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Recent evidence supports the idea that AMD may arise from mechanisms associated with poor blood flow in retinal blood vessels. In addition, new studies have shown that AMD progression may be related to the presence of elevated blood levels of certain vascular risk factors. Rheopheresis reduces these substances in the blood to promote an improvement in blood flow and vascular function in the retina and elsewhere.

The Procedure

Rheopheresis is similar to blood donation. Patients are awake as they recline in a comfortable chair. An IV line is placed in each forearm and connected to the apheresis blood pump with a sterile tube. During the procedure, only about a pint of blood is outside the body at any time. As the patient’s whole blood is withdrawn, it is directed to the cell separator, which divides the whole blood into its cellular and plasma components. The cells are sent to a warming chamber while the plasma portion is pumped to the plasma component separator. This separator collects the high molecular weight compounds as the plasma flows through the filter. The filtered plasma is then reunited with the warmed cells and the reconstituted whole blood is returned into the patient. The procedure takes approximately 2 to 3 hours. Other than a drug to prevent coagulation (clotting), no medications are required.

The Clinical Experience

German ophthalmologists at the University of Cologne accidentally discovered the use of Rheopheresis for the treatment of AMD nearly a decade ago. Since then, numerous studies have been conducted; all of which have demonstrated the potential utility of the treatment for select patients with the disease. In 1999 the results of the German study "MAC-1" were reported (Retina Vol. 20 No.5-2000; 483-91).

In the US, a pilot study of the Rheopheresis MDF system was conducted at the University of Utah in 1998. This prospective, randomized, double-masked, 3-arm clinical trial compared the safety and efficacy of MDF treatment compared to sham apheresis (the patient’s blood was circulated through the system, but without filters) and No-treatment Controls.

The study randomized 30 patients into 3 groups of 10 patients each. Rheopheresis-treated patients showed more improvement in their vision, as well as greater improvement in functional vision tests than the patients in either of the other 2 groups. 30% of all Rheopheresis-treated eyes improved by 3 or more lines as compared to 15% of the sham-treated eyes and 5% of the No-treatment eyes. The only patients who showed improvement in three out of four of the study parameters, vision in both eyes, reading speed and perceived visual function, were the Rheopheresis-treated patients.

During the pilot study over 84,000 lab values were collected and analyzed. Of significance, elevated levels of 4 blood proteins (total cholesterol, HDL cholesterol, IgA and fibrinogen) were positively correlated with both the probability of vision improvement as well as the degree of vision improvement using Rheopheresis treatment.

Safety

The clinical risks of Rheopheresis are similar to those occurring during blood donation and occur in about 2% to 4% of treatments. They are typically minor and transient - occurring only during the procedure itself and are easily treated. They include: fainting, nausea, slow heart rate, flushing, pain or numbness at the IV site, chills, vomiting, tiredness, hypothermia, fatigue and dizziness. Other than some bruising and minor swelling at the IV site, no long-term or significant post-treatment, procedure-related adverse events have been reported.

Conclusion
Rheopheresis is not an approved therapy in the U.S. but is available in Canada and Germany.