Retinal laser photocoagulation and intravitreal injection of anti-VEGF for hemorrhagic retinal arterial microaneurysm

AIM:To evaluate the efficacy of retinal laser photocoagulation and intravitreal injection of anti-vascular endothelial growth factor(anti-VEGF)for hemorrhagic retinal arterial macroaneurysm(RAM).METHODS:This was a retrospective clinical study.Patients with hemorrhagic RAM were divided into 4 groups defined by different treatments:a retinal laser photocoagulation therapy monotherapy group,an anti-VEGF intravitreal injection monotherapy group,a laser and anti-VEGF combination therapy group,and an observation group.Visual acuity(VA),central macular thickness(CMT),and retinal hemorrhage area(RHA)were collected.RESULTS:Forty-seven eyes of 47 patients were enrolled.VA improved and had a significant difference between baseline and final in each treatment group(logMAR;laser group:1.90±0.53 vs 1.05±0.63,P<0.001;anti-VEGF group:1.75±0.63 vs 1.12±0.54,P=0.009;combination group:1.76±0.38 vs 1.01±0.52,P<0.001);however,VA decreased and had no significant difference in observation group(1.63±0.51 vs 1.76±0.61,P=0.660).CMT decreased and had a significant difference between baseline and final in each group(laser group:815.16±310.83 vs 252.05±83.90μm,P<0.001;anti-VEGF group:725.00±290.79 vs 203.56±69.89μm,P=0.001;combination group:595.50±186.51 vs 253.13±55.06μm,P=0.001;observation group:758.88±195.65 vs 267.00±120.90μm,P=0.001).RHA were 28.99±28.15,25.94±11.58,19.64±8.97,and 27.45±13.76 mm^(2) in laser group,anti-VEGF group,combination group and observation group,respectively.RHA was statistically correlated with final VA(P=0.032)in the observation group.CONCLUSION:Both laser and anti-VEGF treatments are effective for hemorrhagic RAM.Combination therapy reduces the number of injections of anti-VEGF.RHA is a visual prognosis predictor in the natural history of hemorrhagic RAM.

Comparison of three fluorescence labeling and tracking methods of endothelial progenitor cells in laser-injured retina

AIM： To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells（EPCs） in a mouse model of laser-induced retinal injury.METHODS： EPCs were isolated from human umbilical cord blood mononuclear cells and labeled with three different fluorescent probes： 5-（and-6）-carboxyfluorescein diacetate succinimidyl ester（CFSE）, 1,1′-dilinoleyl-3,3,3′,3′-tetramethylindo-carbocyanine perchlorate linked acetylated low-density lipoprotein（Di I-Ac LDL）, and green fluorescent protein（GFP）. The fluorescent intensity of EPCs was examined by confocal microscopy. Survival rate of labeled EPCs was calculated with trypan blue staining, and their adhesive capability was assessed. A mouse model of retinal injury was induced by laser, and EPCs were injected into the vitreous cavity. Frozen section and fluorescein angiography on flat-mounted retinal samples was employed to track the labeled EPCs in vivo.RESULTS： EPCs labeled with CFSE and Di I-Ac LDL exhibited an intense green and red fluorescence at the beginning; the fluorescence intensity decreased gradually to 20.23% and 49.99% respectively, after 28 d. On the contrary, the florescent intensity of GFP-labeled EPCs increased in a time-dependent manner. All labeled EPCs showed normal morphology and no significant change in survival and adhesive capability. In the mouse model, transplantation of EPCs showed a protective effect against retinal injury. EPCs labeled with CFSE and Di I-Ac LDL were successfully tracked in mice during the development of retinal injury and repair; however, GFP-labeled EPCs were not detected in the laser-injured mouse retina.CONCLUSION： The three fluorescent markers used in this study have their own set of advantages and disadvantages. CFSE and Di I-Ac LDL are suitable for short-term EPClabeling, while GFP should be used for long-term labeling. The choice of fluorescent markers should be guided by the purpose of the study.