11-cis-retinal and Vitreoretinopathy--Proliferative

Role of intravitreal injection of dexamethasone implant (Ozurdex) for refractory macular thickening.. A case report of a 13-year-old boy with Rhodopsin-positive, CRB1-negative retinitis pigmentosa presenting with Coat's-like exudative vitreoretinopathy and treatment-resistant cystoid macular oedema.. A reduction in the macular thickening following a single injection of Ozurdex.. We present our experience in successful treatment of refractory macular oedema with intravitreal injection of dexamethasone implant resulting in clinically significant resolution of macular thickening.

Topics: Adolescent; Anti-Inflammatory Agents; Dexamethasone; Drug Implants; Exudates and Transudates; Humans; Intravitreal Injections; Macular Edema; Male; Retinitis Pigmentosa; Rhodopsin; Treatment Outcome; Vitreoretinopathy, Proliferative

There is some in vitro evidence that the adult ciliary body might harbor an inactive population of stem/retinal progenitor cells (RPC), or that ciliary epithelial (CE) cells might have the capacity to trans-differentiate, which may result in a balance between neural and epithelial properties. We have reported alterations in the ciliary body (CB) and adjacent vitreous in vivo by endoscopic evaluation of human eyes with a history of retinal detachment (RD) and anterior proliferative vitreoretinopathy (PVR).. The present study examined with light microscopy three paraffin-embedded phthisic human eyes with RD and anterior PVR. One normal eye, exenterated for an orbital tumor, served as the control. All specimens were stained with hematoxilin and eosin safran (HES), and serial sections were immunostained with antibodies against EGFR, Ki67, CD133, NSE, rhodopsin, and GFAP.. We observed: (1) an intense proliferation and displacement of clusters of CE cells into the vitreous base in a "neurosphere-like" fashion; (2) differentiation of CE cells towards early and late neuronal [photoreceptor (PR)] lineages; and (3) strong staining of EGF and EGFR in the CE. Such proliferation, migration, and differentiation were not present in the CE of the control eye. GFAP staining was intensely positive in the three detached retinae, and was negative in the CE of eyes with RD, as well as in the retina of the control eye.. Our observations suggest that EGFR-positive CE cells in the adult human eye in vivo with RD and PVR form "neurosphere-like" structures; their differentiation seems to be directed towards the neural and photoreceptor lineage, and not towards glial formation. In the adult human eye, the CE in a pathological retinal environment such as RD might provide a spontaneous source of donor cells for retinal transplantation.

Topics: AC133 Antigen; Adult; Antigens, CD; Cell Differentiation; Cell Movement; Cell Proliferation; Ciliary Body; ErbB Receptors; Female; Glial Fibrillary Acidic Protein; Glycoproteins; Humans; Immunoenzyme Techniques; Ki-67 Antigen; Male; Middle Aged; Paraffin Embedding; Peptides; Phosphopyruvate Hydratase; Photoreceptor Cells, Vertebrate; Pigment Epithelium of Eye; Retinal Detachment; Retinal Neurons; Rhodopsin; Vitreoretinopathy, Proliferative

In addition to the ability for self-renewal and functional differentiation, neural stem/progenitor cells (NSCs) can respond to CNS injuries by targeted migration. In lower vertebrates, retinal injury is known to activate NSCs in the ciliary marginal zone (CMZ). Cells expressing markers of NSCs are also present in the ciliary body epithelium (CE) and in Müller glia in the peripheral retina (PR) of the adult human eye. However, these cells seem to be quiescent in the adult human eye and recent reports have shown that CE cells have limited properties of NSCs. In order to further clarify whether NSCs exist in the adult human eye, we tested whether NSC-like cells could be activated in eyes with proliferative vitreoretinopathy (PVR). The PR and CE were studied for NSC-associated markers in human enucleated control eyes and eyes with confirmed PVR, as well as in a mouse model of PVR. Furthermore, cells isolated from vitreous samples obtained during vitrectomies for retinal detachment were directly fixed or cultured in a stem cell-promoting medium and compared to cells cultured from the post-mortem retina and CE. In situ characterization of the normal eyes revealed robust expression of markers present in NSCs (Nestin, Sox2, Pax6) only around peripheral cysts of the proximal pars plana region and the PR, the latter population also staining for the glial marker GFAP. Although there were higher numbers of dividing cells in the CE of PVR eyes than in controls, we did not detect NSC-associated markers in the CE except around the proximal pars plana cysts. In the mice PVR eyes, Nestin activation was also found in the CE. In human PVR eyes, proliferation of both non-glial and glial cells co-staining NSC-associated markers was evident around the ora serrata region. Spheres formed in 7/10 vitreous samples from patients with PVR compared to 2/15 samples from patients with no known PVR, and expressed glial - and NSC-associated markers both after direct fixation and repetitive passages. In conclusion, the adult human eye may harbor two different populations of neuroepithelial stem/progenitor cells; a non-glial population located in the proximal pars plana around peripheral cysts in addition to a population with Müller glia characteristics. Yet, we only found that the glial population was able to respond to retinal injury by targeted migration into the vitreous.

Topics: Adolescent; Adult; Aged, 80 and over; Animals; Biomarkers; Cadherins; Ciliary Body; Disease Models, Animal; Eye Proteins; Female; Fluorescent Antibody Technique, Indirect; Glial Fibrillary Acidic Protein; Homeodomain Proteins; Humans; Intermediate Filament Proteins; Male; Mice; Mice, Inbred C57BL; Middle Aged; Nerve Tissue Proteins; Nestin; Paired Box Transcription Factors; PAX6 Transcription Factor; Pigment Epithelium of Eye; Real-Time Polymerase Chain Reaction; Repressor Proteins; Retinal Detachment; Retinal Neurons; Rhodopsin; SOXB1 Transcription Factors; Stem Cells; Vitreoretinopathy, Proliferative; Vitreous Body