Intravitreal use of bone marrow mononuclear fraction containing CD34+ stem cells in patients with atrophic age-related macular degeneration

Purpose: To evaluate the therapeutic potential and safety of intravitreal injections of bone marrow mononuclear fraction (BMMF) containing CD34(+) cells in patients with atrophic age-related macular degeneration (AMD). Methods: Ten patients with atrophic AMD and best-corrected visual acuity (BCVA) in the worse-seeing eye of <= 20/100 were enrolled in this study. The bone marrow from all patients was aspirated and processed for mononuclear cell separation. A 0.1 mL suspension of BMMF CD34(+) cells was injected into the vitreous cavity of the worse-seeing eye. Patients were evaluated at Baseline and 1,3,6,9 and 12 months after injection. Ophthalmic evaluation included BCVA measurement, microperimetry, infrared imaging, fundus autofluorescence and SD-optical coherence tomography at all study visits. Fluorescein angiography was performed at Baseline and at 6 and 12 months after intravitreal therapy. Results: All patients completed the 6-month follow-up, and six completed the 12-month follow-up. Prior to the injection, mean BCVA was 1.18 logMAR (20/320(-1)), ranging from 20/125 to 20/640(-2), and improved significantly at every follow-up visit, including the 12-month one, when BCVA was 1.0 logMAR (20/200) (P<0.05). Mean sensitivity threshold also improved significantly at 6, 9 and 12 months after treatment (P<0.05). Considering the area of atrophy identified by fundus autofluorescence, significant mean BCVA and mean sensitivity threshold improvement were observed in patients with the smallest areas of atrophy. Fluorescein angiography did not identify choroidal new vessels or tumor growth. Conclusion: The use of intravitreal BMMF injections in patients with AMD is safe and is associated with significant improvement in BCVA and macular sensitivity threshold. Patients with small areas of atrophy have a better response. The paracrine effect of CD34(+) cells may explain the functional improvement observed; however, larger series of patients are necessary to confirm these preliminary findings.