RESUMO
Mitochondria are an important eukaryotic cell organelle with inner and outer membranes.They generate the necessary lifecycle energy for cells through aerobic respiration,and plays a role in oxidative stress and cell apoptosis in human body.Mitochondria have their own genetic material and genetic system.In more active structures,such as the retina and the optic nerve,mitochondria are more abundant,providing the necessary energy for visual signaling and intracellular transport of substances.An increasing number of studies have shown that mitochondrial dysfunction is involved in optic nerve degeneration and affects retinal ganglion cell survival.This paper summarized the current research on the distribution and the role of mitochondria in the optic nerve and retinal ganglion cells.
RESUMO
Background The incidence of dry eye is increasing among young adults because of wide usage of video display terminal.But the early diagnosis of dry eye still presents challenge to medical practitioners.The accurate diagnosis and treatment of the dry eye,therefore,is a topic of high interest to researchers.Previous examination outcome of dry eye is interferred primarily due to invasive procedure.It is very important to search an examination approach.Objective This study was to use Keratograph 5M,a non-invasive ocular surface analyzer to evaluate the influence of watching video display terminal on ocular surface and tear film.Methods Eighty-one eyes of 81 health volunteers among 18-30 years were enrolled in Affiliated Eye Hospital of Nanchang University from March 1,2015 to November 10,2015 under the informed consent,including 39 males and 42 females.The subjects watched the computer for continuously 3 hours under the nature light,and ocular surface related examinations were performed and compared before and after video display terminal exposure,including non-invasive tear film break-up time (NITBUT),tear meniscus height,conjunctival hyperemia scoring,limbal congestion scoring,corneal fluorescein staining scoring,meibomian gland imaging and lipid layer analysis.Results The number of eyes with visual fatigue,dryness,pain,blurring and conjunctival congestion was significantly increased after 3-hour video display terminal exposure in comparison with before (all at P＜0.01).The initial NITBUT and mean NITBUT were (6.086± 3.701) s and (9.103 ± 4.680) s,and tear meniscus height was (0.190 ± 0.032) mm after trail,which were significantly lower than (11.445 ±4.964) s,(14.626 ±4.467) s and (0.212 ±0.040) mm of before trail,respectively;The conjunctical hyperemia scoring and limbal congestion scoring were 0.869 ±0.311 and 0.572 ±0.276 after trial,which were significantly higher than 0.780 ± 0.306 and 0.509 ± 0.266 before trail,showing significant differences before and after exposure of video display terminal (all at P＜0.01).The intraocular pressure and the eye number of different scores of corneal fluorescence staining,abnormal meibomian gland and different morphological lipid layer of tear were unchanged before and after exposure of video display terminal.Conclusions Long-term exposure of video display terminal results in significant and temporary adverse influence on tear film and ocular surface.Keratograph 5M non-invasive ocular sudace analyzer can objectively assess overall ocular surface conditions.