ABSTRACT
The association between central corneal thickness and retinal fiber layer thickness with refractive error [emmetropic, myopic and hyperopic eyes]. 180 eyes [64 emmetropic eyes, 70 myopic eyes, 46 hyperopic eyes] in young subjects [18-35 years of age] were randomly selected. The participants in this study didn't have any ocular pathology or any previous surgical history. Pachymetry pattern of RTVUE OCT in central corneal thickness [CCT] and retinal nerve fiber layer [RNFL] thickness were measured. Mean CCT was 539.36 +/- 36.37 microns. Emmetropic eyes had thinner corneas [emmetropic eyes: 536.14, myopic eyes: 539.67, hyperopic eyes: 543.28 microns]. Myopic subjects had thinner RNFL thickness [myopic eyes: 114.21, emmetropic eyes: 121.05, hyperopic eyes: 120.45]. Univariate analysis revealed that CCT is positively correlated with RNFL in hyperopic and myopic eyes. Our findings demonstrate that RNFL may have positively correlated with CCT in hyperopic and myopic eyes. RNFL had inversely correlated with the amount of myopia and positively correlated with hyperopia. CCT was not significantly correlated with refractive error
ABSTRACT
Corneal sensitivity is one of the indicators for corneal health which may be affected by some factors such as age and geographical area. The purpose of this study was to measure normal central corneal sensitivity in different age groups with healthy cornea in Tehran. Central corneal sensitivity of the right eye of 596 volunteers [age ranged 15-81] was measured using a Cochet-Bonnet aesthesiometer. Subjects were divided into six age groups of 1-6 based on age ranges of 15-25, 26-35, 36-45, 46-55, 56-65 and >65 years, respectively. All measurements were performed by the same optometrist in 18 degrees of centigrade temperature, 35% humidity and between 2-5 p.m. There was a significant main effect of age group [f=92.22, p=0.000]. There was statistically significant difference of central corneal sensitivity among all age groups [p
ABSTRACT
Comparison of the results of visual evoked potential [VEP] in time domain and frequency domain between multiple sclerosis [MS] suspected patients and normal individuals. Eleven MS suspected patients with normal visual findings and 20 normal individual were tested by VEP. Results were compared between two groups. The time domain results showed no significant difference between the two groups. Results of the frequency domain showed that F[mod] value in the MS group [4.1 +/- 1.4 Hz] was less than the value in normal subjects [7.9 +/- 2.8 Hz] but, the number of peaks in power spectrum in the MS group [3.8 +/- 0.9] was more than the value in normal subjects [1.5 +/- 0.3]. [P<0.001] Decreased nerve conduction velocity, nerve impulse blockage, and refractory period increase in MS may cause low pass shift in frequency spectrum that may lead to F[mod] decrease and increase the number of peaks in spectrum. These finding may be useful for early diagnosis of MS