Phacoemulsification vs SLT for Pseudoexfoliation Glaucoma

(CANPEX1 Trial)

Overseen By Marcelo Nicolela, MD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Nova Scotia Health Authority

Must not be taking: Oral steroids

Disqualifiers: Age < 50, Angle closure, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 2 years

200 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines two treatments for individuals with pseudoexfoliation glaucoma, a condition characterized by increased eye pressure. The trial compares Phacoemulsification, a procedure to remove cataracts, and Selective Laser Trabeculoplasty, a laser treatment that aids fluid drainage from the eye, to determine which more effectively lowers eye pressure. Participants must have this condition and be newly diagnosed with early-stage cataracts that do not yet cause symptoms. The study will assess whether these treatments reduce the need for additional eye pressure-lowering medication over two years. As an unphased trial, it provides an opportunity to explore effective treatment options for managing eye pressure without extra medication.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications. However, if you have been using IOP lowering medication for more than 6 months, you cannot participate in the trial.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that phacoemulsification, a common cataract surgery, is usually well-tolerated. The chance of complications ranges from 0.1% to 5%. However, cataract surgery can be more challenging and riskier for individuals with pseudoexfoliation syndrome, a condition affecting the eyes.

Selective laser trabeculoplasty (SLT) is also considered safe and effective for lowering eye pressure. Studies indicate that SLT can reduce eye pressure by an average of 4 to 5.7 mmHg, a measure of pressure inside the eye. In real-world settings, SLT has produced positive results for many patients, although some may not respond to the treatment.

Both treatments are generally safe but have specific risks and benefits, particularly for those with pseudoexfoliation. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about Phacoemulsification and Selective Laser Trabeculoplasty (SLT) for pseudoexfoliation glaucoma because both offer unique advantages compared to traditional treatments like medications and conventional surgeries. Phacoemulsification, typically used for cataract removal, can also help lower intraocular pressure by enhancing the eye's fluid drainage, potentially addressing two issues in one procedure. On the other hand, SLT uses laser technology to improve eye fluid outflow without the risks associated with more invasive surgeries, offering a non-invasive option that could be repeated if necessary. These treatments bring hope for more effective management of pseudoexfoliation glaucoma with fewer side effects and less frequent interventions.

What evidence suggests that this trial's treatments could be effective for pseudoexfoliation glaucoma?

This trial will compare Phacoemulsification (PHACO) and Selective Laser Trabeculoplasty (SLT) for their effectiveness in lowering eye pressure in patients with pseudoexfoliation glaucoma. Studies have shown that Phacoemulsification, a type of cataract surgery, can significantly reduce eye pressure, with effects lasting up to 12 months. Specifically, one study found that this surgery alone can lower eye pressure by 2-4 mmHg. For SLT, research has demonstrated a decrease in eye pressure by 11% to 40% in various types of glaucoma. Another study observed an average reduction of 4.0 mmHg in eye pressure after SLT treatment. Both treatments have proven effective in managing eye pressure in glaucoma patients. ^{3 4 6 7 8}

Are You a Good Fit for This Trial?

This trial is for patients with pseudoexfoliation syndrome, which can be seen during an eye exam. They should need treatment to lower their eye pressure and have an early cataract without symptoms. People who don't meet these specific eye conditions or require different treatments are not eligible.

Inclusion Criteria

I have been diagnosed with pseudoexfoliation syndrome.

My doctor thinks I need treatment to lower my eye pressure.

I have an early-stage cataract without symptoms.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants are randomized to receive either Selective Laser Trabeculoplasty (SLT) or Phacoemulsification (PHACO) to lower intraocular pressure

2 years

Follow-up

Participants are monitored for safety and effectiveness after treatment, with a focus on intraocular pressure control and visual function

2 years

Long-term follow-up

Chart review to obtain longer follow-up information beyond two years, conducted 5 and 10 years after randomization

10 years

What Are the Treatments Tested in This Trial?

Interventions

• Phacoemulsification
• Selective Laser Trabeculoplasty

Trial Overview

The study compares two initial treatments for lowering eye pressure in pseudoexfoliation glaucoma: Selective Laser Trabeculoplasty (SLT) and Phacoemulsification (PHACO). Patients will be randomly assigned to one of the treatments and followed for 2 years, with some monitored up to 10 years.

How Is the Trial Designed?

Group I: SLT Experimental Treatment 1 Intervention

Main study intervention will be Selective Laser Trabeculoplasty

Group II: Phacoemulsification Experimental Treatment 1 Intervention

Main study intervention will be Phacoemulsification

Phacoemulsification is already approved in European Union, United States, Canada for the following indications:

Approved in European Union as Phacoemulsification for:

• Cataract removal
• Glaucoma treatment

Approved in United States as Phacoemulsification for:

• Cataract removal
• Glaucoma treatment

Approved in Canada as Phacoemulsification for:

• Cataract removal
• Glaucoma treatment

Who Is Running the Clinical Trial?

Nova Scotia Health Authority

Lead Sponsor

Trials

302

Recruited

95,300+

Jayme Vianna

Lead Sponsor

Trials

1

Recruited

200+

Glaucoma Research Society of Canada

Collaborator

Trials

8

Recruited

1,300+

Canadian Glaucoma Society

Collaborator

Trials

1

Recruited

200+

Published Research Related to This Trial

In a study involving 46 patients (20 with pseudoexfoliative glaucoma and 28 with primary open angle glaucoma), 360-degree selective laser trabeculoplasty (SLT) effectively reduced intraocular pressure (IOP) without requiring additional medications, demonstrating its safety and efficacy as a treatment option.

The success rate of IOP reduction was higher in the pseudoexfoliative glaucoma group (94.1% at 6 months) compared to the primary open angle glaucoma group (75% at 6 months), although both groups showed similar outcomes at the 12-month follow-up, indicating that the initial response may vary between the two types of glaucoma.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Selective laser trabeculoplasty in patients with pseudoexfoliative glaucoma vs primary open angle glaucoma: a one-year comparative study. Miraftabi, A., Nilforushan, N., Nassiri, N., et al.[2020]

Selective laser trabeculoplasty (SLT) can be an effective option for managing intraocular pressure (IOP) in patients with glaucoma who have previously undergone failed phacoemulsification cataract extraction combined with excimer laser trabeculotomy, as it may help slow disease progression.

However, the median time to failure after SLT is relatively short at 7.2 months, indicating that patients will require close monitoring and may need to consider incisional surgery if IOP control is not maintained.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Selective laser trabeculoplasty following failed combined phacoemulsification cataract extraction and excimer laser trabeculotomy can control intraocular pressure for a limited time. Krzyzanowska, I., Ziegler, J., Meier-Gibbons, F., et al.[2022]

Selective laser trabeculoplasty (SLT) is particularly effective for steroid-induced glaucoma, showing a significant reduction in intraocular pressure and a lower treatment failure rate (54%) compared to pseudoexfoliative glaucoma (84%) and primary open-angle glaucoma (84%) over two years.

Patients with steroid-induced glaucoma also experienced a notable decrease in the need for ocular hypotensive medications after 18 months, while those with uveitic glaucoma increased their medication use, indicating differing responses to SLT among these conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Selective laser trabeculoplasty in steroid-induced and uveitic glaucoma. Zhou, Y., Pruet, CM., Fang, C., et al.[2022]

A study comparing argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT) in 207 patients with pseudoexfoliation glaucoma found that both treatments effectively reduced intraocular pressure (IOP) without significant differences in outcomes over 24 months.

Both ALT and SLT showed similar reductions in IOP and the need for glaucoma medications, indicating that either laser treatment can be a viable option for managing PXE glaucoma.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evaluating selective laser trabeculoplasty versus argon laser trabeculoplasty in pseudoexfoliation glaucoma patients. Song, JSA., Vianna, J., Shuba, L., et al.[2022]

In a study of 14 eyes from 13 patients who underwent selective laser trabeculoplasty (SLT) after failed phacoemulsification cataract extraction combined with ab interno trabeculectomy, SLT did not successfully lower intraocular pressure (IOP) in any cases, indicating a lack of efficacy in this context.

The median time to failure for SLT was only 3.6 months, and there was no change in the number of antiglaucoma medications used, suggesting that alternative treatments, like incisional filtration surgery, may be more effective options after a failed phaco-trabectome.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Selective laser trabeculoplasty following failed combined phacoemulsification cataract extraction and ab interno trabeculectomy. Töteberg-Harms, M., Rhee, DJ.[2013]

Selective laser trabeculoplasty (SLT) significantly lowers intraocular pressure (IOP) more effectively in patients with pseudoexfoliative glaucoma (PXG) compared to those with primary open-angle glaucoma (POAG), with mean decreases of -6.1 mmHg and -4.4 mmHg respectively over a 1-year follow-up.

The safety profile of SLT is similar for both types of glaucoma, as the rates of side effects like early IOP spikes and uveitis did not significantly differ between the POAG and PXG groups.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the efficacy and safety of selective laser trabeculoplasty in cases with primary open-angle glaucoma and pseudoexfoliative glaucoma. Kara, N., Altan, C., Yuksel, K., et al.[2013]

Selective laser trabeculoplasty (SLT) significantly reduced intra-ocular pressure (IOP) in patients with uncontrolled pseudoexfoliation glaucoma, with a mean decrease of 31.5% from 26.01 mm Hg to 17.8 mm Hg after one year.

While SLT is generally safe, with most complications being mild (like conjunctival redness), there was a temporary increase in IOP in 3.5% of patients, which resolved quickly with treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Selective laser trabeculoplasty in uncontrolled pseudoexfoliation glaucoma. Goldenfeld, M., Geyer, O., Segev, E., et al.[2019]

In a study of 74 glaucoma patients undergoing combined clear cornea phacoemulsification and Trabectome surgery, those who had prior Selective Laser Trabeculoplasty (SLT) showed significant reductions in intraocular pressure (IOP) at six months, particularly in patients with Pseudoexfoliation Glaucoma (46% decrease) and Pigmentary Glaucoma (38% decrease).

The results suggest that prior SLT treatment does not negatively impact surgical outcomes and may even enhance the effectiveness of the Trabectome procedure, especially in patients with PEX and PG.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of Selective Laser Trabeculoplasty (SLT) on combined clear cornea phacoemulsification and Trabectome outcomes. Klamann, MK., Gonnermann, J., Maier, AK., et al.[2021]

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