Positive Outcomes : Interventional Glaucoma Management

Moderated by Dr Judy Ku (Brisbane), presentations were delivered by Associate Professor Shamira Perera (Singapore), Dr Colin Clement, and Associate Professor Mitchell Lawlor (both from Sydney).

In a thought-provoking presentation, Assoc Prof Perera advocated for a “significant” shift away from the traditional “wait and see” approach to glaucoma management, stressing the importance of early intervention for the most favourable patient outcomes.

Observing the limitations of conventional stepped medication protocols, he said adding a third anti-glaucoma medication only achieves a 20% intraocular pressure (IOP) reduction in 33% of cases. More concerning, in 21% of cases, adding a third drop actually resulted in IOP increases.¹

Additionally, he said, eye care professionals often overlooked the impact of topical medications on a patient’s quality of life, i.e. the side effects.

“They don’t know if the drops are doing well or not until you see them”, Assoc Prof Perera commented, before describing one study that revealed the effect of dry eyes from glaucoma medications was comparable to a 10-decibel loss of visual field.²

Assoc Prof Shamira Perera (Singapore) advocated for a “significant” shift away from the traditional “wait and see” approach to glaucoma management

Alternative Interventions

Moving on to discuss alternative interventions, Assoc Prof Perera spoke about selective laser trabeculoplasty (SLT), referencing the LiGHT study, which showed that first-line SLT resulted in 70% of patients remaining drop-free after six years.³ He also introduced Direct SLT (DSLT), a new technology allowing for wireless-controlled, rapid treatment delivery in just 1.9 seconds without contact lens application.⁴

On the surgical front, Assoc Prof Perera advocated for earlier implementation of minimally invasive glaucoma surgery (MIGS). When combined with cataract surgery, he said MIGS procedures have demonstrated meaningful and sustained IOP reduction. One study showed that early MIGS intervention reduced the incidence of more invasive procedures by 61%.⁵

Suggesting a future where topical medications serve as add-ons rather than the mainstay of treatment, Assoc Prof Perera proposed a new treatment sequence: “SLT, drug delivery, MIGS, and then maybe additional filtering surgery (trabeculectomy)”. However, he acknowledged potential cost-effectiveness considerations for this sequence in different healthcare systems.

“I think the future of glaucoma surgery is going to be with topical medications as an add-on, not as the mainstay. And I think this is going to come soon, certainly within the next 10 years,” Assoc Prof Perera concluded, calling on surgeons to maintain an open mind to newer treatment modalities and to take a more proactive approach to glaucoma management.

iStent Evolution

Dr Colin Clement shared insights into the evolution of the iStent (Glaukos): the device, the surgical technique, and clinical outcomes. Since its Australian launch in 2014, iStent has evolved from a “snorkel” design to a rivet design with increased flange, culminating in the current iStent Infinite system.

The new hand-piece used for implantation brings significant improvements, including unlimited deployment attempts and elimination of the viewing window bridge. “Just like people who drive electric vehicles have range anxiety, we used to have trigger anxiety with the iStent because when you got to the third one, you only had one stent left,” Dr Clement noted. The redesigned trocar is shorter and stiffer, offering enhanced stability during implantation.

Discussing surgical technique with the latest iStent, Dr Clement said he employs a “two plus one technique,” placing two stents in the initial position before repositioning for the third.

Dr Clement referenced clinical data including the United States Food and Drug Administration (FDA) clinical trial data involving 72 eyes, which demonstrated a 25.3% reduction in IOP to 17.5 mmHg and a 12.9% reduction in medications at 12 months. ⁶ However, it was the Australian data that proved particularly compelling. In an ongoing multi-centre study, preliminary results from 43 eyes at 12 months showed marked differences compared with baseline pressure. For patients with baseline IOP over 15 mmHg, 21 out of 23 eyes achieved reduction, with mean IOP decreasing from 23.4 to 14.7 mmHg – a 40% reduction.

Dr Clement compared these outcomes to PreserFlo (Glaukos), noting similar efficacy but highlighting iStent Infinite’s advantage as “a five-minute procedure that’s not touching the conjunctiva at all”.

the MicroShunt might be particularly suitable for older patients who find frequent visits to the ophthalmologist challenging, as well as those living remotely, or high myopes

PreserFlo MicroShunt vs Trabeculectomy

Assoc Prof Mitchell Lawlor shared insights from the FDA pivotal trial comparing the PreserFlo MicroShunt with traditional trabeculectomy, and discussed practical implications for surgical decision-making.

He said the trial revealed some clear distinctions between the procedures. While trabeculectomy achieved lower intraocular pressures after the one-month mark, the MicroShunt demonstrated advantages in other areas.

“The trabeculectomy gets better pressure lowering than the PreserFlo,” Assoc Prof Lawlor said, however, success rates need careful interpretation, with the trial defining success as at least 20% pressure reduction, staying at or below 21 mmHg, without an increase in glaucoma medications.

The data showed trabeculectomy achieved a 65% success rate at two years compared to 50% for the MicroShunt. However, the trade-off became apparent when examining complications: trabeculectomy had a 15% rate of hypotony (pressure below 6 mmHg) compared to just 3% with the MicroShunt.

Assoc Prof Lawlor outlined his approach to patient selection, suggesting the MicroShunt might be particularly suitable for older patients who find frequent visits to the ophthalmologist challenging, as well as those living remotely, or high myopes. Conversely, he advised caution in normal-tension glaucoma cases where very low target pressures are required.

A notable development in surgical technique was presented regarding intraluminal stenting. Drawing from Save Sight Glaucoma Registry data of 183 patients, Dr Lawlor shared compelling evidence for routine stenting. “In the no stent group, 44% had pressures less than six, compared to 24% in the stent group. When we looked at vision loss of more than 10 letters combined with hypotony, there was still a halving of risk – 30% in the no stent versus 15% in the stent group.”

Assoc Prof Lawlor concluded by highlighting the value of the Save Sight Registries in understanding individual surgical outcomes and tailoring procedure selection to both patient needs and surgeon factors.

The dinner was hosted by Glaukos.

1. Neelakantan A, Vaishnav HD, Iyer SA, Sherwood MB. Is addition of a third or fourth antiglaucoma medication effective? J Glaucoma. 2004 Apr;13(2):130-6. doi: 10.1097/00061198-200404000-00008.
2. van Gestel A, Webers CA, Schouten JS, et al. The relationship between visual field loss in glaucoma and health-related quality-of-life. Eye (Lond). 2010 Dec;24(12):1759-69. doi: 10.1038/eye.2010.133.
3. Gazzard G, Konstantakopoulou E, Barton K et al. LiGHT trial study group. Laser in Glaucoma and Ocular Hypertension (LiGHT) Trial: Six-year results of primary selective laser trabeculoplasty versus eye drops for the treatment of glaucoma and ocular hypertension. Ophthalmology. 2023 Feb;130(2):139-151. doi: 10.1016/j.ophtha.2022.09.009.
4. Congdon N, Azuara-Blanco A, Gazzard G, et al. GLAUrious study group. Direct selective laser trabeculoplasty in open angle glaucoma study design: a multicentre, randomised, controlled, investigator-masked trial (GLAUrious). Br J Ophthalmol. 2023 Jan;107(1):62-65. doi: 10.1136/bjophthalmol-2021-319379.
5. McCabe CM. Final results from the HORIZON trial: 5-year follow up of a schlemm’s canal microstent combined with cataract surgery in primary open angle glaucoma. Presented at American Glaucoma Society Virtual Annual Meeting.
6. Sarkasian SR, Grover DS, Naratil T, et al. Effectiveness and safety of iStent infinite trabecular micro-bypass for uncontrolled glaucoma. J Glaucoma 2023 32(1):9-18.

Sarkasian SR, Grover DS, Gallardo MJ, Brubaker JW, Giamporcano JE, Hornbeak DM, Katz LJ, Naratil T Effectiveness and Safety of iStent Infinite Trabecular Micro-Bypass for Uncontrolled Glaucoma J Glaucoma 2023 32(1):9-18