Diffusional kurtosis imaging in differentiating nonarteritic anterior ischemic optic neuropathy from acute optic neuritis

PURPOSE

We aimed to determine the feasibility of using DKI to characterize pathological changes in nonarteritic anterior ischemic optic neuropathy (NAION) and to differentiate it from acute optic neuritis (ON).

METHODS

Orbital DKI was performed with a 3.0 T scanner on 75 patients (51 with NAION and 24 with acute ON) and 15 healthy controls. NAION patients were further divided into early and late groups. The mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) were calculated to perform quantitative analyses among groups; and receiver operating characteristic curve analyses were also performed to determine their effectiveness of differential diagnosis. In addition, correlation coefficients were calculated to explore the correlations of the DKI-derived data with duration of disease.

RESULTS

The MK, RK, and AK in the affected nerves with NAION were significantly higher than those in the controls, while the trend of FA, RD, and AD was a decline; in acute ON patients, except for RD, which increased, all DKI-derived kurtosis and diffusion parameters were significantly lower than controls (all P < 0.008). Only AK and MD had statistical differences between the early and late groups. Except for MD (early group) and FA, all other DKI-derived parameters were higher in NAION than in acute ON; and parameters in the early group showed better diagnostic efficacy in differentiating NAION from acute ON. Correlation analysis showed that time was negatively correlated with MK, RK, AK, and FA and positively correlated with MD, RD, and AD (all P < 0.05).

CONCLUSION

DKI is helpful for assessing the specific pathologic abnormalities resulting from ischemia in NAION by comparison with acute ON. Early DKI should be performed to aid in the diagnosis and evaluation of NAION.

Altered small-world and disrupted topological properties of functional connectivity networks in patients with nonarteritic anterior ischemic optic neuropathy

BACKGROUND

Nonarteritic anterior ischemic optic neuropathy (NAION) is a disease of the optic nerve, but its effect on brain network topology is still unclear.This study aimed to investigate brain network alterations in NAION patients and to explore their relationship with functional impairment.

METHODS

Resting-state functional MRI data were collected from 23 NAION patients and 23 matched healthy control subjects.We used graph theory analysis to investigate the global and nodal network topological properties,and network-based statistical (NBS) methods were used to explore intergroup differences in functional connectivity (FC) strength.

RESULTS

Compared to the control group, NAION patients had lower global efficiency, normalized clustering coefficient and small-world values and higher characteristic path length (P < 0.05). In the hub distributions of functional networks, the NAION group had one hub region disappearing and four hub regions appearing in nodal degree centrality (Dc), and two hubs disappearing and one hub region appearing in nodal betweenness centrality (Bc). The NAION group also had enhanced brain FC primarily associated with the frontal, prefrontal, parietal lobes and cerebellum. Furthermore, the right temporal pole, superior temporal gyrus (r = -0.424), the right inferior temporal gyrus (r = -0.414), the right cerebellar lobule Ⅵ (r = 0.450), and the left cerebellar lobule crus Ⅰ (r = 0.584) were significantly correlated with clinical severity.

CONCLUSION

NAION patients show disruption and redistribution of FC in specific regions of the brain network, which may be associated with visual impairment.

Color Doppler Eye Ultrasonography in giant cell arteritis: differential diagnosis between arteritic and non-arteritic sudden blindness

PURPOSE

Temporal (TA) and axillary (AXA) arteries Color Doppler Ultrasonography (CDUS) is the most reliable diagnostic technique for the diagnosis of giant cell arteritis (GCA), displaying high sensitivity and specificity. Nevertheless, CDUS is still poorly performed in the common clinical practice, being employed only by rheumatologists with a relevant expertise in this field. Color Doppler Eye Ultrasound (CDEUS) is a procedure variously employed in ophthalmology and preliminary findings have displayed a possible role also in the diagnostic work-up of GCA. Aim of this study was to assess whether CDEUS may play a role in the differential diagnosis between arteritic and non-arteritic blindness.

METHODS

We prospectively included all patients evaluated since September 2021 to May 2022 by our Ophthalmology Unit for sudden blindness and referred to our Vasculitis Clinic in the suspicion of GCA. All patients underwent complete ophthalmological evaluation, routine blood tests, AxA and TA CDUS and CDEUS. According to the definite diagnosis, patients were divided in the following subgroups: (A) patients suffering from arteritic central retinal artery occlusion (CRAO), (B) patients suffering from non-arteritic CRAO, (C) patients suffering from arteritic anterior ischemic optic neuropathy (AION), (D) patients suffering from non-arteritic AION.

RESULTS

During the observational period, we included a total of 25 patients suffering from sudden blindness and referred to Vasculitis Clinic for ruling out GCA. Patients belonging to group A showed no flow or reduced flow within the territory of central retinal artery (CRA), no "spot sign" and positive TA CDUS; on the other hand, patients from group B presented normal TA CDUS, no flow or reduced flow within the territory of CRA and the presence of "spot sign". Conversely, no relevant difference was evidenced at CDEUS in patients with and without arteritic AION.

CONCLUSION

Our preliminary data displayed a good reliability of CDEUS in distinguishing between arteritic and non-arteritic CRAO, while no difference was assessed between arteritic and non-arteritic AION. Since AION represents the most common presentation of cranial GCA, CDEUS does not seem a reliable procedure in the diagnostic work-up of GCA and should be restricted only to the exclusion of thrombo-embolic occlusions within the territory of central retinal artery.

Early diffusion-weighted MRI at 3 Tesla detects ischemic changes of the optic nerve in anterior ischemic optic neuropathy

OBJECTIVES

To assess the impact of timing from visual symptoms' onset to diffusion-weighted (DW) 3 T MRI completion to detect ischemic changes of the optic disc and optic nerve in AION patients.

METHODS

This IRB-approved retrospective single-center study included 3 T MRI data from 126 patients with AION and 111 controls with optic neuritis treated between January 2015 and May 2020. Two radiologists blinded to all data individually analyzed imaging. A senior neuroradiologist resolved any discrepancies by consensus. The primary judgment criterion was the restricted diffusion of the optic disc and/or the optic nerve assessed subjectively on the ADC maps. ADC values were also measured. Spearman rank correlations were used to examine the relationships between timing from visual symptoms' onset to MRI completion and both the restricted diffusion and the ADC values.

RESULTS

One hundred twenty-six patients (47/126 [37.3%] women and 79/126 [62.7%] men, mean age 69.1 ± 13.7 years) with AION were included. Restricted diffusion of the optic disc in AION eyes was more frequent in the early MRI group than in the late MRI group: 35/49 (71.4%) eyes versus 3/83 (3.6%) eyes, p < 0.001. ADC values of the pathological optic discs and optic nerves were lower in the early MRI group than in the late MRI group: 0.61 [0.52-0.94] × 10^-3 mm²/s versus 1.28 [1.01-1.44] × 10^-3 mm²/s, p < 0.001, and 0.74 [0.61-0.88] × 10^-3 mm²/s versus 0.89 [0.72-1.10] × 10^-3 mm²/s, p < 0.001, respectively.

CONCLUSIONS

DWI MRI showed good diagnostic performance to detect AION when performed early after the onset of visual symptoms.

KEY POINTS

• Restricted diffusion of the optic disc in eyes affected by AION was significantly more likely to be observed in patients who had undergone MRI within 5 days after onset of visual symptoms. • ADC values of the pathological optic discs and optic nerves were significantly lower in patients who had undergone MRI within 5 days after onset of visual symptoms of AION: 0.61 × 10^-3 mm²/s versus 1.28 × 10^-3 mm²/s, p < 0.001, and 0.74 × 10^-3 mm²/s versus 0.89 × 10^-3 mm²/s, p < 0.001, respectively. • The optimal threshold for timing from visual symptoms' onset to MRI completion to detect restricted diffusion of the optic disc and/or optic nerve was 5 days, with an AUC of 0.88 (CI_95%: 0.82-0.94).

Patterns of Retinal Ganglion Cell Damage in Nonarteritic Anterior Ischemic Optic Neuropathy Assessed by Swept-Source Optical Coherence Tomography

OBJECTIVE

To evaluate the ability of macular ganglion cell and inner plexiform layer (mGCIPL) and retinal nerve fiber layer (RNFL) thickness measurements by long-wavelength swept-source optical coherence tomography (SS-OCT) to assess retinal ganglion cell (RGC) damage in nonarteritic anterior ischemic optic neuropathy (NAION).

METHODS

A retrospective study of 20 patients with unilateral NAION was performed. SS-OCT scanning of the macular and peripapillary areas was performed to measure the total and six-sector thicknesses of macular RNFL (mRNFL) and mGCIPL, as well as peripapillary RNFL (pRNFL) thicknesses in global and 12 clock-hour sectors. Further comparison of these thicknesses between NAION involved eyes and uninvolved counterparts was performed in 12 of the 20 patients at 4 visits. The thickness map and en face images generated by volume data of the posterior pole over a 12 × 9-mm area were used for RNFL analysis.

RESULTS

Median time intervals between the visual symptom onset and first thinning occurrences of mGCIPL, mRNFL, and pRNFL were 17 days (95% Confidence Interval [CI] 14-18 days), 43 days (95% CI 32-48 days), and 70 days (95% CI 62-80 days), respectively. The thickness map indicated a significantly reduced pRNFL in the superior temporal sectors or temporal sectors after 9 weeks, and retinal damage corresponded to the superior hemisphere's mRNFL and mGCIPL. En face images showed that the RNFL thinning area gradually expanded along the retinal nerve fiber direction and progressed toward the optic nerve head.

CONCLUSIONS

The patterns of RGC damage in the macular and peripapillary areas of NAION eyes can be revealed by SS-OCT. Objective measurement of SS-OCT is valuable in characterizing NAION.

Case Report: Combined Ischemic Optic Neuropathy and Central Retinal Artery Occlusion after Starting Hemodialysis

SIGNIFICANCE

This case highlights ocular ischemia after hemodialysis resulting in permanent vision loss. Fifteen percent of the U.S. population suffers from chronic kidney disease. Eye care providers should recommend risk factor modifications to their patients with end-stage renal disease before hemodialysis is started to prevent loss of vision.

PURPOSE

The purpose of this study was to demonstrate a case of concurrent nonarteritic anterior ischemic optic neuropathy and central retinal artery occlusion in the setting of hemodialysis initiation.

CASE REPORT

A 68-year-old Irish man with end-stage renal disease undergoing dialysis presented, complaining of 3 weeks of progressive vision loss in his left eye. His medical history is complex and includes extensive cardiac disease, bilateral carotid stenosis, and peripheral vascular disease. His surgical history includes a right carotid endarterectomy, bilateral lower extremity amputations, and an aortic valve replacement. Clinical examination revealed light perception vision with an afferent pupillary defect in the left eye and count finger peripheral vision only in the superior temporal quadrant of his vision. The dilated fundus examination showed significant pallid disc edema and focal areas of retina whitening with attenuated peripapillary vasculature in the left eye. This edema was confirmed by optical coherence tomography and supported optic nerve and retinal infarction. A temporal artery biopsy confirmed no evidence of arteritis.

CONCLUSIONS

Hemodynamic disruption during dialysis in patients with end-stage renal disease and overlying anemia can result in optic nerve and retinal infarction. Patients who are predisposed to nonarteritic anterior ischemic optic neuropathy or central retinal artery occlusion should be educated on this before starting dialysis to ensure careful blood pressure monitoring.

Quantitative analysis of optical coherence tomographic angiography (OCT-A) in patients with non-arteritic anterior ischemic optic neuropathy (NAION) corresponds to visual function

Purpose

Non-arteritic anterior ischemic optic neuropathy (NAION) is the most common cause of non-glaucomatous optic neuropathy in older adults. Optical coherence tomographic angiography (OCT-A) is an emerging, non-invasive method to study the microvasculature of the posterior pole, including the optic nerve head. The goal of this study was to assess the vascular changes in the optic nerve head and peripapillary area associated with NAION using OCT-A.

Design

Retrospective comparative case series.

Methods

We performed OCT-A in 25 eyes (7 acute and 18 non-acute) in 19 patients with NAION. Fellow, unaffected eyes were analyzed for comparison. Patent macro- and microvascular densities were quantified in the papillary and peripapillary regions of unaffected, acutely affected, and non-acutely affected eyes and compared across these groups according to laminar segment and capillary sampling region, and with respect to performance on automated visual field testing.

Results

In acutely affected eyes, OCT-A revealed a reduction in the signal from the major retinal vessels and dilation of patent superficial capillaries in the peripapillary area. By contrast, non-acutely affected eyes showed attenuation of patent capillaries. The peripapillary choriocapillaris was obscured by edema in acute cases, but was similar between non-acute and unaffected eyes. The degree of dilation of the superficial microvasculature in the acute phase and attenuation in the non-acute phase each correlated inversely with visual field performance. The region of reduced patent capillary density correlated with the location of visual field defects in 80% of acute cases and 80% of non-acute cases.

Conclusions

OCT-A reveals a dynamic shift in the superficial capillary network of the optic nerve head with strong functional correlates in both the acute and non-acute phases of NAION. Further study may validate OCT-A as a useful adjunctive diagnostic tool in the evaluation of ischemic optic neuropathy.

Visual loss due to optic nerve infarction and central retinal artery occlusion after spine surgery in the prone position: A case report

RATIONALE

Visual loss after spine surgery in the prone position is a serious complication. Several cases of central retinal artery occlusion with ophthalmoplegia after spine surgery have been reported in patients with ophthalmic arteries fed by the internal carotid artery (ICA) in a normal manner.

PATIENT CONCERNS

A 74-year-old man developed visual loss after undergoing a spinal decompression and fusion operation in the prone position that lasted approximately 5 hours.

DIAGNOSES

We detected an extremely rare case of visual loss due to optic nerve infarction and central retinal artery occlusion through fundoscopic examination, fluorescein angiogram, brain magnetic resonance imaging, and magnetic resonance angiography. The patient's visual loss may have been caused by compromised retrograde collateral circulation of the ophthalmic artery from branches of the external carotid artery in the presence of proximal ICA occlusion after a spinal operation in the prone position.

INTERVENTIONS

To recover movement of the left extraocular muscles, the patient received intravenous injections of methylprednisolone for 3 days and then oral prednisolone for 6 days.

OUTCOMES

Twenty days after the treatment, the motion of the left extraocular muscles was significantly improved. However, recovery from the left visual loss did not occur until 4 months after the operation.

LESSONS

In high-risk patients with retrograde collateral circulation of the ophthalmic artery from the external carotid artery due to proximal ICA occlusion, various measures, including the use of a head fixator to provide a position completely free of direct compression of the head and face, should be considered to decrease the risk of postoperative visual loss.

The Central Bright Spot Sign: A Potential New MR Imaging Sign for the Early Diagnosis of Anterior Ischemic Optic Neuropathy due to Giant Cell Arteritis

BACKGROUND AND PURPOSE

A rapid identification of the etiology of anterior ischemic optic neuropathy is crucial because it determines therapeutic management. Our aim was to assess MR imaging to study the optic nerve head in patients referred with anterior ischemic optic neuropathy, due to either giant cell arteritis or the nonarteritic form of the disease, compared with healthy subjects.

MATERIALS AND METHODS

Fifteen patients with giant cell arteritis-related anterior ischemic optic neuropathy and 15 patients with nonarteritic anterior ischemic optic neuropathy from 2 medical centers were prospectively included in our study between August 2015 and May 2016. Fifteen healthy subjects and patients had undergone contrast-enhanced, flow-compensated, 3D T1-weighted MR imaging. The bright spot sign was defined as optic nerve head enhancement with a 3-grade ranking system. Two radiologists and 1 ophthalmologist independently performed blinded evaluations of MR imaging sequences with this scale. Statistical analysis included interobserver agreement.

RESULTS

MR imaging scores were significantly higher in patients with giant cell arteritis-related anterior ischemic optic neuropathy than in patients with nonarteritic anterior ischemic optic neuropathy (P ≤ .05). All patients with giant cell arteritis-related anterior ischemic optic neuropathy (15/15) and 7/15 patients with nonarteritic anterior ischemic optic neuropathy presented with the bright spot sign. No healthy subjects exhibited enhancement of the anterior part of the optic nerve. There was a significant relationship between the side of the bright spot and the side of the anterior ischemic optic neuropathy (P ≤ .001). Interreader agreement was good for observers (κ = 0.815).

CONCLUSIONS

Here, we provide evidence of a new MR imaging sign that identifies the acute stage of giant cell arteritis-related anterior ischemic optic neuropathy; patients without this central bright spot sign always had a nonarteritic pathophysiology and therefore did not require emergency corticosteroid therapy.

Clinical and color Doppler imaging features of one patient with occult giant cell arteritis presenting arteritic anterior ischemic optic neuropathy

Anterior ischemic optic neuropathies (AIONs) represent a segmental infarction of the optic nerve head (ONH) supplied by the posterior ciliary arteries (PCAs). Blood supply blockage can occur with or without arterial inflammation. For this reason, there are two types of AIONs: non-arteritic (NA-AION), and arteritic (A-AION), the latter is almost invariably due to giant cell arteritis (GCA). GCA is a primary vasculitis that predominantly affects extracranial medium-sized arteries, particularly the branches of the external carotid arteries (including superficial temporal arteries - TAs). One patient with clinical suspicion of acute left AION was examined at admission following a complex protocol including color Doppler imaging (CDI) of orbital vessels, and color duplex sonography of the TAs and of the carotid arteries. She presented an equivocal combination of an abrupt, painless, and severe vision loss in the left eye, and an atypical diffuse hyperemic left optic disc edema. She had characteristic CDI features for GCA with eye involvement: high resistance index, with absent, or severe diminished blood flow velocities, especially end-diastolic velocities, in all orbital vessels, especially on the left side (A-AION). Typical sonographic feature in temporal arteritis as part of GCA was "dark halo" sign. On the other hand, she did not present classic clinical or systemic symptoms of GCA: temporal headache, tender TAs, malaise (occult GCA). The left TA biopsy confirmed the diagnosis of GCA. The ultrasound investigations enabled prompt differentiation between NA-AION and A-AION, the later requiring in her case immediate steroid treatment, to prevent further visual loss in the right eye.

[Leukoaraiosis as a cause of non-arteritic anterior ischemic optic neuropathy--a case report]

The paper presents the case of a 61-year-old man with specific symptoms of non-arteritic anterior ischemic optic neuropathy. The head computed tomographyscans revealed multiple leukoaraiotic lesions. Leukoaraiosis is a disease affecting small cerebral vessels. Its pathogenesis is associated with a chronic inflammatory process and ischemic vascular endothelial dysfunction which reduce the cerebral blood flow. It cannot be ruled out that this process, alongside with Horton disease, hypertension, diabetes and atherosclerosis, may also be involved in the pathogenesis of non-arteritic anterior ischemic optic neuropathy. leukoaraiosis, non-arteritic anterior ischemic optic neuropathy.

[Peculiarities of ocular blood flow in ischemic optic neuropathy and normal tension glaucoma]

Characteristics of ocular hemodynamics in ischemic optic neuropathy (ION) outcome and normal tension glaucoma (NTG), the conditions that are difficult to be differentially diagnosed, have been investigated. The study enrolled 32 patients (40 eyes) with ION outcome, 26 patients (46 eyes) with NTG, and 20 patients (32 eyes) with no ocular pathology. Besides the standard ophthalmological examination, color Doppler imaging of ocular vessels, evaluation of ocular blood flow volume and individual normal range of intraocular pressure (flowmetry) were performed in all cases. The results showed that an excess of the actual intraocular pressure (IOP) over the individual normal range was much higher in patients with NTG than in patients with ION (39% and 14.5% correspondingly). It was also found that NTG is associated with a more significant decrease of ocular blood flow volume (30.1% in average) in comparison to ION outcome (11%). In both conditions a decrease in velocity parameters of the blood flow in main ocular vessels was registered, however, ocular hemodynamics changes appeared to be more severe in patients with glaucomatous optic neuropathy. A statistically reliable correlation between volumetric and velocity parameters of ocular blood flow has been discovered.

Ocular and optic nerve ischemia: recognition and treatment with intravenous prostaglandin E1

Ischemia of the optic nerve, the retina and the choroid are common problems in ophthalmology. This paper presents the different types of ischemia and their treatment with prostaglandin E1 (PGE1), a powerful vasodilator of the microcirculation. This is a review article of various previously published case reports and studies presenting patients with different types of ocular and optic nerve ischemia. Their treatment with intravenous (IV) PGE1 is described. Treatment for acute and chronic problems is presented. The visual acuity and/or the visual fields improved in almost all the treated patients. When measured, the blood flow velocities also improved. No complications due to the use of PGE1 were seen. Treatment with IV PGE1 should be considered in cases of ocular and optic nerve ischemia to immediately restore blood flow to these structures and improve the visual acuity. Intravenous prostaglandin E1 is an effective treatment for ocular and optic nerve ischemia leading to immediate visual improvement.

[Giant cell arteritis with eye involvment--color Doppler imaging or retrobulabar vessels findings]

BACKGROUND

Giant cell arteritis (temporal arteritis) is a primary vasculitis, that affects large arteries, especially branches of the external carotid artery (ECA).

PURPOSE

To assess the role of CDI of retrobulbar vessels in the study of two patients with giant cell arteritis with eye involvement.

METHODS

We have used a sonographer with 8-15 MHz linear probe.

RESULTS

Both patients presented malaise, temporal headache, tender temporal arteries and signs of inflammation. The first patient had a central retinal artery obstruction of the right eye, and the second had anterior ischaemic optic neuropathy of the left eye. Temporal artery histology was positive in both cases. Ultrasound investigation was performed within the first 10 days of corticosteroid treatment. CDI of retrobulbar vessels detected low blood velocities, especially end-diastolic velocities and high resistance index in all retrobulbar vessels, in both orbits. Typical sonographic features in temporal arteritis were "halo", associated with stenoses or occlusions of branches of ECA.

CONCLUSIONS

Ultrasound investigation is a valuable diagnostic tool to investigate giant cell arteritis.

[Acute anterior ischemic optic neuropathy in the course of optic nerve drusen]

Authors present the case of 48 years old male with acute anterior ischemic optic neuropathy (AION) in presence of optic nerve drusen. AION occurred in both eyes, but not at the same time. Diagnosis was made on the basis of laboratory tests, ultrasonographic examination and fluorescein angiography. In the course of treatment improvement of visual acuity was achieved , but concentric constriction of visual field remained. As no effective treatment of non vascular AION was proposed so far, major stress should be put on elimination of its vascular risk factors.

Retrobulbar haemodynamics in non-arteritic anterior ischaemic optic neuropathy

AIM

To compare retrobulbar haemodynamics in patients with acute non-arteritic anterior ischaemic optic neuropathy (NAION) and age-matched controls by colour Doppler imaging (CDI).

METHODS

25 patients with acute NAION and 35 age-matched controls participated in this study. By means of CDI, the blood flow velocities of the ophthalmic artery, central retinal artery (CRA), and nasal and temporal short posterior ciliary arteries (PCAs) were measured. Peak-systolic velocity (PSV) and end-diastolic velocity (EDV) and Pourcelot's resistive index were determined.

RESULTS

In the ophthalmic artery, no marked differences between patients with NAION and controls were detected. PSV and EDV of the CRA (p<0.001, p = 0.002) and PSV of the nasal PCA (p<0.05) were significantly decreased in patients with NAION compared with healthy controls. No marked differences between patients and controls were detectable for temporal PCAs.

CONCLUSION

Blood flow velocities of the nasal PCA and the CRA are considerably reduced in patients with acute NAION compared with controls. Patients with NAION in part showed markedly different retrobulbar haemodynamics.

[The effect of retrobulbar injection with anisodamine on ocular blood velocity in anterior ischemic optic neuropathy]

OBJECTIVE

To study the effect of retrobulbar injection with anisodamine on ocular blood velocity in anterior ischemic optic neuropathy (AION).

METHODS

15 minutes before injection, 15 minutes and 1 hour after injection, the blood flow velocity in 39 cases (39 eyes) diagnosed as AION was measured and analyzed by CDI, timed average maximum velocity, peak systolic velocity, end diastolic velocity, resistance index and pulsatility index of OA, CRA and PCA were recorded.

RESULTS

Compared with the normal eyes, each parameter of SPCA was statistically significant. 15 minutes and 1 hour after post ocular injection of anisodamine, every parameter examined in the experiment was increased except resistance index compared with pre-injection (P < 0.01).

CONCLUSIONS

retrobulbar injection with anisodamine can effectively improve flow velocity of nasal and tempo short posterior ciliary artery and central retinal artery.

Three-month change in cerebral glucose metabolism in patients with nonarteritic ischemic optic neuropathy

BACKGROUND

No specific therapy is available for non-arteritic ischemic optic neuropathy (NAION), a blinding disease, which is related to microvascular insufficiency of the optic disc and white matter lesions in brain MRI representing ischemia. We hypothesize that pentoxifylline, traditionally used for treatment of peripheral vascular disease due to its ability to decrease viscosity and increase erythrocyte flexibility, may be useful to improve blood flow in patients with NAION. Positron emission tomography (PET) to determine the change in glucose metabolic rate in the visual cortex of patients with NAION versus age-matched controls was performed after 3 months' administration of pentoxifylline.

METHODS

Eight patients clinically diagnosed with NAION underwent clinical and laboratory evaluation, brain MRI and PET with fluoride-18 fluorodeoxyglucose (FDG). All patients were treated with oral pentoxifylline 400 mg three times a day for a period of at least 3 months. Three patients were included in the final PET data analysis.

RESULTS

At baseline, PET revealed bilateral metabolic decreases especially in the ventral visual stream in all patients compared with 56 age- and gender-normalized controls. Metabolic changes were seen in the dorsal stream areas 17, 18, and 19, cerebellar region, dorsolateral prefrontal cortex, medial temporal lobe, and frontal eye fields 8 and 6. At 3 months following pentoxifylline, all three patients included in the final PET data analysis showed partial normalization from the baseline metabolism.

CONCLUSIONS

Metabolic imaging with FDG-PET in NAION provides functional information not attainable with conventional brain MRI. The exact relevance of these results, and the role of pentoxifylline in these metabolic changes, should be determined by means of a larger randomized and controlled trial.

[Application of Color Doppler ultrasonography in the evaluation of the blood flow in the ocular vessels in patients with anterior ischemic optic neuropathy--the preliminary report]

PURPOSE

Anterior ischemic optic neuropathy (AION) is one of the most common causes of acute loss vision in the middle-aged and elderly persons. It occurs due to hypoperfusion in the short posterior ciliary arteries supplying the optic nerve head. The aim of our study was evaluation of the usefulness of colour Doppler ultrasonography in diagnostics of AION.

MATERIAL AND METHODS

Color Doppler imaging of the ophthalmic artery, central retinal artery and posterior ciliary arteries were performed in 10 patients with clinically evident AION. The peak-systolic velocity (PSV), end-systolic velocity (EDV) and resistance index (RI) were measured.

RESULTS

No significant differences in the mean values of PSV, EDV and RI of ophthalmic arteries and posterior ciliary arteries between the affected and non-affected eyes were found. Reduction of mean flow velocities as well as significantly increased resistance index were observed in the central retinal artery in eyes with AION.

CONCLUSIONS

The Color Doppler findings in the ciliary arteries do not reflect the ischemic changes in patients with AION. It is probably due to anatomical limitation of this method in evaluation of the blood flow in posterior ciliary arteries supplying the optic nerve head. Abnormal blood flow parameters in the central retinal artery are secondary changes due to optic disc oedema.

[Hyperpneumatization of sphenoid sinus--a possible etiology of posterior optic neuropathy]

We take in debate a rare cause of compressive retrobulbar optic neuropathy. We present three patients with bilateral retrobulbar optic neuropathy in which these could not be found any other cause, but the hyperpneumatization of sphenoid sinus. We emphasize the role of cranial computer tomography in the diagnosis of this disease and the necessity to keep in mind this possible etiology of posterior optic neuropathy.

[Ultrasound examination methods in diagnostics of ischemic lesions of the eye]

One hundred and thirty-eight patients, aged 35 to 70, with acute ischemic neuroopticopathy (54 patients), occlusion of the central retinal artery (CRA--40 patients), chronic neuroopticopathy (21 patients) and chronic ischemic retinopathy (23 patients) underwent ultrasound examinations of the orbital artery (OA), CRA and internal carotid artery (ICA). A more pronouncedly impaired blood flow was registered in OA and CRA in cases of acute clinical forms of ischemic ocular lesions, i.e. a lack of blood circulation in CRA or a significantly diminished blood flow in it; a 2-fold decrease of the maximum systolic blood velocity; a 5-fold decrease of the terminal diastolic blood-flow velocity; and a 1.5 fold increase of the resistance index versus the normal value. Duplex scanning of the carotid arteries enables a timely diagnosis of a hemodynamically valuable ICA stenosis in different clinical forms of ischemic lesions of the eye.

[Estimation of ocular perfusion: a practical oriented comparison of different methods]

BACKGROUND

Ocular haemodynamics play a prominent part in many ocular diseases. This leads to the need to determine ocular perfusion. Several studies reveal advantages of colour Doppler imaging (CDI) in ophthalmologic diagnostics. Little is known about correlation of CDI results with other methods.

PATIENTS AND METHODS

N = 56 eyes were examined with CDI, laser Doppler flowmetry (LDF) and Langham-OBF (LOBF). Correlations between the methods were identified by the Spearman correlation coefficient (R).

RESULTS

LDF correlated with time average maximum (TAMx) and mean (TAMn) velocity assessed by CDI in the long posterior ciliary artery (TAMx: R = 0.466, p = 0.038, n = 20; TAMn: R = 0.462; p = 0.040, n = 20), but not in the short posterior ciliary artery. LOBF correlated with pulsatility index (PI) and resistive index (RI) of CDI in short (PI: R = 0.514, p = 0.002, n = 35; RI: R = 0.438, p = 0.008, n = 35) and long posterior ciliary arteries (PI: R = 0.436, p = 0.009, n = 35; RI: R = 0.506, p = 0.002, n = 35).

DISCUSSION

Methods strengthen each other by partial correlation. CDI allows a more detailed insight into ocular perfusion than the other methods.

Comparison between color duplex ultrasonography and histology of the temporal artery in cranial arteritis (giant cell arteritis)

BACKGROUND

Duplex sonography of the temporal artery may be helpful in the diagnosis of cranial arteritis.

PATIENTS AND METHODS

The superficial temporal arteries of 36 patients with cranial arteritis or suspected arteritis were examined using both duplex ultrasonography (US) and biopsy. The data of these patients were divided into two groups. Group A consisted of 24 patients (66.7%) with definite positive results using duplex (US) and Group B of 12 patients (33.3%) who showed a suspicious or negative ultrasonographic result.

RESULT

In all patients of Group A, the histological findings corresponded with the ultrasonographic changes in the inflamed artery. - The characteristic ultrasonographic sign was a dark halo around the lumen of the temporal arteries. There was a high correlation between a bilateral halo found by US with an ocular involvement. Ten out of 14 patients with a bilateral halo (71.4%) showed a distinct involvement of the optic nerve or retina. - The characteristic histological signs were infiltration of the vessel wall by inflammatory cells, mainly lymphocytes. Group B: The biopsies of the superficial temporal arteries were positive in 8 patients (66.7 %), negative in 4 other patients (33.3%).

CONCLUSION

Patients with a distinct halo, demonstrated by US, also showed corresponding pronounced inflammatory cell infiltration of the vessel wall. Patients with no ultrasonographic changes presented histological signs of initial inflammation such as isolated inflammatory cells around the vasa vasorum and/or in the adventitial layer.

[Carotid ultrasonographic and brain computerized tomographic findings in patients with vascular ocular syndromes]

To clarify the characteristics of cerebrovascular lesions in subtypes of vascular ocular syndrome, including amaurosis fugax(AF), retinal artery occlusion(RAO), and retinal vein occlusion(RVO), 93 patients with vascular ocular syndrome were studied by means of carotid ultrasonography(US) and brain computerized tomography(CT). The subjects comprised 21 patients with AF, 37 with RAO, and 35 with RVO who were sequentially given these diagnoses by the department of ophthalmology. On the basis of US findings, carotid lesions were defined as the presence of plaque or stenotic changes. CT findings were assessed for the presence and distribution of low-density areas(LDAs). Mean age was similar in each group, ranging from 64.5 to 67.4 years. The RAO group had high rates of men, hypertension, and smokers. US showed that the prevalence of carotid lesions ipsilateral to the affected eye was high in the RAO group and that severe stenosis and ulcerated plaque were present in 28.6% of the AF group and 45.9% of the RAO group. On CT examination, cerebral infarctions appeared as LDAs in about 10% of the patients in each group, and the incidence and distribution of LDAs were similar. Of 13 patients with cerebral infarction, only 2 were presumably due to carotid lesions; the others had a variety of causes. The discrepancy between US and CT findings was attributed to the small number of patients with cerebral infarction, since most patients had visual defects as an initial symptom. Our results suggest that extracranial carotid lesions, considered to be a major risk factor for stroke, should be carefully assessed in patients with AF or RAO to prevent further stroke.

Liposuction and ischemic optic neuropathy. Case report and review of literature

Ischemic optic neuropathy occurred in a patient following liposuction. Perioperative anemia and hypotension may be the cause of this complication. Correction of anemia with transfusion improved the hemoglobin and hematocrit but the right eye remained blind. Liposuction should be added to the list of the surgical procedures that may produce ischemic optic neuropathy as an isolated complication.

Standardized echography, pattern electroretinography and visual-evoked potential and automated perimetry in the early diagnosis of Graves' neuropathy

Twenty-four patients (47 eyes) affected by Graves' disease were enrolled to evaluate the role of standardized echography, pattern electroretinogram (P-ERG), visual evoked potentials (P-VEPs) and automated perimetry in the early diagnosis of the compressive optic neuropathy (CON). The P-ERG amplitude reduction was the most sensitive parameter to demonstrate an early impairment of the optic nerve (ON) function. We found a significant negative correlation between the ON diameter and the P-ERG amplitude. VEPs responses were also altered, but their ability in detecting an early ON damage was less sensitive and specific than P-ERG. The visual field damage was often aspecific and delayed with respect to electrophysiological alterations.

A case of optic neuropathy treated by percutaneous trans-coronary angiography

There are many risk factors involved in the development of ischemic optic neuropathy such as diabetes mellitus, hypertension, arteriosclerosis, and vascular incompetence. Therefore, the treatment of ischemic optic neuropathy should not be solely based on proper diagnosis but should also involve a thorough and systemic investigation to identify those multifactorial possibilities, which may contribute to the pathogenesis of the disease. We report upon a patient who developed non-arteritic ischemic optic neuropathy following treatment of a sphenoethmoid mucocele, which lead to recovered vision and a satisfactory improvement of visual field defects, after percutaneous trans-coronary angiography with stent insertion of the coronary arteries.

Bilateral simultaneous optic nerve dysfunction after periorbital trauma: recovery of vision in association with with chiropractic spinal manipulation therapy

OBJECTIVE

To discuss the recovery of optic nerve function after chiropractic spinal manipulation in a patient with loss of vision as a result of facial fracture from a fall.

CLINICAL FEATURES

In a fall down a stairwell, a 53-year-old woman with migraines fractured her right zygomatic arch, which was later treated surgically. Approximately 3 weeks after the accident, vision in her contralateral eye became reduced to light perception. Electrophysiologic studies revealed that the function of both optic nerves was diminished, the right significantly more than the left. Single photon emission tomography showed pancerebral ischemic foci.

INTERVENTION AND OUTCOME

Chiropractic spinal manipulation was used to aid recovery of vision to normal over a course of 20 treatment sessions. At times, significant improvement in vision occurred immediately after spinal manipulation. Progressive recovery of vision was monitored by serial visual field tests and by electrophysiologic studies. Unfortunately, the patient refused a further single photon emission tomographic study when visual recovery was complete.

CONCLUSION

This case report adds to previous accounts of progressive and expeditious recovery of optic nerve function in association with spinal manipulation therapy.

[Observation of the anterior ischemic optic neuropathy by color Doppler flow imaging]

OBJECTIVE

To study the characteristics of color Doppler flow imaging (CDFI) in anterior optic neuropathy (AION).

METHODS

Forty eyes of 25 patients clinically diagnosed to have progressive AION were studied by using CDFI. The peak systolic velocity (PSV), end-diastolic velocity (EDV), time averaged maximum velocity (TAMV) and resistance index (RI) of the central retinal artery (CRA), nasal and temporal posterior ciliary arteries (PCAs) and ophthalmic artery (OA) were detected. The diameter of retrobulbar optic nerve (ON) was detected at the same time. Thirty-four volunteers were served as the control group.

RESULTS

In the comparison with the control group, there were significantly reduced PSV, EDV and TAMV in PCAs (P < 0.001) and CRA (P < 0.001) and markedly increased RI in PCAs, CRA and OA in AION group. The retrobulbar optic nerve edema was found in 32/40 eyes.

CONCLUSIONS

The characteristics of reduced velocity and increased resistance index in retrobulbar arteries of the AION are demonstrated. CDFI is helpful to the diagnosis of AION.

The role of transcranial Doppler in nonarteritic ischemic optic neuropathy

PURPOSE

To investigate through the use of cerebral Doppler technology whether emboli are a more common cause of nonarteritic anterior ischemic optic neuropathy (NAION) than previously recognized.

METHODS

Eleven patients with a recent (<121 days) history of nonarteritic anterior ischemic optic neuropathy and 10 age-matched controls (event > 121 days) were examined using a Nicolet Pioneer 2020 transcranial Doppler (TCD) unit with a 2-MHz bilateral continuous monitoring capability. The right and left middle cerebral arteries were evaluated simultaneously for 30 minutes at a depth of 50 to 55 mm, and the number of emboli, blood flow velocities, and pulsatility indices were recorded. Data were stored by computer, and hard-copy color recordings were made.

RESULTS

None of 11 patients with a recent history of NAION demonstrated microemboli by TCD examination. One patient in the control group who had a remote history of NAION had a microembolic event rate of 12 per hour (six over 30 minutes). This patient had a history of prosthetic cardiac valve replacement and was taking anticoagulation medication at the time of the examination.

CONCLUSIONS

Our study did not reveal an increased incidence of embolic events in patients with NAION when they were examined in a transcranial Doppler study of the middle cerebral arteries. This study does not support embolism as a frequent cause of NAION.

[Color duplex of retrobulbar arteries in normal pressure and open angle glaucoma]

BACKGROUND

Various authors report that the glaucomatous loss of function is due to a chronic anterior ischemic optic neuropathy, being caused by a disturbed relationship between intraocular pressure and perfusion pressure in the posterior short ciliary arteries, which possibly leads to increased resistance in the ciliary vascular system. The authors attempt to test this hypothesis by measuring the vascular resistance (Resistance Index) in the ciliary vessel system by means of color Doppler sonography.

PATIENTS AND METHODS

35 eyes of 35 patients, suffering from open angle glaucoma (OAG), with a mean age of 65.3 years, were examined as well as 35 eyes of 35 patients with normal tension glaucoma (NTG), whose mean age was 65.8 years. Both glaucoma groups were compared to an age- and sex-matched control group of healthy volunteers. The color-Doppler measurements were performed with an Acuson 128 XP/10, which allows imaging of all retrobulbar arteries, the ophthalmic artery, the central retinal artery and the short posterior ciliary arteries, and also guarantees the precise calculation of blood flow velocity and resistive index (RI). The RI was statistically evaluated.

RESULTS

The resistance index of all retrobulbar arteries showed a statistically significant increase (p < 0.05) according to Wilcoxon's test in the OAG group as well as the NTG group.

CONCLUSIONS

Increased vascular resistance was found in all retrobulbar arteries in OAG and in NTG. These findings point out the pathognomonic importance of perfusion disturbance in glaucoma.

Diameter of the optic nerve in idiopathic optic neuritis and in anterior ischemic optic neuropathy

PURPOSE

There is considerable overlap in the clinical profile of patients with idiopathic optic neuritis (ON) and anterior ischemic optic neuropathy (AION). We tested the hypothesis that the retrobulbar diameter of the optic nerve may be a criterion for the differential diagnosis between ON and AION.

METHODS

The diameter of the optic nerve was measured by B-scan ultrasonography with the eye in an abducted position. Only patients with a unilateral optic neuropathy were included, 16 ON patients (mean age 24 years, 5 with and 11 without disc swelling) and 9 patients with AION (mean age 72 years). As controls for the ON patients 10 young normal subjects (mean age 25 years) and as controls for the AION patients 10 elderly subjects with eye problems not related to the optic nerve (mean age 76 years) were examined.

RESULTS

In the ON patients with disc swelling the diameter of the optic nerve was 5.4 +/- 0.5 mm in the affected and 3.0 +/- 0.3 mm in the unaffected side. This difference was significant (Wilcoxon-test, p = 0.043). In the ON patients without disc swelling the diameter of the optic nerve was 4.4 +/- 0.4 mm in the affected and 3.0 +/- 0.3 mm in the unaffected side. This difference was significant (Wilcoxon-test, p = 0.003). In the AION patients the diameter of the optic nerve was 3.0 +/- 0.3 mm on the affected and 2.8 +/- 0.4 mm on the unaffected side. This difference was not significant (Wilcoxon-test, p = 0.093). Comparing the optic nerves with ON and AION to those of the controls, the diameter was significantly enlarged in the nerves with ON and normal in the nerves with AION (one factor repeated ANOVA).

CONCLUSION

The diameter of the optic nerve is increased in ON without disc swelling and even more so in ON with disc swelling. The enlargement is probably due to edema of the nerve itself, not the surrounding subarachnoidal space. In AION, the diameter of the optic nerve is normal. Measuring the diameter of the optic nerve by B-scan ultrasonography is particularly useful in the differential diagnosis between ON with disc swelling and AION.

Graves ophthalmopathy: intracranial fat prolapse on CT images as an indicator of optic nerve compression

PURPOSE

To determine the usefulness of a number of imaging features in the differentiation of patients with Graves ophthalmopathy who had optic neuropathy from those who did not. Intracranial herniation of orbital fat through the superior ophthalmic fissure and its clinical importance was also assessed.

MATERIALS AND METHODS

The computed tomographic (CT) appearance of the orbital apex was examined in 50 patients without and in 50 patients with Graves ophthalmopathy. The clinical diagnosis of optic neuropathy was made by an ophthalmologist who was unaware of the imaging appearances and was based on clinical features and abnormalities of visual evoked potentials or changes at automated perimetry.

RESULTS

Intracranial fat prolapse (P < .001) and optic nerve crowding (P < .05) were the only imaging features that were independently related to optic neuropathy. The presence of intracranial fat prolapse or optic nerve crowding on CT scans helped identify 16 of 17 patients with optic neuropathy. Sensitivity was 94%, specificity was 91%, positive predictive value was 69%, and negative predictive value was 98%.

CONCLUSION

Intracranial fat prolapse correlates closely to the presence of optic neuropathy in Graves ophthalmopathy. This sign, in combination with optic nerve crowding, demonstrates a closer correlation to optic neuropathy than previously described imaging features.

Colour Doppler imaging in giant cell (temporal) arteritis: serial examination and comparison with non-arteritic anterior ischaemic optic neuropathy

The ophthalmological manifestations of giant cell arteritis (GCA) present a difficult diagnostic and management problem to the ophthalmologist. The orbital circulation is frequently involved in the disease process. The effects of GCA on orbital blood flow assessed by colour Doppler imaging (CDI) were investigated in this study. Serial CDI examinations of the orbital blood vessels were performed (at presentation, 2 days, 1 week and at 1 month) on 7 patients with GCA. CDI examination at presentation was also performed on 4 patients with non-arteritic anterior ischaemic optic neuropathy (AION) for comparison. Blood flow could not be detected in up to three arteries in the affected (ipsilateral) orbit of 6 GCA patients at presentation. Five of these patients were also found to have undetectable blood flow in the posterior ciliary arteries of the contralateral orbit. Serial CDI examination revealed blood flow alterations in arteritic patients despite treatment. Return of blood flow to normal was slow, and related to the clinical features. By contrast, only 1 of the patients with non-arteritic AION showed undetectable blood flow in a posterior ciliary artery. GCA leads to widespread and prolonged alterations in orbital blood flow. CDI allows the detection and monitoring of such alterations in orbital blood flow, which correlate with the clinical features of GCA. Serial CDI examinations in GCA may be used to aid management decisions.

[Assessment of vision disorders using color duplex ultrasonography]

Disturbed circulation is a common cause of visual impairment which time course and severity can vary. Prompt diagnosis and therapy are mandatory to restore visual function in cases of acute drop of vision. Color Doppler imaging is a noninvasive method to investigate blood-flow velocity. During the past years this method has been introduced into ophthalmology. For the first time it is possible to measure the blood-flow velocity in the ophthalmic artery, the central retinal artery and vein as well as the ciliary arteries to quantify the extent of impaired ocular circulation.