Patients with known history or current evidence of retinal vein occlusion (RVO) are not eligible:* History of RVO, or predisposing factors to RVO (e.g. uncontrolled glaucoma or ocular hypertension, uncontrolled systemic disease such as hypertension, diabetes mellitus, or history of hyperviscosity or hypercoagulability syndromes)* Visible retinal pathology as assessed by ophthalmic exam that is considered a risk factor for RVO such as:** Evidence of new optic disc cupping** Evidence of new visual field defects** Intraocular pressure > 21 mmHg** NOTE: Ophthalmic exam is required for all patients; exam must be obtained within 28 days prior to registrationXx_NEWLINE_xXHistory or current evidence/risk of retinal vein occlusion (RVO)Xx_NEWLINE_xXTREATMENT: Patients with a history or current evidence/risk of retinal vein occlusion (RVO) or retinal pigment epithelial detachment (RPED) or predisposing factors to RVO or RPED (e.g., uncontrolled glaucoma or ocular hypertension, uncontrolled systemic disease such as hypertension, diabetes mellitus, or history of hyperviscosity or hypercoagulability syndromes), are ineligible to receive treatment with trametinib DMSO; visible retinal pathology (as assessed by ophthalmic exam) that is considered a risk factor for RVO or RPED includes evidence of new optic disc cupping or new visual field defects, or intraocular pressure > 21 mm HgXx_NEWLINE_xXHistory of retinal vein occlusion (RVO)Xx_NEWLINE_xXHistory or current evidence/risk of retinal vein occlusion (RVO) or central serous retinopathy (CSR):* History of RVO or CSR, or predisposing factors to RVO or CSR (e.g., uncontrolled glaucoma or ocular hypertension, uncontrolled systemic disease such as hypertension, diabetes mellitus, or history of hyperviscosity or hypercoagulability syndromes)* Visible retinal pathology as assessed by ophthalmic exam that is considered a risk factor for RVO or CSR such as evidence of new optic disc cupping, evidence of new visual field defects, and intraocular pressure > 21 mmHgXx_NEWLINE_xXHistory or current evidence/risk of retinal vein occlusion (RVO)Xx_NEWLINE_xXHistory or current evidence/risk of retinal vein occlusion (RVO)Xx_NEWLINE_xXHistory or current evidence/risk of retinal vein occlusion (RVO) or retinal pigment epithelial detachment (RPED):* History of RVO or RPED, or predisposing factors to RVO or RPED (e.g., uncontrolled glaucoma or ocular hypertension, uncontrolled systemic disease such as hypertension, diabetes mellitus, or history of hyperviscosity or hypercoagulability syndromes)* Visible retinal pathology as assessed by ophthalmic exam that is considered a risk factor for RVO or RPED such as evidence of new optic disc cupping, evidence of new visual field defects, and intraocular pressure > 21 mm mercury (Hg)Xx_NEWLINE_xXPatients with a history or current evidence/risk of retinal vein occlusion (RVO)Xx_NEWLINE_xXPatients with the following ophthalmological findings/conditions:* Intraocular pressure > 21 mmHg, or uncontrolled glaucoma (irrespective of intraocular pressure)* Current or past history of central serious retinopathy or retinal vein occlusionXx_NEWLINE_xXPatients with known history or current evidence of retinal vein occlusion (RVO) or central serous retinopathy (CSR) are not eligible:* History of RVO or CSR, or predisposing factors to RVO or CSR (e.g. uncontrolled glaucoma or ocular hypertension, uncontrolled systemic disease such as hypertension, diabetes mellitus, or history of hyperviscosity or hypercoagulability syndromes)* Visible retinal pathology as assessed by ophthalmic exam that is considered a risk factor for RVO or CSR such as:** Evidence of new optic disc cupping** Evidence of new visual field defects** Intraocular pressure > 21 mmHg* NOTE: ophthalmic exam is required for all patients; exam must be obtained within 28 days prior to registrationXx_NEWLINE_xXPatients must not have history of retinal vein occlusion (RVO)Xx_NEWLINE_xXHistory of retinal vein occlusion (RVO)Xx_NEWLINE_xXCentral serous retinopathy (CSR) including presence of predisposing factors to RVO or CSR (e.g., uncontrolled glaucoma or ocular hypertension, uncontrolled diabetes mellitus, or a history of hyperviscosity or hypercoagulability syndromes); or visible pathology (e.g., evidence of optic disc cupping, evidence of new visual field defects on automated perimetry, or intraocular pressure > 21 mmHg as measured by tonography) as assessed by ophthalmic examinationXx_NEWLINE_xXCLINICAL/LABORATORY CRITERIA: Patients must not have untreated or unresolved retinopathy or have a history (or current evidence) of retinal vein occlusion determined by an ophthalmology exam within 42 days prior to registrationXx_NEWLINE_xXHistory or current evidence/risk of retinal vein occlusion (RVO)Xx_NEWLINE_xXPatients with known significant ophthalmologic conditions (uncontrolled glaucoma, history of retinal vein occlusion or retinal detachment, excluding patients with longstanding findings secondary to existing conditions) are not eligibleXx_NEWLINE_xX