The Effect of Dronabinol on Ocular Hemodynamics in Patients With Primary Open Angle Glaucoma

  • End date
    Oct 20, 2023
  • participants needed
  • sponsor
    Medical University of Vienna
Updated on 12 September 2021


Glaucoma is among the leading causes for irreversible blindness worldwide. While lowering intraocular pressure (IOP) remains the mainstay of therapy, there are still some patients who progress despite well-controlled IOP. There is evidence from several studies that ocular blood flow and its regulation is impaired in patients with glaucoma. Tetrahydrocannabinol (THC) has been used in the treatment for glaucoma in some countries for several years due to its IOP lowering effect. In addition, there is also evidence that THC features neuroprotective effects and improves ocular hemodynamics. Dronabinol is a synthetic THC that is legally available in several European countries. It has the advantage that exact dosing of THC is possible in contrast to previously applied administration forms such as smoking. Due to its legal status in the past, data about the effect of THC on ocular blood flow and its regulation are sparse. In a recent study conducted in the investigators laboratory they found that single administration of dronabinol leads to a significant increase in optic nerve head (ONH) blood flow without impairing its autoregulatory capacity.The aim of the present study therefore is to investigate whether single administration of dronabinol alters optic nerve head (ONH) blood flow in patients with open angle glaucoma. In addition, other parameters for ocular blood flow will be measured, in particular retinal blood flow, retinal oxygen saturation and retinal neurovascular coupling. The study will be conducted in a parallel-group, randomized, double-masked, placebo-controlled, cross-over design. Patients will be randomized to either receive 5mg or 10mg dronabinol on one study day. Other studies investigating retinal hemodynamics or IOP after administration of THC also have used similar or slightly higher doses.

Condition Retinal Blood Flow
Treatment Placebo, Dronabinol 5 MG, Dronabinol 10 MG
Clinical Study IdentifierNCT04596826
SponsorMedical University of Vienna
Last Modified on12 September 2021


Yes No Not Sure

Inclusion Criteria

Diagnosis of manifest open angle glaucoma as defined as pathological optic disc appearance, glaucoma hemifield test outside normal limits and/or untreated IOP 21 mmHg on at least three measurements in the medical history
Mean deviation in the visual field test < 10dB
Informed consent signed and dated
Patient aged 18 years old
Ametropia 6 diopters
Normal findings in the medical history and physical examination including ECG unless the investigator considers an abnormality to be clinically irrelevant
Normal findings in the laboratory testing unless the investigator considers an abnormality to be clinically irrelevant

Exclusion Criteria

Exfoliation glaucoma
Pigmentary glaucoma
Secondary glaucoma
History of acute angle closure
Intraocular surgery within the last 6 months
Filtration surgery for glaucoma at any time
Laser procedure for glaucoma within the last 12 months Visual field not performed or not available within 6 months
Ocular inflammation or infection within the last 3 months
Regular use of medication that potentially could interact with THC, abuse of alcoholic beverages or drugs
History of drug or alcohol abuse
Psychiatric disorders in the medical history
Risk for drug dependence as evaluated by a psychiatrist
Participation in a clinical trial in the 3 weeks preceding the study
Positive urine drug test at the screening examination or on the study days
Positive alcohol breath test at the screening examination or on the study days
Regular consumption of cannabis and inability to not consume cannabis during the study period
Symptoms of a clinically relevant illness in the 3 weeks before the first study day
History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with distribution, metabolism or excretion of study drugs
Blood donation during the previous 3 weeks
Known hypersensitivity to any of the components of the IMP under investigation or other study medication
History or family history of epilepsy
Pregnant or breast-feeding women
Women of childbearing potential (neither menopausal, nor hysterectomized, nor sterilized) not using effective contraception (oral contraceptives, intra-uterine device, contraceptive implant or condoms)
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