Supplemental nutrition for retinal health: Evidence based analysis of commercial preparations in India.

Purpose: Antioxidants have been lately postulated as supportive and prophylactic supplements for various retinal disorders, especially age-related macular degeneration (AMD). Forty-eight brands of such supplements containing lutein and zeaxanthin are available in India. The aim of the study was to assess the market leaders in supplements for ophthalmology in view of AREDS recommendations. Methods: Descriptive review of top-selling supplements for eye health were compared to the contents of the AREDS-recommended levels. Results: None of the top 10 selling brands had exact or near similar composition as recommended in the AREDS-2 study, which is the most widely accepted level-1 evidence in AMD prevention. Conclusion: Physicians prescribing these antioxidants, especially for the prevention of advanced AMD, should be vigilant and aware of the contents of the prescribed brands.

Role of Resveratrol in Transmitochondrial AMD RPE Cells.

Resveratrol is a phytoalexin, stilbenoid compound with antioxidant properties attributable to its bioactive trans-resveratrol content. This study characterized the effects of over-the-counter (OTC) resveratrol nutritional supplements and a HPLC-purified resveratrol formulation, in human transmitochondrial age-related macular degeneration (AMD) retinal pigment epithelial (RPE) patient cell lines. These cell lines, which were created by fusing blood platelets obtained from dry and wet AMD patients with mitochondria-deficient (Rho0) ARPE-19 cells, had identical nuclei (derived from ARPE-19 cells) but different mitochondria that were derived from AMD patients. After resveratrol treatment, the levels of cell viability and reactive oxygen species production were measured. Results demonstrated that treatment with different resveratrol formulations improved cell viability and decreased reactive oxygen species generation in each AMD patient cell line. Although further studies are required to establish the cytoprotective potential of resveratrol under different physiological conditions, this novel study established the positive effects of OTC resveratrol supplements in macular degeneration patient cybrid cell lines in vitro.

Nutraceutical effects of Emblicaofficinalis in age-related macular degeneration.

Emblicaofficinalis Gaetrn (i.e., Phyllanthus emblica/ Indian gooseberry/ Amla) (EO) has been used extensively as a nutraceutical in several diseases since it is known to boost immunity and offers numerous health benefits such as antioxidant, anti-inflammatory, and anti-aging effects. The goal of our study was to test the hypothesis that EO will rescue human AMD RPE transmitochondrial cells from mitochondria-induced cellular damage. AMD RPE transmitochondrial cell lines were created by fusion of mitochondria DNA-deficient APRE-19 (Rho0) cells with platelets isolated from AMD patients, and therefore had identical nuclei but differed in mitochondrial DNA content. These AMD RPE cells were treated with EO extract followed by characterization of effects of EO using cellular and molecular assays. Herein, EO significantly improved live cell number and mitochondrial membrane potential, reduced apoptosis and oxidative stress, down-regulated VEGF, and up-regulated PGC-1α. In conclusion, EO improved cellular and mitochondrial health, thereby playing a key cytoprotective role in AMD in vitro. Further studies are required to examine the mechanisms that mediate the cytoprotective effects of EO.

Humanin G (HNG) protects age-related macular degeneration (AMD) transmitochondrial ARPE-19 cybrids from mitochondrial and cellular damage.

Age-related macular degeneration (AMD) ranks third among the leading causes of visual impairment with a blindness prevalence rate of 8.7%. Despite several treatment regimens, such as anti-angiogenic drugs, laser therapy, and vitamin supplementation, being available for wet AMD, to date there are no FDA-approved therapies for dry AMD. Substantial evidence implicates mitochondrial damage and retinal pigment epithelium (RPE) cell death in the pathogenesis of AMD. However, the effects of AMD mitochondria and Humanin G (HNG), a more potent variant of the mitochondrial-derived peptide (MDP) Humanin, on retinal cell survival have not been elucidated. In this study, we characterized mitochondrial and cellular damage in transmitochondrial cybrid cell lines that contain identical nuclei but possess mitochondria from either AMD or age-matched normal (Older-normal (NL)) subjects. AMD cybrids showed (1) reduced levels of cell viability, lower mtDNA copy numbers, and downregulation of mitochondrial replication/transcription genes and antioxidant enzyme genes; and (2) elevated levels of genes related to apoptosis, autophagy and ER-stress along with increased mtDNA fragmentation and higher susceptibility to amyloid-ß-induced toxicity compared to NL cybrids. In AMD cybrids, HNG protected the AMD mitochondria, reduced pro-apoptosis gene and protein levels, upregulated gp130 (a component of the HN receptor complex), and increased the protection against amyloid-ß-induced damage. In summary, in cybrids, damaged AMD mitochondria mediate cell death that can be reversed by HNG treatment. Our results also provide evidence of Humanin playing a pivotal role in protecting cells with AMD mitochondria. In the future, it may be possible that AMD patient's blood samples containing damaged mitochondria may be useful as biomarkers for this condition. In conclusion, HNG may be a potential therapeutic target for treatment of dry AMD, a debilitating eye disease that currently has no available treatment. Further studies are needed to establish HNG as a viable mitochondria-targeting therapy for dry AMD.

Mitochondrial DNA variants can mediate methylation status of inflammation, angiogenesis and signaling genes.

Mitochondrial (mt) DNA can be classified into haplogroups representing different geographic and/or racial origins of populations. The H haplogroup is protective against age-related macular degeneration (AMD), while the J haplogroup is high risk for AMD. In the present study, we performed comparison analyses of human retinal cell cybrids, which possess identical nuclei, but mtDNA from subjects with either the H or J haplogroups, and demonstrate differences in total global methylation, and expression patterns for two genes related to acetylation and five genes related to methylation. Analyses revealed that untreated-H and -J cybrids have different expression levels for nuclear genes (CFH, EFEMP1, VEGFA and NFkB2). However, expression levels for these genes become equivalent after treatment with a methylation inhibitor, 5-aza-2'-deoxycytidine. Moreover, sequencing of the entire mtDNA suggests that differences in epigenetic status found in cybrids are likely due to single nucleotide polymorphisms (SNPs) within the haplogroup profiles rather than rare variants or private SNPs. In conclusion, our findings indicate that mtDNA variants can mediate methylation profiles and transcription for inflammation, angiogenesis and various signaling pathways, which are important in several common diseases.

Mitochondrial DNA variants mediate energy production and expression levels for CFH, C3 and EFEMP1 genes: implications for age-related macular degeneration.

BACKGROUND: Mitochondrial dysfunction is associated with the development and progression of age-related macular degeneration (AMD). Recent studies using populations from the United States and Australia have demonstrated that AMD is associated with mitochondrial (mt) DNA haplogroups (as defined by combinations of mtDNA polymorphisms) that represent Northern European Caucasians. The aim of this study was to use the cytoplasmic hybrid (cybrid) model to investigate the molecular and biological functional consequences that occur when comparing the mtDNA H haplogroup (protective for AMD) versus J haplogroup (high risk for AMD). METHODOLOGY/PRINCIPAL FINDINGS: Cybrids were created by introducing mitochondria from individuals with either H or J haplogroups into a human retinal epithelial cell line (ARPE-19) that was devoid of mitochondrial DNA (Rho0). In cybrid lines, all of the cells carry the same nuclear genes but vary in mtDNA content. The J cybrids had significantly lower levels of ATP and reactive oxygen/nitrogen species production, but increased lactate levels and rates of growth. Q-PCR analyses showed J cybrids had decreased expressions for CFH, C3, and EFEMP1 genes, high risk genes for AMD, and higher expression for MYO7A, a gene associated with retinal degeneration in Usher type IB syndrome. The H and J cybrids also have comparatively altered expression of nuclear genes involved in pathways for cell signaling, inflammation, and metabolism. CONCLUSION/SIGNIFICANCE: Our findings demonstrate that mtDNA haplogroup variants mediate not only energy production and cell growth, but also cell signaling for major molecular pathways. These data support the hypothesis that mtDNA variants play important roles in numerous cellular functions and disease processes, including AMD.

A preliminary evaluation of dexamethasone palmitate emulsion: a novel intravitreal sustained delivery of corticosteroid for treatment of macular edema.

PURPOSE: Dexamethasone palmitate (DXP) is a lipophilic prodrug of dexamethasone (DXM), a potent corticosteroid used to treat a variety of ophthalmic diseases. The aim of the study was to characterize the sustained release capacity (in rabbit), efficacy (in rat and rabbit), and safety (in rabbit, cat, and minipig) of intravitreal (IVT) DXP emulsions in preclinical models. METHODS: Oil-in-water emulsions of DXP were administered by IVT injections in rats, rabbits, cats, or minipigs. Efficacy was assessed in rabbits by the inhibition of VEGF-induced vascular leakage and in rats by inhibition of laser-induced choroidal neovascularization. Concentrations of DXP and DXM in aqueous humor, vitreous, retina, choroid, and blood were determined to characterize the ocular and systemic pharmacokinetic (PK) profile. Complete ophthalmic examinations (indirect ophthalmoscopy, slit-lamp biomacroscopy, electroretinography, tonometry) were performed to assess the ocular safety of IVT DXP doses up to 2,600 µg in minipig, followed by histopathologic examinations. A validated feline model of DXM-induced elevated intraocular pressure (IOP) was used to assess the ocular hypertensive impact (i.e., the safety) of an IVT injection of DXP emulsion. RESULTS: Rat and rabbit efficacy data demonstrated that IVT injections of DXP emulsions were effective. Rabbit PK data demonstrated that following a single 1,280 µg IVT injection resulted in sustained DXM levels in the retina and choroid (1,179.6 and 577.7 ng/g with a half-life of 189 and 103 days, respectively) sufficient to inhibit VEGF-induced vascular hyper-permeability for up to 9 months. No adverse ocular findings were observed in the rabbit at the 1,280 µg DXP dose. Plasma levels of DXP and DXM were close to the lower limit of quantification (0.5 ng/mL). In minipigs, no systemic effects were observed at a dose up to 2,600 µg DXP. In steroid responsive cats, IVT DXP emulsions increased IOP to a lesser extent than triamcinolone acetonide with a more rapid return to basal levels and no evidence of cataract formation. CONCLUSIONS: IVT injections of DXP emulsions were well tolerated and shown to be efficacious for the sustained release of the drug, with the potential to control vascular leakage up to 9 months following a single IVT injection. These data suggest that IVT injections of DXP emulsions could be a safe and effective alternative IVT drug delivery vehicle for corticosteroid to treat back of the eye diseases complicated by macular edema.

Ocriplasmin for pharmacologic vitreolysis.

The vitreous may play an important role in the pathogenesis of various retinal disorders. Pharmacologic vitreolysis uses intravitreal pharmacologic agents to provide liquefaction of the vitreous and complete vitreoretinal separation. Ocriplasmin, a genetically engineered version of plasmin, has been shown in clinical trials to be able to safely release vitreomacular adhesion and close Stage 2 macular holes in a significant number of patients. Advancements in the development of this safe and effective method of vitreolysis have provided an alternative, nonsurgical treatment option to physicians who manage these patients. A roundtable of clinical investigators convened to discuss and summarize recent progress in pharmacologic vitreolysis. Preclinical studies, and efficacy and safety data from controlled clinical trials of ocriplasmin were presented and discussed. Case studies were then presented to provide an opportunity for experts to reveal their specific thoughts regarding ocriplasmin for the treatment of vitreomacular adhesion and resulting vitreomacular traction and macular holes, based on their own interpretation of current clinical data and experience.

Complications of ganciclovir implant surgery in patients with cytomegalovirus retinitis: the Ganciclovir Cidofovir Cytomegalovirus Retinitis Trial.

PURPOSE: To describe the complications of ganciclovir implant surgery in patients with cytomegalovirus retinitis. METHODS: Prospective data collection within the context of a randomized, controlled clinical trial, comparing a regimen of the ganciclovir implant plus oral ganciclovir to one of intravenous cidofovir for the treatment of cytomegalovirus retinitis in patients with AIDS. Adverse events were compared for patients undergoing implant surgery in the following groups: primary versus replacement implant surgery, inpatient versus outpatient surgery, and general versus local anesthesia. RESULTS: Fifty-six eyes of 42 patients underwent a total of 74 ganciclovir implant surgeries. Vitreous hemorrhage was the most common adverse event, occurring in 10% of eyes undergoing surgery with local anesthesia but in no eyes undergoing surgery with general anesthesia. All vitreous hemorrhages resolved within 60 days. Patients in the general anesthesia and inpatient surgery groups tended to have a lower risk of complications in the first 30 days than did patients in the local anesthesia and outpatient surgery groups, but no differences in the complication rate were found after 60 days. Visual acuity was similar among these different groups. There were no cases of endophthalmitis. CONCLUSION: Ganciclovir implant surgery in patients with AIDS and cytomegalovirus retinitis was associated with a low risk of serious complications in the first 60 days after surgery. Vitreous hemorrhage was the most commonly observed complication and resolved in all cases.