Retrobulbar and intraocular blood flow in anterior ischaemic optic neuropathy are linked to the functional impairment.

PURPOSE: Evaluation of ocular haemodynamics in patients with acute non-arteritic anterior ischaemic optic neuropathy (NAION) by colour Doppler imaging and fluorescein angiography and correlation of blood flow parameters to visual field loss and visual acuity. METHODS: Blood flow velocities (peak systolic velocity (PSV), end-diastolic velocity (EDV)) of the ophthalmic artery (OA), central retinal artery (CRA) and nasal and temporal posterior ciliary arteries (PCAs) were measured via colour Doppler imaging. Resistive index (RI) of all vessels was calculated (PSV-EDV/PSV). Retinal arteriovenous passage times (AVP) were evaluated using fluorescein angiography (scanning laser ophthalmoscope) and digital image analysis. The visual field global index mean deviation (MD, 30-2 programme, Humphrey Field Analyzer) and visual acuity (logMar) was used for analysis of functional impairment after NAION. RESULTS: Twenty patients (age: 64.62 ± 11.63 years) with acute NAION were included. Mean duration of symptoms was 7.6 ± 6.9 days. Mean defect was 15.4 ± 8.9 dB, AVP was determined with 1.66 ± 0.37 s. EDV of the CRA was significantly correlated to visual field MD (r = 0.52, p = 0.017) and AVP (r = - 0.49, p = 0.025). The RI of the OA was significantly correlated to visual acuity (r = 0.493, p < 0.037). No significant correlations were recorded for the PCAs. A significant correlation was found between AVP and the EDV of the CRA (r = - 0.49, p = 0.025). CONCLUSION: Decreased EDV in the CRA and increased RI in the OA seem to be linked to the functional damage in NAION. An improvement of the retrobulbar circulation might be beneficial in the treatment of NAION.

Arteriovenous passage times and visual field progression in normal tension glaucoma.

PURPOSE: Fluorescein angiographic studies revealed prolonged arteriovenous passage (AVP) times and increased fluorescein filling defects in normal tension glaucoma (NTG) compared to healthy controls. The purpose of this study was to correlate baseline AVP and fluorescein filling defects with visual field progression in patients with NTG. PATIENTS AND METHODS: Patients with a follow-up period of at least 3 years and at least 4 visual field examinations were included in this retrospective study. Fluorescein angiography was performed at baseline using a confocal scanning laser ophthalmoscope (SLO, Rodenstock Instr.); fluorescein filling defects and AVP were measured by digital image analysis and dye dilution curves (25 Hz). Visual field progression was evaluated using regression analysis of the MD (Humphrey-Zeiss, SITA-24-2, MD progression per year (dB/year)). 72 patients with NTG were included, 44 patients in study 1 (fluorescein filling defects) and 28 patients in study 2 (AVP). RESULTS: In study 1 (mean follow-up 6.6 ± 1.9 years, 10 ± 5 visual field tests), MD progression per year (-0.51 ± 0.59 dB/year) was significantly correlated to the age (P = 0.04, r = -0.29) but not to fluorescein filling defects, IOP, or MD at baseline. In study 2 (mean follow-up 6.6 ± 2.2 years, 10 ± 5 visual field tests), MD progression per year (-0.45 ± 0.51 dB/year) was significantly correlated to AVP (P = 0.03, r = 0.39) but not to age, IOP, or MD at baseline. CONCLUSION: Longer AVP times at baseline are correlated to visual field progression in NTG. Impaired retinal blood flow seems to be an important factor for glaucoma progression.

Ocular Hemodynamics in Acute Nonarteritic Anterior Ischemic Optic Neuropathy Compared With Normal Tension Glaucoma.

PURPOSE: The purpose of this study was to evaluate ocular hemodynamics in patients with a disease believed to be related to a chronic vascular damage [ie, normal tension glaucoma (NTG)] in comparison with an entity with an acute ischemic impact on the optic nerve [ie, acute nonarteritic anterior ischemic optic neuropathy (NAION)]. MATERIALS AND METHODS: Blood-flow velocities [peak systolic velocity (PSV), enddiastolic velocity (EDV)] of the ophthalmic artery (OA), central retinal artery (CRA), and nasal and temporal posterior ciliary arteries were measured using color Doppler imaging. Resistive index (RI) of all vessels was calculated (PSV-EDV/PSV). A total of 41 patients suffering from acute NAION (onset of symptoms <10 d) and 64 age-matched patients suffering from NTG were included in this prospective study. RESULTS: No significant differences were recorded for either age or intraocular pressure inbetween the 2 groups. Systolic blood pressure was significantly higher in the NAION group, whereas no significant differences were recorded for the diastolic blood pressure. Only 3 color Doppler imaging parameters were found to differ significantly. The PSV (P<0.005) and EDV (P<0.02) in the CRA were significantly higher in NTG patients. Furthermore, the RI in the OA was significantly higher in the NAION patients (P<0.005). CONCLUSIONS: Decreased blood-flow velocities in the CRA and a higher RI in the OA can be recorded in NAION patients as compared with NTG. No differences with regard to the posterior ciliary arteries' velocities were recorded. Ocular hemodynamics are suspected to play a critical role in NAION and NTG, whereas the blood-flow disturbances seem to be more severe in NAION than in NTG.

Acute Effect of Hypervolemic Hemodilution on Retrobulbar Hemodynamics in Anterior Ischemic Optic Neuropathy.

PURPOSE: Ischemic ocular disorders may be treated by hypervolemic hemodilution. The presumed therapeutic benefit is based on a volume effect and improved rheological factors. The aim was to investigate the acute effect of intravenous hydroxyethyl starch on retrobulbar hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy (NAION). METHODS: 24 patients with acute NAION were included. Retrobulbar hemodynamics were measured using color Doppler imaging before and 15 min after intravenous infusion of 250 cc 10% hydroxyethyl starch (HES). Peak systolic velocity (PSV), end diastolic velocity (EDV), and Pourcelot's resistive index (RI) were measured in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (PCAs). RESULTS: After infusion of HES blood flow velocities significantly increased in the CRA (PSV from 7.53 ± 2.33 to 8.32 ± 2.51 (p < 0.001); EDV from 2.16 ± 0.56 to 2.34 ± 0.55 (p < 0.05)) and in the PCAs (PSV from 7.18 ± 1.62 to 7.56 ± 1.55 (p < 0.01); EDV from 2.48 ± 0.55 to 2.66 ± 0.6 cm/sec (p < 0.01)). The RI of all retrobulbar vessels remained unaffected. Blood pressure and heart rate remained unchanged. CONCLUSIONS: Hypervolemic hemodilution has an acute effect on blood flow velocities in the CRA and PCAs in NAION patients. Increased blood flow in the arteries supplying the optic nerve head may lead to a better perfusion in NAION patients. This trial is registered with DRKS00012603.

Microangiopathy and mild mixed neuromyopathic alterations in a patient with homozygous PIEZO-2 mutation.

We report a 9-year-old girl homozygous for a loss-of-function mutation in the PIEZO-2 gene. She showed generalized muscular hypotonia with severe scoliosis, joint deformities, deficient proprioceptive function and selective atrophy and signal alterations of both gastrocnemii on whole body MRI scan. Light microscopic and ultrastructural examination showed few atrophic fibres, abnormal mitochondria, focal myofibrillar disruption and endomysial capillary microangiopathy.

Retrobulbar blood flow and visual field alterations after acute ethanol ingestion.

BACKGROUND: The purpose of this study was to test the effect of ethyl alcohol on the koniocellular and magnocellular pathway of visual function and to investigate the relationship between such visual field changes and retrobulbar blood flow in healthy subjects. METHODS: In 12 healthy subjects (mean age 32 ± 4 years), color Doppler imaging, short-wavelength automated perimetry, and frequency doubling perimetry was performed before and 60 minutes after oral intake of 80 mL of 40 vol% ethanol. Mean and pattern standard deviations for short-wavelength automated and frequency doubling perimetry were assessed. End diastolic velocity (EDV) and peak systolic velocity (PSV) were measured in the central retinal and ophthalmic arteries using color Doppler imaging. Systemic blood pressure, heart rate, intraocular pressure, and blood alcohol concentration were determined. RESULTS: Mean PSV and EDV in the central retinal artery showed a significant increase after alcohol intake (P = 0.03 and P = 0.02, respectively). Similarly, we found a significant acceleration of blood flow velocity in the ophthalmic artery (P = 0.02 for PSV; P = 0.04 for EDV). Mean intraocular pressure decreased by 1.0 mmHg after alcohol ingestion (P = 0.01). Retinal sensitivity in short-wavelength automated perimetry did not alter, whereas in frequency doubling perimetry, the mean deviation decreased significantly. Systolic and diastolic blood pressure did not change significantly. Mean blood alcohol concentration was 0.38 ± 0.16 g/L. CONCLUSION: Although ethanol is known to cause peripheral vasodilation, our subjects had no significant drop in systemic blood pressure. However, a significant increase of blood flow velocity was seen in the retrobulbar vessels. Regarding visual function, moderate alcohol consumption led to reduced performance in the magnocellular visual system tested by frequency doubling perimetry, but had no effect on short-wavelength automated perimetry.

Optic disc fluorescein leakage and intraocular pressure in primary open-angle glaucoma.

PURPOSE: To investigate the relationship between increased fluorescein leakage of the optic nerve head and intraocular pressure (IOP), visual field defect, vertical cup-to-disc ratio, disc size and systemic blood pressure in primary open-angle glaucoma (POAG). METHODS: Twenty-seven patients with POAG (aged 63 ± 11 years) and 15 control subjects (aged 58 ± 9 years, p = 0.14) were included in a pilot study. Fluorescein angiography was performed using a Scanning Laser Ophthalmoscope (Rodenstock Instruments, Germany). Fluorescein leakage of the optic disc was quantified using digital image analysis. The change of optic disc fluorescence from 7-8 min to 9-10 min was calculated and correlated to IOP, visual field mean deviation (MD), vertical cup-to-disc ratio, disc size, mean arterial blood pressure (MAP) and ocular perfusion pressure. RESULTS: The change in optic disc fluorescein leakage was significantly increased in patients with POAG compared to control subjects (POAG: 9.7 ± 6.7%; controls: 3.4 ± 4.9%, p = 0.0025). In POAG, fluorescein leakage was significantly correlated to IOP (r = 0.42, p = 0.029), but not to MD (r = -0.13, p = 0.51), vertical cup-to-disc ratio (r = 0.11, p = 0.60) disc size (r = -0.22, p = 0.30), MAP (r = -0.16, p = 0.42) or ocular perfusion pressure (r = -0.32, p = 0.10). In control subjects, a significant correlation was found with vertical cup-to-disc ratios (r = 0.59, p = 0.034), but not to IOP (r = -0.07, p = 0.80), MD (r = -0.26, p = 0.42), disc size (r = -0.10, p = 0.76), MAP (r = 0.09, p = 0.77), or ocular perfusion pressure (r = 0.11, p = 0.72). CONCLUSION: Increased fluorescein leakage of the optic disc was associated with higher IOP levels in patients with POAG. This might reflect a link between vascular damage with increased permeability and uncontrolled IOP.