The aim of this study was to observe the clinical efficacy of intravitreal injection of Conbercept combined with subthreshold micropulse laser (SMLP) in the treatment of diabetic macular edema (DME).

It was a retrospective analysis.Forty-seven patients (47 eyes) with diabetic macular edema (DME) were selected from Department of Ophthalmology in Liangxiang Hospital of Beijing Fangshan District from February 2017 to September 2019. Among them, 25 cases (25 eyes) were male, 22 cases (22 eyes) were female. The average age of the patients was (61.6±9.1) years-old. They were divided into combined treatment group (26 eyes) and injection group (21 eyes) according to the different clinical treatment. The patients in the combined treatment group were treated with intravitreal injection of Conbercept one week before SMLP and the patients in the injection group only were treated with intravitreal injection of Conbercept. There were 26 cases (26 eyes) in the combined treatment group, including 14 males (14 eyes) and 12 females (12 eyes), with an average age of (61.6±8.0) years. There were 21 patients (21 eyes) in the injection group, including 11 males (11 eyes) and 10 females (10 eyes), with an average age of (61.7±10.5) years-old. The best corrected visual acuity (BCVA) were measured by standard logarithmic visual acuity chart and central fovea retina thickness (CFT) were measured by optical coherence tomography (OCT). The CFT and BCVA were compared between two groups at 1, 2, 3 and 4 months after treatment. The data of age, intraocular pressure, BCVA and CFT of two groups were described by mean±standard deviation. Independent sample T test was used for comparison between groups. The BCVA and CMT within and between groups were compared by two-way ANOVA before and after treatment.

In the combined treatment group, the BCVA at 1, 2, 3 and 4 months after treatment were (0.47±0.16), (0.40±0.16), (0.40±0.15), (0.43±0.16) and the CFT were (358.5±51.2) μm, (317.0±43.6) μm, (329.1±32.7) μm and (322.4±41.8) μm, respectively. In the injection group, the BCVA at 1, 2, 3 and 4 months after treatment were (0.54±0.17), (0.63±0.19), (0.66±0.18) and (0.68±0.17), respectively, and the CFT at 1, 2, 3 and 4 months after treatment were (382.9±59.2) μm, (445.0±69.1) μm, (463.7±64.1) μm and (468.7±64.3) μm, respectively. There was no significant difference in BCVA and CFT between two groups one month after SMLP treatment (t=2.593, 2.305; P>0.05). There was significant difference between two groups in terms of BCVA at 2, 3 and 4 months after SMLP treatment (t=21.683, 29.321, 25.948; P<0.05), and there was significant difference between two groups in terms of CFT at 2, 3 and 4 months after SMLP treatment(t=59.960, 86.855, 88.537; P<0.05). Compared with those before treatment, BCVA in the combined treatment group increased at 1, 2, 3 and 4 months after treatment with the significant difference between them (t=11.316, 10.276, 9.718, 7.518; P<0.05); and CFT decreased with the significant difference between them(t=11.863, 19.176, 16.601, 16.928; P<0.05). The injection group only showed an improvement in BCVA at 1 month after anti-VEGF treatment with the significant difference between them (t= 5.966, P<0.05). However, there was no significant difference in BCVA at 2, 3 and 4 months after treatment (t=1.826, -1.369, -1.826; P>0.05), CFT was significantly improved at 1 month after injection(t=9.320, P<0.05), but there was no significant difference at 2, 3 and 4 months after injection (t=1.725, -0.883, -1.777; P>0.05).

Both intravitreal injection of Conbercept combined with SMLP and single intravitreal injection of Conbercept could be of benefit to improve the visual acuity of DME patients in a short time, reduce their macular edema, and have good safety, but the effect of intravitreal injection was more stable and lasting.