Effects of Palmitoylethanolamide on Inner Retinal Function in Glaucoma Patients by Pattern Electroretinogram

Study Overview
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Brief Summary
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The general purpose of the study is to evaluate the potential beneficial effects of PEA 600 mg supplementation on RGCs function in subjects with glaucoma by pattern electroretinogram after three months of therapy. Secondary objectives are to assess effects on intraocular pressure (IOP) values, if any; to record visual acuity, visual field, central corneal thickness (CCT), and Optical coherence tomography (OCT) (ganglion cell complex - GCC) changes, if any and to follow quality of life (QL) perception (general vision -GV and general health - GH of national eye instutute visual functioning questionnaire 25 items - NEI VFQ25)

Detailed Description
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Monocentric, randomized, prospective, single blind, two treatment and two period crossover study. The investigators have proposed a cross-over trial to avoid or to detect the bias due to intra-individual variability and because, from preliminary observation, it has been noted that the effects of PEA on pattern-electroretinogram (PERG) are completely reversible after withdrawal, within one month. The investigators didn't considered a placebo treated group because the patient cannot interfere with the pattern-electroretinogram PERG measurement that is objective and totally patient-independent. Study duration 12 months Enrolment period 6 months Minimum Follow-up 6 months Start: January, 2015; end January, 2016 Total sample size: 40 patients

Official Title
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Effect of Palmitoylethanolamide on Inner Retinal Function in Stable Glaucoma Patients. A Prospective, Randomized, Single Blind, Crossover Clinical Trial by Pattern Electroretinogram.

Conditions
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Glaucoma

Intervention / Treatment
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* Dietary Supplement: palmitoylethanolamide (PEA) 600 mg


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: -age 18 years or older diagnosis of primary open angle glaucoma (POAG) controlled IOP (<18 mmHg, morning value) with any topical lowering medication (beta-blockers, carbonic anhidrase inhibitors, alpha2agonists, prostaglandin analogues as monotherapy or as associative therapy; betablocker/carbonic anhydrase inhibitor, betablocker/alpha2agonist, prostaglandine/betablocker and alpha2agonist/carbonic anhidrase inhibitor fixed combinations as monotherapy or in association); stable IOP<18 mmHg in the last 2 years stable disease in the last 2 years (no more than -1 deciBell-dB/year at MD of visual field) at least two reliable visual fields per year in the last 2 years no filtering surgery or other ocular surgery in the preceding 6 months written consent to participate to study procedures and data utilization in an anonymous form Exclusion Criteria: ocular hypertension with normal optic nerve and visual field contraindication to PEA glaucomatous scotomas within 10 degree from fixation any condition limiting the patient's ability to participate in the study; other causes of visual field changes, such as cataract, myopic chorioretinopathy, macular diseases, retinal vascular occlusion

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Monocentric, randomized, prospective, single blind, two treatment and two period crossover study.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: standard of care+palmitoylethanolamide<br>PEA was supplemented for 3 months to the standard of care (SOC, topical IOP lowering med) | Dietary Supplement: palmitoylethanolamide (PEA) 600 mg<br>* PEA 600 mg was added to topical therapy<br>|
| No Intervention: standard of care<br>patients were only on topical IOP lowering therapy (SOC) | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To assess effects of PEA 600 mg a tablet a day on pattern electroretinogram PERG examination at three months of therapy. | changes in amplitude (microVolt) and changes in latency (millisecond) of p50 and n95 waves | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To assess effects of PEA 600 mg on intraocular pressure (IOP) values | IOP measure in mmHg | 3 months | 
| To record visual field changes | changes in MD (deciBell-dB) and pattern standard deviation-PSD (deciBell-dB) of visual field parameters | 3 months | 
| To follow quality of life - QL - perception using the 25 item National Eye Institute - Visual Functioning Questionnaire (NEI VFQ25) | changes in the total mean score, in the General vision -GV- and in the general health -GH- subscales scores (scores are presented as a number, higher numbers reflect higher QL) | 3 months |