Age-related macular degeneration (AMD) is a leading cause of vision loss in people over 50 years of age. It is related to damage to the macula, a region of light-sensing cells that provide central vision. The mechanism of AMD development is not well known, but there are two forms of the disorder, exudative and dry forms. The exudative form is treated with anti-vascular endothelial growth factor; however, there is no effective and approved treatment for the dry form.
Studies are ongoing that examine the effectiveness of bone marrow−derived autologous hematopoietic stem cell therapy for retinal diseases and tissue regeneration in general. Therefore, a group of scientists conducted a clinical study in patients with AMD who were aged 50 and over to determine the efficacy of bone marrow mononuclear fraction (BMMF) containing CD34+ cells for the treatment of AMD. They evaluated the baseline and post-treatment results of a number of ocular examinations including visual acuity, fluorescein angiography, infrared imaging, fundus autofluorescence, and microperimetry.
Bone marrow aspirates were obtained from the patients of the study, the aspirates were processed, and mononuclear cells were isolated. The percentage of CD34+ stem cells was determined by flow cytometry. The patients received autologous intravitreal injections of the BMMF containing CD34+ stem cells in the AMD-affected eye. The ocular examinations were performed at baseline and every three months after injection for 12 months.
The best-corrected visual acuity was found to improve after treatment, particularly in patients with smaller macular atrophy regions. Improvement in the microperimetry measurements, average threshold sensitivity (measures visual response to stimuli) and bivariate contour ellipse area (examines fixation stability), were improved after BMMF treatment. Infrared imaging and fundus autofluorescence did not reveal differences in the size of the atrophic areas, and fluorescein angiography did not demonstrate changes in perfusion or tumors after the treatment. Visual function and inflammation did not result from the treatment, suggesting that it is a safe procedure. Overall, these results show that autologous CD34+ stem cell treatment can improve visual acuity in patients with small areas of macular atrophy and serve as a foundation for additional larger clinical studies.
Cotrim, C., Toscano, L., Messias, A., Jorge, R., & Siqueira, R. (2017). Intravitreal use of bone marrow mononuclear fraction containing CD34<sup>+</sup> stem cells in patients with atrophic age-related macular degeneration. Clinical Ophthalmology, Volume 11, 931-938. doi:10.2147/opth.s133502