The effectiveness of cervical cerclage in twin pregnancies with a mid-trimester short cervix: A retrospective cohort study.

OBJECTIVE: To analyze the effectiveness of cerclage in twin pregnancies with a short cervix. STUDY DESIGN: Retrospective cohort study performed in two University Institutions in Valencia (Spain) with two different protocols for the management of asymptomatic dichorionic diamniotic twin pregnancies with mid-trimester cervical length ≤ 25 mm: treatment with indomethacin, antibiotics and cerclage (cerclage group) (N = 43) versus expectant management (control group) (N = 37). RESULTS: The initial cervical length was similar in both groups but detection of a short cervix was performed earlier in the cerclage group (21.6 vs 24.1 weeks, p < 0.001). Women with cerclage had a greater pregnancy latency (12.5 vs. 7.7 weeks, p < 0.001); higher gestational age at delivery (34.1 vs. 31.8 weeks, p < 0.04); less spontaneous preterm birth (SPB) < 28 weeks (11.6 % vs 37.8 %, p < 0.009); higher birthweight (2145 vs 1733 g, p < 0.001); lower birthweight < 1500 g (12.5 % vs 40.0 %, p < 0.001); less admissions to the neonatal intensive care unit (NICU) (24.1 % vs 43.3 %, p < 0.03); shorter stay at NICU (25.6 vs 49.4 days, p < 0.02); lower respiratory distress requiring mechanical ventilation (14.9 % vs 36.5 %, p < 0.02); fewer patent ductus arteriosus (8.9 % vs 26.9 %, p < 0.008); and lower composite adverse neonatal outcome (26.6 % vs. 44.8 %, p < 0.03). Cerclage and gestational age at diagnosis were the only independent predictors of SPB < 32 and < 28 weeks by multivariate analysis. The cumulative data in the literature show promising beneficial effects of cerclage. CONCLUSION: Our data suggest that cerclage in asymptomatic twin pregnancies with a short cervix may reduce the earliest SPB and may improve neonatal outcome.

Testosterone does not improve ovarian response in Bologna poor responders: a randomized controlled trial (TESTOPRIM).

RESEARCH QUESTION: Does testosterone, either in a long or short course, before IVF increase the number of mature oocytes retrieved in poor ovarian response? DESIGN: Single-centre, single-blinded, randomized controlled trial. Poor ovarian response is defined according to Bologna criteria. Sixty-three participants were included and assigned to three arms: group 1 (long testosterone [n = 17]) 12.5 mg/day testosterone gel for 56 days before ovarian stimulation; group 2 (short testosterone [n = 16]) 12.5 mg/day testosterone gel for 10 days before ovarian stimulation; and group 3 (control, no intervention). Primary outcome was number of mature oocytes retrieved. Secondary outcomes included other cycle parameters (duration of stimulation, antral follicle count, number of follicles >16 mm, total oocytes retrieved and testosterone levels). RESULTS: The number of mature oocytes retrieved did not differ between the three groups (2.16, 2.71 and 2.91, P = 0.719, groups 1, 2 and 3, respectively). No other significant differences were found in the remaining cycle parameters, except for testosterone levels at the beginning of ovarian stimulation, which were higher in both testosterone groups and relatively higher in group 2 (1.67 and 3.03, respectively versus 0.14 control group, P = 0.01). A Poisson regression model showed no significant differences for the primary outcome (group 3 versus group 2: 0.925, 95% CI 0.572 to 1.508, P = 0.753; group 3 versus group 1: 0.873, 95% CI 0.534 to 1.426, P = 0.587). CONCLUSIONS: The use of testosterone, even when applied for a prolonged period, does not improve the number of mature oocytes in poor ovarian response.

Intravitreal docosahexaenoic acid in a rabbit model: preclinical safety assessment.

PURPOSE: The purpose of the present study was to evaluate the retinal toxicity of a single dose of intravitreal docosahexaenoic acid (DHA) in rabbit eyes over a short-term period. METHODS: Sixteen New Zealand albino rabbits were selected for this pre-clinical study. Six concentrations of DHA (Brudy Laboratories, Barcelona, Spain) were prepared: 10 mg/50 µl, 5 mg/50 µl, 2'5 mg/50 µl, 50 µg/50 µl, 25 µg/50 µl, and 5 µg/50 µl. Each concentration was injected intravitreally in the right eye of two rabbits. As a control, the vehicle solution was injected in one eye of four animals. Retinal safety was studied by slit-lamp examination, and electroretinography. All the rabbits were euthanized one week after the intravitreal injection of DHA and the eyeballs were processed to morphologic and morphometric histological examination by light microscopy. At the same time aqueous and vitreous humor samples were taken to quantify the concentration of omega-3 acids by gas chromatography. Statistical analysis was performed by SPSS 21.0. RESULTS: Slit-lamp examination revealed an important inflammatory reaction on the anterior chamber of the rabbits injected with the higher concentrations of DHA (10 mg/50 µl, 5 mg/50 µl, 2'5 mg/50 µ) Lower concentrations showed no inflammation. Electroretinography and histological studies showed no significant difference between control and DHA-injected groups except for the group injected with 50 µg/50 µl. CONCLUSIONS: Our results indicate that administration of intravitreal DHA is safe in the albino rabbit model up to the maximum tolerated dose of 25 µg/50 µl. Further studies should be performed in order to evaluate the effect of intravitreal injection of DHA as a treatment, alone or in combination, of different retinal diseases.

Retinal neurodegenerative changes in the adult insulin receptor substrate-2 deficient mouse.

Insulin receptor substrate-2 (Irs2) mediates peripheral insulin action and is essential for retinal health. Previous investigations have reported severe photoreceptor degeneration and abnormal visual function in Irs2-deficient mice. However, molecular changes in the Irs2(-)(/)(-) mouse retina have not been described. In this study, we examined retinal degenerative changes in neuronal and glial cells of adult (9- and 12-week old) Irs2(-)(/)(-) mice by immunohistochemistry. 9-week old Irs2(-)(/)(-) mice showed significant thinning of outer retinal layers, concomitant to Müller and microglial cell activation. Photoreceptor cells displayed different signs of degeneration, such as outer/inner segment atrophy, redistribution of rod- and cone-opsins and spatial disorganization of cone cells. This was accompanied by synaptic changes at the outer plexiform layer, including the retraction of rod-spherules, reduction of photoreceptor synaptic ribbons and synaptic remodeling in second order neurons (i.e. loss and sprouting of dendritic processes in rod bipolar and horizontal cells). By 12 weeks of age, the thickness of inner retinal layers was severely affected. Although inner plexiform layer stratification remained unchanged at this stage, rod bipolar cell axon terminals were significantly depleted. Significant loss of Brn3a(+) retinal ganglion cells occurred in 12-week old Irs2(-)(/)(-) mice, in contrast to younger ages. Adult Irs2(-)(/)(-) mice showed clear hallmarks of neurodegeneration and disruption of the inner retina with increasing age. Pharmacological stimulation of Irs2 signaling pathway may provide additional neuroprotection in certain degenerative retinopathies.

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.

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)-1ß, 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-1ß, IL6, IL8, and vascular endothelial growth factor levels, and between the fluorescein breakup time with IL6 and IL8 levels. However, levels of IL-1ß, 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.

Comparative study of central corneal thickness using Fourier-domain optical coherence tomography versus ultrasound pachymetry in primary open-angle glaucoma.

PURPOSE: To compare central corneal thickness (CCT) results measured by Fourier-domain optical coherence tomography (FD-OCT) and ultrasound pachymetry (USP) in glaucomatous eyes. METHODS: In this prospective, observational cross-sectional study, 80 eyes of 80 patients with primary open-angle glaucoma (POAG) and no other ocular abnormality were selected: 28 were treated with 1 drug (subgroup 1), 32 with 2 drugs (subgroup 2), and 20 with 3 drugs (subgroup 3). CCT was measured by FD-OCT (RTVue OCT) and USP (Pachymeter Reichert IOPac). Bland-Altman plots were used to assess the agreement between both instruments. The differences between CCTs measured by USP and FD-OCT were compared among the 3 subgroups. RESULTS: The mean CCT was 537.76 ± 32.24 µm and 520.53 ± 30.44 µm for USP and FD-OCT, respectively. A significant difference was found between the mean values obtained by FD-OCT and USP (17.22 ± 7.96 µm, P < 0.001, paired Student t test). A high correlation was obtained for CCT measured by both methods (Pearson correlation coefficient = 0.969; P < 0.001), and there was good agreement between the 2 pachymetry methods. Similar differences in CCT using USP and FD-OCT were found among the 3 treatment subgroups (P > 0.05 in all pairwise comparisons, analysis of variance). CONCLUSIONS: FD-OCT underestimates CCT compared with CCT measured by USP in POAG. Although highly correlated, the difference between these 2 devices can be clinically significant in the context of refractive surgeries in POAG patients but not in intraocular pressure estimation. This difference also seems to be independent of the number of antiglaucoma treatments used.

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.

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.

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.

Oxidative stress in primary open-angle glaucoma.

PURPOSE: To analyze oxidative stress in primary open-angle glaucoma (POAG). MATERIAL AND METHODS: A 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. RESULTS: Significantly 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). CONCLUSIONS: Aqueous 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.

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. METHODS: In this prospective interventional study, scanning laser polarimetry was performed using GDx variable corneal compensation on 26 eyes of 26 patients who developed clinically significant PCO (after uncomplicated cataract surgery and with no other ocular pathology) both before and between 1 and 4 weeks after Nd:YAG capsulotomy. Best-corrected visual acuity (BCVA), intraocular pressure, corneal polarization axis (CPA), corneal polarization magnitude (CPM) were compared using the Student t-test and Wilcoxon signed ranks test. Spearman correlations between changes (differences between values after and before capsulotomy) in the CPA, CPM, BCVA and RNFL data were also performed. RESULTS: PCO removal is associated with a shift in CPA (from 10.86 to 15.03 degrees, P = 0.004) and CPM (from 28.54 to 37.92 nm, P = 0.004). Significant correlations were found between changes in the parameters of ASB and BCVA. Furthermore, RNFL measurements (nerve fibre indicator, temporal-superior-nasal-inferior-temporal average and superior average) were also well related to the CPA and CPM shifts. CONCLUSIONS: PCO induces an inaccurate compensation of ASB which affects RNFL assessment. Thus, it is necessary to recompensate ASB after posterior capsulotomy.

Myelination changes in the rat optic nerve after prenatal exposure to methamphetamine.

The use of psychostimulants during adolescence and early adult life has increased in recent years. It is known that these substances affect the sensory systems, and the optic nerve has been shown to be a target tissue. This work was conducted to evaluate the effects of prenatal exposure to methamphetamine (MA) on the developmental pattern of the rat optic nerve. Pregnant female rats were given 5 mg/kg body weight/day MA, s.c., in 0.9% saline from gestational days 8 to 22. The control group was injected with an isovolumetric dose of 0.9% saline. Animal model parameters, such as gestational body weight evolution, food intake and pups parameters were registered. The offspring were sacrificed at postnatal days (PND) 7, 14 and 21. Morphometric analyses were performed at light and electron microscopic levels on optic nerve cross sections; parameters measured included optic nerve diameter and area, axonal density, total number of axons and myelin thickness. Myelin basic protein (MBP) was measured by western blotting in optic nerve samples at PND14 and PND21. The animal model parameters, such as maternal and pup weight, showed no significant differences between MA and control groups. Optic nerve diameter was smaller at PND7 in the male MA group and in both male and female MA groups at PND21. The mean cross-sectional area was smaller at PND14 in the male MA group and in both male and female groups at PND21. The total number of myelinated axons did not vary between groups at any of the studied ages. The myelin thickness of the axons in MA-treated females was thinner when compared with the respective control group at PND21. No other differences were found concerning myelin thickness. There was a reduction of MBP protein expression in MA-injected females at PND14 and PND21. The combined results suggest that prenatal exposure to MA affects the myelination process.