Generation of Retinal Pigmented Epithelium-Like Cells from Pigmented Spheres Differentiated from Bone Marrow Stromal Cell-Derived Neurospheres

BACKGROUND: Retinal degeneration causes blindness, and cell replacement is a potential therapy. The purpose of this study is to formation of pigmented neurospheres in a simple medium, low-cost, high-performance manner over a short period of time while expressing markers of RPE cells and the activation of specific genes of the pigment cells. Also, these neurospheres have the ability to produce a monolayer of retinal pigment epithelium-like cells (RPELC) with the ability of photoreceptor outer segment phagocytosis. METHODS: BMSC were isolated from pigmented hooded male rats and were immunoreactive to BMSC markers, then converted into neurospheres, differentiated into pigmented spheres (PS), and characterized using Retinal pigment epithelium-specific 65 kDa protein (RPE65), Retinaldehyde-binding protein 1 (CRALBP) and orthodenticle homeobox 2 (OTX2) markers by immunocytochemistry, RT-PCR and RT-qPCR. The PS were harvested into RPELC. The functionality of RPELC was evaluated by phagocytosis of fluorescein-labeled photoreceptor outer segment. RESULTS: The BMSC immunophenotype was confirmed by immunostained for fibronectin, CD90, CD166 and CD44. These cells differentiated into osteogenic and lipogenic cells. The generated neurospheres were immunoreactive to nestin and stemness genes. The PS after 7–14 days were positive for RPE65 (92.76–100%), CRALBP (95.21–100%) and OTX2 (94.88–100%), and after 30 days RT-PCR, qPCR revealed increasing in gene expression. The PS formed a single layer of RPELC after cultivation and phagocyte photoreceptor outer segments. CONCLUSION: Bone marrow stromal stem cells can differentiate into functional retinal pigmented epithelium cells in a simple, low-cost, high-performancemanner over a short period of time. These cells due to expressing theRPELCgenes andmarkers can be used in cell replacement therapy for degenerative diseases including age-relatedmacular degeneration as well as retinitis pigmentosa.

Characteristics and surgical outcomes of rhegmatogenous retinal detachment following myopic LASIK

To describe the clinical features and surgical outcomes of rhegmatogenous retinal detachment [RRD] following myopic laser in situ keratomileusis [LASIK]. In a retrospective, non-comparative case series, 46 eyes that had undergone vitreoretinal surgery for management of RRD following myopic LASIK were identified. Data was reviewed with emphasis on characteristics of the RRD, employed surgical techniques, and anatomic and visual outcomes. Mean pre-LASIK myopia was -9.7 +/- 3.9 [range -4.00 to -18.00] diopters [D]. Mean interval between LASIK and development of RRD was 11.6 +/- 11.2 months. Posterior vitreous detachment was present in 44 eyes [95.6%]. The retinal breaks included flap tears in 36 [78.3%] eyes, giant tears in 8 [17.4%] eyes and atrophic holes in 2 [4.3%] eyes. In eyes with flap tears, the breaks were multiple, large or posterior to the equator in 24 [66.7%] eyes. Retinal breaks were related to lattice degeneration in 20 [43.5%] eyes of which, three had history of prophylactic barrier laser photocoagulation. Scleral buckling was performed as the initial procedure in 32 [69.6%] eyes and primary vitrectomy was undertaken in 14 [30.4%] eyes. The initial surgical procedure failed in 14 [30.4%] eyes due to proliferative vitreoretinopathy [PVR]. Retinal reattachment was finally achieved in 43 [93.4%] eyes. Postoperative visual acuity >/= 20/40 and >/= 20/200 was achieved in 16 [34.8%] and 25 [54.3%] eyes, respectively. Post-LASIK retinal detachment has a complex nature in eyes with moderate to high myopia. The retinal detachment is complex in terms of size, number and location of retinal breaks, is associated with a high rate of PVR and entails unfavorable visual outcomes