Anterior ischemic optic neuropathy with internal carotid artery occlusion

Optical coherence tomography angiography metrics in diabetes: Focusing on diabetic retinopathy and carotid atherosclerosis

BACKGROUND

To explore the value of Optical Coherence Tomography Angiography (OCTA) metrics in the early diagnosis of vascular complications in diabetes.

METHODS

All participants underwent OCTA with a swept-source OCT device. Automated measurements of the foveal avascular zone (FAZ) area, vessel density (VD), and blood flow density (BFD) of both 3 × 3 and 6 × 6 windows were then obtained after a quality check.

RESULTS

Diagnostic models based on multiple risk factors were developed separately for diabetic retinopathy and carotid atherosclerosis using random forest and multivariate logistic regression methods. The addition of specific OCTA metrics improved the diagnostic prediction of DR compared with the models of risk factors alone (Inner Retinal Blood Flow Density in 3 × 3 window, IRBFD; Brier score 0.124 vs. 0.149; AUC, 0.887 vs. 0.836) (Central Retinal Blood Flow Density in 3 × 3 window, CRBFD; Brier score 0.142 vs. 0.149; AUC, 0.851 vs. 0.836). Adding diabetic peripheral vascular disease (DPVD) indicator improved the prediction of carotid atherosclerosis (Brier score, 0.180 vs. 0.192; AUC, 0.802 vs. 0.781. The FAZ in the 3 × 3 window also achieved this effect when targeting only T2DM patients (AUC, 0.797 vs. 0.766; Brier score, 0.183 vs. 0.195).

CONCLUSIONS

Focusing on IRBFD and CRBFD in the 3 × 3 window of OCTA allows for a more sensitive prediction of the occurrence of DR in diabetic patients. Meanwhile, the quantitative microvascular information provided by OCTA and the occurrence of DPVD may be crucial for diagnosing carotid atherosclerosis. For T2DM patients, we also propose the possibility of FAZ in the 3 × 3 window as a potential diagnostic indicator.

[Ocular blood flow and carotid artery malfunction]

AIM

to evaluate ocular hemodynamics and informativity of estimated individual normal range of intraocular pressure (IOP).

MATERIALS AND METHODS

A total of 12 patients (22 eyes) with carotid artery malfunction were examined. Ocular blood flow (OBF) and IOP were measured with Ocular Blood Flow Analyzer. Actual OBF was then compared with what is considered normal for a given axial length (AL). Individual normal range of IOP was calculated according to an original formula (described in previous publications). Doppler imaging of ocular vessels enabled blood flow velocity measurement. Morphological parameters and functional status of the retina and optic nerve were judged on automated perimetry (Octopus 900) and optical coherence tomography (Cirrus HD-OCT) findings. Statistical analyses were performed using Statistica 10 software.

RESULTS

Generally, OBF showed no correlation with the grade of carotid artery stenosis (p < 0.05), however, was significantly reduced as compared to its AL-dependent norm in patients with greater than 85% narrowing of the internal carotid artery, which can cause misestimating of their individual normal range of IOP. A negative relationship was established between the blood flow velocity in short posterior ciliary arteries and the grade of internal carotid artery stenosis (p < 0.005). Ocular blood flow deficit relative to the AL-dependent norm correlated with ophthalmic artery resistance index.

CONCLUSION

OBF-based estimation of individual normal range of IOP is inexpedient in patients with greater than 80% carotid artery stenosis due to its possible influence on ocular hemodynamics. In most cases of less than 80% carotid artery stenosis OBF is adequate or slightly reduced as compared to its AL-dependent norm and thus, has no significant impact on estimated individual normal range of IOP.

Microsurgical revascularization of the ophthalmic artery

We have developed and performed a microsurgical arterial anastomosis to revascularize the ophthalmic artery in patients with ischemic visual loss, resulting in improvement in visual function. A detailed description of the surgical procedure is discussed as well as the indications for surgery in these cases. An ischemic etiology of visual impairment was predicted by binocular fundus reflectometry, a noninvasive technique to indicate ocular perfusion abnormalities. Encouraging early results suggest that such a revascularization procedure may provide a therapeutic option for a particular group of patients with progressive ischemic visual loss.

Ocular Ischemic Syndrome After Occlusion of Both External Carotid Arteries

The ocular ischemic syndrome (OIS) has been reported in association with high-grade stenosis or occlusion of the common carotid artery (CCA) or internal carotid artery (ICA) but never with high-grade stenosis or occlusion of the external carotid artery (ECA) alone. We describe two patients who developed OIS with bilateral occlusion of the ECAs yet patent CCAs and ICAs. In one case, unilateral OIS followed consecutive bilateral carotid endarterectomies. In the other case, OIS developed spontaneously OU but was exacerbated in one eye after ipsilateral carotid endarterectomy (CE) in the setting of pre-existing contralateral ECA occlusion. In some individuals, the ECA is the primary source of arterial blood flow to the eye. Because of this fact, the endarterectomy surgeon must avoid causing ECA occlusion by meticulously removing not only the ICA plaque, but also the entire ECA plaque.

Neuro-Ophthalmic Emergencies for the Neurologist

A variety of acute neurologic disorders present with visual signs and symptoms. In this review the authors focus on those disorders in which the clinical outcome is dependent on timely and accurate diagnosis. The first section deals with acute visual loss, specifically optic neuritis, ischemic optic neuropathy (ION), retinal artery occlusion, and homonymous hemianopia. The authors include a discussion of those clinical features that are helpful in distinguishing between inflammatory and ischemic optic nerve disease and between arteritic and nonarteritic ION. The second section concerns disc edema with an emphasis on the prevention of visual loss in patients with increased intracranial pressure. The third section deals with abnormal ocular motility, and includes orbital inflammatory disease, carotid-cavernous fistulas, painful ophthalmoplegia, conjugate gaze palsies, and neuromuscular junction disorders. The final section concerns pupillary abnormalities, with a particular emphasis on the dilated pupil and on carotid artery dissection. Throughout there are specific guidelines for the management of these disorders, and areas are highlighted in which there is ongoing controversy.

Carotid endarterectomy in a patient with anterior ischemic neuropathy

A case of anterior ischemic optic neuropathy (AION) associated with 90% stenosis of the ipsilateral internal carotid artery (ICA) and diminished blood flow through the ophthalmic artery was studied. After carotid endarterectomy (CEA), the patient showed subjective and measurable improvement in vision and increased ophthalmic artery flows. This observation supports the role for screening carotid duplex scanning and transcranial Doppler in patients with AION. Early CEA in patients with associated ipsilateral ophthalmic artery hypoperfusion may improve visual outcome.

Blindness as a rare complication of neck dissection

Blindness is a rare and rather unexpected complication of neck dissection. There have been only a few cases reported to date, all following bilateral neck dissections. We present a case of blindness after one-sided neck dissection and an insidious finding of bilateral common carotid artery occlusion.

Anterior ischemic optic neuropathy is not associated with carotid artery atherosclerosis

BACKGROUND AND PURPOSE

The relation between anterior ischemic optic neuropathy and carotid artery atherosclerotic disease is unclear. We studied patients with anterior ischemic optic neuropathy to determine if they had an increased occurrence of carotid artery stenosis.

METHODS

Fifteen consecutive patients with anterior ischemic optic neuropathy were evaluated prospectively for cervical carotid artery stenosis and compared with 30 age- and sex-matched asymptomatic patients and also with 11 age- and sex-matched patients experiencing transient monocular blindness.

RESULTS

There was no difference in the mean stenosis of the internal carotid artery between patients with anterior ischemic optic neuropathy (mean carotid stenosis, 19%) and asymptomatic patients (mean carotid stenosis, 9%; p > 0.05), whereas patients with transient monocular blindness had significantly more stenosis (mean, 77%) in the cervical carotid arteries than both control subjects (p < 0.0001) and patients with anterior ischemic optic neuropathy (p < 0.0001). There was also no difference in the percentage of patients with stenosis > or = 30% in anterior ischemic optic neuropathy (two of 15) and asymptomatic patients (five of 30), whereas 10 of 11 patients with transient monocular blindness had stenoses > or = 30%, significantly more than patients with anterior ischemic optic neuropathy (p < 0.0001) and asymptomatic patients (p < 0.0001).

CONCLUSIONS

Anterior ischemic optic neuropathy is not a marker for atherosclerotic carotid artery stenosis. The pathogenesis of nonarteritic anterior ischemic optic neuropathy does not involve carotid artery stenosis in most patients.

Anterior ischemic optic neuropathy: sense and nonsense in diagnosis and treatment

In 15 consecutive patients with AION the cause was found to be giant-cell arteritis in 3 cases and was thought to be local arteriosclerosis of the posterior ciliary arteries in 12 cases, in spite of rheumatic factors which were found initially. In 87% of cases symptoms or factors indicating generalised arteriosclerosis were found. In one case before the AION cilioretinal emboli had been found. It is reported that the second eye is affected after a varying interval of time in +/- 50% of cases. In our material the arteriosclerotic form of AION occurred bilaterally in +/- 40% of cases with an interval varying from a few days to 5 years. The average interval for this form of AION is 3 years. Cerebral angiography was of no help in tracing the cause of the AION. A fluorescein angiogram is often made too late to show the characteristic circulatory disturbance in the peripapillary choroid and is usually not necessary. Therapy should be started immediately, with large doses of corticosteroids in all cases of AION, until biopsy of the temporal artery proves negative or the ESR is practically normal. Hypertension and diabetes should be treated adequately as protection for the other eye in the arteriosclerotic form of AION. In addition long-term anticoagulant therapy should be considered: a prospective study into this aspect has been started.

Ischemic optic neuropathy associated with retinal embolism

Ischemic optic neuropathy occurred in three patients (a 55-year-old man and two women, 64 and 68 years old). Visual loss followed coronary bypass surgery in two patients who also had diffuse atherosclerotic disease. Retinal emboli were present in both eyes of each. The third patient developed ischemic optic neuropathy with evidence of ipsilateral retinal emboli shortly after cardiac catheterization. Her only other risk factor for ischemic optic neuropathy was systemic hypertension. Although highly unusual, ischemic optic neuropathy may be associated with and possibly caused by a shower of emboli to the eye.

The pupil in congenital third nerve misdirection syndrome

The involved pupil in the syndrome of aberrant regeneration of the oculomotor nerve usually remains larger than the uninvolved side, or approaches equality in size. A 4-year-old child was seen with congenital aberrant regeneration of the right third nerve. The right pupil was consistently smaller than the left, but particularly so in dim illumination. The question can be raised as to whether relative pupillary miosis more commonly follows third nerve misdirection in children than adults.

Ischaemic optic neuropathy in pulseless disease

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