With the increasing popularity of intraoperative optical coherence tomography (iOCT) equipment, the use of iOCT for a variety of fundus diseases is gradually increasing. Most clinical studies on iOCT have a small number of samples and lack of control, and the level and quality of evidence are generally not good. Therefore, the evaluation of the clinical value of iOCT is mainly based on whether it is helpful for surgical manipulation and whether it has influence on intraoperative decision-making. Currently, membrane peeling during vitrectomy is the most common use of iOCT. The current iOCT does not have the automatic tracking function, which requires the surgeon to stop the operation and manually adjust the position of the probe to track the scanning site to obtain the image. The synchronous automatic tracking cannot be achieved. In the future, it is necessary to develop an automatic tracking system to reduce the workload of the surgeon during the operation.
Pharmaceutical therapy, including anti-vascular endothelial growth factor treatment and intravitreal corticosteroids, is the most common treatment for branch retinal vein occlusion (BRVO) and its complications, however there are confusing ideas about the protocol, patient selection, timing and endpoint of this treatment. The disease is easy to relapse with these drugs therapy. Collateral vessel formation was found in patients receiving intravitreal injection of ranibizumab or triamcinolone for BRVO and secondary macular edema. The mechanism of collateral vessel formation has not been carefully investigated. In the past thrombolysis, arteriovenous fasciostomy and laser choroidal retinal vascular anastomosis were used to reconstruct the retinal circulation, but their rationality, effectiveness and safety need to be further were studied. In recent years, because of the key technology is still immature, the artificial vascular bypass surgery experiment is not yet practical, but provides us a new idea worth looking forward to for the treatment of BRVO.
Choroidal nevus is one of the most common benign melanocytic tumor. The prevalence rate of choroidal nevi is 0.15% - 10.00%, which is high among whites and low among colored people, and is obvious higher in male than that in female. Secondary changes in the surrounding retina of the benign tumor, such as subretinal fluid and choroidal neovascularization, may result in vision loss. This benign tumor carries risks for transformation into malignant melanoma. The factors predictive of transformation into melanoma included greater thickness, subretinal fluid, visual symptoms, orange lipofuscin pigment, tumor location (tumor margin near optic disc), ultrasonography hollowness and absence of halo. Early identification of the related features which impair visual acuity is important for early treatment and better prognosis, and it is especially important to monitor the tendency of malignant transformation. Optical coherence tomography (OCT) could provide detailed information which aid in diagnosing, differentiating and monitoring of choroidal nevi. OCT and optical coherence tomography angiography are emerging as excellent techniques to investigate choroidal melanocytic lesions. The treatment modalities, such as laser photocoagulation, photodynamic therapy and intravitreal anti-vascular endothelium growth factor, have been proved to be effective for choroidal nevi with secondary changes. In the future, the relevant researches should be imposed to provide more detailed information in order to explore the nature and characteristics of this disease.
Dissociated optic nerve fiber layer (DONFL) appearance is consists of numerous arcuate dark striae within the posterior pole in the direction of the optic nerve fibers. And on the cross-sectional image, DONFL was correspond to inner retinal dimples. It mainly occurs after the internal limiting membrane (ILM) peeling due to the direct damage on the local retina and the broad tractional effect on the posterior retina during membrane peeling. DONFL appearance is considered to be a spontaneous and delayed morphologic change with a subclinical nature, and appears to have little effect on retinal function. In addition to avoiding the removal of ILM and reducing the area of ILM peeling, a novel technique for reposition of the fixed ILM flap with the assistance of perfluoro-n-octane and the temporal inverted ILM flap technique can also be used to prevent and reduce the occurrence of DONFL appearance. Further studies on its development, clinical features and clinical significance are still required.
Idiopathic macular hole after the internal limiting membrane (ILM) is removed during surgery, the intraoperative optical coherence tomography can be used to observe the presence of debris tissue (RF) protruding into the vitreous cavity at the edge of the hole. Current studies suggest that RF may be caused by epiretinal proliferation and vitreomacular traction, but it is still controversial, and the influence of postoperative anatomical and functional recovery is not clear. Common points can still be found, some of the studies suggest that RF is not conducive to postoperative anatomical and functional recovery during the operation, ILM fragments remain on RF tissues after ILM peeling and re-staining. However, in some studies suggest that RF is beneficial to postoperative anatomical and functional recovery, and ILM fragments on RF are removed. This suggests that whether ILM is removed on RF lead to a certain influence on the postoperative efficacy. There are few researches on RF at present, so it is necessary to understand RF from its essence and assist judgment through histological analysis.
Objective To evaluate quantification of metamorphopsia in eyes with idiopathic macular hole (IMH) before and after surgical treatment, and investigate its relationship between postoperative visual acuity, the macular hole index (MHI), and the macular hole prognostic factor (HPF). Methods Thirty eyes of 30 patients, who underwent successful vitrectomy and internal limiting membrane (ILM) peeling for IMH and were followed up more than 6 months, were included in the study. The uncorrected visual acuity of the fellow eyes was better than 20/25 and there was no metamorphopsia in that eye. The macular hole closure was confirmed by optical coherence tomography (OCT) scans. Metamorphopsia was evaluated by metamorphopsiacharts (M-chart). OCT, best corrected visual acuity (BCVA) and metamorphopsia were obtained before and after surgery. Vertical (MV) and horizontal (MH) metamorphopsia, macular hole index (MHI, the ratio of the height to the diameter of the base), and macular hole prognostic factor (HPF, the ratio of the height to the minimum diameter) were measured. The metamorphopsia score was the average value of MV and MH. SPSS 16.0 statistical analysis software was used for data analysis. Results Preoperative MV and MH were (1.82plusmn;0.04)deg;and (1.81plusmn;0.04)deg;, respectively. Six months after surgery, the MV and MH were (0.17plusmn;0.03)deg;and (0.11plusmn;0.03)deg;respectively. There was significant difference between pre- and post-operative metamorphopsia results (Z=-0.788，P＜0.05). The metamorphopsia score at 6 months after surgery were positively correlated with the value of the postoperative BCVA (LogMAR) (r=0.540,P=0.004) and negatively correlated with the values of preoperative MHI and HPF (r=-0.676, -0.518;P＜0.05). Conclusions Successful vitrectomy and ILM peeling can improve metamorphopsia of IMH. Postoperative metamorphopsia was correlated with the postoperative BCVA and the preoperative macular hole contour.
Objective To investigate the retinal toxicity and verify the safe dose of intravitreal injecting fluconazole. Methods Twelve healthy adult white rabbits were divided at random into 6 groups：a normal control group and 5 groups received intravitreal injection of a single dose of fluconazole ranging from 10 to 200 mu;g respectively.Retinal toxicity was examined by ophthalmoscopy, electroretinography, light and transmission electron microscopy (TEM) on the third and fourteenth day after injection. Results The ultrastructures of the retinal tissues of the normal control group and fluconazole 10～150 mu;g groups were normal on the third and fourteen day after injection.The light microscopy and TEM showed that cells of all the retinal layers in the 200 mu;g group revealed apparent degenerative changes on the fourteenth day after injection, and the light microscopic picture showed the vacuolar degeneration of outer segments of photoreceptors, the nuclei in outer nuclear layer drop out into inner segments, the vacuolar degeneration of nerve fiber layer, and the proliferation of pigment epithelium. TEM revealed expansion of paranucl eus space and karyopyknosis of the bipolar cells, the swelling of nerve fibers and disappearance of the synapses in the inner plexiform layer, the vacuolation and disappearance of microvilli of the pigment epithelium cells. Conclusion The safe dose of fluconazole injected intravitreally should be 100～150 mu;g. (Chin J Ocul Fundus Dis，2000，16：139-212)