ABSTRACT
Purpose: Cannabis is the most prevalent drug in the world and its consumption is growing. Cannabinoid receptors are present in the human central nervous system. Recent studies show evidence of the effects of cannabinoids on the retina, and synthesising the results of these studies may be relevant for ophthalmologists. Thus, this review adopts standardised, systematic review methodology to investigate the effects of exposure to cannabis and components on the retina.Methods: We searched five online databases for the combined terms for outcome ("retina") and exposure ("cannabis"). Eligibility of studies were conducted by two independent reviewers, and risk of bias was assessed.Results: We retrieved 495 studies, screened 229 studies, assessed 52 studies for eligibility, and included 16 studies for qualitative analysis. The cannabinoids most frequently investigated were delta-9-tetrahydrocannabinol (THC), abnormal cannabidiol, synthetic cannabinoid, and cannabidiol (CDB). The outcomes most studied were neuroretinal dysfunction, followed by vascular effects. The studies also included investigation of neuroprotective and anti-inflammatory effects and teratogenic effects.Conclusions: This review suggests that cannabinoids may have an important role in retinal processing and function.
Subject(s)
Cannabinoids/pharmacology , Cannabis , Retina/drug effects , Hallucinogens , HumansABSTRACT
PURPOSE: Experimental data have demonstrated a relevant role for IL-6 in the modulation of acute ocular toxoplasmosis. Therefore, we aim to investigate the possible association between the IL-6 gene polymorphism at position -174 and toxoplasmic retinochoroiditis (TR) in humans. METHODS: Ninety-seven patients with diagnosed TR were recruited from the Uveitis Section, Federal University of Minas Gerais. For comparison, 83 healthy blood donors with positive serology for toxoplasmosis and without retinal signs of previous TR were included in the study. Genomic DNA was obtained from oral swabs of individuals and amplified using polymerase chain reaction (PCR) with specific primers flanking the locus -174 of IL-6 (-174G/C). PCR products were submitted to restriction endonuclease digestion and analysed by polyacrylamide gel electrophoresis to distinguish allele G and C of the IL-6 gene, allowing the detection of the polymorphism and determination of genotypes. RESULTS: There was a significant difference in the genotype (χ(2) = 12.9, p = 0.001) and allele (χ(2) = 6.62, p = 0.01) distribution between TR patients and control subjects. In a subgroup analysis, there was no significant difference in genotypes and allele frequencies regarding TR recurrence. CONCLUSIONS: This study suggests that the genotypes related with a lower production of IL-6 may be associated with the occurrence of TR.
Subject(s)
Chorioretinitis/genetics , DNA/genetics , Interleukin-6/genetics , Polymorphism, Genetic , Toxoplasmosis, Ocular/genetics , Adult , Alleles , Animals , Chorioretinitis/metabolism , Chorioretinitis/parasitology , Electrophoresis, Polyacrylamide Gel , Female , Follow-Up Studies , Gene Frequency , Genotype , Humans , Interleukin-6/metabolism , Male , Polymerase Chain Reaction , Toxoplasmosis, Ocular/metabolism , Toxoplasmosis, Ocular/parasitologyABSTRACT
This study aimed to investigate the serum levels of the cytokine TNF-α and its soluble receptors (sTNFR1 and sTNFR2) in patients with toxoplasmosis retinochoroidits (TR) and controls. 37 patients with TR and 30 subjects with positive serology for toxoplasmosis but without history and signs of uveitis were included in this study. Serum concentrations of TNF-α, sTNFR1, and sTNFR2 were determined by ELISA. Serum concentrations of TNF-α and sTNFR1 were similar in controls (mean ± SD median values; 56.57 ± 141.96 and 504.37 ± 163.87, respectively) and TR patients (mean ± SD values, 121.62 ± 217.56 and 511.15 ± 189.30, respectively). Serum concentrations of sTNFR2 were higher in the uveitis group when compared to the control group (respectively, mean ± SD values, 1734.84 ± 379.32 and 1442.75 ± 309.47; p=0.002). There was no association between the serum levels of the molecules and the time of first symptoms, severity of vitreous haze, size or localization of active lesions, levels of visual acuity, and presence of vasculitis. These results suggest that TR is associated with changes in the circulating levels of inflammatory biomarkers, but they are not correlated with local/ocular signs.
Subject(s)
Adult , Female , Humans , Male , Chorioretinitis/blood , Receptors, Tumor Necrosis Factor, Type I/blood , Receptors, Tumor Necrosis Factor, Type II/blood , Toxoplasmosis, Ocular/blood , Tumor Necrosis Factor-alpha/blood , Biomarkers/blood , Case-Control Studies , Chorioretinitis/parasitologyABSTRACT
This study aimed to investigate the serum levels of the cytokine TNF-α and its soluble receptors (sTNFR1 and sTNFR2) in patients with toxoplasmosis retinochoroiditis (TR) and controls. 37 patients with TR and 30 subjects with positive serology for toxoplasmosis but without history and signs of uveitis were included in this study. Serum concentrations of TNF-α, sTNFR1, and sTNFR2 were determined by ELISA. Serum concentrations of TNF-α and sTNFR1 were similar in controls (mean ± SD median values; 56.57±141.96 and 504.37±163.87, respectively) and TR patients (mean ± SD values, 121.62±217.56 and 511.15±189.30, respectively). Serum concentrations of sTNFR2 were higher in the uveitis group when compared to the control group (respectively, mean ± SD values, 1734.84±379.32 and 1442.75±309.47; p=0.002). There was no association between the serum levels of the molecules and the time of first symptoms, severity of vitreous haze, size or localization of active lesions, levels of visual acuity, and presence of vasculitis. These results suggest that TR is associated with changes in the circulating levels of inflammatory biomarkers, but they are not correlated with local/ocular signs.