Comprehensive evaluation of dehydration impact on ocular tissue during Ramadan fasting

The present study aimed to review the effect of dehydration during Ramadan fasting on the health and ocular parameters leading to changes in eye function. Articles included in the study were taken from PubMed, Ovid, Web of Science and Google Scholar up to 2014. Related articles were also obtained from scientific journals on fasting and vision system. Dehydration and nutrition changes in Ramadan cause an increase in tear osmolarity, ocular aberration, anterior chamber depth, IOL measurement, central corneal thickness, retinal and choroidal thickness, and also a decrease in IOP, tear secretion, and vitreous thickness. Much research related to the effect of dehydration on ocular parameters during Ramadan fasting exists. The findings reveal association with significant changes on ocular parameters. Thus, it seems requisite to have a comprehensive study on "fasting and ocular parameters", which will be helpful in making decisions and giving plan to the patients

Pattern visual evoked potentials in patients with type II diabetes mellitus

To evaluate cortical and retinal activity by pattern visual evoked potentials [PVEP] in patients with type II diabetes mellitus. PVEP was recorded in 40 diabetic patients including 20 subjects with nonproliferative diabetic retinopathy [NPDR] and 20 others without any retinopathy on fundus photography, and compared to 40 age- and sex-matched normal non-diabetic controls. P100 wave latency was significantly longer in diabetic patients as compared to normal controls [P<0.001]; both diabetic subjects without retinopathy and those with NPDR had significantly longer P100 latency than controls [P<0.001 for both comparisons]. There was significant reduction in N75 [P=0.037] and P100 [P=0.001] amplitudes in diabetic subjects. No correlation was observed between VEP amplitude or wave latency, and the level of glycemia or duration of diabetes mellitus. Increased PVEP latency may be a sign of retinal ganglion cell damage which takes place before the appearance of the first ophthalmoscopically detectable signs of diabetic retinopathy. PVEP may be considered as a method for detecting prediabetic retinopathy and has the potential to reduce diabetic complications.

Short-term outcomes of collagen crosslinking for early keratoconus

To assess the efficacy of collagen crosslinking with riboflavin and ultraviolet A [UVA] radiation for treatment of early keratoconus. Thirty-one eyes of 22 patients with early keratoconus were included in this study. All patients underwent slit lamp examination and assessment of uncorrected visual acuity [UCVA], best spectacle-corrected visual acuity [BSCVA], intraocular pressure, corneal topography and pachymetry. Collagen crosslinking was performed without epithelial removal. Riboflavin was applied to the cornea every 3 minutes 30 minutes before UVA irradiation and every 5 minutes thereafter. Patients were re-assessed 1, 3, and 6 months after treatment. Postoperatively, UCVA increased by 2 Snellen lines and BSCVA was improved by 1.7 Snellen lines [P < 0.001]. Spherical equivalent refractive error was reduced by 0.55 D, and maximum and mean K values were decreased by 0.65 D and 0.51 D respectively [P < 0.05 for all comparisons]. Evidence of regression was present in 71% of treated eyes. Collagen crosslinking demonstrated significant improvement in vision with reduction in corneal power and spherical equivalent refractive error in eyes with early keratoconus

[Evaluation of relationship between contrast sensitivity, color vision and visual acuity in diabetic patients with and without retinopathy]

To investigate the discriminative ability of contrast sensitivity [CS], color vision and log MAR visual acuity [VA] in detecting functional losses in diabetic participants with and without retinopathy comparing to the control group. In this cross sectional study in 1388 we examined 105 patients in Mashhad Khatam- Al-Anbia Eye Hospital including 70 diabetic patients [35 with retinopathy and 35 without retinopathy] with 35 control group. Contrast sensitivity was examined by means of CSV-1000 E at 3, 6, 12 and 18 cpd respectively. Color discrimination ability was measured with the Farnsworth D-15 test and log MAR VA by Snellen chart. Contrast sensitivity was significantly lower in the diabetic eyes with retinopathy than in the normal eyes in all spatial frequencies. Comparing to the control group, there was a statistically significant CS loss in spatial frequencies of 3, 6, 18 cpd in the diabetic eyes without retinopathy [p<0.05]. The mean log MAR VA and color vision abnormalities were significantly higher in the diabetic eyes with retinopathy than in the normal eyes or the diabetic eyes without retinopathy [p<0.001]. The sensitivity and specificity of the CS test in 6 cpd were 71% and 82% which were significantly higher than other spatial frequencies. The sensitivity and the specificity of the color vision test and VA [log MAR >/= 0.05, Snellen

[ relation between serum cobalamine, folate, photostress recovery time and age related exudative macular degeneration]

Several studies have reported high prevalence of severe lack of cobalamine and Folate in aged people. The most important causes are: malnutrition, atrophic gastritis and drug use. Age related macular degeneration [ARMD] is a primary degenerative disorder of central retinal area with loss of visual acuity. Recent studies have shown a significant relationship between age related macular degeneration and lack of plasma level of Folate, red blood cells and cobalamine. This study was caried out to investigate the relationship between age related macular degeneration and plasma Folate, Cobalamine and photostress recovery time, in elderly population. This case - control study was done on 124 elderly population. The participants were collected from by cluster sampling in mashhad located in the Noth - East of Iran during 2006. The patients underwent eye examination including indirect ophthalmoscopy. Slit lamp examination and photostress recovery time for age related macular degeneration by an ophthalmologist. After blood sampling, plasma Folate, serum Cobalamine, were determined by RIA method [DRG kit]. The Mean +/- SD of cobalamin and folate in age related macular degeneration patients was 298.848 +/- 288.66 pg/ml and 5.543 +/- 3.58 ng/ml and in normal group was 310.775 +/- 531.38 pg/ml and 5.365 +/- 3.52 ng/ml. There was no significant difference between age related macular degeneration patients and control group. Photostress recovery time was significantly increased in patients with age related macular degeneration [P<0.05]. There was no significant relationship between photostress recovery time and Cobalamine and folate level. This study showed that serum cobalamin and folate non significantly is decreased in age related maucular degeneration patients, with increasing photostress recovery time, we can use this screening test for the dignosis of age related macular degeneration

Prevalence and risk factors of refractive errors among school children in Mashhad, 2006-2007

To determine the prevalence of refractive condition and its risk factors among students in Mashhad. A total of 2510 students representing a cross-sectional of the population of Mashhad were sampled using random cluster sampling strategy. Primary and middle school students underwent cycloplegic refraction. The refractive errors of high school students were measured using non-cycloplegic autorefraction. Myopia was defined as spherical equivalent [SE] of -0.5 diopter [D] or more, and hyperopia was defined as SE of +0.5 diopter [D] or more, and astigmatism of 0.75 cylinder diopter or greater. Examination was carried out in the school using standardized testing protocols. 2150 students [group 1: 1163 primary and middle school, group 2: 947 high school students and 13 missed data] participated. The prevalence of refractive errors in the 1st group was: myopia=2.4%, hyperopia=87.9%, astigmatism=9.8% and anisometropia=3.0% [SE difference at least 1.00 D], and in the 2nd group myopia=24.1%, hyperopia=8.4%, astigmatism=11.8% and anisometropia=5.6%. There was significant difference in refractive errors between girls and boys [P<0.001]. In primary and middle school prevalence of myopia increased with age [OR=1.3 95% CI: 1.03 to 1.7 and P=0.013]. The prevalence of refractive errors among students in Mashhad is high. Effective detection and treatment of these refractive errors is expected to reduce the incidence of amblyopia and strabismus and also can prevent substantive effects on academic performance