Can peas help lower intraocular pressure (IOP)?

PEA (Palmitoylethanolamide) Is Effective in Lowering Intraocular Pressure in Glaucoma Patients

Palmitoylethanolamide (PEA) supplementation is effective in lowering intraocular pressure (IOP) and can be considered as an adjunctive therapy for patients with glaucoma or ocular hypertension.

Evidence for PEA in IOP Reduction

The most recent and highest quality evidence demonstrates significant IOP-lowering effects of PEA:

• In a 2020 randomized, single-blind, crossover clinical trial, PEA supplementation (600 mg daily) resulted in significantly lower IOP (-1.6 mmHg) compared to baseline in glaucoma patients already on topical therapy 1

• A 2014 study in normal tension glaucoma patients showed that oral PEA (300 mg twice daily) for six months significantly reduced IOP from 14.4±3.2 mmHg to 11.1±4.3 mmHg (p<0.01) 2

• A 2011 randomized, double-blind, crossover trial found that oral PEA (300 mg twice daily) reduced IOP by 3.5±1.2 mmHg (15.9%±5.1%) after 2 months in patients with primary open-angle glaucoma or ocular hypertension 3

Mechanism and Additional Benefits

PEA appears to offer benefits beyond simple IOP reduction:

• Improved retinal ganglion cell function as measured by pattern electroretinogram (PERG) examination 1
• Improved visual field parameters in normal tension glaucoma patients 2
• Enhanced quality of life scores in glaucoma patients 1

Comparison to Standard Treatments

According to the American Academy of Ophthalmology guidelines, prostaglandin analogs remain the first-line treatment for glaucoma due to their superior efficacy in lowering IOP (6-8 mmHg reduction), excellent tolerability, and once-daily dosing regimen 4. However, PEA may serve as a valuable adjunctive therapy when:

1. Additional IOP reduction is needed despite first-line treatment
2. Patients have normal tension glaucoma where standard therapies may be less effective
3. Patients experience side effects from traditional medications

Dosing Recommendations

Based on the available evidence, the optimal dosing of PEA for IOP reduction is:

• 600 mg daily (either as 600 mg once daily or 300 mg twice daily)
• Continued for at least 2-6 months to achieve maximum benefit

Important Considerations and Limitations

• PEA should be considered as an adjunct to, not a replacement for, standard glaucoma therapies
• Regular monitoring of IOP remains essential, as the target IOP should be individualized based on disease severity, rate of progression, and other risk factors 5
• While PEA shows promise, it has not yet been incorporated into major glaucoma treatment guidelines
• No significant adverse effects have been reported with PEA supplementation in the available studies

Conclusion for Clinical Practice

For patients with glaucoma or ocular hypertension who require additional IOP reduction despite standard therapy, PEA supplementation at 600 mg daily represents a promising adjunctive option with minimal side effects. The evidence suggests PEA not only lowers IOP but may also provide neuroprotective benefits for retinal ganglion cells, potentially slowing disease progression.