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Mitochondria are organelles which comprise the main respiratory machinery in the eukaryotic cells. In addition to their crucial role in energy production, they have profound effects on apoptosis and retrograde signaling to nucleus. Mitochondria have their own DNA, which codes for different proteins mostly involved in oxidative phosphorylation. Significant changes in the mitochondria of retinal pigment epithelium have been reported in age-related macular degeneration (AMD), which is correlated with the severity of the disease. Cybrid cell lines that have identical nuclei but mitochondria from different individuals can provide a unique means for studying the relationship between mitochondria and AMD. Different approaches for protection of mitochondria have been introduced which can be considered as potential future treatments for AMD and other age- related disorders.

PurposeTo identify inhibitors that could effectively lower reactive oxygen/nitrogen species (ROS/RNS), complement and inflammatory cytokine levels induced by Benzo(e)pyrene [B(e)p], an element of cigarette smoke, in human retinal pigment epithelial cells (ARPE-19) in vitro.MethodsARPE-19 cells were treated for 24 hours with 200 μM, 100 μM, and 50 μM B(e)p or DMSO (dimethyl sulfoxide)-equivalent concentrations. Some cultures were pre-treated with ROS/RNS inhibitors (NG nitro-L-arginine, inhibits nitric oxide synthase; Apocynin, inhibits NADPH oxidase; Rotenone, inhibits mitochondrial complex I; Antimycin A, inhibits mitochondria complex III) and ROS/RNS levels were measured with a fluorescent H2 DCFDA assay. Multiplex bead arrays were used to measure levels of Interleukin-6 (IL-6), Interleukin-8 (IL-8), Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF), Transforming Growth Factor alpha (TGF-α) and Vascular Endothelial Growth Factor (VEGF). IL-6 levels were also measured by an enzyme-linked immunosorbent assay. Real-time qPCR analyses were performed with primers for C3 (component 3), CFH (inhibits complement activation), CD59 (inhibitor of the complement membrane attack complex (MAC)) and CD55/DAF (accelerates decay of target complement target proteins).ResultsThe ARPE-19 cultures treated with B(e)p showed significantly increased ROS/RNS levels (P < 0.001), which were then partially reversed by 6 μM Antimycin A (19%, P = 0.03), but not affected by the other ROS/RNS inhibitors. The B(e)p treated cultures demonstrated increased levels of IL-6 (33%; P = 0.016) and GM-CSF (29%; P = 0.0001) compared to DMSO-equivalent controls, while the expression levels for components of the complement pathway (C3, CFH, CD59 and CD55/DAF) were not changed.ConclusionThe cytotoxic effects of B(e)p include elevated ROS/RNS levels along with pro-inflammatory IL-6 and GM-CSF proteins. Blocking the Qi site of cytochrome c reductase (complex III) with Antimycin A led to partial reduction in B(e)p induced ROS production. Our findings suggest that inhibitors for multiple pathways would be necessary to protect the retinal cells from B(e)p induced toxicity.

Introduction: Photodynamic therapy (PDT) has shown substantial benefit in the treatment of choroidal hemangioma (CH) in recent years. This report describes the use of PDT with overlapping spots in a patient with Sturge-Weber syndrome (SWS) and large circumscribed CH. Case Presentation: A 9-year-old girl with SWS and a history of glaucoma in her left eye was referred to a retina clinic for possible macular changes. Examination revealed decreased vision in the left eye, pigmentary changes in the macula, and choroidal thickening in the posterior pole. After being lost to follow-up for 2 years, the patient returned with further vision deterioration with best-corrected visual acuity (BCVA) of 20/150 and new subretinal fluid (SRF). Imaging findings were consistent with a diagnosis of CH and SRF. PDT with verteporfin was initiated on the entire area with multiple overlapping spots, resulting in resolution of SRF and improvement in visual acuity and choroidal contour. At 18-month post-treatment, the patient's BCVA was 20/25 with no recurrence of SRF or increased choroidal thickening. Significant pigmentary changes and subretinal hyper-reflective material were observed in the OCT of the treated area. Conclusion: Multiple overlapping laser spots of PDT can result in longstanding regression of large circumscribed CH in a patient with SWS with excellent final visual acuity. However, significant subretinal changes may also result following this method of treatment. [ABSTRACT FROM AUTHOR]

Abstract Background To evaluate the efficacy of triple therapy consisting of single-session photodynamic therapy (PDT), intravitreal bevacizumab (IVB) and intravitreal triamcinolone (IVT) as initial pulse therapy followed by repeat intravitreal bevacizumab injections for maintenance treatment in neovascular age-related macular degeneration (AMD). Methods In a prospective interventional case series, patients with subfoveal choroidal neovascularization (CNV) secondary to AMD underwent pulse therapy with single-session PDT according to the standard protocol followed by 1.25 mg IVB and 2 mg IVT 48 hours later. Best corrected visual acuity (BCVA) was assessed and optical coherence tomography (OCT) and fluorescein angiography (FA) were performed prior to treatment. BCVA and OCT measurements were repeated at 6 week intervals and FA was obtained after 12 weeks and when necessary thereafter. Repeat injections of IVB were performed based on fluorescein angiographic evidence of CNV leakage. Results This series included 17 eyes of 17 patients with mean age of 67.6 ± 7.2 years. Mean follow up duration was 50.4 ± 15.5 weeks. Mean BCVA prior to treatment was 0.74 ± 0.33 logMAR which improved to 0.52 ± 0.36 logMAR after 12 weeks (P = 0.012) and 0.41 ± 0.38 logMAR after 24 weeks (P = 0.001). Mean pretreatment central macular thickness (CMT) was 395 ± 181μ which was significantly reduced to 217 ± 69μ (P = 0.005), 231 ± 79μ (P = 0.028) and 221 ± 87μ (P = 0.05) six, twelve and twenty-four weeks after initial treatment respectively. Visual acuity improvement and CMT reduction was maintained during the follow-up period. IVB injections were repeated once, twice and three times in 10, 7 and 2 eyes at a mean interval of 20.2 ± 10.1, 19 ± 13.7 and 15 ± 1.4 weeks after initial therapy, respectively. Conclusion Initial pulse triple therapy consisting of single-session PDT combined with IVB and IVT improves vision and reduces CMT in neovascular AMD. Repeat IVB injections maintain the visual gain from the initial combination therapy.

Purpose: To evaluate the incidence and risk factors of post-intravitreal injection (IVI) endophthalmitis in a single center modified operating room (OR) setting.Methods: In a retrospective chart review study, patients who underwent IVI in a modified OR between September 2014 and November 2016 were included. Cases of post-IVI endophthalmitis were identified from the Hospital Infection Control Committee records, which tracks all post-procedure infections.Results: 51 472 IVIs (37 814 patients) including 13 658 bilateral simultaneous injections were performed during the study period. There were 17 cases of endophthalmitis (0.033%, 95% CI 0.019%-0.052%). There were no cases of bilateral endophthalmitis. Age, sex, indication for IVI, simultaneous bilateral injections, number of previous injections, and type of injected drug were not significantly associated with incidence of endophthalmitis.Conclusion: Post-IVI endophthalmitis is rare in this modified OR setting. Simultaneous bilateral IVIs and on-site preparation of injections are safe under these conditions. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate sensitivity and specificity of digital retinal image reading in the diagnosis of referral-warranted retinopathy of prematurity (ROP). Methods: Infants referred to the ROP clinic underwent fundus examination through indirect ophthalmoscopy. Fundus photographs were acquired using RetCam (shuttle 2; Clarity medical systems, Pleasanton, CA, USA). Four retinal specialists who were blind to patients' information reviewed the RetCam fundus photographs. By comparing the results of photographs' readings with that of indirect ophthalmoscopy as the gold standard, the sensitivity and specificity of telescreening was determined. Results: A total of 147 treatment-naïve patients met the inclusion criteria and were enrolled in the study. Mean gestational age (GA) was 28.6 ± 2.0 weeks. Digital retinal imaging had sensitivity of 85% and specificity of 35% in detecting referral-warranted ROP in our study. Positive predictive value of digital photography was 80%, and negative predictive value was 43%. Conclusion: Digital photography for diagnosis of ROP may show good potential as a screening modality in developing countries. It can facilitate early diagnosis, prevent unnecessary referrals, and be implemented for investigational purpose. However, the overall study result did not provide evidence to propose digital photography as a substitute for indirect ophthalmoscopy in the diagnosis of ROP. [ABSTRACT FROM AUTHOR]

Stem cell-based therapies are attraction approaches for regenerative medicine for treating retinal diseases. One of the limitations in cell therapy is cell death following post-injection whit preventing functional integration with retinal tissue. Fibrin gel, a bio-polymeric material with excellent biocompatibility, provides numerous advantages as a tissue engineering scaffold and a stem cell carrier. Therefore, current research is focusing on developing fibrin hydrogel scaffolds to protect stem cells during delivery and to stimulate endogenous regeneration through interactions of transplanted stem cells and retinal tissue. In this study fibrin gel was used as hydrogel scaffold for immobilization of cells. The structural characteristics of fibrin gel scaffold were examined with SEM. Rheological properties of fibrin gel were measured by rheometer and biodegradation rate of fibrin were assayed for 2 weeks. After isolation of stem cells CJMSCs, the cells were differentiated into photoreceptor-like cells by exposing with taurin for 14 days in tissue culture plate (TCP group) and fibrin hydrogel (3 D group). The attachment of cells was analyzed with SEM and MTT. The expression of rhodopsin, PKC, CRX, recoverin, peripherin, nestin and RPE65 as photoreceptor-like cell markers was evaluated by immunocytochemistry and quantitative real-time PCR (RT-PCR) in TCP and 3 D groups. The results of SEM analysis showed CJMSCs were well attached in fibrin gels and there were good integrity between cells and scaffold. The elastic modulus and constant degradation of the gel contributes to the growth and proliferation of cells. There was no toxicity effect of fibrin hydrogel on cells and the viability of cultured cells was higher in 3 D fibrin gels in comparison with TCP groups. After 2 weeks, the expression of rhodopsin, PKC, CRX, peripherin, recoverin, nestin and RPE65 as special markers of photoreceptor cells were detected by Real time PCR and immunofluorescence that these expressions in 3 D groups were higher than TCP groups. In conclusion, our findings showed that application of readily available sources of adult stem cells like human conjunctiva stem cells encapsulated in fibrin gel could be interesting strategy to enhance photoreceptor progenitor cell numbers for repair and regeneration of retina disease such as photoreceptor injury. [ABSTRACT FROM AUTHOR]