Sheila Pons-Vazquez

Oxidative stress in primary open-angle glaucoma.

PurposeTo analyze oxidative stress in primary open-angle glaucoma (POAG). Material and MethodsA case-control study including 90 eyes of 90 patients who needed antiglaucomatous surgery in the course of POAG (glaucoma group, n=50) and from patients who were operated of nonpathologic cataracts (cataract group, n=40). Free radical formation via lipid peroxidation by malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS) test and total antioxidant status in the aqueous humor samples of both groups were determined. Statistical analyses were carried out in relation to MDA-TBARS and total antioxidant status and their correlations with glaucoma risk factors. ResultsSignificantly higher MDA-TBARS were detected in the POAG with respect to the comparative group of cataract subjects (P<0.001). Antioxidant activity was significantly lower in the POAG than in the cataract group (P<0.001). ConclusionsAqueous humor samples may be used for determining oxidative and antioxidant status in pathologic processes. Glaucomatous eyes had a significant increase in oxidative status and decreased antioxidant activity in the aqueous humor than the cataract eyes. Oxidative stress may play a pathogenical role in the POAG.

Effects of a nutraceutical formulation based on the combination of antioxidants and ω-3 essential fatty acids in the expression of inflammation and immune response mediators in tears from patients with dry eye disorders

Background Women, and those older than 65 years of age, are particularly susceptible to dry eye disorders (DEDs). Inflammation is clearly involved in the pathogenesis of DEDs, and there is mounting evidence on the antioxidant and antiinflammatory properties of essential polyunsaturated fatty acids (EPUFAs). Objective To analyze whether a combined formulation of antioxidants and long-chain EPUFAs may improve the evolution of DEDs. Methods We used a prospective study to address the relationship between risk factors, clinical outcomes, and expression levels of inflammation and immune response (IIR) mediators in human reflex tear samples. Participants included: (1) patients diagnosed with nonsevere DEDs (DED group [DEDG]); and (2) healthy controls (control group [CG]). Participants were randomly assigned to homogeneous subgroups according to daily oral intake (+S) or not (−NS) of antioxidants and long-chain EPUFAs for 3 months. After an interview and a systematized ophthalmic examination, reflex tears were collected simultaneously from both eyes; samples were later subjected to a multiplexed particle-based flow cytometry assay. A specific set of IIR mediators was analyzed. All data were statistically processed through the SPSS 15.0 software program. Results Significantly higher expressions of interleukin (IL)-1β, IL6, and IL10 and significantly lower vascular endothelial growth factor expressions were found in the DEDG as compared to the CG. In the DEDG, significant negative correlations were detected between the Schirmer test and IL-1β, IL6, IL8, and vascular endothelial growth factor levels, and between the fluorescein breakup time with IL6 and IL8 levels. However, levels of IL-1β, IL6, and IL10 in tears were significantly lower in the DEDG+S versus the DEDG−NS and in the CG+S versus the CG−NS. Subjective symptoms of dry eye significantly improved in the DEDG+S versus the DEDG−NS. Conclusion IIR mediators showed different expression patterns in DED patients, and these patterns changed in response to a combined formulation of antioxidant and EPUFAs supplementation. Our findings may be considered for future protocols integrating clinical/biochemical data to help manage DED patients.

A 5-year follow-up of antioxidant supplementation in type 2 diabetic retinopathy.

Purpose This study was designed to evaluate the effect of antioxidant supplementation on diabetic retinopathy (DR) over a 5-year follow-up period. To our knowledge, this is the first such clinical trial performed. Methods We recruited 105 type 2 diabetic patients with nonproliferative DR. A complete ophthalmic checkup and a plasma determination of oxidative (malonyldialdehyde [MDA]) and antioxidant parameters (total antioxidant status [TAS]) were obtained as the baseline. One part of the cohort was randomly assigned to oral antioxidant supplementation at nutritional doses. The same examinations were performed with 97 diabetic patients who completed the 5-year follow-up period. The best-corrected visual acuity, DR score, MDA, and TAS values were compared at the beginning and the end of the follow-up. Results Best-corrected visual acuity did not change during the follow-up, irrespective of supplementation. However, the retinopathy stage showed a retardation of progression in the subgroup with supplementation, but worsened in the subgroup with no antioxidant supplementation. Furthermore, the antioxidant supplementation group maintained its antioxidant plasma status levels, which was related to decreased oxidative plasma activity. Conclusions Oral antioxidant supplementation could be a useful adjunctive long-term therapy in the treatment of nonproliferative DR.

Smoking and Age-Related Macular Degeneration: Review and Update

Age-related macular degeneration (AMD) is one of the main socioeconomical health issues worldwide. AMD has a multifactorial etiology with a variety of risk factors. Smoking is the most important modifiable risk factor for AMD development and progression. The present review summarizes the epidemiological studies evaluating the association between smoking and AMD, the mechanisms through which smoking induces damage to the chorioretinal tissues, and the relevance of advising patients to quit smoking for their visual health.

Thyroid hormone deficiency disrupts rat eye neurodevelopment.

Clinical and experimental studies have highlighted the role played by thyroid hormones (TH) in neural and neuro-sensorial development. However, knowledge on TH mechanisms on the developing visual system is still incomplete. To uncover TH actions on the eyes and vision we carried out a microscopical study on the role of TH in the developing retina and optic nerve, in a rat model of controlled TH deficiency (THD). Morphometric and stereological analyses of the retina and optic nerve showed a reduction in the volume of the eye (p<0.001) and optic nerve cross-sectional area (p<0.001), and thinning of the retinal layers (p<0.001). Glial development and myelination was significantly delayed in the THD optic nerves (p<0.001), as compared to controls. The data indicate that TH play an essential role in neuro-retinogenesis. Substitutive TH therapy in critical periods, should be considered in hypothyroidism-related eye disorders as well as neurodegenerative retinal processes.

Glutathione-dependent formaldehyde dehydrogenase (ADH3) and low km mitochondrial aldehyde dehydrogenase (ALDH2). New evidence for differential expression in the rat retina in response to oxidative stress.

Objectives: Epidemiological and experimental studies support the involvement of lipid peroxidation (LPO) in retinal diseases. In addition to other pathogenic mechanisms not fully understood, the possibility remains that peroxidic aldehydes, acting as cytotoxic chemicals, mediate in the progression of chronic ocular disorders. Methods: To test proper mechanisms involved in removing peroxidic aldehydes from the retina, in an attempt to understand long-lasting changes induced by LPO, the oxidative and antioxidant enzymatic activities, as well as the retinal distribution and activity of glutathione-dependent formaldehyde dehydrogenase (ADH3) and low km mitochondrial aldehyde dehydrogenase (ALDH2), were studied and compared with induced LPO sites in the adult rat retina. Biochemical enzymatic-colorimetric assays, histochemical and immunocytochemical analyses were carried out in the mature rat retinal tissues. Statistics were performed by the SPSS 15.0 program. Results: Data revealed (1) the noticeable LPO and glutathione (GSH) enzymatic system retinal and optic nerve activities; (2) the retinal expression and distribution of both the ADH3 and ALDH2; and (3) the co-localisation of iron/nicotine adenine dinucleotide phosphate (Fe/NADPH)-induced LPO, mainly in the outermost and innermost retinal strata, as compared to the rest of the retinal layers (p < 0.001). Conclusions: Changes in the GSH and GSH enzymatic system, and in the ADH3 and ALDH2 retinal expression and distribution might be crucial in assessing the intrinsic mechanisms of LPO-mediated retinopathies. Further research is needed to evaluate these findings and their application to new ophthalmological therapy.

Combined pre- and postnatal ethanol exposure in rats disturbs the myelination of optic axons.

AIMS To analyse myelination and outgrowth of the optic axons in relation to the neuro-ophthalmological manifestations of ethanol (EtOH) abuse during pregnancy. METHODS An experimental model of chronic EtOH exposure was developed in rats and their offspring by subjecting the dams to a liquid diet (35% of the daily total calories as either EtOH or maltose-dextrose nutritional controls (Con). Eyeballs and optic nerves were obtained at key developmental stages and processed for morphologic, immunocytochemical and immunoblotting procedures, using alternatively antibodies against myelin basic protein (MBP) or neurofilament (NF) protein, and image analysing. RESULTS A significant delay in onset of optic axons myelination, as well as a significant reduction in optic nerve size (P < 0.001), optic axons number (P < 0.001), myelinated axons density (P < 0.001), number of myelin lamellae linked to axon diameter (P < 0.001) and optic axon cross-sectional area (P < 0.001) were detected in the global morphometric assessment of the EtOH nerves with respect to the Con. Expression of MBP and NF was noticeably reduced in the EtOH optic nerves when compared with the Con. CONCLUSION Disturbed myelination of optic axons, caused by EtOH abuse, strongly disrupts the optic nerve development and the establishment of definitive retinal and optic nerve targets, and subsequently the visual patterns.

The influence of posterior capsular opacification removal on anterior segment birefringence parameters as measured by scanning laser polarimetry

Purpose:  To determine the effect of posterior capsular opacification (PCO) removal on anterior segment birefringence (ASB) and its influence on peripapillary retinal nerve fibre layer (RNFL) retardation measurements obtained by means of scanning laser polarimetry.

Restrictive anorexia nervosa: a silent enemy for the eyes and vision

Anorexia nervosa (AN) is an eating disorder (ED) characterised by the refusal to maintain body weight at or above normal, intense fear of gaining weight, disturbance of body shape perception, and amenorrhoea in women.1 There are two types of AN3: restrictive (reduction in daily energy intake) and binge/purging (binge-eating episodes followed by compensatory behaviour to prevent weight gain: vomiting, drug misuse, excessive physical exercise).2 A recent publication by Moschos et al 3 showed a lower foveal and inferior retinal nerve fibre layer (RNFL) …

Erratum to “Thyroid hormone deficiency disrupts rat eye neurodevelopment” [Brain Res. 1392 (2011) 16–26]

Maria D. Pinazo-Durana,⁎, Sheila Pons-Vazquez, Roberto Gallego-Pinazo, Carmen Galbis Estrada, Vicente Zanon-Moreno, Vicente Vila Bou, Pedro Sanz Solana Opthalmology Research Unit “Santiago Grisolia” University Hospital Dr. Peset, Valencia, Spain Ophthalmology Department, University and Polytechnic Hospital La Fe, Valencia, Spain Prevention Medicine and Public Health Department, Faculty of Medicine, University of Valencia, Valencia, Spain