Vasoactive intestinal peptide,a promising agent for myopia?

AIM： To investigate the role of vasoactive intestinal peptide（VIP） in form-deprivation myopia（FDM）.METHODS： FDM was created in three groups of eight chicks by placing a translucent diffuser on their right eyes.Intravitreal injections of saline and VIP were applied once a day into the occluded eyes of groups 2 and 3,respectively.Retinoscopy and axial length（AL） measurements were performed on the first and 8^th days of diffuser wear.The retina mR NA levels of the VIP receptors and the ZENK protein in right eyes of the three groups and left eyes of the first group on day 8 were determined using real time polymerase chain reaction（PCR）.RESULTS： The median final refraction（D） in right eyes were-13.75（-16.00,-12.00）,-11.50（-12.50,-7.50）,and-1.50（-4.75,-0.75） in groups 1,2,and 3,respectively（P〈0.001）.The median AL（mm） in right eyes were 10.65（10.00,11.10）,9.90（9.70,10.00）,and 9.20（9.15,9.25） in groups 1,2,and 3,respectively（P〈0.001）.The median delta-delta cycle threshold（CT） values for the VIP2 receptors were 1.07（0.82,1.43）,1.22（0.98,1.65）,0.29（0.22,0.45） in right eyes of groups 1,2,and 3,and 1.18（0.90,1.37） in left eyes of group 1,respectively（P=0.001）.The median delta-delta CT values for the ZENK protein were 1.07（0.63,5.03）,3.55（2.20,5.55）,undetectable in right eyes of groups 1,2,and 3 and 1.89（0.21,4.73） in left eyes of group 1,respectively（P=0.001）.CONCLUSION： VIP has potential inhibitory effects in the development of FDM.

Prevalence of pseudoexfoliation syndrome and its association with ocular and systemic diseases in Eskisehir,Turkey

AIM： To investigate the prevalence of pseudoexfoliation syndrome （PEX） and its associations with ocular and systemic diseases in a population sample aged over 40y. METHODS： A total of 2356 subjects were randomly chosen for the sample population based on the database of the Turkish Statistical Agency in Eskisehir. Of the invited 2356 subjects, 2017 subjects participated, out of which 2009 were eligible for the study. Systemic diseases, drug use, smoking and body mass index were assessed using questionnaires. Measurements of central corneal thickness （CCT）, anterior chamber depth （ACD） and intraocular pressure （IOP） were performed during June to December, 2015. After pupillary dilation, the anterior segment and lenses were evaluated using a slit lamp.RESULTS： Prevalence of PEX in this sample was 5.0% （n=100）. Of patients with PEX, 26% also had glaucoma. Incidence of cataracts, and using drugs for hypertension, cardiac and psychiatric conditions was higher in patients with PEX compared to normal cases （P〈0.05）. Hearing loss was more common in PEX cases （34.0% vs 5.4%; P〈0.001）. The mean CCT, ACD and IOP were not significantly different between PEX and non-PEX cases.CONCLUSION： This study is the first population-based, randomized trial in Turkey. Prevalence of PEX in patients over 40 years old was found to be 5.0%. Besides glaucoma and cataract, hypertension, hearing loss, using drugs for cardiac and psychiatric diseases were associated with PEX.

Comparison of Goldmann applanation tonometry,rebound tonometry and dynamic contour tonometry in normal and glaucomatous eyes

AIM: To compare the intraocular pressure(IOP)measurements obtained with the rebound tonometry(RT), dynamic contour tonometry(DCT) and Goldmann applanation tonometry(GAT) in normal and glaucomatous eyes and investigate the effects of central corneal thickness(CCT) and corneal curvature(CC) on IOP measurements.METHODS: One hundred and twenty-four eyes of 124 subjects were enrolled in this cross-sectional study.Fifty-six of participants were healthy individuals and 68 of them were glaucomatous patients. IOP was measured on each subject always in the same order, ICare RT-Pascal DCT-GAT, after a minimum interval of 10 min between measurements. CCT and CC were measured using a rotating Scheimpflug camera before the IOP measurements in all subjects. One way repeated measures ANOVA, Pearson correlation coefficient and regression analysis, and Bland-Altman analysis was used for the statistical assessment.RESULTS: Mean IOP for all enrolled eyes was 16.00±3.80 mm Hg for GAT, 16.99 ±4.91 mm Hg for RT, and20.40 ±4.44 mm Hg for DCT. Mean differences between GAT and RT was-1.75±3.41 mm Hg in normal(P 【0.001)and-0.37 ±3.00 mm Hg in glaucomatous eyes(P =0.563).Mean differences between GAT and DCT was-4.06 ±3.42 mm Hg in normal(P 【 0.001) and-4.67 ±3.12 mm Hg in glaucomatous eyes(P 【0.001). GAT and RT were significantly positive correlated with CCT in normal(r2=0.101, P =0.017 and r2=0.331, P 【0.001, respectively) and glaucomatous eyes(r2=0.084, P =0.016 and r2=0.123,P =0.003, respectively). DCT was also significantly positive correlated with CCT in normal eyes( r2=0.179,P =0.001) but not in glaucomatous eyes(r2=0.029, P =0.165).All tonometers were unaffected by CC.CONCLUSION: IOP measurements by RT and DCT were significantly higher than GAT. DCT has highest IOP measurements among these tonometers. RT was most influenced tonometer from CCT although all tonometers were significantly positive correlated with CCT except DCT in glaucomatous eyes. CC did not influence IOP measurements.