Palmitoylethanolamide effects on intraocular pressure after Nd:YAG laser iridotomy: an experimental clinical study

J Ocul Pharmacol Ther. 2011 Dec;27(6):629-35. doi: 10.1089/jop.2010.0191. Epub 2011 Aug 10.


Purpose: The purpose of this article was to evaluate whether the anti-inflammatory agent palmitoylethanolamide (PEA) can counteract the increase of intraocular pressure (IOP) that may occur after neodymium-doped: yttrium aluminum garnet (Nd:YAG) laser iridotomy.

Methods: Fifteen patients underwent bilateral laser iridotomy (Visulas YAG III Laser; Zeiss) for the prevention of primary closed-angle glaucoma. The IOP was measured at the beginning of the study (t-1), after 15 days of pretreatment with placebo or PEA (t0), and at 15, 30, and 120 min after the iridotomy (t1, t2, t3). The pretreatment consisted of 2 tablets of placebo or PEA per day for 15 days.

Results: The t-test did not show a significant difference between the preoperative mean values of IOP t-1 and t0 in both the pretreatments. Analysis of variance/Tukey's test pointed out a significant increase of the postoperative IOP values in placebo pretreated patients (P≤0.05), but not in those who were pretreated with PEA. The trend analysis confirmed the significant positive trend in placebo pretreatment. The parallelism test between the 2 regressions showed a significant difference for the slopes (P=0.022) and not for the intercepts (P=0.520).

Conclusions: PEA can counteract the increase of IOP that occurs after iridotomy. It is likely that PEA controls the inflammatory process after iridotomy.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Amides
  • Anti-Inflammatory Agents, Non-Steroidal / administration & dosage
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Endocannabinoids
  • Ethanolamines
  • Female
  • Glaucoma, Angle-Closure / prevention & control
  • Glaucoma, Angle-Closure / surgery*
  • Humans
  • Intraocular Pressure / drug effects*
  • Iris / surgery*
  • Laser Therapy* / adverse effects
  • Laser Therapy* / instrumentation
  • Lasers, Solid-State*
  • Male
  • Middle Aged
  • Palmitic Acids / administration & dosage
  • Palmitic Acids / therapeutic use*
  • Single-Blind Method
  • Treatment Outcome


  • Amides
  • Anti-Inflammatory Agents, Non-Steroidal
  • Endocannabinoids
  • Ethanolamines
  • Palmitic Acids
  • palmidrol