Clinicopathologic Correlations of Retinal Membranes Associated With Intravitreal 'Stem Cell' Injections.

The histologic findings of a subretinal band and epiretinal membrane (ERM) excised from two patients who developed retinal detachments (RDs) after non-U.S. Food and Drug Administration-regulated intravitreal "stem cell" injections are reported. Both membranes were composed of fibrocellular tissue that stained positively with Smooth Muscle Actin and Masson's trichrome, consistent with collagenous and smooth muscle composition. CD34 immunostain (for hematopoietic cells) was negative for the subretinal band and minimally positive for the ERM. The authors speculate that the "stem cells" may cause RDs by differentiation into myofibroblasts that cause tractional membranes, though further studies are warranted. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:125-131.].