Doppler ultrasound features of ophthalmic artery in diabetic retinopathy in a Nigerian Teaching Hospital

Background: Diabetes mellitus is a metabolic disease characterized by elevated blood glucose level due to impaired insulin secretion, insulin action or both with diabetic retinopathy being the most common microangiopathic complication. A comparative, cross- sectional study aimed at evaluating Doppler blood flow indices in the ophthalmic artery in diabetic retinopathy and non-retinopathy patients when compared to normal controls in a Nigerian tertiary hospital.Methods: Data were collected over 7 months (April 2017-October 2017) in Lagos University Teaching Hospital, Idi-Araba Lagos, Nigeria. Sixty-five diabetic retinopathy patients, 65 diabetic patients without retinopathy and 65 non-diabetic controls had their ophthalmic artery Doppler indices assessed for comparison.Results: The end diastolic velocity (EDV) of the ophthalmic arteries in the diabetic patients were significantly lower than those of control group (EDV=5.84±2.59 cm/s, p<0.001 bilaterally). In diabetic patients with retinopathy, the end diastolic velocity of the ophthalmic arteries was significantly lower than those of diabetic patients without retinopathy (EDV=5.84±2.59 cm/s right eye, EDV=5.75±2.39 left eye, p<0.001 bilaterally). The resistivity index (RI) of the ophthalmic arteries was significantly higher in both diabetic patients with retinopathy and those without retinopathy compared to control group (RI=0.92±0.07 right eye, p=0.044 right eye, p<0.001 left eye) with resistivity index of diabetic retinopathy respondents significantly higher than the diabetic patients with no retinopathy.Conclusions: The study showed that Doppler is a useful screening parameter in identifying eyes at risk of developing sight threatening proliferative disease in diabetic patients. Significant differences exist in ophthalmic artery Doppler flow indices of diabetics with retinopathy compared to the healthy controls.

P.135 Willisian collateral and cervical carotid stenosis during large vessel occlusion stroke: Observations from computed tomography angiography

Background: The circle of Willis (CoW) and cervical carotid arteries are important sources of collateral flow during acute large vessel occlusion (LVO) in the anterior circulation. We examined the anatomical components of the circle and the cervical carotid arteries to determine relationship to acute stroke severity. Methods: Consecutive patients with acute LVO who underwent EVT were assessed. Measurements were made of the luminal diameters of 16 anatomical vascular components. Admission NIHSS, ASPECTS and mCTA collateral scores were statistically analyzed for any relationship to vascular measurements. Results: 100 patients were studied. No relationship was found between the collateral Willisian pathways and measures of stroke severity. However, the ophthalmic arteries exhibited a relationship to stroke severity. In adjusted analysis, 1-mm increases in the ipsilateral and contralateral ophthalmic artery diameter were independently associated with a 4.80-point decrease and a 6.31-point increase in the NIHSS scale, respectively. Similarly, a 1.53-point increase and a 2.62-point decrease in the ASPECTS. In the neck a majority showed 0-55% stenosis, with no stenosis between 55% and 95%, and 14% at 95% to 100%. Conclusions: Stroke severity and collateral during LVO is unrelated to Willisian collateral. Ophthalmic artery calibers are related. Acute progression of 55-95% stenoses to complete occlusion occurs in LVO stroke

Angiotensin II Induces Oxidative Stress and Endothelial Dysfunction in Mouse Ophthalmic Arteries via Involvement of AT1 Receptors and NOX2

Angiotensin II (Ang II) has been implicated in the pathophysiology of various age-dependent ocular diseases. The purpose of this study was to test the hypothesis that Ang II induces endothelial dysfunction in mouse ophthalmic arteries and to identify the underlying mechanisms. Ophthalmic arteries were exposed to Ang II in vivo and in vitro to determine vascular function by video microscopy. Moreover, the formation of reactive oxygen species (ROS) was quantified and the expression of prooxidant redox genes and proteins was determined. The endothelium-dependent artery responses were blunted after both in vivo and in vitro exposure to Ang II. The Ang II type 1 receptor (AT1R) blocker, candesartan, and the ROS scavenger, Tiron, prevented Ang II-induced endothelial dysfunction. ROS levels and NOX2 expression were increased following Ang II incubation. Remarkably, Ang II failed to induce endothelial dysfunction in ophthalmic arteries from NOX2-deficient mice. Following Ang II incubation, endothelium-dependent vasodilation was mainly mediated by cytochrome P450 oxygenase (CYP450) metabolites, while the contribution of nitric oxide synthase (NOS) and 12/15-lipoxygenase (12/15-LOX) pathways became negligible. These findings provide evidence that Ang II induces endothelial dysfunction in mouse ophthalmic arteries via AT1R activation and NOX2-dependent ROS formation. From a clinical point of view, the blockade of AT1R signaling and/or NOX2 may be helpful to retain or restore endothelial function in ocular blood vessels in certain ocular diseases.

Comparison of the Doppler Indices in the Ophthalmic Artery and Central Retinal Artery in Diabetic and Nondiabetic Individuals

Objective: Diabetes can lead to diabetic retinopathy, which damages the retina due to blood flow remodeling of occular vessels. Early stages of diabetic retinopathy may not present with patient symptoms. Doppler indices, of the ophthalmic arteries, could help in determining the effect of diabetic vascular remodeling. This research was designed to compare the Doppler indices, in the ophthalmic artery and central retinal artery, in both diabetic and nondiabetic patients. Materials and Methods: This was a cross-sectional observational study of 72 total patients. Sonography was performed on the ophthalmic arteries of 36 diabetics and 36 nondiabetics, to compare Doppler indices. All patients were voluntarily consented to this research that was approved by the university’s Institutional Review Board (IRB). Doppler parameters recorded were peak systolic velocity, end dystopic velocity, resistive index, and pulsatility index, which were taken in both patient groups and compared. Results: A significant difference was noted in the ophthalmic artery peak systolic velocity, end-diastolic velocity, pulsatility index, and resistive index for diabetic and nondiabetic individuals, with a statistically significant set at .01. Conclusions: There was a significant difference between diabetic and nondiabetic ophthalmic Doppler indices in this cohort of patients. This cohort demonstrated vascular remodeling of the ophthalmic arteries, caused by diabetes; therefore, blood flow resistance was increased due to diabetes.

A case of meningolacrimal artery aneurysm associated with meningioma

Background: Intraorbital aneurysms are rare, and most of them originate from the ophthalmic arteries. Herein, we report a case of meningolacrimal artery aneurysm associated with a meningioma. Case Description: A 55-year-old woman had a frontal convexity meningioma identified by brain magnetic resonance imaging during a checkup. Cerebral angiography revealed the middle meningeal artery as a feeding artery as well as the presence of an aneurysm associated with the meningolacrimal artery. Embolization of the feeding artery was performed before the removal of the meningioma. The meningioma was resected, and the aneurysm was removed with a bone flap. The patient was discharged without any complications. Conclusion: We report a meningolacrimal artery aneurysm associated with a meningioma. Embolizing the feeding artery of the aneurysm was helpful in safely resecting the meningioma.

A case of bleeding from maxillary carcinoma embolized from the maxillary and ophthalmic arteries

Background The majority of maxillary sinus cancers are advanced at initial detection due to anatomical limitations and lack of early symptoms. In patients with orbital invasion, the feeding arteries of the tumor are often associated with the ophthalmic artery in addition to the maxillary artery. We describe a case of tumor bleeding in a patient with recurrent maxillary carcinoma that was treated with embolization from the maxillary and ophthalmic arteries. Case presentation A 70-year-old man was treated for left maxillary carcinoma from the maxillary artery with 6 cycles of selective intra-arterial cisplatin infusion with concomitant radiation therapy. He subsequently had epistaxis and underwent arterial embolization for hemostasis. He had almost no sight by this time. Angiography of the left external carotid artery and internal carotid artery revealed blood supply from the maxillary and ophthalmic arteries. Regarding the maxillary artery, coil embolization was performed after embolization with 300-500 μm Embosphere. On the other hand, for the ophthalmic artery, the 3rd portion, supratrochlear artery and dorsal nasal artery, were selected and embolized with coils. Final angiography revealed disappearance of tumor staining and a residual choroidoretinal blush. There was no bleeding that needed treatment up to 2 months after embolization. Conclusions In embolization of the ophthalmic artery, it is necessary to embolize the second and subsequent parts because the arteries associated with visual function branch off from the first part. Even in patients whose visual acuity has been almost lost, like in this case, there is a risk of eye pain from embolization at the proximal end, and distal embolization is necessary.

Angiographic investigation of orbital vascular variations in the rabbit and implications for endovascular intra-arterial chemotherapy models

BackgroundThe New Zealand White rabbit (NZWR) is the first small-animal experimental model of intra-arterial chemotherapy (IAC) for retinoblastoma treatment. The NZWR has dual ophthalmic arteries (OA): the external OA (EOA) arises from the external carotid artery and the internal OA (IOA) from the internal carotid artery. We describe the technique that we have refined for OA catheterization in rabbits, and describe the angioanatomical variations in the OA supply to the NZWR eye and implications for IAC delivery, which were identified as part of a larger project exploring IAC effects in a rabbit retinoblastoma model.MethodsWe developed techniques to perform angiography of the external and internal carotid arteries and superselective angiography of the EOA and IOA in NZWR using transfemoral access and a microwire/microcatheter system. EOA and IOA supply to the eye was determined angiographically and recorded before selective OA catheterization and angiography.Results114 rabbits underwent carotid angiographic evaluation and OA catheterization (161 total eyes evaluated, 112 right, 49 left). Most eyes had a single dominant arterial supply; either IOA or EOA. EOA was dominant in 73% (118/161), and IOA was dominant in 17% (27/161). Co-dominant supply was seen in 10% (16/161). Of the rabbits with bilateral OA catheterization, 25/47 (53%) had bilateral dominant EOA.ConclusionSuccessful catheterization of the OA in the NZWR can be readily accomplished with nuanced technique. The external OA is the dominant arterial supply in the majority of NZWR eyes. These findings allow for successful reproduction of OA catheterization studies of IAC for retinoblastoma in NZWR.