ObjectiveTo observe the changes of retinal morphology and function of macular-off rhegmatogenous retinal detachment (RRD) after scleral bulking. MethodsIn this prospective study, 42 eyes of 41 patients who underwent scleral bulking were enrolled. There were 26 males (27 eyes) and 15 females (15 eyes), with an average age of (33.78±11.21) years. Best corrected visual acuity (BCVA), intraocular pressure, indirect ophthalmoscope, visual fields, optical coherence tomography (OCT) and B scan of ocular ultrasound were measured for all patients. The average BCVA was 0.29±0.18. The retinal detachment time was (21.12±3.71) days. The mean visual field defect (MD) was (13.54±6.44) dB. The mean loss variance (LV) was (8.43±2.11) dB. All the patients were performed cryotherapy and sub-choroidal fluid drain out. The mean follow-up was 12.4 months (from 6 to 24 months). At two weeks, 1, 3, 6, 12 months after surgery, the changes of BCVA, visual fields, retinal morphology and subretinal fluid were observed. ResultsIndirect ophthalmoscope combined with B scan showed the time of retinal reattachment was (7.32±2.53) days. Subretinal fluid was found completely absorbed by OCT with a mean of (7.82±3.52) months. At 12 months after surgery, subretinal fluid was completely absorbed in 37 eyes (88.10%). In these 37 eyes, 15 eyes had normal retinal microstructure, 5 eyes had neuroepithelial cystoid edema; 12 eyes had disrupted inner segment/outer segment (IS/OS) junction, and 5 eyes had disrupted IS/OS and external limiting membrane (ELM). BCVA at 6 months after surgery was no significant difference with that at 12 months after surgery (t=-0.636, P=0.529). At 12 months after surgery, there were 4 retinal patterns on OCT examination, including normal retinal microstructure, neuroepithelial cystoid edema, IS/OS line disruption, and IS/OS and ELM disruption. The BCVA difference among these 4 groups was significant (F=52.42, P < 0.05). The BCVA difference between eyes with or without residual subretinal fluid was significant (t=-5.747, P=0.000). At 1, 2 weeks and 1, 3, 6, 12 months after surgery, the MD were (11.38±2.53), (10.14±2.19), (9.17±2.13), (6.63±1.70), (5.71±1.89), (5.14±1.69) dB respectively, with a significant difference between these time-points (F=63.528, P=0.00). However, the MD at 6 months after surgery was no significant difference with that at 12 months after surgery (t=1.442, P=0.157). At 12 months after surgery, there were 12 eyes with normal MD, 30 eyes with higher MD. There was no significant difference between surgery eyes with higher MD and fellow eyes in MD (t=-1.936, P=0.06). The MD value was positively correlated to the time of retinal detachment in patients with normal retinal microstructure (r=0.84, P=0.00). There were differences in LV during different periods after surgery (F=57.25, P=0.00). ConclusionsThe retinal microstructure, visual acuity, visual fields were gradually improved after scleral bulking. The patients had better vision with normal retinal microstructure. The time of retinal detachment positively correlated with visual fields damage.
ObjectiveTo explore the effect and mechanism of netrin-1 on blood-retinal barrier permeability in diabetes mellitus (DM) rats. MethodsEighty Sprague-Dawley rats were randomly divided into the normal control group, DM+balanced salt solution (BSS) group, DM+netrin-1 low dose group and DM+netrin-1 high dose group, with 20 rats in each group. DM rats were induced by intraperitoneal injection of streptozocin (STZ). These rats were feed with high sugar and fat for 3 months after STZ injection. All rats were sacrificed at 1 month after intravitreal injection. Retinal vascular permeability was measured by Evans blue. The expression level of occludin was determined by immunohistochemistry. Hematoxylin-eosin (HE) staining of retina was used to observe the pathological change of DM and the level of occludin mRNA was analyzed by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR). Five rats of each group. ResultsHE staining of retina showed that the degree of edema and vascularization in DM+netrin-1 high dose group was better than DM+BSS group. Staining of occludin in retina was limited to nerve fiber layer, ganglion cells, inner plexiform layer and inner nuclear layer in normal rats, but in DM+BSS group, the color of staining positive of occludin was lighter and more reduced. However, DM+ netrin-1 group occludin staining was deepen and enlarged. The result of RT-PCR showed that the expression of occludin mRNA in other three groups was less than normal control group (P < 0.05). The significant difference during DM+BSS group, low dose group and DM+netrin-1 high dose group (F=177.13, P=0.00), and the more concentrate of netrin-1 the higher expression of occluding. Compared the DM+netrin-1 low dose group with DM+BSS group, there was significant difference expression of occludin (t=-13.98, P=0.00). There was significant difference between the DM+netrin-1 high dose group and normal control group (t=12.87, P=0.00). There was statistically significant difference in DM+BSS group, DM+netrin-1 low dose group and DM+netrin-1 high dose group (F=179.69, P=0.00). Compared the two group of different concentration netrin-1, the quantification of vascular permeability in DM+netrin-1 high dose group reduced more (t=12.73, P=0.00). ConclusionsNetrin-1 can protect the blood-retinal barrier in DM rats. Netrin-1 may decrease BRB leakage in DM rats by protecting the expression of occludin.