Glaucoma Related to Ocular and Orbital Tumors

Abstract

Secondary glaucoma due to ocular and orbital tumors can be a diagnostic challenge. It is an essential differential to consider in eyes with a known tumor as well as with unilateral, atypical, asymmetrical, or refractory glaucoma. Various intraocular neoplasms including iris and ciliary body tumors (melanoma, metastasis, lymphoma), choroidal tumors (melanoma, metastasis), vitreo-retinal tumors (retinoblastoma, medulloepithelioma, vitreoretinal lymphoma) and orbital tumors (extra-scleral extension of choroidal melanoma or retinoblastoma, primary orbital tumors) etc. can lead to raised intraocular pressure. The mechanisms for glaucoma include direct (tumor invasion or infiltration related outflow obstruction, trabecular meshwork seeding) or indirect (angle closure from neovascularization or anterior displacement or compression of iris) or elevated episcleral venous pressure secondary to orbital tumors. These forms of glaucoma need unique diagnostic techniques and customized treatment considerations as they often pose therapeutic dilemmas. This chapter will review and discuss the mechanisms, clinical presentations and management of glaucoma related to ocular and orbital tumors.