OBJECTIVE: To study the characters of oscillatory potentials (OPs) of electroretinogram (ERG) after methanol intoxication in rats. METHOD: The SD rat models of methanol intoxication were established and divided into control group, 3-day intoxication group, 7-day intoxication group. The changes of OPs of ERG were recorded in a dark room. RESULTS: The total amplitudes of 3-day and 7-day intoxication groups decreased approximately 50% compared with that of the control group, while the schedule delayed approximately 16% and 61%, respectively. CONCLUSION The characters of methanol intoxication in rats included delay in schedule and decline in the total amplitude of OPs.
Animals ; Electroretinography ; Methanol/poisoning* ; Rats ; Retina/physiopathology*

OBJECTIVETo observe the effect of rapid decompression on rat multifocal electroretinogram (mfERG) and to explore the characteristics of the retinal function impairment due to decompression sickness at early stage.

METHODSTwenty rats were randomly divided into 4 groups: normal control (NC) group, safe decompression (SD) group, 0 h and 6 h after rapid decompression (RD0 and RD6) groups. The treated rats in safe decompression group and each rapid decompression group were exposed in hyperbaric cabin and air pressure in the cabin rose up to 1.0 MPa in 30 s and lasted for 5.5 min. The pressure decreased to normal pressure in 55 s as for the treatment of rapid compression while air pressure of safe decompression decreased to normal pressure according to an animal safe decompression protocol. The mfERG parameters of one eye each rat were recorded by RETIscan 3.15 system.

RESULTSRapid decompression increased noise, delayed latent period and reduced amplitude in mfERG. The topographic map showed that the P1 wave response density in RD0 group was lower than that in NC and SD groups and higher than that in RD6 group in peripheral regions. The amplitudes of sum response density in NC, SD, RD0 and RD6 groups were (71.1 ± 7.5), (53.6 ± 9.3), (38.2 ± 13.1) and (18.4 ± 7.7) µV, respectively, and there was statistical difference among them (F = 17.313, P < 0.01). The P1 wave response densities of RD0 and RD6 groups were lower than that of NC group in 4 quadrants (P < 0.05) and the P1 wave amplitudes of RD0 and RD6 groups decreased in supranasal and supratemporal quadrants (P < 0.05). The P1 wave amplitudes of RD0 and RD6 groups were less than these of NC and SD groups in supranasal and supratemporal quadrants (P < 0.05). In 5 rings, the response densities of RD0 and RD6 groups were lower than these of NC and SD groups (P < 0.05) and the P1 and N1 wave amplitudes were less than these of NC and SD groups (P < 0.05). The P1 and N1 wave amplitudes of RD6 group were lower than those of RD0 group (P < 0.05).

CONCLUSIONRapid decompression can cause characteristic changes of mfERG and the major involved parts are superior retina and juxtaprepapillary region.

Animals ; Decompression Sickness ; physiopathology ; Electroretinography ; Rats ; Rats, Wistar ; Retina ; physiopathology ; Retinoscopy ; Visual Acuity

Aged ; Diabetic Retinopathy ; physiopathology ; surgery ; Electroretinography ; Female ; Humans ; Macular Edema ; physiopathology ; surgery ; Male ; Middle Aged ; Retina ; physiopathology ; Visual Acuity ; Vitrectomy

OBJECTIVETo explore the clinical feature, imaging and their diagnostic value for Joubert syndrome (JS).

METHODThe clinical data, imaging feature, and 31 references from China Biomedical literature database (CBMdise) were reviewed and analyzed.

RESULTThe age of onset of 32 patients including male 20 and female 12 ranged from 3 days to 6 years (mean 2.2 years). All the 32 patients with Joubert syndrome showed "slow growth" and "reduced muscle tension", 26 cases (81.3%) showed "gasp for breath", 26 cases (81.3%) showed "unusual motion of eyeball", 2 cases (6.3%) showed additional fingers (toes), 6 cases (18.8%) showed stretching tongue with agape. The typical imaging features of Joubert syndrome included "molar tooth sign", "midline cleavage" between cerebellar hemispheres and "bat-wing" like fourth ventricle, all the 32 patients with Joubert syndrome showed "midline cleavage", "molar tooth sign" was present in 29 cases (90.1%), and "bat-wing" like fourth ventricle in 30 cases (93.8%).

CONCLUSIONJoubert syndrome is a rare congenital brain malformation. The typical clinical manifestations included "gasp for breath", "reduced tension of muscle", "slow growth" and "unusual motion of eyeball", and at the same time the patients had the following typical imaging features of brain: "molar tooth sign", "midline cleavage" and "bat-wing" like fourth ventricle.

Abnormalities, Multiple ; Cerebellar Diseases ; diagnosis ; physiopathology ; Cerebellum ; abnormalities ; Child ; Eye Abnormalities ; diagnosis ; physiopathology ; Female ; Humans ; Kidney Diseases, Cystic ; diagnosis ; physiopathology ; Male ; Retina ; abnormalities ; physiopathology

BACKGROUNDObstructive sleep apnea syndrome (OSAS) has been shown to generate hypertension and endothelial dysfunction. Retinal vessel is the only vessel that can be observed directly and noninvasively; retinal vascular abnormalities can serve as a predictive marker for the occurrence, clinical course, and prognosis of cardiovascular and cerebrovascular diseases. The objective of this study was to identify the effect of OSAS severity on the morphological changes of retinal vessels.

METHODSAdult patients complained of snoring were included in this study. The patients' general information, polysomnography, and fundus photography parameters including central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole-to-venule ratio (AVR) were collected. Patients were divided into four groups according to their apnea-hypopnea index (AHI) results: Group I, AHI ≤5/h; Group II, 5/h < AHI ≤30/h; Group III, 30/h < AHI ≤60/h; and Group IV, AHI> 60/h.

RESULTSA total of 133 patients were included in this study with 111 males (83.5%) and 22 females (16.5%). Mean age was 41.6 ± 9.9 years, and the mean body mass index was 28.1 ± 4.0 kg/m2. AHI ranged between 0 and 130.8/h with a mean of 39.1 ± 30.7/h. There were 24, 34, 35, and 40 patients in Group I, Group II, Group III, and Group IV, respectively. Significant differences were found for AHI (F = 388.368, P< 0.001), minimal pulse oxygen saturation (F = 91.902, P< 0.001), and arousal index (F = 31.014, P< 0.001) among four groups; no significant differences were found for CRAE (F = 0.460, P = 0.599) and CRVE (F = 0.404, P = 0.586) among groups; there were significant differences for AVR between Group I and Group IV (63.6 ± 5.1% vs. 67.2 ± 5.5%, P = 0.010) Group II and Group IV (64.5 ± 6.0% vs. 67.2 ± 5.5%, P = 0.030), and Group III and Group IV (64.7 ± 4.1% vs. 67.2 ± 5.5%, P = 0.043). A main group-by-AHI effect was found on the AVR: patients with higher AHI showed higher AVR results (r = 0.225, P = 0.009). Multivariate logistic regression analysis was used for multi-variable factors. A group-by-age effect was found on the AVR: younger patients showed higher AVR results (β = -0.001, P = 0.020).

CONCLUSIONSThis study indicated that increased AVR of retinal vessel can be observed in extremely severe OSAS patients. For patients with OSAS, retinal vascular abnormalities may become an early indication for further cardiovascular abnormalities.

Adult ; Female ; Humans ; Male ; Middle Aged ; Polysomnography ; Retina ; pathology ; physiopathology ; Retinal Artery ; pathology ; physiopathology ; Retinal Vein ; pathology ; physiopathology ; Sleep Apnea, Obstructive ; pathology ; physiopathology ; Young Adult

This study investigated the baseline predictors of best corrected visual acuity (BCVA) and central retinal thickness (CRT) at 6 months in patients with treatment-naive branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). This multicenter, interventional case series included 208 BRVO and 123 CRVO patients with follow-up period of 6 months or more. Outcome measures of BCVA (logMAR) included absolute change from baseline and a gain or loss of > or = 0.3 from baseline. Outcome measures of CRT included absolute change from baseline and a measurement of < or = 250 microm or > or = 400 microm at 6 months. Univariate and multiple regression analyses were done to find baseline predictors. For BRVO, younger age, worse baseline BCVA, and shorter duration of symptom were associated with more gain in BCVA. For CRVO, worse baseline BCVA was associated with more gain in BCVA. For CRT outcomes, higher baseline CRT predicted greater decrease at 6 months in both BRVO and CRVO. Younger age and better baseline BCVA were associated with an increased likelihood of measurement of a < or = 250 microm outcome for BRVO and CRVO, respectively. For CRVO, smoking was associated with greater decrease from baseline and decreased likelihood of measurement of a CRT > or = 400 microm at 6 months. In conclusion, several baseline factors including age, symptom duration, and baseline BCVA and CRT are associated with BCVA and CRT outcomes at 6 months, which may help to predict disease course for RVO patients.
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Retina/*pathology ; Retinal Vein Occlusion/pathology/*physiopathology ; *Visual Acuity

In the vertebrate retina, Müller cells are principal glial cells which stretch across the whole thickness of the retina and contact with the somata and processes of all retinal neurons, thus forming an anatomical and functional link between glial cells and retinal neurons. Numerous studies have shown that Müller cells express various neurotransmitter receptors, transporters, ion channels and enzymes that are relative to cellular activities. In addition, the cells also release factors, such as D-serine and glutamate etc., to regulate the neuron excitability. Therefore, retinal Müller cells may play more curious roles in addition to supporting the retinal neurons. The information exchange and interaction between Müller cells and neurons may regulate and maintain retinal neuronal functions. In the glaucomatous retina, Müller cells are reactivated (gliosis). Reactivated Müller cells undergo a variety of changes in cellular physiology, biochemistry and morphological features. Meanwhile, the reactivated Müller cells may produce and release cytotoxic factors, such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), reactive oxygen species (ROS) and prostaglandin E2 (PGE2), thus involving in the induction of retinal ganglion cell apoptosis and death. Here, we reviewed the physiological properties of retinal Müller cells, and the functional changes of Müller cells in the glaucomatous retina.
Ependymoglial Cells ; pathology ; physiology ; Glaucoma ; physiopathology ; Humans ; Neurons ; physiology ; Retina ; cytology

Intragcular pressure (lOP) was artificially elevated and maintained in rabbits for up to 12 hours at levels 40, 60, 80, and 100 mmHg. Electroretinographic (ERG) responses showed gradual decline and later disappeared depending on the pressure. ERG responses were initially normal to supernormal at all lOP levels except 100 mmHg, and then showed gradual decline to extinction except in one eye of the 40 mmHg group. Ultrastrurtural damage was also pressure and time dependent. After 12 hours of the increased lOP, no damage to the ultrasfrurture of the retina was detected at 40mmHg, although the ERG was severely affected. Electron microscopic studies showed flattening of the pigment epithelium and swelling of mitochondria which appeared first at 60 mmHg; severe damage of mitochondria and the basal infoldings of the pigment epithelium at 80mmHg; and severe damage of all the retinal tissues at 100 mmHg. The critical duration of the elevated lOP which decreased the amplitude of the ERG was found to be 5 hours for 40 mmHg, 1 hour for 60 mmHg, and 30 minutes for 80 mmHg. The critical lOP which affected the ultrastrurture after 12 hours, lied between 40 and 60 mmHg.
Animals ; *Electroretinography ; Intraocular Pressure ; Ocular Hypertension/*physiopathology ; Pigment Epithelium of Eye/ultrastructure ; Rabbits ; Retina/physiopathology/*ultrastructure ; Time Factors

The latest development and the merit of using flexible neural microelectrodes are mainly reported in the paper, in which the properties of based-material, the micro-structure of neural microelectrodes and the method about how to test the microelectrodes are also included.
Blindness ; physiopathology ; rehabilitation ; Electric Stimulation Therapy ; instrumentation ; Electrodes, Implanted ; Evoked Potentials, Visual ; physiology ; Humans ; Microelectrodes ; Prosthesis Implantation ; Retina ; physiopathology

OBJECTIVETo investigate the characteristics of multifocal electroretinograms (mf-ERG) of different phases in diabetic retinopathy (DR) and its clinical significance.

METHODSMultifocal electroretinograms in patients with DR (I - II stage) were tested with VERIS IV system.

RESULTSIn I - II stage, the absolute values of N1, P1 and N2 response densities, and the N1-P1 and P1-N2 response densities were attenuated is a field of about 45 degrees in diameter.

CONCLUSIONAs a new objective and quantitative examination for spatial visual function, multifocal electroretinograms may be valuable in the diagnosis of diabetic retinopathy.

Aged ; Diabetic Retinopathy ; pathology ; physiopathology ; Electroretinography ; methods ; Female ; Humans ; Male ; Middle Aged ; Retina ; pathology ; physiopathology ; Time Factors