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.

Effect of vasoactive intestinal peptide on the wound healing of alkali-burned corneas

AIM： To study the effect of vasoactive intestinal peptide （VIP） on wound healing in experimental alkali burns of the cornea. METHODS： Twenty-seven albino rabbits, weighing 3.2 -0.75 kg were used. Alkali burns were induced on corneas by applying 10 mm Whatman paper No：50 soaked in 1 mol/L NaOH. They have further classified into 5 groups as follows： 1） control group given no treatment （n=5）; 2） VIP given subconjunctivally （n=6）; 3） VIP injected into anterior chamber （n=6）; 4） NaCI 0.9% given subconjunctivally （n=5）; 5） NaCI 0.9% given into the anterior chamber （n=5）. All treatment protocols except control group were followed by topical eye drops composed of VIP at two hourly intervals for one week from 8 a.mo to 6 p.m, RESULTS： VIP treated groups of rabbits with alkali burns were found to have better wound healing findings histo-pathologically when compared to those of control group who have received no treatment on day 30. No differences were observed between groups in respect to degree of polymorphonuclear leukocytes （PMNL） infiltration and degree of loss of amorphous substrate on day 15. However, PMNL infiltration and degree of loss of amorphous substrate were lower in Groups 2 and 3 when compared to that of control group on day 30 （P〈0.05）. CONCLUSION： We have shown that VIP has positive effects on alkali induced corneal burns. VIP may inhibit PMNL migration to cornea through an immunomodulatory effect. Inhibition of PMNL migration might reduce the release of collagenaees and this might prevent the extracellular amorphous substance loss.

Association of eleven single nucleotide polymorphisms with refractive disorders from Eskisehir,Turkey

AIM:To investigate relationship between refractive errors and eleven single nucleotide polymorphisms(SNPs)in HGF,GC,MFN1,GNB4,and VDR genes in Turkish population.METHODS:A group of 212 participants with myopia(n=91),hyperopia(n=45),and emmetropia(n=76)were investigated in this study.SNPs in HGF,GC,MFN1,GNB4 and VDR genes were studied by Snap Shot technique.RESULTS:The patients in this study consists of 47 female/44 male(age:23.47±4.30)patients with myopia,20 female/25 male(age:31.20±8.02)with hyperopia and 33 female/43 male(age:25.22±6.60)with emmetropia.The genotype distribution of the rs7618348 polymorphism,which was the only statistically significant one between myopia and emmetropia group.The genotype distribution of the rs3819545,rs3735520,rs7041,and rs2239182 polymorphisms,which were statistically significant between hyperopia and emmetropia groups.CONCLUSION:The importance of genetic predisposition to refractive errors with respect to etiology of the disease is revealed.It is known that polymorphism studies may differ because of genetic diversity among populations so larger cohort studies are required in different populations to enlighten the etiology of the refractive errors.

Transmittance Spectrum of Unbranded Sunglasses Using Spectrophotometer

Background: The sunglass standards are not strictly implemented in many countries except Aus-tralia. The purpose of the study was to evaluate the optical properties of unbranded sunglasses for light transmittance. Methods: Unbranded sunglasses with no information about their specifications were included. They were allocated to two groups based on their prices;the ones > 25 US$ (Group A) and the cheaper ones (Group B). Their transmittance spectrum was measured between 190 nm and 900 nm using a double beam scanning spectrophotometer. The European standard for sunglasses was used to evaluate their compliance regarding ultraviolet radiation (UVR) transmittance and minimum requirement for wearing when driving. Results: Thirty-eight sunglasses (Group A = 20 and Group B = 18) were evaluated. Four sunglasses in each group were non-compliant. Percentage transmittance of visible light was <8% in five sunglasses of Group A and in three of Group B, so these were not appropriate to wear when driving. Totally six sunglasses of Group A and five of Group B were non-compliant and/or inappropriate to wear when driving. Conclusions: Based on our findings about their UVR protection and visible light transmittance %, eye care professionals must warn people against the use of unbranded sunglasses without any information about their specifications.