Glaucoma Care: What To Expect

New therapies, designed with innovative approaches to enhance patient outcomes, are reshaping the landscape of glaucoma treatment

From minimally invasive surgeries to implantable drug delivery systems and groundbreaking genetic therapies, these advancements in glaucoma treatments promise safer procedures, faster recovery times, and potentially transformative outcomes for millions affected by this sight threatening condition..

Most people of a certain age (or slightly younger) ought to be familiar with the 1968 classic by the British rock band The Beatles called ‘Revolution.’ But in case you aren’t, here are the opening lyrics:

Well, it seems that, in recent years, ophthalmologists are seeing a revolution in the fight against glaucoma. But instead of overthrowing a government, cuttingedge technological innovations are offering new techniques for delivering glaucoma medications to lower intraocular pressure (IOP), as well as minimally invasive glaucoma surgeries (MIGS). These approaches are relatively safe and effective with faster recovery time and better outcomes.

Here are our top 5 picks:

1. Deviceless MIGS

“One of the most notable developments is the rise of MIGS procedures,” said Dr. Sudhashini Chandrasekaran, an ophthalmologist from Columbia Asia Hospital, Puchong, Malaysia.

According to Dr. Sudhashini, MIGS techniques have become popular due to the fewer complications and quicker recovery times in comparison to conventional surgeries. “Often performed in combination with cataract surgery, MIGS procedures are playing an increasingly important role in glaucoma management. With careful patient selection, MIGS procedures may yield excellent results, which can reduce glaucoma progression and improve the glaucoma patient’s quality of life,” she added.

Among the newer innovations in the MIGS category are the deviceless MIGS, such as laser trabeculotomy (the ELIOS, MLase GmbH; Germering, Germany, and ViaLase, ViaLase, Inc.; California, USA ), abinterno canaloplasty (the iTrack and iTrack Advance devices, Nova Eye Medical; Kent Town, South Australia), and the combined canaloplasty and trabeculotomy (the OMNI System; California, USA).

These procedures aim to enhance the natural outflow pathways of the eye without the need for implanted devices, hence reducing the risk of foreign body-related complications, such as endothelial cell loss, inflammation, and surgical trauma.

“The MIGS has been making its rounds in most countries, either as a bridging therapy for mild to moderate glaucoma using the trabecular bypass MIGS (iStent, Glaukos Corporation; California, USA, and Hydrus, Alcon; Geneva, Switzerland), or subconjunctival MIGS like the PreserFlo (Santen Pharmaceutical; Osaka, Japan) for severe glaucoma,” said Prof. Dr. Norshamsiah Md Din, an ophthalmologist and glaucoma specialist at the Faculty of Medicine, Universiti Kebangsaan Malaysia.

Prof. Norshamsiah has used all three devices and she noted that there is a steep learning curve to implant the Hydrus trabecular bypass. But with practice, it becomes easier.

These devices offer modest (trabecular bypass MIGS) to substantial IOP lowering (subconjunctival MIGS) results. According to Prof. Norshamsiah, the advantages of these devices over traditional glaucoma surgery like trabeculectomy and glaucoma drainage device (GDD) include a shorter operating time, faster recovery, and safer surgery with minimal risks and complications.

“However, the biggest stumbling block to using these devices is the cost, especially the smaller trabecular bypass MIGS,” she noted.

2. Intracameral implantable drug delivery systems

In addition to surgical advancements, pharmacological innovations are also making waves in the glaucoma scene.

The use of daily eye drops to lower IOP has been a mainstay in glaucoma therapy for decades. However, a 2018 study put the rates of nonadherence as high as 67%.1 This increases the risk of glaucoma progression and vision loss.

Two intracameral implantable drug delivery systems aim to address this.

The iDose TR (travoprost intracameral implant, 75 mcg; Glaukos Corporation; California, USA) and the Durysta (bimatoprost implant, 10 mcg; Allergan; Dublin, Ireland) are minuscule implants that release potent glaucoma medications continuously over several months, ensuring consistent therapeutic levels.

While the biodegradable Durysta was approved by the U.S. Food and Drug Administration in March 2020, the iDose TR was approved in December 2023 and is the first eye implant to deliver medication 24/7 for an extended period.

The iDose TR treats glaucoma by automatically releasing the same type of medication used for decades in the most commonly prescribed eye drops, a prostaglandin analog, which reduces pressure in the eye by increasing the outward flow of fluid from the eye. After 12 months of a clinical study, 81% of people were able to eliminate the burden of taking daily eye drops.2

“As with any new invention, the use of these devices is limited at the moment by their cost and availability. But they are definitely a promising option for glaucoma treatment in the near future,” said Dr Chandrasekaran.

3. Glaucoma polygenic risk score

A new genetic test for glaucoma could hold the key to identifying and prioritizing the treatment of those at high risk of losing their sight due to the disease. Until recently, there was no way of determining who will develop vision loss and how to better manage individuals at risk of developing glaucoma.

Ophthalmologists at Flinders University and The Council of the Queensland Institute of Medical Research have devised a glaucoma polygenic risk score that identifies individuals at high risk of losing their sight.

The deceptively simple saliva-based test kit can strongly predict severe and sight-threatening glaucoma and therefore identify patients at high risk of losing their sight. This helps prioritize their treatment with regular monitoring.

“Its use has been approved in Australia and we hope it will soon be available worldwide,” said Prof. Norshamsiah.

This test also removes the onesize-fits-all approach in glaucoma management where high-risk patients are managed by a glaucoma specialist, while patients at a lowand intermediate-risk level can be managed safely and less frequently in a primary care setting, she added.

4. eyeWatch

In severe and recalcitrant glaucoma, a GDD is often the treatment of choice as it offers better long-term IOP control. However, the early hypertensive phase and hypotony, especially in non-valved GDD, often limit its use. New devices to titrate the flow through the GDD are now available to overcome these problems.

The new eyeWatch (HomeBrite Corp.; CA, USA) implant is said to be the world’s first adjustable GDD. The unique and innovative mechanism using a small magnetic device inside the eyeWatch allows surgeons to titrate the aqueous outflow postoperatively, and therefore lowers or increases the patients’ IOP in an efficient, painless, and non-invasive inoffice manner.

More than 90% of patients have a successful treatment after one year, meaning that their pressure is effectively managed.3 On average, anti-glaucoma medications are reduced to about one-third after one year.4

5. Gene therapies

While gene therapies are in various stages of development, they hold great potential in transforming glaucoma management in the future. The hope is that gene therapy for glaucoma provides a new treatment option for a disease that is incurable. Early treatment may prevent damage, but it is yet unknown if gene therapy can reverse damage that has already occurred.

In April 2023, scientists at Trinity College Dublin in Ireland announced a significant development towards a new treatment of glaucoma.5 While topical eye drops are critical in preventing disease progression, up to 10% of patients become treatmentresistant, putting them at risk of permanent vision loss.

The College noted in its news release that a team at the Smurfit Institute of Genetics, in collaboration with biotechnology company Exhaura Ltd. (Dublin, Ireland), has shown that a gene therapy-based approach can decrease IOP in pre-clinical models of glaucoma.

A single injection of a viral vector can increase the flow of aqueous fluid from the front of the eye and thereby decrease pressure in the eye. The key instructions are for cells to produce an enzyme matrix (metalloproteinase-3, or MMP-3) that helps kick this process into gear.

“This exciting project allowed us to bridge the gap between academia and industry and work very closely with a gene therapy company to develop a cutting-edge therapy that we believe holds immense promise for patients in the future,” said Dr. Matthew Campbell, professor of genetics at Trinity College Dublin in the news release.

The study used multiple models of disease as well as donor human eyes to screen the therapeutic efficacy of the gene therapy approach.

Dr. Jeffrey O’Callaghan, a postdoctoral research fellow at Trinity and first author of the study, also said in the news release: “We are now hopeful that this therapy will pave the way for the development of treatments for other forms of blinding eye diseases.”

A remarkable year for glaucoma management

“Glaucoma is one of the most rapidly evolving fields in ophthalmology. Traveling back in time to just a few decades ago, the progress we see today would have been unimaginable,” Dr. Chandrasekaran said.

Although the mechanism of the disease remains unclear, 2024 is a remarkable period for glaucoma management with the rapidly evolving advancements happening in the field, she noted.

The vast number of treatment options available today has transformed how the treating doctor approaches glaucoma. “This paradigm shift aligns well with the changing expectations of patients today, who seek beyond just eye drops, even in the early stages of the disease,” she added.

The year 2024 brings much hope to glaucoma patients, with safer, more efficient, and less burdensome treatment options. Perhaps, there may even come a day when vision loss may be reversed.

For this, the lyrics of Imagine by John Lennon come to mind:

“You may say I’m a dreamer But I’m not the only one…”

References

1. Robin, AL, Muir, KW. (2019). Medication adherence in patients with ocular hypertension or glaucoma. Expert Rev Ophthalmol. doi.org/10.1080/17469899.2019.1635456.
2. Glaukos Transforming Vision. Glaukos announces positive topline outcomes for both phase 3 pivotal trials of iDose TR, achieving primary efficacy endpoints and demonstrating favorable tolerability and safety profiles. Available at https://investors.glaukos.com/investors/news/news-details/2022/ Glaukos-Announces-Positive-Topline-Outcomes-for-Both-Phase-3-Pivotal-Trials-of-iDose-TRAchieving-Primary-Efficacy-Endpoints-and-Demonstrating-Favorable-Tolerability-and-Safety-Profiles/ default.aspx. Accessed on June 22, 2024.
3. Roy S, Villamarin A, Stergiopulos C, et al. Initial Clinical Results of the eyeWatch: a New Adjustable Glaucoma Drainage Device Used in Refractory Glaucoma Surgery. J Glaucoma. 2019;28(5):452- 458.
4. Roy S, Villamarin A, Stergiopulos C, et al. Comparison Between the eyeWatch Device and the Ahmed Valve in Refractory Glaucoma. J Glaucoma. 2020;29(5):401-405.
5. Trinity College Dublin. Scientists develop novel gene therapy for glaucoma. Available at https:// www.tcd.ie/news_events/articles/2023/scientists-develop-novel-gene-therapy-for-glaucoma/. Accessed on June 22, 2024.

Editor’s Note: A version of this article was first published in COOKIE magazine Issue 16.