Polymer Ring Drug Delivery System for Non-invasive Treatment in Early Glaucoma Patients

Using an insert, it should be possible to deliver a consistent dose of medication to the eye while reducing the initial sting or burn, with less of the medication lost to the tear duct or sinuses.

Early diagnosis and treatment are crucial in slowing or preventing progression of glaucoma. This can be especially tricky, since medication compliance can be difficult for patients, and doctors often prefer not to use surgical procedures until other treatment options have been exhausted. Recently, researchers have created a temporary insert that may assist in medication adherence in a non-invasive way.

Current Compliance Complications

One of the most common therapies for early glaucoma treatment is eye drops to reduce intraocular pressure (IOP). Unfortunately, adherence to the medication schedule tends to be low amongst patients of all ages for a number of reasons:

Patient Forgets
If you have a once or twice daily medication, it can be easy to forget to administer it. Changes in routine, such as travelling, illness, a move, or other circumstances, might cause you to forget to take your medication. For glaucoma patients hoping to control their disease at the earliest stages, this can be especially problematic, due to the lack of symptoms early in the disease process.

Refill Complications
Whether due to economic strife, forgetfulness or time constraints, getting a refill on time can be complicated. A bottle of eye drops may last only a short period of time and it can be easy to forget to refill a prescription. Then, upon realizing it is necessary to get a refill there may be lengthy delays while attempting to visit a doctor or challenges getting to the pharmacy. There is the potential for a number of missed treatments during this time.

Undesirable Side Effects
When your eyes are burning or you’re suffering from medication-related fatigue, it can be difficult to remember that the benefits of the medication outweigh the costs. Under these circumstances some patients may decide to stop taking their medication and put themselves in danger of their disease progressing.

By working to remove reliance on patient compliance from the treatment regimen, it should be possible to increase the effectiveness of the medication. Research, and research funding, for newer delivery methods is crucial to both existing and future glaucoma patients. One way this research has begun to address this issue is through the development of non-invasive polymer rings.

Non-Invasive Polymer Doles Daily Dosage

Over the last decade, researchers and pharmaceutical companies have pursued the idea of continuous therapeutic delivery. Using an insert, it should be possible to deliver a consistent dose of medication to the eye while reducing the initial sting or burn, with less of the medication lost to the tear duct or sinuses.

To this end, researchers have developed a small polymer ring that sits around the eyeball to release a prostaglandin analog. The bimatoprost insert is a foldable device that comes in a number of different sizes to fit comfortably underneath the eyelid in the fornix. It is composed of an inner support structure surrounded by a silicone-bimatoprost matrix, which is the portion responsible for drug dispersal. At only 1 mm thick, most patients in the clinical trial said that they stopped noticing it within the first few days.

Dr. Brandt, the lead author on the results of the extension study, says the key to a helpful new glaucoma treatment is to balance efficacy with safety. With the current device, it appears to reduce and sustain a reduction in IOP of 4-5 mmHg when the inserts were replaced as designed out to 19 months, which is a clinically relevant reduction. There is still further research to be done to assess safety beyond this mark, as well as efficacy. It will be interesting to see what research yields regarding both the delivery method and long-term effects of a sustained release of Bimatoprost on the body; however, based on current data regarding the Bimatoprost eye drop, it is likely that there will be very few or no complications.

What’s Next In Non-invasive Glaucoma Treatment?

The Bimatoprost ring is still in clinical trials. From this stage, it is likely that the researchers will expand the study to encompass a larger patient-base and compile reported side-effects, overall effectiveness, and which kinds of people respond best to this new treatment. As researchers continue to investigate non-invasive medication methods, experiments with other innovative ways to treat glaucoma that would increase medication adherence and reduce the progression of this challenging illness.


First posted on May 5, 2017; Reviewed June 16, 2022