Influence of T- and B-cell-deficiency on retinal neurocytes of mice withacute ocular hypertension

Background Recently,the study on the cause of optic nerve damage induced by glaucoma is of concern in ophthalmology.Some research showed that the immune system is associated with glaucoma-induced optic neuropathy.Acute ischemia-reperfusion is an ideal model of studying optic neuropathy.ObjectiveThe present study investigates the effect of T and B lymphocyte deficiency on the retinal neurocytes of mice with acute intraocular hypertension.Methods Sixteen SPF CB-17/Icr.Cg-Prkdc~(scid)Lyst~(bg)/CrlVR mice 6-8 week-old (severe combined immunodeficiency mouse,SCID) were used in this study and 16 age-matched SPF wild type (C57BL/6) mice served as controls.The ischemia-reperfusion injury models were induced in the right eyes of 10 SCID mice and 10 C57BL/6 mice through intra-anterior chamber infusion of balanced saline solution for 45minutes to increase the intraocular pressure to 104mmHg,and the left eyes served as model controls.The other 6 SCID mice and 6 C57BL/6 mice served as normal control group.10g/L (2μL) of FlouroGold was injected into the brains of the mice for the labeling of surviving retinal ganglion cells 21 days after ischemia-reperfusion.The thickness of retinal inner nuclear layer was measured by H&E staining under the fluorescent microscope 21 days after ischemic insult.The use of the animals followed the Standard of Association for Research in Vision and Ophthalmology.Results In normal control mice,the morphology of retinal ganglion cells (RGCs) and retinal structure were similar between SCID mice and C57BL/6 mice.The differences in the numbers of RGCs and retinal thickness were insignificant between the two types of mice(P＞0.05).In the experimental mice,the surviving RGCs were strikingly increased in SCID mice (91%±5%) compared with C57BL/6 mice(78%±5%)(P=0.003).The thickness of the retinal inner nuclear layer was obviously thinner in the model eyes (22.44±1.70μm) compared to model control eyes (31.06±3.75μm) in C57BL/6 mice(P=0.004),but no statistically significant difference was found between the model eyes and model control eyes in SCID mice (33.52±2.13μm vs 34.06±3.00μm) 21 days after ischemia-reperfusion injury(P＞0.05).Conclusion T and B lymphocytes deficient mice show a better tolerance to acute intraocular hypertension than the wild type C57BL/6 mice. Key words: acute ocular hypertension; retina ganglion cells; immunodeficient; retinal ischemia-reperfusion