THC Eye Drops Now in Clinical Trial for Glaucoma Patients

THC eye drops are designed to give consistent and directed dosing. We’ll soon know if these also keep the pressure down.

Dr. Mahmoud ElSohly, one of the co-directors of the Marijuana Project at the University of Mississippi (UM), is leading a noteworthy clinical study to evaluate and develop THC eye drops. Instead of smoking cannabis to reduce intra-ocular pressure (IOP), glaucoma patients would simply apply the drops. Patients would avoid the elevated feeling often resulting from the use of tetrahydrocannabinol (THC) and still experience its healing properties.

What is Glaucoma?

Glaucoma is a group of diseases that exhibit increased IOP, caused by an imbalance of fluid within the eye. This can damage the optic nerve and ultimately lead to reduced vision and even blindness. There are often no noticeable symptoms until a patient begins having trouble with their vision. Once damage has occurred, it is irreversible, so it is extremely important to have screenings for glaucoma. This is particularly for populations with an increased risk, including people of color, those over the age of sixty, and anyone with a parent or sibling with glaucoma.

Doctors regularly perform tonometry, or the “air puff” test, during eye exams. This is a quick, painless (although often startling) procedure that allows optometrists and ophthalmologists to get a basic reading of IOP. If there is an abnormal reading, doctors will perform further tests and procedures to assess the severity of a patient’s glaucoma and determine a treatment plan.

Typical Treatment for Glaucoma 

Treatment for glaucoma uses a multifaceted approach, which may evolve over time if a patient’s condition changes or worsens. Glaucoma patients can make several additional lifestyle changes to reduce their IOP, including eating a healthy diet, exercising, sleeping with their head in an elevated position, limiting caffeine, and managing their fluid intake. Eye drops see the most commonly use, which also reduce IOP. These medications can cause uncomfortable side effects, but it is imperative that patients follow their prescribed regimen and work with their physician to avoid any further ocular damage or vision loss.

Surgery is another possibility, with either a laser procedure or a standard operating room procedure. The type of surgery required depends on the type of glaucoma as well as severity of the patient’s condition. Patients may likely still require glaucoma medication after having surgery.

Researchers Have Limited Access to Cannabis 

In 1968, the University of Mississippi entered into a lucrative contract with the federal government. The aim of the contract was for them to be the exclusive grower of cannabis for government research purposes. Therefore, until very recently, researchers within the U.S. have only had access to cannabis from UM to be used for FDA-approved clinical trials.

Unfortunately, the cannabis provided by UM is not of the best quality—samples are often received damaged or unusable and have been deemed to be low in strength compared to what is available from legal dispensaries. Additionally, there have been legal challenges to the original contract. As of 2019, the Drug Enforcement Administration (DEA) stated that it will review applications submitted by other growers to allow higher quality cannabis to be used for research purposes.

In his discussion of these issues, Dr. ElSohly is misguided at best. At worst, considering his statements that anyone using more than eight percent THC is an “addict,” ElSohly is spreading some potent misinformation.

Other Potential Challenges

Considering the reduced strength and quality of the cannabis available to researchers, ElSohly’s study is at a potential disadvantage. However, making THC eye drops available to patients may be a challenge for other reasons, too. Similar previous studies did not yield the desired results, and several doctors have denied THC’s efficacy in treating glaucoma.

Furthermore, when extracted from cannabis, THC is in the form of an oil. Eye drops, however, come from a water base. Since oil and water do not mix, this separation would not allow for consistent dosing.  Additionally, having an oily substance in their eyes would not be a comfortable experience for patients.

Why THC Eye Drops in Development Could be a Better Option

Other trials have studied THC eye drops, but the new study is different as it uses a modified THC molecule. In addition to reducing IOP, THC is neuroprotective. This is an added benefit for glaucoma patients; the optic nerve can become damaged as part of the disease process. It is unclear whether there would be any potential for reversal, but it is, unfortunately, unlikely.

Doctors undertook tests on other novel treatments, but these are yet to yield positive results. There has been a reduction in research of cannabis-based glaucoma treatments in part because pharmaceuticals used to treat the condition have improved, have longer lasting effects, and their results have surpassed those previously received from cannabis.

If the researchers formulate the new THC eye drops appropriately, they could significantly benefit current glaucoma patients. This would also pave the way for additional research using modified THC molecules. These could greatly help to develop treatments for other conditions. Studies of this nature have already occurred.