Comparison of total/active ghrelin levels in primary open angle glaucoma,pseudoexfoliation glaucoma and pseudoexfoliation syndrome

AIM：To investigate the levels of ghrelin（Gh）,acylated ghrelin（AGh） and AGh/Gh ratio in the humor aqueous（HA） of cases with pseudoexfoliation syndrome（PXS）,pseudoexfoliation glaucoma（PXG）,primary open angle glaucoma（POAG） and to compare these with control subjects.METHODS：A prospective examination was made of the total Gh,and AGh levels in HA of 67 patients undergoing cataract surgery.Patients were divided into 4 groups.HA samples were aspirated at the beginning of the surgery,stored at -70℃.Gh and AGh quantification was performed with ELISA kits and the AGh/total-Gh ratios were calculated.ANOVA,Kruskal-Wallis,Chi-square and post-hoc tests were used for statistical analysis.RESULTS：Total Gh levels in HA were 189.2±45.6 pg/mL in the control group,199.2±32.9 pg/mL in PXS,180.6±20.9 pg/mL in PXG and 176.8±21.4 pg/mL in POAG groups（P〉0.05）.AGh levels in HA were 23.09±5.01 pg/mL in the control group,24.13±5.22 pg/mL in PXS,22.29±1.55 pg/m L in PXG and 19.69±2.93 pg/mL in POAG groups（P〉0.05）.The ratio of AGh/Gh was 10.3%±2.34% in the control group,13.03%±2.58% in PXS,12.3%±1.54% in PXG and 11.79%±1.41% in POAG groups（P=0.044）.The difference between the PXS and control groups was significant（P=0.03）.CONCLUSION：In spite of statistically insignificant results,the HA total Gh levels were lower than those of the control subjects but not parallel with the AGh levels in glaucoma patients.The relative increase in the AGh/Gh ratio in glaucoma cases supports the view that proportional increases of AGh might play a role in the pathogenesis of glaucoma.

Effect of oral administration of vitamin C on human aqueous humor ascorbate concentration

AIM:To study oral administration of vitamin C on human aqueous humour ascorbate concentration.METHODS:High performance liquid chromatography(HPLC)coupled with electrochemical detector(BCD)was used.The effect of oral administration of various doses of ascorbic acid,0(control),1.0,1.5,2.0,3.0,and 5.0 g,on its concentration in aqueous humour,obtained from volunteer cataract patients was studied.RESULTS:The concentration of ascorbic acid in aqueous humour of control group without administration of vitamin-C tablet or drug containing ascorbic acid was(254±119)mg·L^(-1).This study revealed that the administration of 2.0 g of.ascorbic acid saturate the aqueous humour and further increase in the dose(3.0 g and 5.0 g)did not increase its concentration in aqueous humour,although its concentration was increased in plasma.CONCLUSION:Oral administration of 2.0 g of Vc is sufficient to saturate the aqueous humour where it may be helpful in controlling the intra-ocular pressure.

Sensitivity,specificity and predictive values of anterior chamber tap in cases of bacterial endophthalmitis

Background:To assess the sensitivity,specificity,positive predictive value and negative predictive value of anterior chamber tap for the diagnosis of bacterial endophthalmitis on a population with high prevalence.Methods:Retrospective,single centre,case series study.We reviewed all medical records with clinical diagnosis of bacterial endophthalmitis in our hospital from January 1st,2000 to December 31st 2014.From each record,we documented general demographic data,best corrected visual acuity and vitreous and aqueous tap microbiological results.All cases were further divided according to the endophthalmitis aetiology to perform individual calculations of sensitivity,specificity,positive predictive value,negative predictive value,accuracy and prevalence.We used the results of the vitreous tap as the gold standard for diagnosis of bacterial endophthalmitis.We excluded those records in which the aqueous and vitreous samples were not taken simultaneously or had an incomplete microbiological report.Significance were assessed with chi squared statistics,with an alpha value of 0.05 for statistical significance.Results:A total of 190 cases fulfilled the inclusion/exclusion criteria.Positive culture rate from vitreous samples was 64.74%.Positive culture rate from aqueous sample was 32.11%.Bacteria isolated from aqueous samples matched those isolated from vitreous samples 78.68%of the time.The overall sensitivity was 38.21%,specificity:75.51%,positive predictive value:79.66%,negative predictive value:32.74%(p=0.08).Subgroup analysis showed that anterior chamber taps in cases of post-surgical endophthalmitis had a moderate to low sensitivity(37.73%),high specificity(93%)and high positive predictive value(95%)(p<0.04).Conclusion:The sensitivity and specificity of anterior chamber tap are low and should not be used for critical therapeutic decisions in patients with suspected bacterial endophthalmitis.In cases of post-surgical endophthalmitis,the result of an anterior chamber tap could be used for therapeutic guidance,but only in conjunction with clinical presentation and in the absence of a better method for diagnosis.