PURPOSE:To evaluate the activitv of protein kinase C(PKC) in response to retinal photochemical insult in rat. Furthermore, to investigate the effect of dexamethasone(DXM ) on PKC activity. METHODS :The experiments were performed on 48 SI') rats whieh were separated into two groups,control and treated groups,and the latter received daily intraperitoneal injections of DXM (1 mg/kg)for 5 consecutive days,starting 3 days before light exposure. The animals were continually exposed to green fluorescent light (510nm~560nm) with an illuminance level of (1 900plusmn;106.9)lx for 24 hrs.The retinal enzyme activity of PKC was tested at 6 hrs,1 day,3 days,7 days,and 14 days after light exposure respectively. RESULTS:In animal models,PKC activity showed a transient increase in both groups at 6 hrs after light exposure and then decrease persistently there alter. The activity of PKC was unresponsive to DXM intervention. CONCLUSIONS :These results suggested that the persistent lower PKC activity might result in disturbance of retinal function in rat retinal photochemical injury. （Chin J Ocul Fundus Dis,1997,13: 78-80）
Chronic central serous chorioretinopathy (CSC) usually demonstrates frequent recurrence, diffuse leakage and persistent subretinal fluid, which cannot be absorbed, thus lead to photoreceptor damage and poor visual acuity. As glucocorticoids have been implicated in the pathogenesis of chronic CSC, various anti-glucocorticoids oral drugs were used in the clinic to promote retinal fluid absorption and reduce the central retinal thickness of the macula and improve the vision outcomes. In addition, the 5α-reductase-specific inhibitor finasteride, the P450-3A4 inducer rifampicin, circadian rhythmic regulator melatonin, and systemic anti-inflammatory drug methotrexate have also been put into clinical trials for chronic CSC, and achieved certain effects. However, most of the clinical studies on these oral drugs were case reports, but not multi-center randomized clinical trials. The long-term effects of these oral drugs need to be observed and studied further.
Retinitis pigmentosa (RP) is a disease that seriously affects vision. It mainly affects rod cells and causes night blindness. At the end of the disease, due to the simultaneous involvement of cone cells, the patient’s central vision and peripheral vision loss are not effective. There is no effective treatment method. However, some studies have found that although the function of photoreceptors is lost in the pathological process of RP, the function of bipolar cells and ganglion cells and the neural connection with the visual center are preserved, which provides a condition of therapeutic application in optogenetics for optogenetics. Optogenetics controls the excitability of neurons by expressing the light-sensitive protein represented by rhodopsin ion channel protein-2 on neurons, and has shown great application prospects in reshaping the photoreceptor function of the retina. The treatment of a type of retinal degenerative disease provides an effective treatment option.
ObjectiveTo assess the efficacy and safety of intravitreal aflibercept injection (IAI) compared with photodynamic therapy (PDT) in the treatment of Chinese patients with predominantly classic subfoveal choroidal neovascularization (CNV) lesions secondary to neovascular age-related macular degeneration (nAMD).MethodsA randomized, double-blind, multi-center phase-3 clinical trial lasting for 52 weeks (from December 2011 to August 2014). Subjects were randomized in a 3:1 ratio to either IAI group or PDT-to-IAI group. Subjects in the IAI group received 2 mg IAI at baseline and at week 4, 8, 16, 24, 32, 40, 48, with sham injection at week 28, 36. Subjects in the PDT-to-IAI group were forced to receive PDT once at baseline and more time at week 12, 24 if PDT retreatment conditions were met. Sham injections were given in PDT-to-IAI group at baseline and at week 4, 8, 16 and 24, followed by 2 mg IAI at week 28, 32, 36, 40, 48. The primary outcome of efficacy were the change in mean Best Corrected Visual Acuity (BCVA) from baseline to week 28, and that of week 52. Safety evaluation included the percentage of subjects who suffered treatment emergent adverse events (TEAEs).ResultsAmong the 304 subjects enrolled, there were 228 and 76 cases in IAI group and PDT-to-IAI group respectively. At week 28, the changes of mean BCVA in IAI group, PDT-to-IAI group compared to baseline were +14.0, +3.9 letters, respectively. At week 52, the changes of mean BCVA in two groups were +15.2, +8.9 letters respectively with the difference of +6.2 letters (95%CI 2.6−9.9, P=0.000 9). At week 52, the mean foveal retinal thickness in the two groups decreased by −189.6, −170.0 μm, respectively. Subjects with the most BCVA increase in IAI group were those aged ＜65, and those with active CNV lesion area ＜50% of total lesion area. The most common TEAEs in IAI group and PDT-to-IAI group are macular fibrosis [11.8% (27/228), 6.6% (5/76)] and BCVA decline [6.6% (15/228), 21.1% (16/76)]. There were 3 cases of arterial thromboembolic events defined in the antiplatelet experimental collaboration group, but all were considered unrelated to interventions.ConclusionsThe efficacy of aflibercept is superior to that of PDT in nAMD patients in China. The therapeutic effect of aflibercept persisted to week 52 in all subjects. The rate of adverse events was consistent with the safety data of aflibercept known before.