No abstract

Retinoblastoma is an severe ophthalmic disease and the most common type intraocular malignant tumor, particularly in infants. Currently, few drugs and therapies are available. Gene therapy has been considered to be a potential treatment to cure cancer effectively and Herpes simplex virus type 1 thymidine kinase/ganciclovir (HSV-TK/GCV) is one type of suicide gene therapy that has been extensively studied. Numerous in vitro and in vivo studied have shown that this system can kill tumor cells, including liver and lung cancer cells. GCV is used as an antiviral drug, and the thymidine kinase, HSV-TK can phosphorylate GCV to GCV-TP, a competitive inhibitor of DNA synthesis, instead of guanine-5′-triphosphate in the process of DNA synthesis. This process prevents DNA chain elongation causing cell death via apoptosis. However, the toxic effects of HSV-TK/GCV on retinoblastoma cells remain unknown, and the molecular mechanisms of its therapeutic effects have not been fully elucidated. Our results suggest that HSV-TK/GCV can significantly cause the death of retinoblastoma cell lines, HXO-RB44 and Y79. Further studies have reported that this cell death is induced by the inhibition of autophagy by activating the MAPK/ERK (mitogen-activated protein kinase/ERK) signaling pathway. The mTOR inhibitor Torin1 can partially block the toxic effects of HSV-TK/GCV on HXO-RB44 cells. The above results demonstrate that the mechanism undertaken by HSV-TK/GCV to exhibit therapeutic effects mechanism may inhibit autophagy by activating MAPK/ERK. The findings of the present study may provide novel insight for the exploration of HSV-TK/GCV in the treatment of retinoblastoma.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

No abstract

AIM: To introduce and evaluate the clinical efficacy of a new technique, the use of viscoelastic substances (VS) to close leaking sclerotomy in 23G microincision vitrectomy, and to observe its effect on the visual acuity and intraocular pressure (IOP) of patients. METHODS: Patients who underwent 23G vitrectomy in Ningbo Eye Hospital before the use of VS technique (June 2019 to September 2020) and after the use of VS technique (October 2020 to December 2021) were selected as the subjects of this study. The above cases underwent operation by the same surgeon and were retrospectively analyzed. VS technique was used as the alternative to suturing, in which a small amount of VS was injected at the leaking sclerotomy and then gently massaged to confirm leaking sclerotomy closure. RESULTS: A total of 174 eyes were covered in the study, including 84 eyes in the control group (before the use of VS technique) and 90 eyes in the VS technique group. The number of eyes that needed to be sutured decreased considerably from 42.9% in the control group to 3.3% in the VS technique group, and the proportion of subconjunctival hemorrhage at 1-2d after surgery decreased remarkably from 35.7% in the control group to 2.2% in the VS technique group. No substantial differences in the incidence of mean IOP and low IOP were found between 1-2 and 3-20d after surgery in the VS technique group. No major complications associated with VS technique were identified during the study. CONCLUSION: In 23G microincision vitrectomy, VS technique is a safe, simple, and effective method to close leaking sclerotomy.

Objective. To examine the use of a viscoelastic agent instead of air in the vitreous cavity during surgery for scleral buckling. Methods. This was a retrospective cohort study of patients who underwent scleral buckling surgery for bulging rhegmatogenous retinal detachment (RRD) at Ningbo Eye Hospital from 07/2016 to 12/2019. The patients were grouped into drainage, air injection, cryotherapy and explant (DACE) and drainage, viscoelastic injection, cryotherapy, and explant (DVCE) groups, which were comparatively assessed. Results. There were 25 and 22 patients in the DVCE and DACE groups, respectively. The surgery was significantly shorter with DVCE than DACE ( P < 0.05 ), with less intraoperative external pressure adjustment ( P < 0.05 ). BCVA was lower in the DVCE group at 1 week compared with the DACE group ( P < 0.05 ). Successful retinal reattachment was observed in 92.0% and 81.8% of the DVCE and DACE groups, respectively ( P < 0.05 ). Cases requiring laser replenishing after the operation were less in the DVCE group compared with the DACE group ( P < 0.05 ). There were no differences in complications and intraocular pressure between the two groups (all P < 0.05 ). Conclusion. DVCE has better operative characteristics and faster vision recovery than DACE, with similar outcomes.