Effect of Music During General Anesthesia on Anesthetic Consumption During Vitrectomy Surgery.

Background: Controversy remains about the positive role of music during general anesthesia and postoperative recovery. We, therefore, tested the hypothesis that intraoperative exposure to classical music reduces the propofol necessary to maintain the bispectral index (BIS) close to 50 during vitrectomy surgery. Materials and Methods: This double-blind clinical study is evaluating 50 patients undergoing vitrectomy surgery under general anesthesia. Patients were randomly assigned to music and white noise groups, and relevant sounds were played to patients after induction of anesthesia. The two groups were compared for the use of propofol as an anesthetic to maintain a BIS near 50 and for postoperative pain, anxiety, nausea, and vomiting. Results: Propofol consumption to maintain the set BIS score was much lower in the music group than in the white noise group (78.72 ± 25.76 microgram/kg/min and 117.91 ± 36.78 microgram/kg/min, respectively, P-value = 0.000). Postoperative pain scores were also much lower in the music group than in the white noise group (P-value = 0.000) and anxiety levels between these two groups did not differ (P-value = 0.870). No patient in the music group had complaints of postoperative nausea and vomiting (PONV) compared to six patients in the white noise group (P-value = 0.011). Conclusions: Listening to music during general anesthesia for vitrectomy surgery can reduce the use of anesthetics, postoperative pain, and PONV. Further, controlled studies are necessary to confirm our results.

Identification of three novel homozygous variants in COL9A3 causing autosomal recessive Stickler syndrome.

BACKGROUND: Stickler syndrome (STL) is a rare, clinically and molecularly heterogeneous connective tissue disorder. Pathogenic variants occurring in a variety of genes cause STL, mainly inherited in an autosomal dominant fashion. Autosomal recessive STL is ultra-rare with only four families with biallelic COL9A3 variants reported to date. RESULTS: Here, we report three unrelated families clinically diagnosed with STL carrying different novel biallelic loss of function variants in COL9A3. Further, we have collected COL9A3 genotype-phenotype associations from the literature. CONCLUSION: Our report substantially expands the molecular genetics and clinical basis of autosomal recessive STL and provides an overview about allelic COL9A3 disorders.

The Inhibitory Effect of Connective Tissue Growth Factor Antibody on Postoperative Fibrosis in a Rabbit Model of Trabeculectomy.

Purpose: To compare the efficacy of subconjunctival injection of an anti-connective tissue growth factor antibody (anti-CTGF) versus mitomycin-C (MMC) and placebo in reducing scar formation in a rabbit model of trabeculectomy. Methods: A total of 14 rabbits were included. Nine rabbits underwent trabeculectomy with subconjunctival injections of either anti-CTGF antibody, MMC, or balanced salt solution (BSS), each administered in three eyes, before peritomy. The anti-CTGF group received a repeated dose of the antibody five days after surgery. All nine rabbits were euthanized on day 14; the globes were stained with hematoxylin & eosin, Masson's Trichrome, and immunohistochemistry for detecting alpha-smooth muscle (α-SMA) actin. RNA extraction was performed on five eyes of the remaining rabbits which included one eye without any surgery, one eye 5 hr after trabeculectomy without any injection, one eye five days after trabeculectomy without any injection, and two eyes five days after trabeculectomy with administration of MMC and BSS, respectively. Results: The mean bleb area in the anti-CTGF, MMC, and control groups was 3.8 ± 1.45, 5.9 ± 1.4, and 3.5 ± 1.9 mm2, respectively. Collagenous tissue was found to occupy the bleb area by 13.7%, 13.5%, and 18.5%, respectively. This ratio was significantly higher in the BSS group (P = 0.04). The expression of CTGF mRNA after 5 hr and five days in eyes undergoing trabeculectomy were significantly more pronounced as compared to the unoperated eye. The mean H-SCORE of α-SMA-immune reactive cells calculated as the grade of staining multiplied by the percentage of immune stained cells was 14.6, 10.22, and 140.58 in the anti-CTGF, MMC, and control groups, respectively. While the control eyes had a significantly higher score (Ps < 0.001), the anti-CTGF and MMC groups were comparable (P = 0.87). Conclusion: Based on the results of this animal study, the anti-CTGF antibody injection resulted in a significant reduction in collagenous tissue and myofibroblast cells after trabeculectomy.

Autosomal Recessive Bestrophinopathy: Clinical and Genetic Characteristics of Twenty-Four Cases.

BACKGROUND: To describe ocular manifestations, imaging characteristics, and genetic test results of autosomal recessive bestrophinopathy (ARB). The study design is an observational case series. METHODS: Forty-eight eyes of 24 patients diagnosed with ARB underwent complete ophthalmic examinations including refraction, anterior and posterior segment examination, enhanced depth imaging optical coherence tomography (EDI-OCT), fluorescein angiography (FA), electroretinography (ERG), and electrooculography (EOG). Optical coherence tomography angiography (OCTA) and BEST1 gene sequencing were performed in selected patients. RESULTS: The age at onset was 4-35 years (mean: 18.6 years). The male-to-female ratio was 0.45. All patients were hyperopic, except one with less than one diopter myopia. EOG was abnormal in 18 cases with near-normal ERGs. Six patients did not undergo EOG due to their young age. Eighteen patients (75%) had a thick choroid on EDI-OCT, of which three had advanced angle-closure glaucoma, 15 patients were hyperopic, and eight of them had more than four diopters hyperopia in both eyes. Macular retinoschisis was observed in 46 eyes of 23 patients (95%) with cysts mostly located in the inner nuclear layer (INL) to the outer nuclear layer (ONL). Of the 18 patients who underwent FA, mild peripheral leakage was seen in eight eyes of four patients (22%). Subfoveal choroidal neovascularization (CNV) was seen in three eyes of two patients (6%) that responded well to intravitreal bevacizumab (IVB). Seven mutations of the bestrophin-1 (BEST1) gene were found in this study; however, only two of them (p.Gly34 = and p.Leu319Pro) had been previously reported as the cause of ARB based on ClinVar and other literature studies. CONCLUSIONS: ARB can be presented with a wide spectrum of ocular abnormalities that may not be easily diagnosed. Pachychoroid can occur alongside retinal schisis and may be the underlying cause of angle-closure glaucoma in ARB. Our study also expands the pathogenic mutation spectrum of the BEST1 gene associated with ARB.

Intravitreal connective tissue growth factor neutralizing antibody or bevacizumab alone or in combination for prevention of proliferative vitreoretinopathy in an experimental model.

Connective tissue growth factor (CTGF) is released by retinal pigment epithelial (RPE) cells and detectable in proliferative membranes (PrMs). This experimental study was performed to investigate the mRNA and protein levels of both CTGF and vascular endothelial growth factor A (VEGF-A) in a rabbit model of proliferative vitreoretinopathy (PVR). In addition, the effects of a single intravitreal injection of the safe dose of anti-CTGF or bevacizumab as monotherapy and in combination were evaluated. PVR was induced in the right eye of albino rabbits by intravitreal injection of cultured adult human RPE cells. Quantitative real-time reverse transcription PCR (qRT-PCR) and Western blot analysis of CTGF and VEGF-A were performed on whole eye tissue in the PVR model versus controls at different time points. In the next step, the PVR models were assigned to five groups. The monotherapy groups received a single intravitreal injection of 0.1 ml of anti-CTGF 100 µg/ml (final concentration of 6.6 µg/ml in the vitreous) or 0.03 ml of 25 mg/ml bevacizumab. In the combined group, the abovementioned amounts of anti-CTGF and bevacizumab were injected intravitreally from separate sites in one session. No antibody injection was performed in the control group. Intravitreal injection of 0.1 ml of control IgG (1 mg/ml of isotype matched) antibody was performed in the placebo group. After 2 weeks, histologic evaluation including, trichrome staining for collagen, immunostaining by anti-alpha-smooth muscle actin for myofibroblasts, and anti-collagen type-1 antibody on paraffin embedded anterior-posterior sections was done. In addition, fundus photography was performed for clinically equivalent PVR staging. Twenty-four hours following PVR induction, CTGF mRNA and protein levels increased five- and- three-fold compared to controls, respectively (P < 0.001). VEGF-A mRNA and protein levels decreased significantly after 72 h of PVR induction compared to controls (P < 0.05). Means of PrM thickness and myofibroblast cell counts significantly decreased in the anti-CTGF group (P < 0.001 and P < 0.05, respectively). The mean area of collagen type-1 fibers of PrM in the mono- and combination therapy groups that received intravitreal anti-CTGF was significantly reduced (P < 0.001); in addition, mild PVR (stage-1 and 2) formation occurred in comparison with moderate to severe PVR (stage-4 and higher) in other groups. In conclusion, we found that intravitreal injection of CTGF neutralizing antibody resulted in a reduction in PrM thickness, collagen fibers and myofibroblast density in the PVR model. CTGF inhibition may represent a potential therapeutic target for PVR.

Peripheral blood CD163(+) monocytes and soluble CD163 in dry and neovascular age-related macular degeneration.

Macrophages are the main infiltrating immune cells in choroidal neovascularization (CNV), a hallmark of the human wet, or neovascular age-related macular degeneration (AMD). Due to their plasticity and ability to adapt to the local microenvironment in a tissue-dependent manner, macrophages display polar functional phenotypes characterized by their cell surface markers and their cytokine profiles. We found accumulation of hemoglobin-scavenging cluster of differentiation 163 (CD163)(+) macrophages in laser-induced CNV lesions and higher expression of CD163(+) monocytes in the peripheral blood on day 7 post injury in mice. In comparison, CD80(+) macrophages did not differ with laser-injury in young or aged mice and did not significantly change in the peripheral blood of CNV mice. We examined the percentages of CD163(+), CD206(+), and CD80(+) monocytes in the peripheral blood of patients with wet AMD, patients with dry AMD, and in age-matched individuals without AMD as controls. Percentages of peripheral blood CD163(+) monocytes in both dry AMD (P < .001) and wet AMD (P < .05) were higher than in age-matched non-AMD controls, while there was no difference between the groups in the percentages of peripheral CD206(+) and CD80(+) monocytes. Further, serum level of soluble CD163 (sCD163) was elevated only in patients with wet AMD (P < .05). An examination of 40 cytokine levels across the study groups revealed that anti-VEGF treated patients with wet AMD, who showed no exudative signs on the day of blood drawing had a cytokine profile that was similar to that of non-AMD individuals. These results indicate that CD163 could be further evaluated for its potential as a useful marker of disease activity in patients with neovascular AMD. Future studies will address the origin and potential mechanistic role of CD163(+) macrophages in wet AMD pathologies of angiogenesis and leakage of blood components.

Trimethyl chitosan-hyaluronic acid nano-polyplexes for intravitreal VEGFR-2 siRNA delivery: Formulation and in vivo efficacy evaluation.

As vascular endothelial growth factor in choroidal neovascularization is a major cause of visual loss of the elderlies and diabetics, gene therapy may offer an alternative treatment. However, siRNA instability and inefficient delivery are the main hindrances. To address this issue, we developed a nano-sized siRNA loaded therapeutic delivery system. The chitosan-hyaluronic acid nano-polyplexes were prepared by the modified ionic gelation method. The obtained nano-polyplex with a narrow size distribution, indicated no significant cytotoxicity in the MTT test and proper cellular uptake in confocal images. The RT-PCR analysis indicated remarkable gene silencing on HUVEC cells. The intravitreally administered nano-polyplexes in rabbits overcame both the vitreous and retina barriers and reached the posterior tissues efficiently. Intravitreal injections of the VEGFR-2 siRNA nano-polyplexes significantly reduced the size of the laser-induced choroidal neovascularization, compared to the control group. Consequently, the developed formulation can be a promising candidate for intravitreal delivery of siRNA.

Combination of intravitreal bevacizumab and erythropoietin versus intravitreal bevacizumab alone for refractory diabetic macular edema: a randomized double-blind clinical trial.

PURPOSE: To evaluate the effect of three intravitreal bevacizumab (IVB) injections alone or in combination with intravitreal erythropoietin (EPO) in the treatment of refractory diabetic macular edema (DME). METHODS: In a randomized double-blind clinical trial, 48 eyes of 34 diabetic patients with refractory DME were enrolled. Eyes were randomly assigned to receive either 3 monthly injections of 0.05 cc (1.25 mg) IVB plus 0.05 cc (1000 unit) EPO or 0.05 cc (1.25 mg) IVB alone. Main outcome was best-corrected visual acuity (BCVA) changes and secondary outcome was central macular thickness (CMT). The patients were followed for 6 months. RESULTS: Mean BCVA changes up to 4 and 6 months were insignificant in both groups. It changed from 0.72 ± 0.56 logMAR at baseline to 0.74 ± 0.5 (P = 0.85) and 0.71 ± 0.44 (P = 0.40) in the combination group and from 0.48 ± 0.39 logMAR to 0.47 ± 0.35 (P = 0.48) and 0.52 ± 0.33 (P = 0.69) in the IVB alone group, at 4 and 6 months, respectively. The difference of mean BCVA changes between the groups was insignificant at both 4 and 6 months (P = 0.07 and P = 0.36, respectively). Within the group changes of mean CMT were significant only in the combination group at 4 and 6 months, from 518 ± 134 µ at baseline to 472 ± 151 to 475 ± 167 µ, respectively (P = 0.01 and P = 0.05). Corresponding changes were not significant in the IVB alone group. However, the difference between the groups was not significant at all visits (P = 0.51 and P = 0.71, respectively). CONCLUSIONS: This clinical trial demonstrated that intravitreal erythropoietin had no additional effect to IVB in the treatment of refractory DME in the short term. TRIAL REGISTRATION: Clinical trials.gov identifier: NCT03821168.

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-performance manner over a short period of time. These cells due to expressing the RPELC genes and markers can be used in cell replacement therapy for degenerative diseases including age-related macular degeneration as well as retinitis pigmentosa.

Effects of intravitreal connective tissue growth factor neutralizing antibody on choroidal neovascular membrane-associated subretinal fibrosis.

Connective tissue growth factor (CTGF) plays an essential role in the regulation of extracellular matrix proteins and pro-fibrotic and angiogenic factors. This experimental research was conducted to evaluate if CTGF is elevated after induction of a choroidal neovascular membrane (CNVM) and whether intravitreal anti-CTGF without and with intravitreal bevacizumab (IVB) may have any effect on the CNVM associated sub-retinal fibrosis. In adherence to ARRIVE guidelines, CNVM was induced by laser spots in the right eye retinas of ninety-four pigmented rats. Quantitative real-time reverse transcription PCR (qRT-PCR) and western-blot analysis were performed on sclerochoroidal tissues of forty-four rats before and at different time intervals after laser application. The remaining fifty rats were randomly divided into five groups after laser application. Group A received intravitreal injection of 2  µl of the 50 µg/ml anti-CTGF. In group B, intravitreal injection of 2  µl of 25 mg/ml bevacizumab was performed. Group C received 1  µl intravitreal anti-CTGF and 1  µl IVB. Group D did not receive any intravitreal injection as the control group. In group E, intravitreal injection of 2  µl of nonspecific purified mouse IgG antibody was performed as the placebo group. After two weeks, double immunohistochemistry was performed by isolectin B4 and anti-collagen type1 on the sclerochoroidal flat-mounts. Masked measurement of the fluorescent images of the CNVM and CNVM associated sub-retinal fibrosis areas was performed using the image J software. Ctgf mRNA and CTGF protein levels increased to the maximum level in 24 h after laser application and remained higher than the control level up to the 14th day for the Ctgf mRNA and up to the 7th day for the CTGF protein level. Means of CNVM associated sub-retinal fibrosis areas in three treatment groups (A, B and C) were significantly less than the control (D) and placebo (E) groups (P < 0.001, <0.05, <0.001 respectively). For groups A and C, mean CNVM associated sub-retinal fibrosis areas were also significantly less than group B (P < 0.05 and < 0.01, respectively). In conclusion, this study showed significant reduction of the CNVM associated sub-retinal fibrosis via inhibition of the CTGF which mediates the final steps of fibrosis in various inflammatory and angiogenic pathways.

Effects of fibrin glue as a three-dimensional scaffold in cultivated adult human retinal pigment epithelial cells.

This study was conducted to examine morphological, genotypic, and phenotypic alterations occurring in cultured adult human retinal pigment epithelial cells when encapsulated with different concentrations of fibrin glue. Cultivated adult human retinal pigment epithelial cells were encapsulated with different concentrations of fibrin glue, namely FG1 (42 mg/dl), FG2 (84 mg/dl), FG3 (124 mg/dl), FG4 (210 mg/dl), followed by the evaluation of genetic and cytomorphological changes and protein expression. Cultured adult human retinal pigment epithelial cells showed dendritiform morphology during the early days of encapsulation with fibrin glue. Moreover, an increasing inhibitory effect on cell growth was observed with increasing concentrations of fibrin glue. At the transcriptional level, the expression of MMP2, PAX6, and ITGB1 in FG1-encapsulated cells was significantly higher than that in other treated groups; however, the expression of ACTA2 was lower in all fibrin glue-encapsulated groups compared to that in the controls. Immunocytochemistry showed that FG2-encapsulated cells expressed cytokeratin 8/18, RPE65, and ZO-1 proteins, but not PAX6. In conclusion, fibrin glue at a concentration of 84 mg/dl allows proper encapsulation of adult human retinal pigment epithelial cells, while preserving the morphometric, genotypic, and phenotypic features of the cells. This three-dimensional biopolymer can be considered a reliable vehicle for retinal pigment epithelium cell transplantation in cell-based therapies.

Survival and Migration of Adipose-Derived Stem Cells Transplanted in the Injured Retina.

OBJECTIVES: Transplantation of stem cells is one of the approaches to treat retinal diseases. Our objective was to determine whether adipose-derived stem cell transplant can survive and migrate in the injured retina using a sodium iodate model for the pigmented retinal epithelium injury. MATERIALS AND METHODS: The adipose-derived stem cells were isolated from male albino Sprague-Dawley rats and labeled with DiI so as to track the transplants in the subretinal space. Retinal pigmented epithelium damage was induced by retro-orbital sinus sodium iodate injection (40 mg/kg) into albino Sprague-Dawley rats. Four weeks after transplantation, the eyeballs were fixed in 4% paraformaldehyde and cut with cryostat. The eyeballs were serially sectioned along the vertical meridian. Cryosections were from the full length of the retina and passing through the optic nerve head. The survival and migration of transplanted cells were assessed. RESULTS: Sodium iodate selectively destroyed the retinal pigmented epithelium layer. The transplanted cells incorporated into the retinal pigmented epithelium layer, perhaps differentiating into a retinal pigmented epithelium phenotype. The transplanted cells were located in the subretinal space; after 4 weeks, some were observed in the retinal pigmented epithelium layer. CONCLUSIONS: We found that adipose-derived stem cells survived for 4 weeks after transplantation and migrated into the retinal pigmented epithelium layer.

Pharmacologic Treatment of Wet Type Age-related Macular Degeneration; Current and Evolving Therapies.

Age-related macular degeneration as the major cause of blindness in the elderly population has remained at the epicenter of clinical research in ophthalmology. This retinal disorder is characterized by the photoreceptor and retinal pigment epithelial cells loss, occurring within the macula. The disease represents a spectrum of clinical manifestations. It is a multifactorial disease resulting from a combination of genetic predispositions and environmental risk factors. AMD is classified into two different types, dry and wet. Wet AMD is in close relation with angiogenesis and inflammatory processes.A variety of anti-angiogenesis and anti-inflammatory drugs have been proposed for the treatment of the disease. The purpose of this paper is to briefly review the pharmacological therapies of the wet form of AMD and focus on new drugs that are currently in different stages of research and development.

Toward the Art of Robotic-assisted Vitreoretinal Surgery.

New technological progress in robotics has brought many beneficial clinical applications. Currently, computer integrated robotic surgery has gained clinical acceptance for several surgical procedures. Robotically assisted eye surgery is envisaged as a promising solution to overcome the shortcomings inherent to conventional surgical procedures as in vitreoretinal surgeries. Robotics by its high precision and fine mechanical control can improve dexterity, cancel tremor, and allow highly precise remote surgical capability, delicate vitreoretinal manipulation capabilities. Combined with magnified three-dimensional imaging of the surgical site, it can enhance surgical precision. Tele-manipulation can provide the ability for tele-surgery or haptic feedback of forces generated by the manipulation of intraocular tissues. It presents new solutions for some sight-threatening conditions such as retinal vein cannulation where, due to physiological limitations of the surgeon's hand, the procedure cannot be adequately performed. In this paper, we provide an overview of the research and advances in robotically assisted vitreoretinal eye surgery. Additionally the barriers to the integration of this method in the field of ocular surgery are summarized. Finally, we discuss the possible applications of the method in the area of vitreoretinal surgery.

Intravitreal Injection of Bone Marrow Mesenchymal Stem Cells in Patients with Advanced Retinitis Pigmentosa; a Safety Study.

PURPOSE: To examine the safety of a single intravitreal injection of autologous bone Marrow Mesenchymal stem cells (MSCs) in patients with advanced retinitis pigmentosa (RP). METHODS: A prospective, phase I, nonrandomized, open-label study was conducted on 3 eyes of 3 volunteers with advanced RP. Visual acuity, slit-lamp examination, fundus examination, optical coherence tomography, fundus auto-fluorescence, fluorescein angiography and multifocal electroretinography were performed before and after an intravitreal injection of approximately one-million MSCs. The patients were followed for one year. Further evaluation of MSCs was performed by injection of these cells into the mouse vitreous cavity. RESULTS: No, adverse events were observed in eyes of 2 out of 3 patients after transplantation of MSCs. These patients reported improvements in perception of the light after two weeks, which lasted for 3 months. However, severe fibrous tissue proliferation was observed in the vitreous cavity and retrolental space of the third patient's eye, which led to tractional retinal detachment (TRD), iris neovascularization and formation of mature cataract. Injection of this patient's MSCs into the vitreous cavity of mice also resulted in fibrosis; however, intravitreal injections of the two other patients' cells into the mouse vitreous did not generate any fibrous tissue. CONCLUSION: Intravitreal injection of autologous bone marrow MSCs into patients' eyes with advanced RP does not meet safety standards. Major side effects of this therapy can include fibrosis and TRD. We propose thorough evaluation of MSCs prior to transplantation by intravitreal injection in the laboratory animals.\.

Novel Mutations in TACSTD2 Gene in Families with Gelatinous Drop-like Corneal Dystrophy (GDLD).

In the current study, we conducted a mutation screening of tumor-associated calcium signal transducer 2 (TACSTD2) gene in six consanguineous Iranian families with gelatinous drop-like corneal dystrophy (GDLD), in order to find the causative mutations. Detailed eye examination was performed by ophthalmologist to confirm GDLD in patients. To detect the possible mutations, direct Sanger sequencing was performed for the only exon of TACSTD2 gene, and its boundary regions in all patients. In the patients with GDLD, the corneal surface showed lesions with different shapes from mild to severe forms depending on the progress of the disease. The patients showed grayish corneal deposits as a typical mulberry form, corneal dystrophy along with corneal lipid deposition, and vascularization. Targeted Sanger sequencing in TACSTD2 gene revealed the causative mutations in this gene in all studied families. Our study expanded the mutational spectrum of TACSTD2 which along with the related symptoms could help with the diagnosis, and management of the disease.

Pten Regulates Retinal Amacrine Cell Number by Modulating Akt, Tgfß, and Erk Signaling.

UNLABELLED: All tissues are genetically programmed to acquire an optimal size that is defined by total cell number and individual cellular dimensions. The retina contains stereotyped proportions of one glial and six neuronal cell types that are generated in overlapping waves. How multipotent retinal progenitors know when to switch from making one cell type to the next so that appropriate numbers of each cell type are generated is poorly understood. Pten is a phosphatase that controls progenitor cell proliferation and differentiation in several lineages. Here, using a conditional loss-of-function strategy, we found that Pten regulates retinal cell division and is required to produce the full complement of rod photoreceptors and amacrine cells in mouse. We focused on amacrine cell number control, identifying three downstream Pten effector pathways. First, phosphoinositide 3-kinase/Akt signaling is hyperactivated in Pten conditional knock-out (cKO) retinas, and misexpression of constitutively active Akt (Akt-CA) in retinal explants phenocopies the reduction in amacrine cell production observed in Pten cKOs. Second, Akt-CA activates Tgfß signaling in retinal explants, which is a negative feedback pathway for amacrine cell production. Accordingly, Tgfß signaling is elevated in Pten cKO retinas, and epistatic analyses placed Pten downstream of TgfßRII in amacrine cell number control. Finally, Pten regulates Raf/Mek/Erk signaling levels to promote the differentiation of all amacrine cell subtypes, which are each reduced in number in Pten cKOs. Pten is thus a positive regulator of amacrine cell production, acting via multiple downstream pathways, highlighting its diverse actions as a mediator of cell number control. SIGNIFICANCE STATEMENT: Despite the importance of size for optimal organ function, how individual cell types are generated in correct proportions is poorly understood. There are several ways to control cell number, including readouts of organ function (e.g., secreted hormones reach functional levels when enough cells are made) or counting of cell divisions or cell number. The latter applies to the retina, where cell number is regulated by negative feedback signals, which arrest differentiation of particular cell types at threshold levels. Herein, we show that Pten is a critical regulator of amacrine cell number in the retina, acting via multiple downstream pathways. Our studies provide molecular insights into how PTEN loss in humans may lead to uncontrolled cell division in several pathological conditions.

Identification of mutation in GTPBP2 in patients of a family with neurodegeneration accompanied by iron deposition in the brain.

We aimed to identify the genetic cause of a neurologic disorder accompanied with mental deficiency in a consanguineous family with 3 affected siblings by linkage analysis and exome sequencing. Iron accumulation in the brain of the patients was a notable phenotypic feature. A full-field electroretinography revealed generalized dysfunction of photoreceptors, bipolar cells, and amacrine cells. A splice site mutation in GTPBP2 that encodes GTP-binding protein 2 was identified in the patients and considered possible cause of their disease. The mutation was empirically shown to cause deletion of exon 9 of the gene and result in production of a truncated protein-lacking conserved C-terminus domains. GTPBP2 is a member of the GTPase superfamily of proteins. A recent report of identification of another splice site mutation in GTPBP2 in mice that causes neurodegeneration, and retinal damage provides supportive evidence for our finding. The conditions in the affected individuals of the family studied may define a novel form of neurodegeneration with brain iron accumulation, and GTPBP2 may be a novel neurodegeneration with brain iron accumulation gene.

A new efficient protocol for directed differentiation of retinal pigmented epithelial cells from normal and retinal disease induced pluripotent stem cells.

We describe a new, efficient protocol that involves the serial addition of noggin, basic fibroblast growth factor (bFGF), retinoic acid, and sonic hedgehog (Shh) for the differentiation of human induced pluripotent stem cells (hiPSC) to retinal pigmented epithelium (RPE) in a serum- and feeder-free adherent condition. hiPSC-RPE cells exhibited RPE morphology and specific molecular markers. Additionally, several hiPSC lines were generated from retinal-specific patients with Leber's congenital amaurosis, Usher syndrome, two patients with retinitis pigmentosa, and a patient with Leber's hereditary optic neuropathy. The RPE cells generated from these disease-specific hiPSCs expressed specific markers by the same RPE lineage-directed differentiation protocol. These findings indicate a new short-term, simple, and efficient protocol for differentiation of hiPSCs to RPE cells. Such specific retinal disease-specific hiPSCs offer an unprecedented opportunity to recapitulate normal and pathologic formation of human retinal cells in vitro, thereby enabling pharmaceutical screening, and potentially autologous cell replacement therapies for retinal diseases.

Intravitreal bevacizumab versus combined intravitreal bevacizumab and triamcinolone for neovascular age-related macular degeneration: six-month results of a randomized clinical trial.

PURPOSE: To determine whether combined intravitreal bevacizumab (IVB) and triamcinolone (IVT) is more effective than IVB alone in neovascular age-related macular degeneration. METHODS: This was a prospective, randomized clinical trial performed at two centers. Eligible eyes were assigned randomly to one of the two study arms. In the IVB group, 3 consecutive injections of 1.25 mg of bevacizumab were given 6 weeks apart, while in the IVB/IVT group, the first of the triple IVB injections was combined with 2 mg of IVB. A fourth IVB was injected in eyes demonstrating active choroidal neovascularization at Week 24. RESULTS: Sixty and 55 eyes were in the IVB and IVB/IVT groups, respectively. Best-corrected visual acuity improved, and central macular thickness was reduced significantly in both groups at all time points. Visual improvement was more pronounced in the IVB/IVT group compared with the IVB group 6 weeks (8.5 ± 14.4 vs. 3.8 ± 8.9 letters, P = 0.04) and 12 weeks (11.8 ± 16.6 vs. 6.2 ± 10.8 letters, P = 0.03) after initiation of therapy. However, there was no significant difference in visual improvement at Week 24 (11.3 ± 17.2 letters in the IVB/IVT group vs. 8.7 ± 15.6 letters in the IVB group, P = 0.40). The IVB/IVT group showed significantly less need for a fourth injection at Week 24 (34.5% vs. 53.3% in the IVB/IVT and IVB groups, respectively, P = 0.04). CONCLUSION: Mandated therapy with IVB improved best-corrected visual acuity and decreased central macular thickness in neovascular age-related macular degeneration. The addition of low-dose IVT temporarily increased the therapeutic efficacy in the early postinjection period and resulted in fewer requirements for repeat IVB injections at 6 months; however, final levels of visual improvement were comparable in the 2 study groups.