Topcon’s Vision for the New Future of Glaucoma Crystallizes at APAO 2024

New developments in glaucoma diagnosis and treatment have changed the way ophthalmologists approach and manage the disease. For some of the Asia Pacific region’s most eminent glaucoma experts,Topcon’s suite of cutting- edge tools are bridging the gulf between these innovations and everyday use in the clinic.

The treatment paradigm for glaucoma is changing. A day hardly passes now when one of the most vexing pain points for glaucoma disease detection and management hasn’t been conquered in the lab.

Topcon Healthcare (Topcon; Tokyo, Japan) has made the translation of these critical innovations into reality its sole mission through its suite of modern glaucoma tools, like Triton™ OCT, Maestro2, and the IRIDEX Cyclo G6® Glaucoma Laser System and MicroPulse P3® Delivery Device.

Moderated by Prof. Widya Artini Wiyogo (Indonesia), a recent symposium at the 39th Congress of the Asia-Pacific Academy of Ophthalmology (APAO 2024) focused on what the fruits of the latest research are bearing in the clinic, with eminent specialists Prof. Victor Koh (Singapore), Dr. Eun Ji Lee (South Korea) and Dr. Virna Asrory (Indonesia) on the podium reporting on their experiences.

These top names in glaucoma covered a wide range of applications, from understanding glaucomatous disease genesis, to monitoring and predicting optic nerve damage and treating it — and how they use Topcon’s offerings to unlock it in their clinics.

Hood reports with Triton and Maestro2 OCT

One of the promises of modern glaucoma research has been the usage of new tools like swept-source optical coherence tomography (SS-OCT) for earlier detection of glaucoma and treatment guidance.

With her turn at the podium, Dr. Asrory explored the practical usage of the Hood Report and where it fits into her practice.

The Hood Report report uses Topcon’s Triton and Maestro2 SS-OCT to look at the retinal nerve fiber layer (RNFL) and coordinate structural damage and functional information from tests like visual field perimetry.

“It aids the decision-making process when determining which areas of the visual field should be examined for agreement between structural and functional loss,” Dr. Asrory said.

But why do glaucoma physicians need this aid when they have tools like visual field testing at their disposal? Dr. Asrory’s answer was simple: Visual field tests can be unreliable at best, and even misleading in extreme cases.

Patients, she said, get fatigued—especially when the test is being performed on the second eye. There is also a learning curve, which can cause issues for those with undetected glaucoma who have never taken a visual field test. This, and many other factors, can cause reliability problems in the form of false positives and negatives.

These problems can be addressed with the Hood report, which uses OCT images from Topcon’s Triton and Maestro2 by boosting the meaning of visual field data points. By comparing probabilities against a reference database the report is able to pinpoint problem areas warranting further investigation.

“The Hood Report compares structural and functional data to support management decisions, particularly if insufficient historical data is available.”

— Dr. Virna Asrory

“The Hood Report compares structural and functional data to support management decisions, particularly if insufficient historical data is available,” Dr. Asrory said.

Historical data, she concluded, likely to be absent in newer patients more likely to encounter problems with visual field tests. In other words, patients who are more likely treatment naive or with undetected glaucoma that need accurate screening the most.

Another key feature of the report is the arrangement of the circumpapillary RNFL scan (cpRNFL) into a nasal-superior-temporal- inferior-nasal (NSTIN) arrangement, as opposed to the traditional temporal-superior-inferior-nasal-temporal (TSINT) order.

“This positions the structures most vulnerable to glaucomatous damage in the center of the graph,” explained Dr. Asrory. “The traditional TSINT format splits these vulnerable areas.” In the end, Dr. Asrory asserts that the Hood Report functionality on Topcon’s Triton and Maestro2 adds up to a new, powerful tool in the fight against glaucoma in the stages that it is most needed. “All of the essential elements affected by glaucoma are on one page,” she said.

“Because of these characteristics of the structure-vascular relationship, [OCT-A] can be used to monitor glaucoma.”

— Dr. Eun Ji Lee

“The Hood Report is a single wide-field OCT analysis that aids in detecting glaucomatous damage, especially for early screening. It increases confidence for glaucoma management for our patient based on structural and functional analyses,” she concluded.

The OCT-A advantage

Translational medicine again took center stage when Dr. Eun Ji Lee, one of South Korean and Asian glaucoma’s most recognizable names, took the stage. She tackled translating research in OCT angiography (OCT-A) and glaucoma into clinical practice.

According to Dr. Lee, one of the immediate benefits of the OCT-A capabilities of Triton and Maestro2 in glaucoma is the ability to look at the vasculature around two retinal layers—the RNFL and the ganglion cell inner plexiform layer (GCIPL). Localized loss of deep retinal vasculature in these layers, she noted, is correlated with loss of structure in the retinal.

“Because of these characteristics of the structure-vascular relationship, [OCT-A] can be used to monitor glaucoma,” Dr. Lee said. “As glaucoma progresses, there is a gradual decrease in vascular density, and the location of the glaucomatous damage is also shown in the vascular map.” Dr. Lee also noted that OCT-A presents unique advantages when it comes to the so-called ‘floor effect’, where limits in the dynamic range of OCT images make it difficult to measure glaucomatous damage and progression in more severe cases.

This is not the case with OCT-A. “Because OCT-A does not measure thickness, it should be more free from the ‘floor effect’, she said. “A study compared OCT-A and OCT to see the visual field damage, and compared the structural function and vascular function relationship. [The study] found that this vascular function relationship performed better in eyes with severe visual field damage.”_¹

Dr. Lee went over further advantages of OCT-A immediately applicable to the clinic, including her own research on using choroidal OCT-A in detecting choroidal microvascular dropout for prediction of glaucoma progression.²

“We can use OCT-A in glaucoma,” she said. “It can be used in diagnosis, especially in highly myopic eyes or eyes with pathologic myopia—and it could potentially also be useful in advanced glaucoma.”

Most importantly, though, is the view that OCT-A gives into the future of glaucomatous disease. “It can also be used to predict the prognosis by the presence of microvascular dropout by predicting rapid progression in adjacent areas.

“In the future, I hope that OCT-A can be used to tailor treatment in individual patients to determine whether the patient needs further IOP lowering or not,” Dr. Lee concluded.

New frontiers in MicroPulse TST and cataract

Prof. Victor Koh, head of the department of ophthalmology at National University Hospital and National University of Singapore, brought the session to a close with his presentation on his research with combined MicroPulse transscleral laser therapy and cataract surgery.

Using the IRIDEX Cyclo G6 Laser and the MicroPulse P3 delivery device, Prof. Koh’s work compares combined MicroPulse TLT and phacoemulsification cataract surgery with phacoemulsification with iStent and phacoemulsification with endoscopic cyclophotocoagulation.

After reviewing the importance of patient selection, Prof. Koh first gave the guidelines he uses in his own MicroPulse TLT practice. This includes patients not suitable for incisional or prolonged glaucoma surgery, those who have had prior incisional glaucoma surgery to lower IOP, those who have just had incisional glaucoma surgery, or those who have uncontrolled IOP in eyes with a poor prognosis and need a reduction in medication burden.

This indicates a long list of potential patients for what Prof. Koh ultimately believes is an invaluable and versatile procedure. His results in the iStent study speak to this, as well. Patients receiving TLT with phacoemulsification saw an IOP reduction to 14.0±2.2 and 14.5±2.2 at 6 and 12 months postoperatively from 16.8±3.5, compared to the iStent group, which went from 16.6±3.6 at baseline to 14.4±3.6 and 15.7±3.1, also at 6 and 12 months, respectively.

“I think combined cataract surgery with MicroPulse laser is effective and safe. This is a viable option for patients with both cataract and mild glaucoma.”

— Prof. Victor Koh

For medication decrease, Prof. Koh was enthusiastic. “There was also a significant reduction in the number of medications after surgery, and this was sustained up to one year, where the majority of them are off medications” he said, noting the importance of how patients were selected for TLT.

These results were echoed in the second study, where phacoemulsification with TLT and with endoscopic photocoagulation were compared. “There is a higher rate of success and a higher rate of survival for patients who underwent phaco and MicroPulse laser,” he said.

Ultimately, the conclusion for MicroPulse TLT for Prof. Koh was clear. “I think combined cataract surgery with MicroPulse laser is effective and safe. This is a viable option for patients with both cataract and mild glaucoma,” he said.

“I now also use this procedure if I’m not sure of the visual deficiencies of this patient. Someone, for example who might be elderly with dense, wide massive cataract,” Prof. Koh continued.

“The other group of patients that might benefit are patients with more advanced PACG, who don’t have too much pressure and just want to do a cataract surgery. And lastly, if you have someone with a cataract and a request to have the burden of medications after surgery lowered, this is something to consider as well.”

With Triton OCT, Maestro2 and MicoPulse TLT leading the way, patient-tailored and optimized glaucoma screening, diagnosis, prediction and management are here. This is what Topcon technology is all about, and the presentations by these three glaucoma experts have showcased how these cutting-edge solutions are now ready to be incorporated into everyday practice for improved quality of care.

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