 publications were searched, and 34 articles published between January 2000 and July 2021 were included. Twenty-seven case reports and seven case series were evaluated. The nose was the most common site of injection (n = 25; 40.67%). Ocular pain was the most common initial symptom of ocular complications (n = 13, 22.41 %). The most common complication was vision loss (n = 17, 50%). The majority of patients received hyaluronidase, aspirin, and steroids. Regarding the outcome, 15 (45.45%) of the published studies showed no improvement in complications even after management. HA is gaining popularity in cosmetic applications. Post-HA ocular complications nearly always have an immediate onset. Proper knowledge of potential adverse events is crucial for clinicians to attempt to decrease complications and improve outcomes. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

ET‐1 plasma levels and scleral rigidity as risk factors in neovascular age‐related macular degeneration

AbstractPurposeTo study the ocular blood flow, the corneal biomechanics, the scleral rigidity and the endothelin‐1 (ET‐1) plasma levels in patients with neovascular age‐related macular degeneration (ARMD).MethodsWe enrolled 20 patients with ARMD and 20 age‐matched control patients. Retrobulbar blood flow was examined by Colour Doppler Aplio 500 (Toshiba Medical System, Tokyo, Japan). Peak systolic velocity (PSV) and resistivity index (RI) was measured from ophthalmic artery (OA), central retinal artery (CRA) and posterior ciliary arteries (PCA’s). The corneal hysteresis CH and the corneal resistance force (CRF) values were achieved by Ocular Response Analyzer (ORA). Scleral rigidity (E) was determined by using Friedenwald nomograms. ET‐1 plasma levels were determined using a specific radioimmunoassay (Sigma‐Aldrich, Merck, Germany).ResultsWe found a statistically significant difference in the CRF between patients with ARMD and control subjects (ARMD 11.23 ± 1.30 vs. Controls 9.82 ± 1.37; p&lt;0.0025) was found. The CH index between patients with ARMD and control subjects was not statistically significant (ARMD 10.15 ± 1.25 vs. Controls 10.02 ± 1.70; p&lt;0.617). With CDI in PCA’s we found PSV (ARMD 12.37 ± 2.80 cm/sec vs. Controls 15.44 ± 3.59 cm/sec; p&lt;0.0063); RI (ARMD 0.80 ± 0.03 vs Controls 0.74 ± 0.02; p&lt;0.0001). The E had a significant increase in ARMD group (ARMD 0.0358 ± 0.004 vs. Controls 0.0328 ± 0.004; p&lt;0.008) as well as ET‐1 plasma levels (ARMD 2.060 ± 0.276 vs. Controls 1.492 ± 0.0.560; p&lt;0.001). Finally, in ARMD we found that the decrease of PSV and the increase of RI in PCA’s was correlated with the ET‐1 plasma levels (PSV r‐0.615; p&lt;0.0039 and r 0.764; p&lt;0.0001) and not with the values of E, CH and CRF.ConclusionsOur data indicate that patients with neovascular ARMD had a significant increase of RI in all vessels examined with increased corneal CRF index, scleral rigidity values and ET‐1 plasma levels. The decreased blood flow in APC’s was correlated to the increase of ET‐1 plasma levels. These data indicate that elevated plasma ET‐1 and not the scleral rigidity may be an important risk factor in the development of neovascular ARMD.

New Research Advances in the Treatment of Nonarteritic Anterior Ischemic Optic Neuropathy

Ophthalmic diseases evidently affect people’s daily lives. Nonarteritic anterior ischemic optic neuropathy (NAION) is an acute optic neuropathy and has a complex etiology and pathogenesis. NAION causes acute ischemia and structural and functional disorders of the optic nerve resulting from insufficient perfusion of the short posterior ciliary artery. NAION may cause irreversible vision loss, visual field defects, and even blindness if it is not treated early. There is no definite and standard treatment plan for NAION. To treat NAION more effectively, herein, we reviewed the clinical treatment of NAION in recent years and the latest treatment research progress, which will provide a systematic guidance for the treatment of NAION.

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.

Retrobulbar Short Posterior Ciliary Artery Hemodynamics in Patients with Pseudoexfoliation Glaucoma and Primary Open-Angle Glaucoma.

Purpose:To investigate retrobulbar blood flow changes in the short posterior ciliary arteries (SPCAs) in patients with pseudoexfoliation glaucoma (PEG) and primary open-angle glaucoma (POAG).Methods:In this prospective study, there were 22 eyes in the PEG group, 28 eyes in the POAG group, and 28 eyes with senile cataract in the control group. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (Vm), and resistivity index (RI) parameters of the temporal and nasal SPCAs were compared between the study groups.Results:Mean temporal PSV, EDV, and Vm value were significantly lower in both the POAG group and the PEG group (P = 0.049, P = 0.004, P = 0.020), respectively. Temporal SPCA RI values were not significantly different between the groups (P = 0.115).Conclusion:There are retrobulbar blood flow changes in glaucomatous compared to nonglaucomatous eyes. However, SPCAs blood flow characteristics are similar between PEG and POAG subtypes.

Assessment of the degree of restoration of the retinal structure and chorioretinal blood flow after surgical treatment of large-diameter macular holes

The aim: to evaluate the restoration features of the structural relationships of the retina and chorioretinal blood fl ow after surgical treatment of large-diameter macular hole (MH) using a modifi ed technology.Material and methods. A prospective study of 14 patients (14 eyes), 13 women and 1 man, with medium-and large-diameter MH was conducted. The mean age of the patients was 67.7 ± 5.38 (55–80) years. The study included patients with endto-end MH of the 3rd–4th stage according to the classifi cation of J. Gass. All patients underwent surgical treatment of macular rupture according to the proposed method of inverted fl ap of the internal limiting membrane (ILM) and fi lling it into a “pocket” formed between the retina and the ILM.Optical coherence tomography (OCT) was performed along with traditional research methods. The obtained images were used to measure manually the parameters of retinal MH, the thickness of the choroid in the projection of the rupture and the fovea zone before the operation and 1, 3 and 6 months after the operation. In the angio-mode, the foveal avascular zone (FAZ) was evaluated, as well as the density of capillaries of the superfi cial and deep retinal plexus in four quadrants, with the exception of the central zone.Results. In all patients, it was possible to achieve MH blocking. Visual acuity in the eyes with MH varied from 0.02 to 0.3, while in the comparison group, the best corrected visual acuity was from 0.3 to 1.0 (p = 0.002). An increase in the diameter of large choroidal vessels, as well as a pronounced decrease in the diameter of the posterior short ciliary artery, attracted attention. However, despite the improvement in visual acuity, patients retained a signifi cant expansion of the FAZ, which by 6 months exceeded the FAZ area of the paired eye by 25.8 % (p = 0.01).Conclusion. The results obtained indicate that the achievement of an anatomicalreconstructive effect and even a moderate improvement in visual acuity during surgical treatment of macular holes by the modifi ed inverted flap technology of the internal limiting membrane does not determine the restoration of retinal perfusion in full.

Quantitative evaluation of retinal microvasculature and retrobulbar vessels after intravenous chemotherapy for retinoblastoma

BackgroudTo evaluate the changes in retinal microvasculature and retrobulbar blood flow, using optical coherence tomography angiography (OCTA) and Color Doppler imaging (CDI) after intravenous chemotherapy (IVC) in patients with retinoblastoma (RB).MethodsThis was a retrospective comparative case control series involving 30 patients. Ten bilateral RB patients that had a preserved eye with extramacular tumours (group I), 10 unilateral RB treated with IVC that had a normal fellow study eye (group II), and 10 age-matched healthy controls. The macular retinal thickness, foveal avascular zone (FAZ) area, and the macular and peripapillary retinal vessel densities (RVD) were measured. The peak systolic and end diastolic velocities of the ophthalmic, central retinal and posterior ciliary arteries were determined. A comparison among the three groups was conducted.ResultsBetween the three cohorts, OCTA revealed no significant difference in FAZ area, superficial foveal and parafoveal RVD, deep parafoveal RVD and peripapillary RVD, (P > 0.05). By contrast, the mean deep foveal RVD, the full, inner and outer foveal and the parafoveal retinal thickness were significantly lower in group I compared with the controls, (P = 0.0329, 0.0153, 0.0311 0.0352, 0.0215). No significant difference in the blood flow velocities occurred in the retrobulbar circulation (P > 0.05).ConclusionsIn patients with retinoblastoma, OCTA did not detect significant changes of retinal thickness and vessel density in the eyes treated with IVC, but a slight reduction in retinal thickness and the deep foveal RVD seemed to occur in bilateral RB eyes. The retrobulbar blood flow parameters showed no measurable changes.

Ocular blood flow and choroidal thickness in ocular hypertension.

Ocular hypertension (OHT) is a clinical entity characterized by elevated intraocular pressure (IOP) without optic nerve damage. In the presence of other risk factors, OHT may progress to glaucoma. This study aimed to evaluate ocular blood flow (OBF) and choroidal thickness (CT), which may be markers and/or risk factors that could assess the progression of OHT to glaucoma. Age and gender matched 60 eyes of 32 patients with OHT and 61 eyes of 31 control patients were included for this study. All participants underwent a detailed ophthalmological examination including best-corrected visual acuity, IOP measurement with Goldmann applanation tonometry, gonioscopy, optic nerve evaluation with 78 D lens, and visual field test with Humphrey visual field analyzer. Retinal nerve fiber layer, ganglion cell complex, and central corneal thickness measurements were performed by optical coherence tomography (OCT). CT was measured with OCT in the fovea, 1.5mm, 2mm, 2.5mm nasal and temporal to the fovea and from nasal and temporal to the optic disk. OBF data including peak systolic velocity (PSV), end-diastolic velocity (EDV), resistivity index (RI) and pulsatility index (PI) were measured with color Doppler imaging (CDI) from the ophthalmic artery (OA), central retinal artery (CRA), medial and lateral branches of short posterior ciliary arteries (MPCA, LPCA). Systolic (SBP) and diastolic arterial blood pressure were also noted. CT measurement at each point in the OHT group compared to the control group were found to be significantly thinner (p = 0.001). There was a decrement in CT from the fovea to the nasal and temporal retina in both groups. In the OHT group, there was a significant decrease in PSV and EDV of OA, CRA, MPCA, and LPCA, and a significant increase in PI and RI of measured arteries. (EDV p = 0.036, PI p = 0.006, RI p = 0.006 for OA and p = 0.001 for other arteries and all OBF measurements). There was a negative correlation between CT and age, IOP and axial length (AL) in OHT group (r = - 0.529, p = 0.001; r = - 0.258, p = 0.047; r = - 0.345, p = 0.007, respectively, for fovea). But there was no statistically significant correlation between CT and other measurements in the control group, except age (r = - 0.860 p = 0.001 for fovea). We found that OBF decrement and choroidal thinning in OHT group compared with controls. Interpretation both of CT measurements with OCT and OBF parameters with CDI and new imaging technologies may help to prevent and reduce the possible optic nerve damage.

Colour Doppler imaging of retrobulbar circulation in different severity of glaucoma optic neuropathy.

To compare retrobulbar hemodynamic measured by colour Doppler imaging (CDI) in patients with a different severity of glaucoma and to correlate variables CDI with the structural parameters of the retina and optic disc. Of 89 eyes studied, 31 had preperimetric, 29 early, 12 moderate and 17 advanced glaucoma. Peak systolic velocity (PSV), end-diastolic velocity (EDV), resistance index (RI) in ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCAs) were evaluated by CDI and compared between study groups. Retinal nerve fibre layer thickness (RNFL) and optic disc parameters measured with optical coherent tomography (OCT) were correlated with the Doppler variables. In eyes with advanced, moderate and early glaucoma EDV SPCAs were significantly lower as well as RI SPCAs were significantly higher compared to the eyes with preperimetric glaucoma. In eyes with advanced and moderate glaucoma RI CRA (0.74 and 0.71) were significantly higher than in eyes with preperimetric glaucoma (0.68) (p=0.014 and 0.026). In eyes with advanced glaucoma PSV OA and PSV CRA were significantly lower than in eyes with preperimetric glaucoma (32.5 vs. 40.7 cm/s p=0.034 and 8.25 vs. 9.7 cm/s p=0.022, respectively). Positive, variable correlations were found between RNFL and EDV of all measured arteries (0.21<R<0.50, p<0,05). Statistically significant alterations in the Doppler parameters of retrobulbar arteries in association with thinning of the RNFL were observed in patients with glaucoma along with a greater severity of optic neuropathy.

O31 Giant cell arteritis - a rare ocular presentation

O31 Giant cell arteritis - a rare ocular presentation