›Timolol 0.5% 1 drop affected eye, may repeat once in 15 minutes
›Avoid in asthma, COPD, or second or third degree AV block
›Brimonidine 0.2% 1 drop affected eye, may repeat once in 15 minutes
›Avoid in infants due to apnea risk
›Dorzolamide 2% 1 drop affected eye, may repeat once in 15 minutes
›Sulfonamide-related reaction caution, additive with systemic acetazolamide
›Critical caveat
›These measures are adjuncts only
›None of them substitutes for lateral canthotomy and cantholysis when compartment syndrome criteria are met
›Do not let initiation of medical therapy delay the procedure
Anticoagulation and coagulopathy management
›Reversal in the actively bleeding patient
›Warfarin reversal
›Vitamin K 10 mg IV once
›4-factor prothrombin complex concentrate dosed per INR and local protocol
›Direct oral anticoagulant reversal
›Andexanet alfa per labeled weight and dose-based regimen for factor Xa inhibitors when available
›4-factor prothrombin complex concentrate 25 to 50 units/kg IV once as an alternative when a specific reversal agent is unavailable
›Heparin reversal
›Protamine sulfate 1 mg IV per 100 units of heparin received in the preceding 2 to 3 hours, maximum single dose 50 mg
›Slow infusion to reduce hypotension risk
›Antiplatelet management
›Hold further antiplatelet dosing
›Platelet transfusion considered only for severe thrombocytopenia or ongoing surgical bleeding per hematology input, not routinely for antiplatelet effect alone
›Sequencing principle
›Do not delay lateral canthotomy and cantholysis while awaiting reversal agents
›Reversal proceeds in parallel with, not instead of, mechanical decompression
Analgesia and antiemetic adjuncts
›Symptom control that also protects against pressure spikes
›Analgesia
›Acetaminophen 650 to 1000 mg PO or IV every 6 hours, maximum 4000 mg per 24 hours
›Fentanyl IV 25 to 50 mcg titrated every 5 minutes for severe pain, with respiratory monitoring
›Avoid NSAIDs such as ketorolac 15 to 30 mg IV due to antiplatelet effect worsening hemorrhage
›Antiemesis
›Ondansetron 4 mg IV or PO, may repeat once
›Prevents vomiting-related Valsalva that raises orbital venous pressure and can worsen hemorrhage
›Rationale
›Adequate analgesia limits pain-driven hypertension and straining
›Adequate antiemesis limits vomiting-driven venous pressure surges
Iatrogenic harms from routine ED interventions
›Intubation
›Succinylcholine causes a transient rise in intraocular pressure
›Use a non-depolarizing agent such as rocuronium when RSI is needed and time allows
›Blunt the hemodynamic and coughing response to laryngoscopy to avoid a venous pressure surge
›Positive pressure ventilation and bucking on the tube raise venous pressure
›Adequate sedation and paralysis during the peri-intubation period
›Avoid unnecessary coughing or straining against the ventilator
›Sedation
›Prevents pain- and agitation-driven Valsalva and venous congestion
›Use short-acting agents to allow frequent neuro-ophthalmic reassessment
›Oversedation can mask a declining exam, titrate to the minimum effective level
›Fluid loading
›Not directly implicated in worsening orbital compartment pressure
›Balance overall trauma resuscitation volume against concurrent traumatic brain injury when polytrauma is present
›No specific fluid restriction required for isolated retrobulbar hematoma
›Oxygen and non-invasive ventilation
›Supplemental oxygen itself is not contraindicated
›Standard titration to target saturation
›Positive pressure devices such as CPAP or BiPAP
›Avoid when concurrent orbital or paranasal sinus fracture is present due to orbital emphysema risk
›Orbital emphysema can further raise orbital compartment pressure
›Vasopressors
›No specific contraindication from the orbital process itself
›Isolated retrobulbar hemorrhage rarely causes hemodynamic instability
›Use per standard indications for concurrent shock from other injuries
›Mechanical circulatory support including intra-aortic balloon pump
›Systemic anticoagulation required for mechanical circulatory support directly conflicts with an active or recent orbital hemorrhage
›Multidisciplinary risk-benefit discussion before initiating or continuing anticoagulation
›Perform lateral canthotomy and cantholysis before escalating anticoagulation whenever feasible
›Anticoagulation
›Therapeutic anticoagulation or antiplatelet initiation should be held
›Worsens an active or recently decompressed hematoma
›Reassess need and timing with the treating specialty once the eye is stabilized
›Fibrinolysis
›Systemic thrombolytics for another indication, such as stroke, pulmonary embolism, or STEMI, carry a direct conflict with active retrobulbar hemorrhage
›Treat similarly to another closed-space hemorrhage when weighing thrombolysis risk
›Multidisciplinary discussion before administration when both conditions coexist
›Analgesia
›Opioids preferred over NSAIDs due to bleeding risk from antiplatelet effect
›Adequate analgesia reduces pain-driven hypertension and straining that can worsen hemorrhage
›See dosing above under Analgesia and antiemetic adjuncts
Evidence framing for emergency practice
›Guideline strength interpretation
›Strong consensus that lateral canthotomy and cantholysis should not be delayed for imaging or specialist arrival
›Treated as a Class I-style time-critical recommendation
›Based on the irreversible nature of retinal and optic nerve ischemia beyond the tolerance window
›Evidence grading note
›No formally published ACEP or AAO letter-grade recommendation specific to canthotomy timing
›Follow local ocular trauma protocol and emergent ophthalmology guidance for institutional protocoling