Evidence of the protective role of Carvacrol in a retinal degeneration animal model.

Neurodegenerative pathologies affecting the posterior segment of the eye, are characterized by being devastating and responsible for the majority of visual dysfunctions worldwide. These diseases are primarily degenerative, progressing chronically, and can inflict gradual harm to the optic nerve, retinal ganglion cells (RGC), photoreceptors, and other retinal cells. This retinal damage leads to a progressive loss of vision, marking these conditions as a significant health concern worldwide. The intravitreal administration of the phytochemical Carvacrol (CAR) is expected to demonstrate a neuroprotective and antiapoptotic effect on retinal cells, with a specific focus on RGC. This effect will be observed in a retinal degeneration model (RDM) in rabbits induced by cytotoxic and oxidative agents, namely glutamate (GLUT) and L-buthionine-S, R-sulfoximine (BSO). An in vivo study was conducted using New Zealand rabbits in which retinal damage was created to evaluate the effectiveness of CAR. The effectiveness of CAR on the functionality of retinal neuronal cells in RDM was evaluated using pupillary light reflection (PLR). Furthermore, the phytotherapeutic's influence on cell viability was determined through flow cytometry analysis. Finally, the neuroprotective and antiapoptotic capabilities of CAR were specifically scrutinized in RGC through histological studies, quantifying cell survival, and employing immunohistochemical assays to detect the apoptotic index (%) using the TUNEL technique. Our results demonstrated that CAR promoted the recovery of the pupillary contraction profile over time, maintaining the functionality of retinal cells as healthy controls. Additionally, it showed increased cell viability under oxidative and cytotoxic conditions given by GLUT-BSO agents. Finally, we found that CAR protects the survival of RGC and decreases the percentage of apoptotic cells when compared to RDM. CAR demonstrated to have positive effects on the functionality of photoreceptive nerve cells by restoring pupillary contraction. Likewise, it was shown to have neuroprotective and antiapoptotic effects when evaluated in a general and specific way on retinal nerve cells.

Ocular biocompatibility of polyquaternium 10 gel: functional and morphological results.

This paper deals with the characterization study of topical and intraocular biocompatibility and toxicity of cationic hydroxyethylcellulose Polyquaternium 10 (PQ10). It also evaluates the rheological properties of gels. The cytotoxicity assays were done in two cell lines: HEp-2 and VERO (human larynx epidermoid carcinoma cell and African green monkey kidney cells respectively). For the in vivo study, New Zealand albino rabbits were used. The in vitro cytotoxic activity of PQ10 shows no statistically significant differences in relation to the control of hydroxypropylmethylcellulose (HPMC) in any of the cell lines used in this study. Similarly, the signs of inflammation observed after treatment showed no significant difference between the groups of animals treated with the polymer compared to the control group. Normal histological characteristics were seen in both groups with no histological inflammatory reaction. After 1 month of the intracameral application of 2% PQ10 (treatment group) or 0.3% HPMC (control group), electroretinograms showed similar levels of a- and b-waves latencies and amplitude. In summary, PQ10 gel was well tolerated in these experiments, with proper monitoring, it could stand as a new alternative in the development of ophthalmic viscosurgical devices.

Risk factors of age-related macular degeneration in Argentina.

PURPOSES: To assess the risk factors of age-related macular degeneration in Argentina using a case-control study. METHODS: Surveys were used for subjects' antioxidant intake, age/gender, race, body mass index, hypertension, diabetes (and type of treatment), smoking, sunlight exposure, red meat consumption, fish consumption, presence of age-related macular degeneration and family history of age-related macular degeneration. Main effects models for logistic regression and ordinal logistic regression were used to analyze the results. RESULTS: There were 175 cases and 175 controls with a mean age of 75.4 years and 75.5 years, respectively, of whom 236 (67.4%) were female. Of the cases with age-related macular degeneration, 159 (45.4%) had age-related macular degeneration in their left eyes, 154 (44.0%) in their right eyes, and 138 (39.4%) in both eyes. Of the cases with age-related macular degeneration in their left eyes, 47.8% had the dry type, 40.3% had the wet type, and the type was unknown for 11.9%. The comparable figures for right eyes were: 51.9%, 34.4%, and 13.7%, respectively. The main effects model was dominated by higher sunlight exposure (OR [odds ratio]: 3.3) and a family history of age-related macular degeneration (OR: 4.3). Other factors included hypertension (OR: 2.1), smoking (OR: 2.2), and being of the Mestizo race, which lowered the risk of age-related macular degeneration (OR: 0.40). Red meat/fish consumption, body mass index, and iris color did not have an effect. Higher age was associated with progression to more severe age-related macular degeneration. CONCLUSION: Sunlight exposure, family history of age-related macular degeneration, and an older age were the significant risk factors. There may be other variables, as the risk was not explained very well by the existing factors. A larger sample may produce different and better results.

Risk factors of age-related macular degeneration in Argentina / Fatores de risco para degeneração macular relacionada à idade na Argentina

PURPOSES: To assess the risk factors of age-related macular degeneration in Argentina using a case-control study. METHODS: Surveys were used for subjects' antioxidant intake, age/gender, race, body mass index, hypertension, diabetes (and type of treatment), smoking, sunlight exposure, red meat consumption, fish consumption, presence of age-related macular degeneration and family history of age-related macular degeneration. Main effects models for logistic regression and ordinal logistic regression were used to analyze the results. RESULTS: There were 175 cases and 175 controls with a mean age of 75.4 years and 75.5 years, respectively, of whom 236 (67.4%) were female. Of the cases with age-related macular degeneration, 159 (45.4%) had age-related macular degeneration in their left eyes, 154 (44.0%) in their right eyes, and 138 (39.4%) in both eyes. Of the cases with age-related macular degeneration in their left eyes, 47.8% had the dry type, 40.3% had the wet type, and the type was unknown for 11.9%. The comparable figures for right eyes were: 51.9%, 34.4%, and 13.7%, respectively. The main effects model was dominated by higher sunlight exposure (OR [odds ratio]: 3.3) and a family history of age-related macular degeneration (OR: 4.3). Other factors included hypertension (OR: 2.1), smoking (OR: 2.2), and being of the Mestizo race, which lowered the risk of age-related macular degeneration (OR: 0.40). Red meat/fish consumption, body mass index, and iris color did not have an effect. Higher age was associated with progression to more severe age-related macular degeneration. CONCLUSION: Sunlight exposure, family history of age-related macular degeneration, and an older age were the significant risk factors. There may be other variables, as the risk was not explained very well by the existing factors. A larger sample may produce different and better results.

OBJETIVO: Determinar os fatores de risco para degeneração macular relacionada à idade na Argentina utilizando um estudo caso-controle. MÉTODOS: Questionários foram usados para a obtenção de informações dos participantes em relação à ingesta de antioxidantes, idade/sexo, raça, índice de massa corporal, hipertensão, diabetes (e tipo de tratamento), tabagismo, exposição à luz solar, consumo de carne vermelha/peixe, presença de degeneração macular relacionada à idade e história familiar de degeneração macular relacionada à idade. Modelos de efeito principal para regressão logística e regressão logística ordinal foram usados para analisar os resultados. RESULTADOS: Foram recrutados 175 casos e 175 controles com uma média de idade de 75,4 anos e 75,5, respectivamente, dos quais 236 (67,4%) eram mulheres. Cento e cinquenta e nove (45,4%) tinham degeneração macular relacionada à idade em seus olhos esquerdos, 154 (44,0%) em seus olhos direitos, e 138 (39,4%) em ambos os olhos. Entre os casos de degeneração macular relacionada à idade no olho esquerdo, 47,8% apresentavam o tipo seca, 40,3% o tipo úmida, e o tipo era desconhecido em 11,9%. Os achados para os olhos direitos foram: 51,9%, 34,4% e 13,7%, respectivamente. O modelo de efeito principal foi dominado por maior exposição à luz solar (OR [odds ratio]: 3,3) e história familiar de degeneração macular relacionada à idade (OR: 4,3). Outros fatores incluindo hipertensão (OR: 2,1), tabagismo (OR: 2,2), e pertencente à raça mestiça, que diminuiram o risco de degeneração macular relacionada à idade (OR: 0,40). Consumo de carne vermelha e de peixe, índice de massa corporal e coloração da íris não foram fatores de risco. Idade avançada foi associada com progressão para degeneração macular relacionada à idade mais grave. CONCLUSÃO: Exposição à luz solar, história familiar de degeneração macular relacionada à idade, e idade avançada foram os fatores de risco significativos. Podem existir outras variáveis, já que os riscos não foram bem explicados pelos fatores existentes. Um maior tamanho amostral poderia produzir resultados diferentes e melhores.