جستجوی مقالات مرتبط با کلیدواژه « Retinal » در نشریات گروه « پزشکی »

To compare peripapillary retinal nerve fiber layer thickness (RNFLT) between patients with multiple sclerosis (MS) and healthy controls using optical coherence tomography (OCT).

In this prospective case control study, peripapillary RNFLT of 120 eyes from 60 patients with multiple sclerosis (MS)  was compared to 120 eyes from 60 age and sex matched healthy controls using OCT.  The RNFLT in 4 peripapillary quadrants and the mean RNFLT of all four quadrants were compared between the case and control groups. The relation between MS variables such as age of onset, type and duration of disease, history of optic neuritis (ON) and other non-ocular episodes with RNFLT was evaluated in the case group.

The mean RNFLT of all four quarters was significantly lower in patients with MS compared to the controls (P < 0.001). Also RNFLT was significantly lower in each of 4 quadrants (superior, temporal, inferior; P < 0.001, nasal P = 0.003). There was no significant relation between RNFLT, the age of onset of MS disease, and history of non-ocular episodes. RNFLT had a significant relation with duration of the disease (P < 0.001), the type of MS (P < 0.001), history of ON (P = 0.002), and the number of ON episodes (P = 0.021). 

We found that RNFLT decreases in MS patients and its reduction is related to the duration and type of disease as well as history and number of ON episodes. Therefore measuring RNFLT may help in estimating the progress of MS and can potentially be included as a part of patients’ follow up protocol.

Multiple Sclerosis (MS) is a disease of nervous system which is accompanied by degeneration of visual pathway in certain cases. Magnetic Resonance Imaging (MRI) and Visual Evoked Potentials (VEP) are among the diagnostic techniques in detecting this disease. The aim of the present study was to evaluate the possible electroretinography (ERG) changes among these patients. Patients and

Thirty eyes of the patients with definite diagnosis of multiple sclerosis and delay in latency of visual evoked potential P100 peak entered the present prospective case control study as the case group. Latency and amplitude of ERG b-wave peak were measured in each eye. The result was compared with normal eyes thirty from age and sex marched individuals to evaluate the possible differences between the two groups.

There was no statistically significant difference regarding the demographic data (age, UCVA) between the case and control groups. The b-wave latency did show a statistically significant difference between patients with MS and normal controls (P < 0.001). The ERG b-wave amplitude did not show statistically significant difference between patients with MS and the control group.

From the result of the present study it seems that the latency of b-wave in flash ERG might be used as an indicator to evaluate the retinal dysfunction in MS patients with abnormal VEP pattern.Keywords:  Multiple sclerosis; retinal changes; flash electroretinography

Bacteriorhodopsin operates as a light/proton transfer pump which converts the light energy into a proton gradient. Energy stored in the proton gradient can be used in a variety of ways. Bacteriorhodopsin producing sources are some Halobacterium species such as Halobacterium sodomense and Halobacterium salinarum which continue to grow in harsh and salt-saturated conditions. Two types of red pigment (IRLS.1) and orange pigment (IRLS.2) producing strains were isolated in order to isolate bacteriorhodopsin producing strains from Aran-Bidgol Lake. Spectroscopy reviews and the results of SDS Page of membrane proteins of two isolated strains and Iranian native Halobacterium salinarum showed that there is bacteriorhodopsin protein in the sample. Spectroscopic studies showed that Halobacterium salinarum produces the maximum amount, then IRLS 1 and finallyIRLS.2 with the lowest amount of bacteriorhodopsin. The results of biochemical and molecular identification based onthe16srRNA of both mentioned strains indicated their highest similarity with Natrinema sp. XA3-1 and Archaeon RC34, respectively. In this study, the presence of bacteriorhodopsin protein in Iranian native strains was examined for the first time and was isolated purely from Halobacterium salinarum membrane by gel filtration chromatography that given the widespread use of bacteriorhodopsin protein, it will be so effective.

To evaluate diurnal variations in intraocular pressure (IOP), central corneal thickness (CCT), and macular and retinal nerve fiber layer (RNFL) thickness in diabetic patients and normal individuals.
This study included 11 diabetic patients with macular edema and 11 healthy individuals. IOP, CCT, and macular and RNFL thickness were measured every 3 hours on a single day between 9 AM and 6 PM. Diurnal variations in IOP, CCT, total macular volume (TMV), central macular thickness (CMT), average macular thickness (AMT), and RNFL thickness were measured.
None of the parameters showed a significant absolute or relative change over the course of the day. However, the following non‑significant changes were observed. In the control group, all parameters demonstrated the highest values at 9 AM. The lowest IOP, TMV and AMT occurred at 12 PM; lowest CCT and RNFL at 6 PM; and the lowest CMT at 3 PM. Diabetic subjects had the highest values of RNFL, CMT and TMV at 9 AM, and that for IOP, CCT and AMT at 6 PM. The lowest RNFL and CMT values occurred at 6 PM; lowest IOP at 12 PM; and the lowest CCT, TMV and AMT were observed at 3 PM. In the diabetic group, TMV, CMT, AMT and CCT were significantly higher and RNFL was significantly lower than the control group at all time points (all P-values While there were slight decreases in IOP, RNFL thickness and CMT during the day, these changes were not significant between 9 AM and 6 PM and probably do not affect the interpretation of measurements.