Alginate sodium-retinoic acid microspheres suppress the subretinal proliferation after laser coagulation

Objective To observe the inhibiting effects of alginate sodium-retinoie aeid(AGS-RA) microspheres release system on the laser coagulation-induced subretinal proliferation.Methods RA were dissolved by absolute alcohol,then mixed with 1.5% AGS and made into AGS-RA microspheres by a microcapsule electrostatic generator.The parameter of laser injury include irradiation time (0.20 s),spot diameter (200 μm) and output power (420 mW).Thirty pigmented rabbits were randomly divided into 3 groups (laser injury,experimental and control group).After laser coagulation,AGS-RA or blank microspheres were immediately injected into the vitrous of experimental and control rabbits respectively.The height,width and area of 6 retinal spots of laser coagulation at each time-point were analyzed histopathologically with serial retinal sections at 1,2,3,4,and 6 weeks after laser coagulation.Results Histopathological examination showed that there were morphological and distribution changes of retinal cells in all layers,and localized fibroblasts proliferation in the retina after laser injury.The laser-induced responses in experimental group were much milder(P 0.05)and height/area of laser spots(P>0.05).Conclusion AGS-RA release system can alleviate the subretinal proliferate after laser injury. Key words: Tretinoin retinoic acid/therapeutic use; Lasers/adverse effects; Hyperplasia/drug therapy; Animals,laboratory