Age and intraocular pressure in murine experimental glaucoma

• Published in: Progress in retinal and eye research 2022-05, Vol.88, p.101021-101021, Article 101021
• Main Authors: Di Pierdomenico, Johnny, Henderson, Delaney C.M., Giammaria, Sara, Smith, Victoria L., Jamet, Aliénor J., Smith, Corey A., Hooper, Michele L., Chauhan, Balwantray C.
• Format: Article
• Language: English
• Subjects: Age; Animals; Disease Models, Animal; Experimental glaucoma; Glaucoma - pathology; Glaucoma, Open-Angle; Humans; In vivo imaging; Intraocular Pressure; Mice; Mouse; Retinal ganglion cell; Tonometry, Ocular
• ISSN: 1350-9462; 1873-1635
• DOI: 10.1016/j.preteyeres.2021.101021

Age and intraocular pressure (IOP) are the two most important risk factors for the development and progression of open-angle glaucoma. While IOP is commonly considered in models of experimental glaucoma (EG), most studies use juvenile or adult animals and seldom older animals which are representative of the human disease. This paper provides a concise review of how retinal ganglion cell (RGC) loss, the hallmark of glaucoma, can be evaluated in EG with a special emphasis on serial in vivo imaging, a parallel approach used in clinical practice. It appraises the suitability of EG models for the purpose of in vivo imaging and argues for the use of models that provide a sustained elevation of IOP, without compromise of the ocular media. In a study with parallel cohorts of adult (3-month-old, equivalent to 20 human years) and old (2-year-old, equivalent to 70 human years) mice, we compare the effects of elevated IOP on serial ganglion cell complex thickness and individual RGC dendritic morphology changes obtained in vivo. We also evaluate how age modulates the impact of elevated IOP on RGC somal and axonal density in histological analysis as well the density of melanopsin RGCs. We discuss the challenges of using old animals and emphasize the potential of single RGC imaging for understanding the pathobiology of RGC loss and evaluating new therapeutic avenues. •Age and intraocular pressure are key risk factors for glaucoma.•There is more damage in old versus adult mice for the same intraocular pressure.•Serial change in ganglion cell dendritic structure are pronounced in old mice.•In vivo single ganglion cell imaging is a valuable tool in experimental glaucoma.