Efficacy and necessity of prophylactic vitrectomy for acute retinal necrosis syndrome

AIM: To compare the efficacy of prophylactic vitrectomy for acute retinal necrosis syndrome(ARN) with routine treatment in Chinese patients, thereby investigate the necessity of prophylactic vitrectomy for ARN. METHODS: Thirty patients (37 eyes) were retrospectively included in this study. The eyes were divided into 2 groups by treatment, including routine treatment, which consisted of antiviral medication and vitrectomy after retinal detachment (RD) (n=21), and prophylactic vitrectomy, which consisted of antiviral medication and vitrectomy for the prevention of RD performed during the active inflammatory phase (n=16). The extent of necrosis was determined by fundus photographs at the time of presentation (for eyes with mild vitreous opacity) or the drawings in the operation records. Necrosis of the 37 eyes was divided into 3 grades, including peripheral, middle-peripheral and extensive. The follow-up period ranged from 8 to 57 months. Differences in visual acuity and necrosis between groups were identified using independent samples t-test. RESULTS: Necrosis was more extensive in the routine treatment group than in the prophylactic vitrectomy group (P<0.05). In the routine treatment group, conservative treatment improved necrosis and prevented RD in 6 eyes (29%). Seven eyes (33%) obtained anatomical success, but retinal redetachment occurred in 8 eyes (57%). There were also 5 eyes (24%) developed ocular hypotony or atrophy. Ten eyes (48%) achieved equal or increased visual acuity. In the prophylactic vitrectomy group, RD occurred in 2 eyes (13%). Twelve eyes (75%) were completely anatomically successful, and 10 eyes underwent silicone oil removal. Only one eye (6%) became ocular hypotony. Fourteen eyes (88%) achieved equal or increased visual acuity. The prophylactic vitrectomy group achieved better vision trends than the routine treatment group (P<0.05). Eyes with peripheral necrosis had better visual outcomes than those with mid-peripheral (P<0.05) or extensive (P<0.05) necrosis. However, there was no significant difference between eyes with mid-peripheral and extensive necrosis (P=0.3008) CONCLUSION: Prophylactic vitrectomy can prevent RD and improve the prognosis of ARN, making it an option for cases with rapidly progressing necrosis despite antiviral treatment and cases with moderate to extensive necrosis and severe vitreous opacity.

Diverse roles of macrophages in intraocular neovasculardiseases:a review

Macrophages are involved in angiogenesis, and might also contribute to the pathogenesis of intraocular neovascular diseases. Recent studies indicated that macrophages exert different functions in the process of intraocular neovascularization, and the polarization of M1 and M2 phenotypes plays extremely essential roles in the diverse functions of macrophages. Moreover, a large number of cytokines released by macrophages not only participate in macrophage polarization, but also associate with retinal and choroidal neovascular diseases. Therefore, macrophage might be considered as a novel therapeutic target to the treatment of pathological neovascularization in the eye. This review mainly summarizes diverse roles of macrophages and discusses the possible mechanisms in retinal and choroidal neovascularization.

Survivin and p53 expression in primary and recurrent pterygium in Chinese patients

AIM: To assess the expression of anti-apoptotic protein survivin and tumor suppressor p53 protein in primary and recurrent pterygium and to investigate the relationship between them. METHODS: Survivin was assessed immunohistochemically using rabbit polyclonal antibody and p53 using mouse monoclonal antibody in a study sample of 20 cases of primary pterygium, 10 cases of recurrent pterygium and 10 cases of normal conjunctiva. RESULTS: In our study, 35% of primary (7 of 20) and 40% of recurrent (4 of 10) pterygium specimens were positive for survivin staining; 45% of primary (9 of 20) and 50% of recurrent (5 of 10) pterygium specimens were positive for p53 expression; and all normal conjunctiva showed no staining of either survivin or p53. The p53 and survivin immunoreactivity in primary and recurrent pterygium groups was greater than those in normal conjunctiva group (P<0. 05). There were no differences in p53 and survivin immunoreactivity between groups of primary and recurrent pterygium (P >0.05). The expression of survivin clearly segregated with p53-positive pterygium as compared with p53-negative cases [8 of 14 cases (57.1%) vs ersus 3 of 16 cases (15.2%)]. The Fisher's exact test analysis confirmed a highly statistically significant correlation between survivin and p53 expression (P <0.05). CONCLUSION: The survivin and p53 are overerpressed with correlation between them in primary and recurrent pterygium.

Rhegmatogenous retinal detachment associated with massive spontaneous suprachoroidal hemorrhage and prognosis of pars plana vitrectomy

AIM:To describe the clinical characters of rhegmatogenous retinal detachment(RRD) associated with massive spontaneous suprachoroidal hemorrhage(SSCH). To evaluate optimal timing and prognosis of pars plana vitrectomy.METHODS:A retrospective review of 6 cases(6 eyes)of RRD and massive SSCH among 3772 cases of RRD was conducted. All of 6 patients were treated with twenty-gauge vitrectomy, suprachoroidal blood drainage,phacoemulsification(PHACO) or lensectomy and silicon oil tamponade. The clinical characters, intraoperative findings and treatment outcomes were reported.RESULTS:In the 6 affected eyes of 6 patients(3 men and 3 women; mean age, 53.83y; range 34-61y),preoperative visual acuity ranged from faint light perception(LP) to counting finger(CF). The average interventional duration from visual decreased to surgery was 12.8 d(range 9-15d). All eyes were associated with high myopia and the mean ocular length was 30.32 mm(range 28.14-32.32 mm). Choroidal hemorrhage were successfully drained in the operation of all 6 eyes.Intraoperative findings showed there were multiple retinal breaks in all 6 eyes and in 4 eyes breaks were along supratemporal and/or infratemporal retinal vascular arcade, especially in the edge of chorioretinal atrophy areas. These patients were followed up from 6 to 34mo(Mean, 23.5mo). The best-corrected visual acuity after surgery varied from CF to 20/100, with improvement in 5eyes(83.33%) and no change in 1 eye(16.67%). Ocular hypertension ocurred in 1 eye(16.67%), which wassuccessfully treated by silicon oil removal combined with trabeculectomy. In 4 eyes, tractional retinal detachment caused by proliferative vitreoretinopathy(PVR) appeared and a secondary surgery of pre-retinal membrane peeling and silicon oil retained were performed. In 4eyes, silicon oil cannot be removed. The initial and final reattachment rates were 33.33% and 66.67%, respectively.CONCLUSION:RRD associated with massive SSCH is an extremely rare event. The most common risk factor is long axial length. Vitrectomy and choroidal blood drainage can effectively remove suprachoroidal hemorrhage and promote retinal reattachment in these eyes. However, silicon oil could not be removed in most eyes and final visual acuities are generally poor.

Characteristics of neural growth and cryopreservation of the dorsal root ganglion using three-dimensional collagen hydrogel culture versus conventional culture

In vertebrates, most somatosensory pathways begin with the activation of dorsal root ganglion(DRG) neurons. The development of an appropriate DRG culture method is a prerequisite for establishing in vitro peripheral nerve disease models and for screening therapeutic drugs. In this study, we compared the changes in morphology, molecular biology, and transcriptomics of chicken embryo DRG cultured on tissue culture plates(T-DRG) versus three-dimensional collagen hydrogels(C-DRG). Our results showed that after 7 days of culture, the transcriptomics of T-DRG and C-DRG were quite different. The upregulated genes in C-DRG were mainly related to neurogenesis, axon guidance, and synaptic plasticity, whereas the downregulated genes in C-DRG were mainly related to cell proliferation and cell division. In addition, the genes related to cycles/pathways such as the synaptic vesicle cycle, cyclic adenosine monophosphate signaling pathway, and calcium signaling pathway were activated, while those related to cell-cycle pathways were downregulated. Furthermore, neurogenesis-and myelination-related genes were highly expressed in C-DRG, while epithelial–mesenchymal transition-, apoptosis-, and cell division-related genes were suppressed. Morphological results indicated that the numbers of branches, junctions, and end-point voxels per C-DRG were significantly greater than those per T-DRG. Furthermore, cells were scattered in T-DRG and more concentrated in C-DRG, with a higher ratio of 5-ethynyl-2′-deoxyuridine(EdU)-positive cells in T-DRG compared with C-DRG. C-DRG also had higher S100 calcium-binding protein B(S100 B) and lower α-smooth muscle actin(α-SMA) expression than T-DRG, and contained fewer terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)-positive cells after 48 hours of serum starvation. After cryopreservation, C-DRG maintained more intact morphological characteristics, and had higher viability and less TUNEL-positive cells than T-DRG. Furthermore, newly formed nerve bundles were able to grow along the existing Schwann cells in C-DRG. These results suggest that C-DRG may be a promising in vitro culture model, with better nerve growth and anti-apoptotic ability, quiescent Schwann cells, and higher viability. Results from this study provide a reference for the construction, storage, and transportation of tissue-engineered nerves. The study was approved by the Ethics Committee of Aier School of Ophthalmology, Central South University, China(approval No. 2020-IRB16), on March 15, 2020.

Applications of CRISPR/Cas9 in retinal degenerative diseases

Gene therapy is a potentially effective treatment for retinal degenerative diseases.Clustered regularly interspaced short palindromic repeats（CRISPR）/CRISPR-associated protein 9（Cas9） system has been developed as a new genome-editing tool in ophthalmic studies.Recent advances in researches showed that CRISPR/Cas9 has been applied in generating animal models as well as gene therapy in vivo of retinitis pigmentosa（RP） and leber congenital amaurosis（LCA）.It has also been shown as a potential attempt for clinic by combining with other technologies such as adeno-associated virus（AAV） and induced pluripotent stem cells（i PSCs）.In this review,we highlight the main points of further prospect of using CRISPR/Cas9 in targeting retinal degeneration.We also emphasize the potential applications of this technique in treating retinal degenerative diseases.

Episcleral macular buckling for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole

AIM: To evaluate anatomical and visual outcomes of episcleral macular buckling (EMB) for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole.METHODS: Five cases of EMB for initial failure of retinal reattachment after internal limiting membrane (ILM) peeling and silicone oil tamponade caused by myopic macular hole were retrospectively reviewed. A silicone sponge sutured directly across the macular region was performed on the silicone oil filled eyes. Silicone oil was removed no sooner than 1 month post- EMB. The duration of follow -up time after removal of silicone oil was more than 3 months.RESULTS: Retinas of five eyes were all reattached at the last follow-up. The postoperative vision ranged from counting fingers to 0.08.CONCLUSION: Anatomical results improved after EBM for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole, which was not evident for visual outcome.