The novel chalcone analog L2H17 protects retinal ganglion cells from oxidative stress-induced apoptosis.

Chalcone is a plant metabolite widely found in fruits, vegetables, spices and tea, and has anti-tumor, anti-inflammation, immunomodulation, antibacterial and anti-oxidation activities, as well as many other pharmacological and biological effects. Our team has shown that its analogs have antioxidant activity, and oxidative stress is a pathological hallmark of retinal ischemia/reperfusion injury that can lead to retinal damage and visual loss. This investigation aims to identify a chalcone that protects retinal ganglion cells in vitro from the effects of oxidative stress and examine its mechanism. Rat retinal ganglion cell-5 cells were pretreated with chalcones and then exposed to tert-butyl hydroperoxide that causes oxidative damage. Controls received dimethyl sulfoxide only or tert-butyl hydroperoxide in dimethyl sulfoxide. Only (E)-3,4-dihydroxy-2'-methylether ketone (L2H17), of the five chalcone analogs, markedly increased the survival rate of oxidatively injured RGC-5 cells. Thus, subsequent experiments only analyzed the results of the L2H17 intervention. Cell viability and apoptosis were measured. Intracellular superoxide dismutase and reactive oxygen species levels were used to assess induced oxidative stress. The mechanism of action by L2H17 was explored by measuring the ER stress/UPR pathway and the expression and localization of Nrf2. All results demonstrated that L2H17 could reduce the apoptosis of oxidatively injured cells, inhibit caspase-3 activity, increase Bcl-2 expression, decrease Bad expression, increase the activity of superoxide dismutase, inhibit the production of reactive oxygen species, increase Nrf2 immunoreactivity, and reduce the activating transcription factor 4, phospho-eukaryotic initiation factor 2 and CHOP expression. L2H17 protects retinal ganglion cells induced by oxidative stress by regulating Nrf2, which indicates that it has the potential to become a drug for retinal ischemia/reperfusion.

A modified approach to actively remove high viscosity silicone oil through 23-gauge cannula.

AIM: To report a simple approach to actively remove high viscosity silicone oil through a 23-gauge cannula via pars plana. METHODS: Forty-eight eyes of 48 patients underwent silicone oil (5700 centistokes) removal (SOR) were enrolled. A section of blood transfusion set was prepared to connect a standard 23-gauge cannula and vitrectomy machine. Silicone oil was removed with suction of 500-mm Hg vacuum through the cannula. Main outcome measures were SOR duration, number of sutured sites, intraocular pressure (IOP), best-corrected visual acuity (BCVA), and complications. RESULTS: Silicone oil was successfully removed in all cases. The mean SOR time was 5.70±0.85min. Nine eyes (18.75%) needed suture partial sclerotomies. No intraoperative complications were noted. Transient hypotony (≤8 mm Hg) was seen in 3 eyes (6.25%) on postoperative day 1, but all resolved within 1wk. Retinal reattachment was achieved in all cases and no other postoperative complications were noted during 3-month following-up. BCVA at the final visit improved or stabilized in all patients comparing to the preoperative level. CONCLUSION: Active removal of high viscosity silicone oil through a 23-gauge instrument cannula jointed with blood transfusion set is a practical and reliable technique when considering two sides of efficacy and safety.

Passive Removal of Silicone Oil with Temporal Head Position through Two 23-Gauge Cannulas.

Purpose. To report a new approach for removal of silicone oil. Methods. All surgeries were performed using 23-gauge vitrectomy system with two transconjunctival sutureless cannulas. At the beginning, most of the silicone oil was removed by traditional microinvasive vitrectomy system through inferior-temporal cannula. Then, the blood transfusion tube is removed from the inferior-temporal cannula, and the fluid-air exchange is performed. A passive fluid-air exchange was performed to aspirate the residual silicone oil after gradually turning the patient's head temporally by approximately 90° gradually. Results. After the surgery, all patients had a clear anterior chamber and vitreous cavity on slit lamp and B scan examination, respectively. The mean time taken for silicone oil removal and total surgery was 8.0 ± 1.4 minutes and 12.4 ± 2.5 minutes, respectively. The mean intraocular pressure 1 day, 3 days, 1 week, 1 month, and 3 months after surgery was 9.0 ± 5.8 mmHg, 11.3 ± 7.6 mmHg, 16.1 ± 6.9 mmHg, 17.7 ± 4.8 mmHg, and 17.1 ± 3.5 mmHg, respectively. Conclusion. This new approach may provide a safe and fast method to remove the silicone oil.

[Vitrectomy without internal limiting membrane peeling associated with gas tamponade for treatment of foveoschisis in pathologic myopia].

OBJECTIVE: To evaluate the efficacy of vitrectomy without internal limiting membrane (ILM) peeling associated with gas tamponade in eyes with myopic foveoschisis. METHODS: A prospective study was conducted, in which 49 pathological myopia patients (52 eyes) with myopic foveoschisis were enrolled and divided into three groups according to the different therapeutic procedures: 22 patients (24 eyes) underwent vitrectomy without internal limiting membrane (non-gas tamponade group), 15 patients (16 eyes) received vitrectomy without internal limiting membrane peeling but combined with gas tamponade (gas tamponade group) and 12 patients (12 eyes) did not receive surgical treatments (control group). SAS 9.13 was used for the statistic analysis. Best-corrected visual acuity (BCVA) and optical coherence tomographic (OCT) findings of the foveal thickness before and after the operation (the 3rd, 6th, and 9th month postoperatively) were obtained and compared by the Wilcoxon Rank-Sum test. Non-parameters Wilcoxon symbols test was used to compare the BCVA, the central foveal thickness (CFT) and maximum foveal thickness (MxFT) of each group before and after the surgery. RESULTS: Postoperative visual acuity was significantly increased in the two operation groups (t = 2.57, P < 0.05; t = 3.58, P < 0.05) but not increased in the control group (t = 1.84; P > 0.05). The difference of BCVA between these three groups was not significant (χ(2) = 0.24, P > 0.05). OCT showed the mean foveal thickness was significantly decreased postoperatively. Vitrectomy without peeling of the ILM significantly promoted the retinal reattachment in eyes with myopic foveoschisis. No retinal reattachment was found in the control group while 16 and 13 retinal reattachment were found in the non-gas tamponade (66.7%) and gas tamponade group (81.3%), the difference between these two operation groups and the control was statistically significant (χ(2) = 20.50, P < 0.05). During the follow-up, two eyes in the control group developed a macular hole and both developed retinal detachment (RD) in the 6 and 8 month, respectively. The remaining 10 eyes did not develop any complications, although the thickness of the macula increased significantly. A transient increase of intraocular pressure occurred in three eyes and had been cured by medications within 2 weeks after gas tamponade. A macular hole was recognized in one eye 2 months after surgery and the retina was reattached at the fovea 1 month after reoperation. CONCLUSIONS: Vitrectomy without ILM peeling could be a safe and effective surgical approach for the treatment of foveoschisis in pathologic myopia. In addition, gas tamponade can improve the success rate of the operation.

Proposed classification of lens capsule defects.

BACKGROUND: Capsule defects are common during or after intraocular surgery of various kinds. The purpose of this work is to establish a classification system of lens capsule defects to provide uniform description of these defects for ophthalmic research and IOL implantation. METHODS: A retrospective study of 128 patients (156 eyes) with lens capsule injury after ocular trauma and intraocular surgery was performed. The patients were divided into two groups. Capsule defects were defined and classified according to the location, size, shape and tension of the capsule and its effect on posterior chamber IOL implantation. RESULTS: Lens capsule defects were classified into four types: Type I - complete capsule; Type II - incomplete capsule, but has enough area and tension to support two IOL haptics; Type III - incomplete capsule, is able to support only one IOL haptic and the other haptic needs a suture; Type IV - no capsule, both IOL haptics need suture fixation. Type I and Type II were each divided into three subtypes. Type III was divided into two subtypes. The shape of the capsule defects included fissure-like, triangle, round, irregular and fan-like. All eyes with capsule defects can be sorted into one of these types, and it is easy to guide IOL implantation according to the classification. Type II was the most common among the two groups in this study. CONCLUSION: The classification of lens capsule defects is feasible and favorable for uniform clinical description, clinical research and IOL implantation.