Objective To observe the efficacy of intravitreal injection of ranibizumab (IVR) for different patterns of optical coherence tomography (OCT) of diabetic macular edema and the relationship between integrity of ellipsoidal zone and visual acuity outcomes. Methods Eighty-five IVR treated eyes were enrolled. The examination of BCVA was according to Early Treatment Diabetic Retinopathy Study, and the results were recorded as logarithm of the minimum angle of resolution (logMAR). Frequency-domain OCT was used to measure the central foveal thickness (CFT) and the integrity of ellipsoidal zone. All eyes were classified as diffuse macular edema (DRT group, 31 eyes), cystoid macular edema (CME group, 29 eyes), and serous retinal detachment (SRD group, 25 eyes). All the patients were treated with intravitreal injection of 0.05 ml (0.5 mg) ranibizumab. The mean follow-up time was (9.21+3.56) months after IVR treatment. The changes of BCVA and CFT in 3 groups were compared and analyzed after 3, 6 and 12 months. According to visual acuity at different ranges, the relationship between integrity of ellipsoidal zone and BCVA was analyzed. Results Compared with the average logMAR BCVA before treatment, except for 12 months after treatment in group SRD (t=2.104,P=0.053), the average logMAR BCVA after IVR at 3 months, 6 months and 12 months improved in DRT group (t=7.847, 6.771, 6.426;P=0.000, 0.000, 0.000), CME group (t=8.560, 6.680, 5.082;P=0.000, 0.000, 0.000) and SRD group (t=5.161, 3.968, 2.104;P=0.000, 0.001, 0.053). The average logMAR BCVA of the DRT group was lesser than that in CME and SRD group after 12 months treatment (t=–2.043, –3.434;P=0.030, 0.001). The average CFT after IVR at 3 months, 6 months and 12 months reduced significantly in DRT group (t=12.746, 10.687, 9.425;P=0.000, 0.000, 0.000), CME group (t=13.400, 11.460, 10.169;P=0.000, 0.000, 0.000), and SRD group (t=11.755, 10.100, 9.173;P=0.000, 0.000, 0.000). After 12 months of treatment, the average CFT of the SRD group was thicker than that in DRT group and CME group (t=–3.251, –1.227;P=0.003, 0.025); there was significant difference in the integrity of ellipsoidal zone among 3 groups (χ2=1.267,P=0.531). The results showed that there were significant differences in the integrity of ellipsoidal zone with different ranges of BCVA before and after 12 months treatment (χ2=20.145, 41.035;P=0.000, 0.000). Conclusions IVR could significantly improve the visual acuity of different patterns of DME, reduced the CFT, and had the best efficacy in the DRT group. There was relationship between the integrity of ellipsoidal zone and the visual acuity outcomes.
Objective To observe the effect of different concentration netrin-1 on retinal vascular permeability in diabetes mellitus (DM) rats. Methods Eighty adult Sprague-Dawley rats were randomly divided into 8 groups, 10 rats in each group, including normal control group (group A), normal＋balanced salt solution (BSS) group (group B), normal＋netrin-1 (500 μg/ml) group (group C) and DM group (50 rats in 5 sub-groups). DM rats were induced by intraperitoneal injection of streptozocin. Three months after intraperitoneal injection, 10 DM rats in the control group were injected with BSS (group D). Forty DM rats were injected with 5 μl of different concentrate netrin-1, and were divided into DM+netrin-1 10 μg/ml group (group E), DM+netrin-1 50 μg/ml group (group F), DM＋netrin-1 100 μg/ml group (group G), DM＋netrin-1 500 μg/ml group (group H) according to the different concentration. Non-DM rats in group C were injected with netrin-1 500 μg/ml. The expression of occludin was determined by immunohistochemistry for protein, and by real-time fluorescence quantitative reverse transcription polymerase chain reaction for mRNA level. Retinal vascular permeability was measured by Evans blue infusion. Results The expression of occludin protein and mRNA in group D were less than group A (t=27.71, 8.59;P=0.00, 0.00). However, the retinal vascular permeability increased in group D (t=−42.72,P=0.00). The expression of occluding protein, occludin mRNA and retinal vascular permeability showed significant differences between group D, E, F, G and H (F=146.31, 16.54, 67.77;P=0.00, 0.00, 0.00). Compared the group B with group C, there was no significant differences between the expression of occludin protein, occludin mRNA and the retinal vascular permeability (t=−1.13, 0.93, 1.04;P=0.27, 0.36, 0.31). The concentrate of netrin-1 showed a significant positive correlation to the expression level of occludin and occludin mRNA (r=0.73, 0.81;P=0.00, 0.00), but negative correlation to the vascular permeability (r=−0.61,P=0.00). Conclusion Netrin-1 can reduce the DM rats' retinal vascular permeability, which depended on the concentration of netrin-1.