Assessment of retinal structure and intraocular pressure changes of two rat chronic ocular hypertension models / 眼科新进展

ABSTRACT

Objective To evaluate the effects of two different chronic glaucoma models on intraocular pressure elevation and retinal structure changes in rat.Methods Two different chronic ocular hypertension (COH) models were made by three episcleral vein cauterization or latex microspheres injection into anterior chamber,6 cases of each model.IOP measurements of right eyes (COH eye) and left eye (control eye) were taken weekly by TonoPen (an applanation tonometer).Retinal ganglion cells (RGCs) were retrogradely labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) seven weeks later.Retina structure was observed by immunofluorescence.Results IOP was elevated at postoperative 1-8 weeks,and the mean IOP in the episcleral vein cauterization group was (27.20 ± 1.83) mmHg (1 kPa =7.5 mmHg),whereas the control group was (19.80 ± 1.35) mmHg (P =0.001,n =6).The mean IOP in the latex microspheres injection group was (27.40 ± 1.88) mmHg,whereas the control group was (19.40 ± 1.00) mmHg (P =0.000,n =6).Compared with control rat at postoperative 8 weeks,RGCs loss in episcleral vein cauterization group were 37.9％,39.6 and 33.5％ (all P =0.000,n =6),latex microspheres injection group were 37.3％,39.4％ and 33.5％ (all P =0.000,n =6).There was no statistical difference between episcleral vein cauterization group and latex microspheres injection group (P =0.855,0.949,0.634,n =6).Compared with control rat at postoperative 8 weeks,GCL thickness in both COH models were also significant reduced,but there was no statistical difference in GCL thickness among control group (7.32 ± 0.39) μm,episcleral vein cauterization group (4.97 ±0.33) μm,latex microspheres injection group (5.00 ±0.31) μm.Misoperation or careless operation may lead to microspheres particle residual on flat-mounted rat retina.Conclusion The episcleral vein cauterization or latex microspheres injection into anterior chamber can all increase the IOP.However,there are some advantages in episcleral vein cauterization such as few costs than latex microspheres injection and no microsphere contamination.