Idiopathic macular hole (IMH) refers to full thickness defects of retina in macular area with no clear reasons. The management of IMH includes vitrectomy combined with internal limiting membrane (ILM) peeling and pharmacological vitreolysis. But ILM peeling may damage the inner retina; novel techniques, such as inverted ILM flap technique and foveola non-peeling ILM surgery, autologous ILM transplantation had made the method of ILM peeling more diversified with less damage. Pharmacological vitreolysis targeting fibronectin and laminin is considered to work in a two-step mechanism, involving both vitreoretinal separation and vitreous liquefaction. Furthermore, IMH judgment and prognosis indicators like ellipsoid zone, macular hole index, hole formation factor, diameter hole index and tractional hole index based on spectral domain optical coherence tomography enriched the assessment of macular hole diameter, depth and shape. How to make full use of new interventions to reduce the incidence of macular hole and obtain a better visual acuity with closed holes is an important direction for future research.
Optogenetics is a novel technique which combines optics with genetics. Using genetic means, a selected opsin protein is ectopically expressed in target neurons, which are then stimulated by light to moderate the neuronal circuit, as a consequence to regulate the animal's behaviors. Retinal degeneration like retinitis pigmentosa and aged macular degeneration causes visual impairment and eventual blindness. Optogenetics techniques have opened the door to creating artificial photoreceptors in the remaining retinal circuits of retinal degeneration retinas via gene therapy. However, there are still limitations in optogenetics technique, for example, potential risk in virus infection, the choice of target cells and the low visual resolution of the experiment animal. It has been reported that vision was successfully restored to a certain extent in animal model using optogenetics technique. With higher photosensitivity of opsin protein, longer activation kinetics and higher transfection efficiency of virus vector, optogenetics techniques' application in ophthalmology will be improved.
ObjectiveTo observe the changes in physical properties of silicone oil after intraocular tamponade. MethodsThe silicone oil was removed from 99 patients (99 eyes) of primary retinal detachment with 23G vitreous cutter system. The upper silicone oil was collected after put the vitrectomy samples at room temperature for 3 days. According to the time of intraocular tamponade, the silicone oil samples were divide into six groups including group A (1 month, 12 samples), group B (2 months, 15 samples), group C (3 months, 25 samples), group D (6 months, 22 samples), group E (1-2 years, 13 samples) and group F (above 2 years, 12 sample). Fresh unused silicone oil was set as blank control group. Then the emulsion particles, kinematic viscosity, surface tension, density, transmittance and refractive index were measured. ResultsThe difference between group A-F and the control was statistical significant (P<0.05) in emulsion particles (F=89.337), kinematic viscosity (F=10.660), surface tension (F=11.810), density (F=13.497), transmittance of wavelengths (F=455.496, 566.105, 525.102, 767.573, 622.961, 601.539), but not statistical significant at refractive index (F=2.936, P>0.05). The number of silicone oil emulsion particles has no statistical difference between group A and the control (P>0.05), but was significantly different between group B-F (P<0.05). The kinematic viscosity of silicone oil has no statistical difference between group A, B and the control (P>0.05), but was significantly different between group C-F (P<0.05). The surface tension of silicone oil has no statistical difference between group A-D and the control (P>0.05), but is significantly different between group E and F (P<0.05). The density of silicone oil has no statistical difference between group A-D and the control (P>0.05), but was significantly different between group E and F (P<0.05). The transmittance of silicone oil has statistical difference between group A-F and the control(P<0.05). The refractive index of silicone oil has no statistical difference between all the groups and the controls significantly (P>0.05). ConclusionsThe physical properties of silicone oil will change during the intraocular tamponade. The emulsion particles number will increase and the transmittance will decrease after 2 months, the kinematic viscosity of silicone oil will decrease significantly after 3 months, and the density and surface tension will change significantly after 1 year of tamponade.
ObjectiveTo observe the influence of down-regulation of HtrA1 expression by small interfering RNA on light-injured human retinal pigment epithelium (RPE) cells. MethodsCultured human RPE cells(8th-12th generations)were exposed to the blue light at the intensity of (2000±500) Lux for 6 hours to establish the light injured model. Light injured cells were divided into HtrA1 siRNA group, negative control group and blank control group. HtrA1 siRNA group and negative control group were transfected with HtrA1 siRNA and control siRNA respectively. The proliferation of cells was assayed by CCK-8 method. Transwell test was used to detect the invasion ability of these three groups. Flow cytometry was used to detect the cell cycle and apoptosis. The expression of HtrA1 and vascular endothelial growth factor (VEGF)-A was detected by real time-polymerase chain reaction and Western blot respectively. ResultsThe mRNA and protein level of HtrA1 in the light injured cells increased significantly compared to that in normal RPE cells (t=17.62, 15.09; P<0.05). Compared with negative control group and blank control group, the knockdown of HtrA1 in HtrA1 siRNA group was associated with reduced cellular proliferation (t=6.37, 4.52), migration (t=9.56, 12.13), apoptosis (t=23.37, 29.08) and decreased mRNA (t=17.36, 11.32, 7.29, 4.05) and protein levels (t=12.02, 15.28, 4.98, 6.24) of HtrA1 and VEGF-A. Cells of HtrA1 siRNA group mainly remained in G0/G1 phase, the difference was statistically significant (t=6.24, 4.93; P<0.05). ConclusionKnockdown of HtrA1 gene may reduce the proliferation, migration capability and apoptosis of light-injured RPE cells, and decrease the expression of VEGF-A.
ObjectiveTo investigate the effect of DJ-1 encoded by Park7 gene on retinal ganglion cells (RGC) and visual function after optic nerve crush injury (ONC) in mice.MethodsThirty-seven and 116 healthy male C57BL/6J mice were randomly divided into group normal, group ONC 2d, group ONC 5d, group ONC 7d and group control, group Park7, group Park7-ONC, group ONC and group green fluorescent protein (GFP)-ONC. Group ONC 2d, group ONC 5d and group ONC 7d were sacrificed on the 2nd, 5th and 7th day after the establishment of ONC model, and the follow-up experiments were carried out. The mice in group Park7 and group Park7-ONC were injected 1 μ recombinant adeno-associated virus (rAAV) with knocking down Park7 gene into vitreous cavity, and 1 μ l rAAV with only GFP was injected into vitreous cavity of mice in group GFP- ONC, and virus transfection was observed 4 weeks after injection. The injury of ONC was perfomed at 23 days after vitreous injection in group ONC, group Park7-ONC and group GFP-ONC, and the samples were taken for follow-up experiment 5 days after modeling. The average density of RGC was observed by immunofluorescence staining, the latencies and amplitudes of a-wave, b-wave and photopic negative response (phNR) and the amplitude of oscillatory potential (OPs)were detected by full-field flash electroretinogram,and the visual acuity of mice was measured by optomotor response (OMR). The relative expression levels of DJ-1, Bax and B lymphoblastoma / leukemia-2 (Bcl-2) protein in the retina of mice in each group were detected by Western blot. One-way ANOVA was used to compare the data between groups, and t-test was used for pairwise comparison between groups.ResultsCompared with the normal group, the relative expression of DJ-1 protein in the retina of the ONC 2 d group and ONC 5 d group increased significantly, and the difference was statistically significant (t=16.610, 5.628, P＜0.01,＜0.05). Four weeks after virus transfection, strong GFP expression was seen in the RGC layer and inner plexiform layer of the retina of mice in the Park7 group. Compared with the control group, the RGC density of the retina in the ONC group decreased significantly, and the difference was statistically significant (t=16.520, P＜0.000); compared with the ONC group, the RGC density of the retina in the Park7-ONC group decreased significantly, and the difference was statistically significant (t=6.074, P＜0.01). With the increase of stimulus light intensity, the dark adaptation a wave and b wave latency of the mice in the control group gradually shortened, and the amplitude gradually increased. The stimulus light intensity was 3 cd·s/m2. There was no statistically significant difference in the dark adaptation a wave and b wave latency and amplitude of the control group, Park7 group, Park7-ONC group, ONC group, and GFP-ONC group (Incubation period: F=0.503, 2.592; P=0.734, 0.068. Amplitude: F=0.439, 1.451; P=0.779, 0.247). Compared with the control group, the Ops and PhNR amplitudes of the ONC group mice were significantly decreased (t=15.07, 12.80; P＜0.000,＜0.001). Compared with the ONC group, the Ops and PhNR amplitudes of the mice in the Park7-ONC group were significantly decreased (t=4.042, 5.062; P＜0.05,＜0.01); there was no statistically significant difference in the PhNR latency of the mice in each group (F=1.327, P=0.287). Compared with the control group, the visual acuity of the mice in the ONC group was significantly decreased, and the difference was statistically significant (t=23.020, P＜0.000); compared with the ONC group, the visual acuity of the mice in the Park7-ONC group was significantly decreased, and the difference was statistically significant (t=3.669, P＜0.05). Compared with the control group, Park7-ONC group and ONC group, the relative expression of DJ-1 protein in the mouse retina was significantly down-regulated, and the difference was statistically significant (t=47.140, 26.920; P＜0.000,＜0.000). There was no significant difference between ONC group and GFP-ONC group (t=0.739, P=0.983). Compared with the ONC group, the relative expression of Bax protein in the mouse retina of the Park7-ONC group was significantly increased, and the relative expression of Bcl-2 protein was significantly reduced. The differences were statistically significant (t=5.960, 9.710; P＜0.05,＜0.05); the relative expression ratio of Bcl-2/Bax in the Park7-ONC group was significantly lower than that in the ONC group, and the difference was statistically significant (t=13.620, P＜0.01).ConclusionThe expression of DJ-1 encoded by Park7 gene is down-regulated after Park7 gene was knocked down, which aggravates the RGC damage and the decrease of retinal electrophysiological response and visual function in ONC injury mice.