脂联素对小鼠氧诱导视网膜病变的保护作用

目的：观察脂联素对C57BL/6J小鼠氧诱导视网膜病变的影响。

方法：将新生C57BL/6J小鼠随机分为3组,分别为常氧对照组、生理盐水注射氧诱导视网膜病变(oxygen-induced retinopathy,OIR)组和脂联素注射OIR组。将后两组小鼠于生后第7d(P7)至P12置于体积分数75%±2%高氧氧箱中以诱导OIR模型。脂联素注射OIR模型组在P7～P15每天接受腹腔注射重组鼠脂联素蛋白(3.0μg/g),生理盐水注射OIR组则于上述相同时间点注射同等剂量的生理盐水。三组小鼠均于P17时取右眼行视网膜铺片和Lectin染色,观察视网膜中央无血管区及病理性新生血管的情况; 取左眼行视网膜切片和HE染色,观察视网膜组织病理学变化; 应用Western-blot测定左眼视网膜组织中iNOS、nNOS、eNOS的表达; 取右眼视网膜组织定量检测ROS/RNS含量以及NO水平。

结果：脂联素注射OIR组小鼠视网膜中央无血管区面积较生理盐水注射OIR组明显减少(t=7.304,P<0.01),病理性新生血管数目明显减少(t=2.654,P<0.01); 脂联素注射OIR组小鼠视网膜组织ROS含量较生理盐水注射组明显降低(t=13.349,P<0.01); 脂联素注射OIR组小鼠视网膜组织NO含量明显高于生理盐水注射组(t=3.023,P<0.01),iNOS表达明显低于生理盐水注射组(t=5.112,P<0.01),eNOS表达明显高于生理盐水注射组(t=7.421,P<0.01),nNOS的表达无统计学差异(t=1.074,P>0.01)。

结论：脂联素可以通过激活内源性eNOS促进生理性NO生成,同时又能抑制ROS/RNS的产生,在OIR进程中发挥视网膜血管的保护作用。     

Development of macular holes in diabetic retinopathy with fibrovascular proliferation: Report of four cases

There are yet no reports in the literature describing the mechanism of macular hole (MH) formation associated with fibrovascular proliferation in proliferative diabetic retinopathy. We report four cases of MHs in diabetic retinopathy with fibrovascular proliferation; formation of MHs were studied using sequential pre-MH optical coherence tomography (OCT). In Case 1, initial OCT revealed tractional schisis and cysts with fovea detachment. An MH with bowl-shaped detachment was noted within 6 weeks. In Case 2, initial OCT revealed thickened posterior hyaloid membrane with vitreomacular traction. Five and a half years later, OCT showed MH formation with possible vitreomacular separation. Some epiretinal membrane was also noted in the macula area. In Case 3, initial OCT revealed tractional retinal elevation from the superonasal area to the fovea with macular thinning. An MH with detachment developed 7 weeks later. In Case 4, initial OCT revealed macula-involved retinal detachment with traction. An MH was noted 4 weeks later. The analysis of sequential OCT findings in these four cases suggests that strong vitreoretinal adhesion and traction of fibrovascular proliferation may induce an MH without going through the same evolutionary phases as those characteristic of idiopathic MHs.     

糖尿病大鼠视网膜中内质网应激蛋白、HIF-1α和血管内皮生长因子的表达

目的：探索糖尿病大鼠视网膜中内质网应激相关BIP (蛋白重链结合蛋白)、HIF-1α(低氧诱导因子-1α)和VEGF (血管内皮生长因子)的表达及意义。
　　方法：72只雄性SD大鼠,随机分为6组：正常2月对照组(C2m),糖尿病2月组(D2m),正常4月对照组(C4m),糖尿病4月组(D4m),正常6月对照组(C6m),糖尿病6月组(D6m),每组各12只。实验组给予一次性腹腔注射65mg/kg STZ建立糖尿病模型。 ELISA法检测BIP、HIF-1α和VEGF表达水平,免疫组化法观察大鼠BIP、HIF-1α和VEGF视网膜内定位情况。
　　结果：BIP表达随DM 病程的延长而增加( P<0.05),且DM各组与对照组相比,其差异均有统计学意义( P<0.01)。 HIF-1α在DM组中表达较对照组增加,其差异有统计学意义(P<0.05),但DM组各组间差异无统计学意义。 VEGF蛋白在D2 m组与对照组间差别无统计学意义,但 D4 m、D6 m 与对照组间差别有统计学意义( P<0.05),且D4 m和D6 m两组间差别有统计学意义。免疫组化：BIP在对照组视网膜神经节细胞层中少量表达,DM组主要分布于视网膜内核层和神经节细胞层;HIF-1α在对照组基本不表达, DM组各层均有表达;VEGF在对照组大鼠中视网膜各层中少量表达,而DM组大鼠的内核层、外核层及视网膜血管、神经节细胞层中 VEGF 阳性表达。
　　结论：糖尿病大鼠视网膜组织中的 BIP、HIF-1α、VEGF均较对照组增加且随糖尿病病程进展而增加,内质网应激和低氧诱导因子途径均可能在糖尿病视网膜病变的进展中起重要作用。     

Activated complement classical pathway in a murine model of oxygen-induced retinopathy

AIM: To investigate whether the complement system is involved in a murine model of oxygen-induced retinopathy (OIR). METHODS: Forty C57BL/6J newborn mice were divided randomly into OIR group and control group. OIR was induced by exposing mice to 75%±2% oxygen from postnatal 7d (P7) to P12 and then recovered in room air. For the control group, the litters were raised in room air. At the postnatal 17d (P17), gene expressions of the complement components of the classical pathway (CP), the mannose-binding lectin (MBL) pathway and the alternative pathway (AP) in the retina were determined by quantitative real-time polymerase chain reaction (RT-PCR). Retinal protein expressions of the key components in the CP were examined by Western blotting. RESULTS: Whole mounted retina in the OIR mice showed area of central hypoperfusion in both superficial and deep layers and neovascular tufts in the periphery. The expressions of C1qb and C4b genes in the OIR retina were significantly higher than those of the controls. The expression of retinal complement factor B (CFB) gene in OIR mice was significantly lower than those of the controls. However, the expressions of C3 and complement factor H (CFH) genes were higher. The protein synthesis of the key components involved in the CP (C1q, C4 and C3) were also significantly higher in OIR mouse retina. Although MBL-associated serine protease 1 (MASP1) and MASP2 were detected in both the OIR and the control groups, the expressions were weak and the difference between the two groups was not significant. CONCLUSION: Our data suggest that the complement system CP is activated during the pathogenesis of murine model of OIR.     

Longitudinal Commercial Claims–Based Cost Analysis of Diabetic Retinopathy Screening Patterns

Background

Diabetic retinopathy is one of the most common complications of diabetes. The screening of patients with diabetes to detect retinopathy is recommended by several professional guidelines but is an underutilized service.

Objective

To analyze the relationship between the frequency of retinopathy screening and the cost of care in adult patients with diabetes.

Methods

Truven Health MarketScan commercial databases (2000–2013) were used to identify the diabetic population aged 18 to 64 years for the performance of a 2001–2013 annual trend analysis of patients with type 1 and type 2 diabetes and a 10-year longitudinal analysis of patients with newly diagnosed type 2 diabetes. In the trend analysis, the prevalence of diabetes, screening rate, and allowed cost per member per month (PMPM) were calculated. In the longitudinal analysis, data from 4 index years (2001–2004) of patients newly diagnosed with type 2 diabetes were combined, and the costs were adjusted to be comparable to the 2004 index year cohort, using the annual diabetes population cost trends calculated in the trend analysis. The longitudinal population was segmented into the number of years of diabetic retinopathy screening (ie, 0, 1–4, 5–7, and 8–10), and the relationship between the years of screening and the PMPM allowed costs was analyzed. The difference in mean incremental cost between years 1 and 10 in each of the 4 cohorts was compared after adjusting for explanatory variables.

Results

In the trend analysis, between 2001 and 2013, the prevalence of diabetes increased from 3.93% to 5.08%, retinal screening increased from 26.27% to 29.58%, and the average total unadjusted allowed cost of care for each patient with diabetes increased from $822 to $1395 PMPM. In the longitudinal analysis, the difference between the screening cohorts’ mean incremental cost increase was $185 between the 0- and 1–4–year cohorts (P <.003) and $202 between the 0- and 5–7–year cohorts (P <.023). The cost differences between the other cohorts, including $217 between the 0- and 8–10–year cohorts (P <.066), were not statistically significant.

Conclusions

Based on our analysis, the annual retinopathy screening rate for patients with diabetes has remained low since 2001, and has been well below the guideline-recommended screening levels. For patients with type 2 diabetes, the mean increase in healthcare expenditures over a 10-year period after diagnosis is not statistically different among those with various retinopathy screening rates, although the increase in healthcare spending is lower for patients with diabetes who were not screened for retinopathy compared with patients who did get screened.     

Permanent Bilateral Vision Loss in Eclamptic Posterior Reversible Encephalopathy Syndrome

Posterior reversible encephalopathy syndrome (PRES) classically consists of reversible vasogenic oedema in the posterior circulation territories, which is reversible both clinically and radiologically in the majority of patients after the control of hypertension. The authors describe a 27-year-old eclamptic patient with PRES in accelerated hypertension who revealed permanent vision loss associated with bilateral Purtscher retinopathy. One of the two competing theories that explain vasogenic brain oedema in PRES is excessive autoregulation leading to the dilation of cerebral arterial vessels, particularly in the occipito-parietal vasculatures. Dysfunction of endothelial cells that results in constriction of vessels has also been hypothesised as a cause of PRES. The concurrence of bilateral vaso-occlusive retinopathy and PRES supports the hypothesis that vasoconstriction is a more plausible mechanism of vasogenic oedema in PRES.     

Cost-utility Analysis of Screening for Diabetic Retinopathy in Japan: A Probabilistic Markov Modeling Study

ABSTRACT

Purpose: To evaluate the cost-effectiveness for a screening interval longer than 1 year detecting diabetic retinopathy (DR) through the estimation of incremental costs per quality-adjusted life year (QALY) based on the best available clinical data in Japan.

Methods: A Markov model with a probabilistic cohort analysis was framed to calculate incremental costs per QALY gained by implementing a screening program detecting DR in Japan. A 1-year cycle length and population size of 50,000 with a 50-year time horizon (age 40–90 years) was used. Best available clinical data from publications and national surveillance data was used, and a model was designed including current diagnosis and management of DR with corresponding visual outcomes. One-way and probabilistic sensitivity analyses were performed considering uncertainties in the parameters.

Results: In the base-case analysis, the strategy with a screening program resulted in an incremental cost of 5,147 Japanese yen (¥; US$64.6) and incremental effectiveness of 0.0054 QALYs per person screened. The incremental cost-effectiveness ratio was ¥944,981 (US$11,857) per QALY. The simulation suggested that screening would result in a significant reduction in blindness in people aged 40 years or over (?16%). Sensitivity analyses suggested that in order to achieve both reductions in blindness and cost-effectiveness in Japan, the screening program should screen those aged 53–84 years, at intervals of 3 years or less.

Conclusions: An eye screening program in Japan would be cost-effective in detecting DR and preventing blindness from DR, even allowing for the uncertainties in estimates of costs, utility, and current management of DR.