LDL-apheresis in Acute Anterior Ischemic Optic Neuropathy

Heparin-Mediated Extracorporeal Low-Density Lipoprotein Precipitation Apheresis for Treating Peripheral Arterial Disease in Patients with Chronic Kidney Disease

Patients with chronic kidney disease (CKD), particularly those with end-stage renal disease (ESRD), have a high prevalence of cardiovascular disease and peripheral arterial disease (PAD). Medical treatment is mainly based on risk factor management, and the surgical approach remains the gold standard treatment in specific conditions. Heparin-mediated extracorporeal low-density lipoprotein precipitation (H.E.L.P.) apheresis is effective in reducing circulating lipoprotein, fibrinogen, inflammatory mediators and procoagulant factors, thereby reducing cardiovascular risk in patients with familial hypercholesterolemia and hypertriglyceridemia. These activities may be effective in reducing symptoms and ischemic vascular lesions even in patients with severe PAD. We reported the application of a treatment protocol with H.E.L.P. apheresis in an ESRD patient with severe PAD without clinical improvement after severe revascularization who was not suitable for further surgical approaches, despite normal LDL cholesterol and lipoprotein (a). The H.E.L.P. protocol was characterized by an intensive first phase with weekly treatments followed by a single session every 10-15 days for 6 months of treatment. The overall clinical condition, foot lesions and walking distance improved significantly after the first 2 months of treatment, and foot amputation was avoided. Here, we review the main pathogenetic mechanisms through which LDL apheresis improves microcirculation and clinical outcomes. Its wider application may represent an optimal therapeutic option for patients unresponsive to standard treatment.

Quantification of peripapillary vessel density in non-arteritic anterior ischemic optic neuropathy patients with optical coherence tomography angiography

BACKGROUND

Quantitative assessments based on optical coherence tomographic angiography (OCTA) may have potential promising value in the early detection of non-arteritic anterior ischemic optic neuropathy (NA-AION), but there is limited information on the ability of OCTA to distinguish eyes with NA-AION. This study was conducted to evaluate the ability of measurements of peripapillary perfusion using OCTA to distinguish healthy eyes from eyes with NA-AION.

METHODS

In this retrospective case-control study, newly diagnosed NA-AION patients and healthy controls matched at a ratio of 1:3 by gender and age (±5 years) were enrolled from 1 September 2020 to 30 June 2021. Peripapillary vessel density (pVD) was examined based on the area of vessels by means of a 4.5 mm OCTA scan. In addition, peripapillary retinal nerve fiber layer (pRNFL) thickness was obtained from structural optical coherence tomography (OCT), as was the area under the receiver operating characteristic (ROC) curve (AUC).

RESULTS

A total of 29 eyes from 28 cases with NA-AION and 99 healthy eyes from 68 participants were imaged. All participants were Chinese. The NA-AION group showed a significant reduction of the pVD (P<0.001), while all subregions of pRNFL thickness were prominent in all 8 quadrants (P>0.05). The pVD of the optic disc in the superior temporal (ST) region showed better diagnostic accuracy (AUC =0.86) in discriminating the NA-AION group from healthy controls. After adjusting for confounders, ST was independently associated with the presence of NA-AION [odds ratio (OR) =0.971, 95% confidence interval (CI): 0.943-0.990, P=0.048].

CONCLUSIONS

Decreased pVD was detected by non-invasive measurements of OCTA in the eyes of NA-AION patients. This finding may reveal an association between the ST region and the presence of NA-AION. The pVD may have potential diagnostic ability and may serve as an additional biomarker in the management of the disease.

New Treatments for Nonarteritic Anterior Ischemic Optic Neuropathy

Despite increasing knowledge about the risk factors and clinical findings of nonarteritic anterior ischemic optic neuropathy (NAION), the treatment of this optic neuropathy has remained limited and without clear evidence-based benefit. Historical treatments of NAION are reviewed, beginning with the Ischemic Optic Neuropathy Decompression Trial. More recent treatments are placed within the historical context and illustrate the need for evidence-based therapy for ischemic optic neuropathy.

Therapeutic apheresis in peripheral and retinal circulatory disorders

In microcirculation disorders, the therapeutic apheresis seems to have two different effects. The first, achieved after only a few sessions, is acute, consisting of drastic reduction of blood viscosity and obtained with the use of low-density lipoprotein (LDL) apheresis, rheopheresis, or fibrinogen apheresis. The second effect is long term, or chronic, and needs to be evaluated after a long course of treatment. The mechanisms underlying the chronic effect are still objects of debate and take into account the pleiotropic effects of apheresis. However, it is likely that the acute effect of apheresis mainly influences the functional components of the vascular damage, and so the derived rheological benefit might last only for a short period. The chronic effect, on the contrary, by acting on the morphological alterations of the vascular walls, requires the apheresis treatment to be prolonged for a longer period or even cycles of treatment to be programmed.

LDL apheresis in the treatment of non-arteritic ischaemic optic neuropathy: a 6-month follow-up study

PURPOSE

Verify the recovery of visual capacity after the administration of a combination of LDL apheresis (LA) and conventional therapy (CT). Design, prospective and interventional case series.

METHODS

20 patients affected by NAION were randomly subdivided into two groups of 10 patients (Group 1 and Group 2). Group 1 underwent three sessions of LA associated with CT, whereas group 2 received only CT. At discharge and at the 6 months follow-up visit, assessment in both groups was made of the best corrected visual acuity (BCVA) and the computerised visual field (CVF), comparing the findings with those at admission in each patient.

RESULTS

Only the mean deviation (MD) at CVF was statistically improved in group 1 as compared with group 2 at discharge, judged against the values at admission (-11.08+/-6.51 vs -16.53+/-10.03, P=0.039; -17+/-5.24 vs -14.14+/-9.42, respectively). However, this increase was not confirmed at 6 months (-16.83+/- -10.72, group 1; -13.56+/-3.60 group 2).

CONCLUSION

In NAION, LA induced a short term improvement in the MD, but by 6 months this had disappeared.

Is the Efficacy of LDL Apheresis in Ischemic Optic Neuropathy Linked to a Reduction in Endothelial Activation Markers?

Endothelial dysfunction of the optic microcirculation is considered to be the main pathogenetic mechanism in nonarteritic ischemic optic neuropathy. The aim of the present work was to assess whether a clinical improvement is correlated with a reduction in the endothelial activation markers by means of LDL apheresis (LDLA). Three weekly sessions of LDLA were administered in 23 patients affected by nonarteritic ischemic optic neuropathy. Statistically significant reductions were achieved in all parameters: total cholesterol (44.6%), LDL cholesterol (54.6%), fibrinogen (60.9%), von Willebrand factor (38.6%), sE-Selectin (22.6%), sICAM-1 (14%) and sVCAM-1 (15.5%), each of which was correlated with an improvement in the mean deviation of the visual field, although statistical significance for the single parameters was not reached. However, analysis of variance between the mean deviation improvement and the set of parameters taken together yielded highly significant results (p < 0.0001). LDLA was effective in reducing the values of all evaluated endothelial activation markers, and this trend was correlated with an improvement in the visual field.

LDL-apheresis therapy

Low-density lipoprotein (LDL)-apheresis is an effective means for acutely lowering plasma cholesterol (LDL reduction > 60%) and reducing cardiovascular events in patients with uncontrolled hypercholesterolemia who are genetically predisposed or resistant to standard therapy. Despite its known benefit, apheresis is performed in only a minority of qualified patients. In addition to reducing plasma cholesterol, apheresis can alter other markers of vascular disease (inflammation, rheology, thrombosis, and fibrinolysis). The acute and chronic changes to the vascular system may warrant LDL-apheresis use in other diseases.

LDL-Apheresis Accelerates the Recovery of Nonarteritic Acute Anterior Ischemic Optic Neuropathy

Nonarteritic acute anterior ischemic optic neuropathy (NAION) is a disabling disease which impairs visual function. It is presumed to result from disturbances of microcirculation in the anterior portion of the optic nerve head due to hemodynamic factors derived from excessive blood viscosity, or restriction of the vasal lumen in hypertensive, hypercholesterolemic, diabetic patients. We aimed to determine whether acute reduction of plasma fibrinogen and serum low-density lipoprotein (LDL) cholesterol is effective for treatment of NAION. We recruited 11 patients (7 females, 4 males) with a mean age of 57.2 +/- 19.6 years. All except one of them presented risk factors for atherosclerosis. The mean values of LDL-cholesterol and fibrinogen before treatment were 144 +/- 32 mg/dL and 341 +/- 80 mg/dL, respectively. All were treated with standard therapy (prednisone, salicylate, pentoxiphyllin) and underwent three sessions of LDL-apheresis (HELP system-B Braun) that can reduce plasma LDL-cholesterol and fibrinogen by more than 50% in a very short time. In all patients we observed a drastic reduction of LDL cholesterol and fibrinogen and a clear improvement in the visual functional data. In fact, mean values of corrected vision increased from 3.7/10 +/- 3/10 to 7.9/10 +/- 2.2/10 (P = 0.002) after the third session, while the scotomatous portion of the visual field regressed after the first session, and in 5 patients further regressed after the third session. This improvement had remained stable after 3 months. Thanks to it's effect of antagonizing hemorheologic disorders of the ocular microcirculation, fibrinogen/LDL-apheresis seems to be an efficacious treatment of NAION.