The potential of stem cell-based therapy for retinal repair

Like injured neurons in the brain or spinal cord, neurons in the retina are incapable to regenerate following injury and ultimately would lead to irreversible neuronal loss and vision impairment. Over decades, extensive effort has been made to develop strategies to protect retinal neurons from death; however, the outcome is limited （Pettmann and Henderson, 1998; Bahr, 2000; Lagali and Picketts, 2011）. Replacing the degenerated retinal neurons by newly generated and functional neurons would be an ideal scenario. The rapid development of stem cell biology has recently demonstrated that stem cells could be a potential source of cells for cell replace- ment therapy because these cells have the self-renewal capacity and could be differentiated into many cell types. This review will dis- cuss the therapeutic potential of stem cell-based therapy to retinal degenerative diseases.

Improvement of Optical Reactivity for Nano-TiO2 Film by Nitrogen ECR Plasma

Nitrogen ion was implanted into the nano-TiO2 film surfaces by electron cyclotron resonance （ECR） plasma modification to improve the optical reactivity in visible-light region for nano-TiO2. Diagnosing the N2 plasma by optical emission spectroscopy （OES） was applied to the process of plasma modification. X-ray photoelectron spectroscopy （XPS） was used for analysis of the binding of element after plasma modification. It is shown that the surface modification was caused by excitated N. The injecting of N2 and N＋ leads to the increase in the dissociative interstitial state N in the films. The doped N makes for TiO2-xNx appearing in the TiO2 films. TiO2-xNx forms the impurity energy state in the TiO2 energy band gap and reduces the energy band gap. This is the main reason leading to the red shift of absorption edge.

Comparison of Ex‑PRESS implantation versus trabeculectomy combined with phacoemulsification in primary open‑angle glaucoma:a retrospective in vivo confocal microscopy study

Background:To compare the efficacy of Ex-PRESS implantation versus trabeculectomy combined with phacoemulsification.Methods:A retrospective 12-month study on patients with coincident primary open-angle glaucoma(POAG)and cataract.The patients underwent combined phacoemulsification and Ex-PRESS implant(Phaco-ExPRESS,n=35)or phacotrabeculectomy(Phaco-Trab,n=35).The morphological structures of the filtering bleb were examined by slitlamp,anterior segment optical coherence tomography(AS-OCT)and in vivo confocal microscopy(IVCM).Complete success was defined as postoperative intraocular pressure(IOP)<18 mmHg without the use of anti-glaucoma medication.Qualified success was defined as postoperative IOP<18 mmHg with or without anti-glaucoma medications.The data were collected preoperatively and postoperatively at 2 weeks,1 month,3 months,6 months,and 12 months.Results:No significant difference in the variables such as age,IOP and perimetry was found between the groups of Phaco-ExPRESS and Phaco-Trab.At the one-year postoperative visit for filtering blebs,Phaco-ExPRESS increased the mean area of epithelial microcysts significantly from 0.10±0.05 to 0.20±0.09μm^(2)perμm^(2),while Phaco-Trab decreased the mean area significantly from 0.08±0.04 to 0.04±0.06μm^(2)perμm^(2).Notably,the hyperreflective dots detected by IVCM decreased by 84.9%in Phaco-ExPRESS but increased by 36.3%in Phaco-Trab.The hyperreflective dots were further identified as neutrophil-and monocyte-like cells.The number of these cells were negatively correlated with the microcysts area(r=−0.7,P<0.01)but positively associated with the grade of connective tissue(r=0.5,P<0.01).By creating different microstructural changes in the filtering blebs,Phaco-ExPRESS produced a higher complete success rate(84.9%vs.41.2%,P<0.01)and significant decrease in the number of anti-glaucoma medications(P<0.01)when compared with those in Phaco-Trab.However,the qualified success showed no significant difference between the two groups(100.0%vs.91.2%,P=0.24).Conclusions:At the one-year follow-up,Phaco-ExPRESS generated better filtering bleb with larger area of microcysts,looser connective tissues,and less inflammation than that of Phaco-Trab,providing adequate IOP control and less IOP-lowering medications.These findings indicate that Phaco-ExPRESS could be more preferred than Phaco-Trab for the treatment of patients with coincident POAG and cataract.