A pilot study of viscoelastic agent to prevent recurrent vitreous hemorrhage after vitrectomy for proliferative diabetic retinopathy.

BACKGROUND: To evaluate the possibilty of preventing recurrent vitreous hemorrhage (RVH) after vitrectomy in proliferative diabetic retinopathy (PDR) patients with unabsorbed vitreous hemorrhage (VH) by intravitreal injection of viscoelastic agent (VA) at the end of the surgery and compared its effect with triamcinolone acetonide (TA). METHODS: This was a pilot prospective, observational study. PDR patients with VH who underwent vitrectomy were assigned to 3 groups according to the tamponade applicated at the end of the surgery, including VA group (intravitreally injected 1 ml VA if the retina was prone to bleed during the operation), TA group (intravitreally injected 2 mg TA when there was much exudates), or balanced salt solution (BSS) group (no tamponade). Then postoperative follow-up was performed routinely until 6 months after surgery. The primary outcome was the incidence of RVH, secondary outcome were the best-corrected visual acuity (BCVA) and introcular pressure (IOP). Cataract formation and other complication were also assessed. RESULTS: A total of 68 eyes, from 68 patients, were included. 18,18,32 eyes were enrolled in the VA group, TA group and BSS group, respectively. The integral incidence of RVH after vitrectomy was 5.6%, 5.6% and 12.5% respectively (P = 0.602). There was no early RVH in VA or TA group, whereas 3 early RVHs were identified in BSS group, however there was no significant difference (P = 0.171). Every group had one late RVH case. In all groups, final BCVA showed significant improvement compared to baseline. BCVA at any postoperative visit showed no significant differences among 3 groups. Mean IOP was higher 1 week after surgery in VA group compared with the other groups; however, in other times the differences were not significant. No cataract formation and other complication was noted in 3 groups. CONCLUSION: Intravitreal injection of VA or TA at the end of vitrectomy for PDR patients with unabsorbed VH tend to reduce the incidence of early RVH after vitrectomy similarly. As VA was preferred to applicate in the eyes that were prone to bleed, intravitreal injection of VA at the end of vitrectomy might be a promising method for preventing RVH in PDR patients.

Epigenetic modifications in chronic rhinosinusitis with and without nasal polyps.

Chronic rhinosinusitis (CRS) has brought a huge socioeconomic burden. However, its mechanism is still elusive, which may involve genetic, environmental and some other factors. Epigenetic analyses have been conducted to explore the mechanisms underlying CRS. Here, we reviewed the fruits in the epigenetic studies on DNA methylation, histone modification, and non-coding RNA regulation. We concluded that the epigenetic research on CRS has made great breakthroughs, especially in the past 5 years and the field of microRNAs. "Epigenetic therapies" are expected to be designed to treat CRS in the future.

CircRNA expression profiles and circRNA-miRNA-mRNA crosstalk in allergic rhinitis.

BACKGROUND: Circular RNAs (circRNAs) are involved in inflammation; however, their role in allergic rhinitis (AR) remains unclear. In this study, we analyzed circRNA expression and identified a circRNA-miRNA-mRNA network through which circRNAs regulate AR pathogenesis. METHODS: We analyzed circRNA, miRNA, and mRNA expression profiles in the nasal mucosa by high-throughput sequencing (HTS), using a fold-change >1.5 and p-value < 0.05 to pinpoint significantly differentially expressed (DE) circRNAs, miRNAs, and mRNAs in AR. A DEcircRNA-DEmiRNA-DEmRNA crosstalk network was then constructed using bioinformatics and statistical analysis. Gene ontology and Kyoto encyclopedia of genes and genomes pathway analyses were performed to identify the biological terms enriched in the network; whereas RT-PCR and Sanger sequencing were used to confirm the circRNAs. RESULTS: A total of 264 DEcircRNAs were identified by HTS, including 120 upregulated and 144 downregulated in AR compared to controls. A DEcircRNA-DEmiRNA-DEmRNA crosstalk network was constructed with 17 miRNAs, 11 circRNAs, 29 mRNAs, and 64 interaction pairs. These genes were involved in the Wnt signaling pathway, TNF biosynthesis, inflammatory responses, the PI3K-Akt signaling pathway, and Toll-like receptors. Of the 11 DEcircRNAs, hsa_circ_0008668 and circTRIQK were upregulated, whereas hsa_circ_0029853 and circRNA_01002 were downregulated in AR tissues. Sanger sequencing confirmed the back-splicing junctions of these circRNAs. CONCLUSIONS: We constructed a novel DEcircRNA-DEmiRNA-DEmRNA network for AR that provides a basis for future studies to investigate its underlying molecular mechanisms.

A nationwide survey of otolaryngologists' compliance with Chinese guidelines for diagnosis and treatment of allergic rhinitis.

BACKGROUND: A higher compliance with clinical guidelines helps improve treatment outcomes. But the clinical practice of otolaryngologists is not always consistent with guidelines. OBJECTIVE: To describe otolaryngologists' compliance with guidelines about allergic rhinitis (AR) management and identify factors responsible for the discordance between clinical practice and guideline recommendations in China. METHODS: A cross-sectional nationwide survey was designed and conducted via an online platform. Recruitment was done by emailing otolaryngologists registered in the Chinese Society of Otorhinolaryngology-Head and Neck Surgery or by inviting otolaryngologists to scan a Quick Respond (QR) code that linked to the questionnaire at various academic meetings. RESULTS: A total of 2142 otolaryngologists were eligible and completed the survey. Of them, 64.7% had over 10 years work experience and 97.4% had a bachelor's degree or higher. About 18.3% of the participants strictly copied the guideline in clinical practice, while 73.7% used the guideline that had been adjusted according to their clinical experience. Otolaryngologists were most concerned about the efficacy, safety, and minimum age of AR medications, and least concerned about patient preferences. Regarding the use of intranasal steroids (INS), leukotriene receptor antagonists (LTRA), and H1-antihistamines, 86.8%, 55.7% and 51.2% of otolaryngologists complied with the guideline recommendations, respectively. Educational background was a factor affecting the compliance with guidelines and acceptance of INS. CONCLUSION: A vast majority of Chinese otolaryngologists complied with the current Chinese AR guidelines. A difference still existed between the otolaryngologists' real-world and guideline-recommended management. The otolaryngologists should pay more attention to patient preferences. A higher education could improve otolaryngologists' adherence to the guidelines.

Management of allergic rhinitis with leukotriene receptor antagonists versus selective H1-antihistamines: a meta-analysis of current evidence.

BACKGROUND: Inconsistencies remain regarding the effectiveness and safety of leukotriene receptor antagonists (LTRAs) and selective H1-antihistamines (SAHs) for allergic rhinitis (AR). A meta-analysis of randomized controlled trials (RCTs) was conducted to compare the medications. METHODS: Relevant head-to-head comparative RCTs were retrieved by searching the PubMed, Embase, and Cochrane's Library databases from inception to April 20, 2020. A random-effects model was applied to pool the results. Subgroup analyses were performed for seasonal and perennial AR. RESULTS: Fourteen RCTs comprising 4458 patients were included. LTRAs were inferior to SAHs in terms of the daytime nasal symptoms score (mean difference [MD]: 0.05, 95% confidence interval [CI] 0.02 to 0.08, p = 0.003, I2 = 89%) and daytime eye symptoms score (MD: 0.05, 95% CI 0.01 to 0.08, p = 0.009, I2 = 89%), but were superior in terms of the nighttime symptoms score (MD: - 0.04, 95% CI - 0.06 to - 0.02, p < 0.001, I2 = 85%). The effects of the two treatments on the composite symptom score (MD: 0.02, 95% CI - 0.02 to 0.05, p = 0.30, I2 = 91%) and rhinoconjunctivitis quality-of-life questionnaire (RQLQ) (MD: 0.01, 95% CI - 0.05 to 0.07, p = 0.71, I2 = 99%) were similar. Incidences of adverse events were comparable (odds ratio [OR]: 0.97, 95% CI 0.75 to 1.25, p = 0.98, I2 = 0%). These results were mainly obtained from studies on seasonal AR. No significant publication bias was detected. CONCLUSIONS: Although both treatments are safe and effective in improving the quality of life (QoL) in AR patients, LTRAs are more effective in improving nighttime symptoms but less effective in improving daytime nasal symptoms compared to SAHs.

Ultrastructural study of closed macular hole- preliminary application of a novel high magnification module combining with OCT.

BACKGROUND: As a novel high magnification module (HMM) combining with OCT (OCT-HMM) is able to detect the microstructure of retina, we apply it to explore the ultrastructure of the macula after closure of the idiopathic macular hole (IMH) by surgery. METHODS: This is an observational case series study in which patients with full-thickness IMHs who had undergone successful macular closure by vitrectomy and internal limiting membrane peeling and healthy subjects were recruited. After comprehensive ophthalmic examinations, the images of macular area were obtained and collected by professional operators using OCT-HMM. Then images were independently analyzed by 4 masked vitreoretinal specialists. RESULTS: A total of 24 IMH eyes and 42 healthy eyes were examined. HMM images were obtained in 10 IMH eyes. Among them, 4 eyes whose macula closed completely with recovery of photoreceptor layer presented a dark arc nasal to the fovea, oriented to the optic, and the notch of arc faced temporally. Six eyes in which the macula closed incompletely with photoreceptor cells loss revealed a dark ring with uneven bright spots inside. The other 14 eyes failed to obtain clear images by OCT-HMM. The contra lateral eyes of the patients and the healthy subjects' eyes succeeded to obtain the HMM images which displayed evenly grey background thickly covered with tiny bright dots that was in similar size and evenly and widely distributed and there no dark arc or ring. OCT B-scan and IR images could be acquired in all of the IMH and healthy eyes. CONCLUSION: The preliminary application of HMM has supplied us a brand-new insight into the microstructure of closed IMH. A dark arc sign could be detected with OCT-HMM in the macula which was functionally closed after surgery that was probably the healing mark on a microstructure photoreceptors level. Its existence and shape indicated that the functional closure followed by a retinal displacement mainly horizontally from temporal side to nasal side but not symmetric centripetally.

Effect of long-term weightlessness on retina and optic nerve in tail-suspension rats.

AIM: To evaluate the effect of long-term weightlessness on retina and optic nerve in tail-suspension (TS) rats. METHODS: A stimulated weightlessness model was established by suspending rats' tail. After 12wk, the ultrastructure and the number of optic nerve axons were observed by transmission electron microscope. The number of survival retinal ganglion cells (RGCs) was calculated by fluorescent gold retrograde labeling. Retina cells apoptosis was detected by TUNEL staining. The function of optic nerve and retina was evaluated by the visual evoked potential (VEP) and oscillatory potentials (Ops). RESULTS: The optic nerve axons were swollen and sparsely aligned, and the lamellar separation and myelin disintegration occurred after 12wk in TS rats. The density of optic nerve axons was 32.23±3.92 (vs 37.43±4.13, P=0.0145), the RGCs density was 1645±46 cells/mm(2) (vs 1867±54 cells/mm(2) P=0.0000), the incidence rate of retinal cells apoptosis was 5.38%±0.53% (vs 4.75%±0.54%, P=0.0238), the amplitude of VEP-P100 was 15.43±2.14 µV (vs 17.67±2.17 µV, P=0.0424), the latency of VEP-P100 was 69.05±5.34ms (vs 62.43±4.87ms P=0.0143) and the sum amplitude of Ops was 81.05±8.34 µV (vs 91.67±10.21 µV, P=0.0280) in TS group and the control group, respectively. CONCLUSION: Long-term weightlessness can induce the ultrastructural changes and functional depress of the optic nerve, as well as retinal cell damages in TS rats.

Influence of N(2)O(4) on multifocal electroretinogram in winstar mice.

AIM: To record multifocal electroretinogram from different dosage of N(2)O(4) injected mice. In order to provide a foundation for further study. METHODS: Normal winstar mice which were injected by different dosage of N(2)O(4) were studied for recording multifocal electroretinogram in the same time in the evening after N(2)O(4) injection. RESULTS: The latency and amplitude density of "b" wave of each ring of multifocal electroretinogram was studied. The latency of "b" wave of each ring of multifocal electroretinogram of each group varies to each other. But the difference of the amplitude of "b" wave of multifocal electroretinogram of each ring between each group had no significance. CONCLUSION: Recording multifocal electroretinogram of N(2)O(4) injected mice will give more support for further study in related science and clinic research.

[The experimental histopathologic changes of applying perfluoropropane to filtering surgery in rabbits].

OBJECTIVE: To study the histopathologic changes of filtering blebs by subconjunctival application of perfluoropropane (C(3)F(8)) after trabeculectomy in rabbit eyes. METHODS: Twenty rabbits were randomly divided into two groups, each group consisting of 10 rabbits. Trabeculectomy with topical application of C(3)F(8) was performed on one eye and trabeculectomy alone on the other eye in first group. Whereas, trabeculectomy with topical application of mitomycine (MMC) was performed on one eye and trabeculectomy with topical application of C(3)F(8) on the other eye in second group. Histopathologic changes in filter bleb were investigated by immunostaining at 3 days, and at week 1, 2, 3, and 4 after surgery. RESULTS: Fibroblasts: The numbers of fibroblasts in eyes after trabeculectomy with C(3)F(8) gas as well as trabeculectomy with MMC were significantly reduced (P < 0.05) compared to eyes with trabeculectomy alone. There was no significant statistical difference in the numbers of fibroblasts between trabeculectomy with C(3)F(8) gas group and trabeculectomy with MMC group. Newly formed collagen fiber: Immunostaining of collagen fibers showed that the numbers of newly formed collagen fibers in trabeculectomy with C(3)F(8) gas group and trabeculectomy with MMC group were significantly decreased compared to trabeculectomy alone group. However, there was no significant statistical difference between numbers of fibers in trabeculectomy with C(3)F(8) gas group and trabeculectomy with MMC group. Neovascularization and inflammation of filtering blebs: The differences were not statistically significant among trabeculectomy with C(3)F(8) gas, trabeculectomy with MMC group and trabeculectomy alone group. CONCLUSION: Trabeculectomy with subconjunctival retention of C(3)F(8) gas can enhance the success rates of surgery by suppressing the growth of fibroblasts and synthesis of newly formed collagen fibers, and by inhibiting scar formation.