Hyperbaric Oxygen Therapy in Glaucoma Patients
Direct Answer
Hyperbaric oxygen therapy (HBOT) can be used in patients with glaucoma and may provide temporary visual field improvement, but it does not lower intraocular pressure and requires specific delivery precautions to minimize oxidative stress risk. 1, 2
Evidence for HBOT Use in Glaucoma
Visual Field Benefits Without IOP Reduction
HBOT at 2.0 bars for 90 minutes daily over 20 sessions significantly improved visual field area in open-angle glaucoma patients (p < 0.01), with benefits persisting for 3 months but declining by 6 months. 1
A double-blind trial demonstrated significant visual field improvement (p < 0.05) in glaucoma patients receiving HBOT, with stability maintained for 3 months before gradual decline at 6 months. 2
Critically, HBOT did not influence intraocular pressure in either study, meaning it does not address the primary modifiable risk factor in glaucoma management. 1, 2
The mechanism of benefit appears related to improved oxygenation of chronically ischemic retinal ganglion cells rather than IOP reduction. 2
Safety Considerations and Delivery Method
Oxidative Stress Risk
The primary concern with HBOT in glaucoma is increased production of reactive oxygen species (ROS), which can damage trabecular meshwork cells and retinal ganglion cells—the exact cells already compromised in glaucoma. 3
Retinal function is highly sensitive to fluctuations in hemoglobin oxygen concentration, and reperfusion injury with ROS production occurs when oxygen delivery exceeds autoregulatory capacity. 3
Critical Delivery Precaution
Oronasal mask delivery of HBOT is strongly preferred over hood delivery in glaucoma patients. 3
Hood delivery exposes the anterior ocular surface to higher oxygen concentrations, increasing oxygen levels in aqueous humor and elevating the risk of oxidative damage to trabecular meshwork cells. 3
Oronasal mask limits anterior segment oxygen exposure while still providing systemic hyperbaric oxygenation. 3
Clinical Context: When HBOT Is Indicated
Established Ophthalmologic Indications
HBOT has recognized efficacy for specific acute vision-threatening conditions that may coexist with glaucoma:
Central retinal artery occlusion (CRAO): HBOT (100% oxygen over 9 hours) demonstrated efficacy over observation alone in small randomized trials. 4
Other established indications include decompression sickness with visual symptoms, arterial gas embolism, radiation optic neuropathy, and periocular necrotizing infections. 5
For acute retinal artery occlusion, patients should receive normobaric oxygen at the highest inspired fraction possible until HBOT can be arranged. 5
HBOT Is NOT Standard Therapy for Glaucoma Itself
No major ophthalmology guideline recommends HBOT as standard or adjunctive therapy for glaucoma management. 4, 6
The American Academy of Ophthalmology guidelines on glaucoma management do not mention HBOT as a treatment modality. 4, 6
The primary goal of glaucoma treatment remains IOP reduction to a target at least 20% below baseline, achieved through medical therapy (prostaglandin analogs first-line), laser, or surgery. 4, 6
Practical Algorithm for Decision-Making
When to Consider HBOT in a Glaucoma Patient
Patient presents with acute vision-threatening condition with established HBOT indication (e.g., CRAO, radiation optic neuropathy): Proceed with HBOT using oronasal mask delivery. 4, 3, 5
Patient has stable glaucoma on adequate IOP-lowering therapy with progressive visual field loss despite target IOP: HBOT may be considered as investigational adjunctive therapy for 20 sessions, with understanding that benefits are temporary (3-6 months). 1, 2
Patient has uncontrolled IOP or is not on optimal glaucoma therapy: Optimize standard glaucoma management first—HBOT does not lower IOP and should not substitute for proven therapies. 4, 6, 1
Monitoring During HBOT
Visual acuity alone is inadequate—automated perimetry evaluating the central 30 degrees of visual field must be performed before, during (at appropriate intervals), and after HBOT. 5
Continue regular glaucoma monitoring including IOP measurement, optic nerve imaging, and visual field testing every 6-12 months for high-risk patients. 6
Common Pitfalls to Avoid
Do not use hood delivery of HBOT in glaucoma patients—this increases anterior segment oxygen exposure and oxidative stress risk to already vulnerable trabecular meshwork. 3
Do not expect IOP reduction from HBOT—it provides no benefit to the primary pathophysiologic mechanism and cannot replace standard IOP-lowering therapy. 1, 2
Do not assume HBOT benefits are permanent—visual field improvements decline significantly by 6 months, requiring repeat courses if continued benefit is desired. 1, 2
Do not delay standard glaucoma treatment in favor of HBOT—prostaglandin analogs remain first-line therapy with proven long-term efficacy in preventing optic nerve damage and preserving quality of life. 4, 6