The Effects of Cannabis on Visual Functions in Healthy and Retinitis Pigmentosa Patients

A Controlled Study of the Effect of Cannabis on Visual Functions in Healthy Subjects and in Retinitis Pigmentosa Patients

Status

UNKNOWN

Phases

Early Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03078309

Enrollment

Registered

2017-03-13

Start date

2018-09-01

Completion date

2021-12-31

Last updated

2021-02-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cannabis, Retinal Degeneration, Retinitis Pigmentosa

Keywords

retinitis pigmentosa, retinal degeneration, cannabis, THC, CBD, electrophysiology, visual functions, eye, retina

Brief summary

Medical Marijuana is used widely, and its effects on the visual system and the function of the retina have not been investigated thoroughly. Some evidence suggests that cannabinoids may be beneficial in certain degenerative diseases of the retina. The purpose of the study is 1. To determine whether cannabis derivatives affect the visual functions in healthy adults 2. To examine the effect of cannabis derivatives on the retina of retinitis pigmentosa patients

Detailed description

Twenty five healthy subjects and 25 retinitis pigmentosa patients will be recruited and will sign an informed consent form. An initial eye exam will include visual acuity and stereo vision, eye movements and eye movement recording, a full slit lamp eye exam, intra-ocular pressure measurement, visual field, OCT and electrophysiology. The subjects will receive a single sublingual dose of cannabis (THC:CBD 1:1, THC 5 mg, or THE:CBD 1:40, THC 5 mg), and will undergo the above examination again. Subjects will be monitored for 5 hours after the administration of cannabis.

Interventions

DRUGcannabis

single dose sublingual cannabis (THC:CBD 1:1, THC:CBD 1:40)

Study design

Allocation

NON_RANDOMIZED

Intervention model

PARALLEL

Primary purpose

BASIC_SCIENCE

Masking

SINGLE (Outcomes Assessor)

Masking description

Electrophysiology will be analyzed by a blinded investigator.

Intervention model description

Arm 1 - healthy subjects. Arm 2 - subjects with retinitis pigmentosa All subjects will undergo a full ocular exam and visual functions will be assessed before and after the administration of a single dose of cannabis (THC:CBD 1:40). On the second study day all subjects will receive a single dose of cannabis (THC:CBD 1:1) and undergo the full ocular exam again.

Eligibility

Sex/Gender

ALL

Age

18 Years to 70 Years

Healthy volunteers

Yes

Inclusion criteria

* consenting adults * generally healthy with or without retinitis pigmentosa

Exclusion criteria

* chronic or acute disease other than retinitis pigmentosa * use of medication * congestive heart failure * recent use of illicit drugs (past month) * history of drug dependency * history of psychiatric disorder in subject or immediate relatives * pregnancy

Design outcomes

Primary

Measure	Time frame	Description
Electroretinogram (ERG) - acivity of the neural retina mixed cone-rod response, cone flicker, rod response	3 hours	microvolt
Electroretinogram (ERG) - acivity of the neural retina cone flicker latency	3 hours	milliseconds

Secondary

Measure	Time frame	Description
Eye movements	3 hours	degrees/second
Visual acuity	3 hours	LogMAR ETDRS
Macular thickness (OCT)	3 hours	micrometers
Intra ocular pressure	3 hours	mmHg
Titmus stereo eye movements	3 hours	seconds of arc

Countries

Israel

Contacts

Primary ContactHadas Mechoulam, MD

hadasm@gmail.com9293077002

Backup ContactHadas Lemberg, PhD

lhadas@hadassah.org.il00 972 2 6777572

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026