Technologies Focus on Improving Glaucoma Drop Adherence

Ensuring patients take their medications is a challenge for clinicians across medical disciplines — but it’s especially challenging in eye care. Most patients with mild to moderate glaucoma are treated with eye drops to prevent the minimal symptoms they experience at those stages of the disease from progressing to severe disease and, eventually, blindness.¹ However, these drops can be expensive, uncomfortable, and difficult for patients to instill properly.

Mitch Ibach, OD, FAAO, of Vance Thompson Vision in Sioux Falls, South Dakota estimates that about 30% to 50% of his patients who take glaucoma medications are noncompliant. In fact, that number is reflected throughout the academic literature, including in a South Korean study of 1050 participants with glaucoma, which found 27.4% were noncompliant with their medication, and a small study of 100 participants with glaucoma treated at the Manchester Royal Eye Hospital, which found 30% were noncompliant.^2,3  

Remembering to take the medications, obtaining the medications, and any change to their regimen throughout the course of their treatment can present challenges for patients. The confluence of the need for drops to be delivered accurately and on schedule and the high rate of patients unable to accomplish this has created a vacuum, and smart technologies abhor a vacuum.  

Such wearable, trackable tech promises to monitor both drug delivery and intraocular pressure (IOP), communicate with eye care clinics, and even automatically release medication via implanted devices. Researchers are exploring the capabilities of contact lenses that can communicate with a patient’s phone, changes to dropper bottles, and at-home tonometry devices. While some of that is years down the line, some is changing glaucoma care today. 

Here, Optometry Advisor provides an overview of some of the technologies developers are working on, and what optometrists are able to do today to keep their patients from losing vision.     

Monitoring Intraocular Pressure

A 2020 study published in Medical Devices & Sensors evaluated the use of a soft contact lens-based IOP reader that partners with a smartphone application that analyzes the contact lens and determines displacement of the fluid.⁴ The researchers found that the contact lens indicator consistently measured IOP in multiple patients whose corneal shape varied. In future models of the device, patients could someday be fitted with a microfluidic contact lens and have IOP changes tracked with indicator fluid in reference to an initial measurement with Goldmann applanation tonometry (GAT). Optometrists could use that data to better target a treatment regimen.

Tonometry measurements taken outside the clinical setting are possible today in the form of home tonometry devices. These allow patients with glaucoma to track their own IOP and offer their physician a more complete picture of their disease. Dr Ibach believes this technology could indirectly motivate patients to commit to their medication..

Another technology recently reviewed in a Journal of Glaucoma case report shows the success of an implantable IOP sensor placed in the ciliary sulcus during cataract surgery. Using the device, surgeons were able to monitor for sustained high IOP readings, and refer the patient to surgery in a timely manner. It also “allowed accurate identification of IOP reductions with each intervention and subsequent increase in IOP as the interventions failed,” the report explains. “It also provided insight into the timing of IOP increases, for example, showing each needling procedure was associated with an increase in IOP to preneedling levels in <7 days.”⁵ 

Digital Sensors

In glaucoma, smart technologies don’t necessarily have to focus on monitoring the patient. An alternative approach is to monitor the dropper bottle itself. One such device can actually record the number of times a pill bottle or box containing oral medications is opened, which may indicate the patient’s consumption of medication. Some of these smart pill bottles can detect the removal of the medication and even use that knowledge to provide patients with visual, auditory or text reminders to take medication, when necessary, and deliver feedback reports to their physicians.⁶ If it can be done with a pill bottle, some researchers are asking, can it also be done with an eyedropper? So far, investigators have explored the use of smart tech eye drop bottles that can track the time and number of drops dispensed, detect the motion of the eye drop bottle using motion sensors, and measure fluid level. 

“Monitoring devices on eye drop bottles is a great wish, but realistically, ways of delivering the medication that don’t require the patient to take the medication every day is probably the better way to go,” according to Michael Chaglasian, OD, president of the Optometric Glaucoma Society and an educator at the Illinois College of Optometry. “While it would be a nice thing to have, I don’t see there being much business need to develop a monitoring system that tells us whether a patient takes their eye drop medications every day. The cost/benefit doesn’t seem to work in our current healthcare environment,”said Dr Chaglasian, who also serves as Chief of Staff at the Illinois Eye Institute.

Not all of these developments are practical in Dr Chaglasian’s view. Timers to remind patients to take their medications may help some, but older patients, whose vision is decreasing, may struggle to use smartphone apps, he said.

“If there was a way to inexpensively, affordably put chip technology into the bottle so that it’s registered when it’s used by the patient and it could effectively and efficiently transmit that information, that may be very helpful if we can do it across the board for all patients, but I see so many challenges there,” Dr Chaglasian said.

While it isn’t a smart device, per se, Dr Ibach reported some success with a Nanodropper adapter, which fits onto glaucoma medications to reduce drop size from bottles and thereby help patients avoid spilling medication onto their cheeks.

Drug Delivery Devices

While wearables and smart bottles may have flashy, headline-grabbing appeal, the experts interviewed for this article were more interested in the potential of drug delivery devices.These technologies come in the form of punctal plugs or dissolvable inserts that minimize what patients need to do to take glaucoma medications 

“These are most commonly going to be in-office procedures,” Dr Ibach said. “Or, if done in the operating room, we’re talking a 3-to-4-minute procedure. These procedures can be done with minimal anesthesia. Patients are going to be on some postoperative antibiotics afterward to cut down on the risk of infection.”

He said his office has seen success with an implantable bimatoprost-eluting device, which releases the prostaglandin analog for a period of 12 weeks. The device was approved by the US Food and Drug Administration last year. The technology is promising, but trials show the potential for complications, with 64% of eyes implanted experiencing one or more ocular adverse events, most commonly ​​conjunctival hyperemia (​​likely attributable to the application of ophthalmic povidone-iodine used to prepare the eye for the implant, according to investigators).⁷ Notably, researcher reported no serious ocular adverse events in the study eyes.⁷ Dr Chaglasian added that implant could eliminate the need for patients to instill eye drops daily. However, the current guidelines are limited to a single injection.

A 2020 review of contact lens-based drug delivery systems published in Applied Sciences found that while contact lenses may be uncomfortable and older patients may have difficulty wearing them, they provide new avenues and prolong release of drugs.⁸ Studies show that functional monomers, molecular imprinting, and colloidal nanoparticles can help facilitate the release of medication.⁸

While drops continue to be the standard of care for first line glaucoma treatment, more patients are deciding to undergo laser procedures, such as selective laser trabeculoplasty, Dr Chaglasian added. Laser treatment is limited, however, as the effects are not long term. Still, laser treatment and minimally invasive glaucoma surgeries (MIGS) are options for addressing glaucoma in patients who have demonstrated they cannot keep up with the rigor of taking eye drops, he said.

“Until we have a mechanical device that is effective in sounding alarms, tracking whether or not the patient is taking it, giving us this information back in a graph so that we can really have hard data as to what they’re doing, those are basically the approaches,” Dr Chaglasian said.

In The Office

Dr Ibach always tells patients that the drops are effective for treating glaucoma — as long as patients instill them correctly and consistently. He explains that the intention of the regimen is to avoid allowing intraocular pressure to spike. While developers and engineers tinker away with digital devices, optometrists can help patients maintain vision by investing in patient education and listening to their concerns, especially around adverse effects commonly associated with the medicines, which may lead to noncompliance. According to Dr Ibach, optometrists need to be comfortable talking with their patients about noncompliance. Some techniques to consider include referring to their medications by the color of the cap, rather than by name, and asking patients to report how many doses they missed, rather than how many doses they took

“Glaucoma fights back,” Dr Ibach said. “Whether it’s glaucoma medications or laser procedures or drug delivery or intraocular glaucoma surgery, most patients are going to need a combination of treatment approaches. We usually just won’t have a single magic silver bullet that keeps their glaucoma from progressing year after year.”

Reference

1. Kim S, Tong B, Lee, J, et al. Lifestyle counseling for medication adherence in glaucoma. Clin Ophthalmol. 2021:15 3521–3529. doi: 10.2147/OPTH.S321351

2. Kim CY, Park KH, Ahn J, et al. Treatment patterns and medication adherence of patients with glaucoma in South Korea. Bri J Ophthalmol. 2017;101(3):801-807. doi:10.1136/bjophthalmol-2016-308505,

3. Buller AJ, Connell B, Spencer AF. Letter: Compliance: clear communication’s critical. Bri J Ophthalmol. 2005;89(9):1368–1387. doi:10.1136/bjo.2005.066175

4. Campigotto A, Lai Y. A novel non-invasive wearable sensor for intraocular pressure measurement. Med Devices Sens. 2020;3:1-10. doi: 10.1002/mds3.10086

5. Saxby E, Mansouri K, Tatham A. Intraocular pressure monitoring using an intraocular sensor before and after glaucoma surgery. J Glaucoma. 2021;30(10):941-946. doi:10.1097/IJG.0000000000001916

6. Erras A, Shahrvini B, Weinreb RN, Baxter SL. Review of glaucoma medication adherence monitoring in the digital health era. Br J Ophthalmol. 2021;0:1-7. doi: 10.1136/bjophthalmol-2020-317918

7. Craven ER, Walters T, Christie WC, et al. 24-month phase i/ii clinical trial of bimatoprost sustained-release implant (bimatoprost sr) in glaucoma patients. Drugs. 2020;80:167–179. doi:10.1007/s40265-019-01248-0.

8. Peral A, Martinez-Aguila A, Pastrana C, et al. Contact lenses as drug delivery system for glaucoma: a review. Appl Sci. 2020;10(15):5151. doi:10.3390/app10155151