Laser Treatment for Glaucoma Prevention in Corneal Disease

Overseen By Soumaya Bouhout, MD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)

Disqualifiers: Age, Other glaucoma study, others

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

Compensation: Varies

Number of Visits: 3

20 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment for glaucoma prevention in corneal disease?

Research shows that Micropulse Transscleral Cyclophotocoagulation (MP-CPC) is effective in treating glaucoma, with studies indicating it has a favorable safety profile and can reduce intraocular pressure, which is crucial in managing glaucoma. ^{1 2 3 4 5}

Is laser treatment for glaucoma prevention in corneal disease safe?

Research shows that Micropulse Transscleral Cyclophotocoagulation (a type of laser treatment) is generally safe for treating glaucoma, with studies indicating a favorable safety profile compared to other methods. However, it can cause some inflammation in the eye, which is a common side effect. ^{3 4 6 7 8}

How does the laser treatment for glaucoma prevention in corneal disease differ from other treatments?

This laser treatment uses micropulse technology, which delivers laser energy in short bursts, reducing the risk of damage compared to continuous-wave laser treatments. It is considered safer and has a favorable safety profile, making it a novel option for managing glaucoma. ^{3 4 8 9 10}

What is the purpose of this trial?

The Boston keratoprosthesis (KPro) is a special plastic device that is used to replace a sick cornea (transparent part of the eye, in front of the iris) in order to restore vision in patients who have failed traditional corneal transplants or have a very poor prognosis of success. Glaucoma is a chronic disease which causes optic nerve damage secondary to high pressure inside the eye and could lead to vision loss in the long term. Glaucoma is highly prevalent in patients who require a KPro and even more after their procedure. In order to decrease the intra-ocular pressure, surgeons can use multiple eyedrops. Unfortunately, following the KPro surgery, eyedrops lose their efficiency because they are less absorbed by the eye. The transscleral cyclophotocoagulation (TS-CPC) is a laser treatment used in advanced refractory glaucoma. This laser helps decrease the intra-ocular pressure and have a better control of the disease. There are different methods of laser transmission, including the continuous transmission (G-Probe) and the micro-pulsation method (Micopulse). Given the high prevalence of glaucoma in patients receiving a KPro, the investigators are studying the effect of giving the TS-CPC treatment prophylactically to patients before their Boston keratoprosthesis. Our hypothesis is that prophylactic TS-CPC will decrease glaucoma progression as well as the risks of developing glaucoma following the Boston keratoprosthesis . METHOD The investigators aim to recruit twenty (20) patients who are scheduled to receive Boston KPro. Participants will be randomized into two groups: 1) Groupe 1 will receive a prophylactic treatment of transscleral cyclophotocoagulation a G-Probe. 2) Groupe 2 will receive a prophylactic treatment of transscleral cyclophotocoagulation with a micropulse transmission (MicroPulse). The patients will receive their laser treatment by a glaucoma specialist 4 to 8 weeks before their KPro surgery. One week following their laser treatment, the participants will be examined by their glaucoma specialist. Following their KPro surgery, patients will have a follow-up at day-1, weeks 1 and 2, months 1 and 3, then every 4 to 6 months for 5 years. Additional non-invasive glaucoma tests will be performed twice during the first 3 months following the surgery and will be repeated every 4-6 months. Visual acuity results, the visual field tests and rates of post-operative complications will be compared between the different groups.

Research Team

Marie-Claude Robert, MD, MSc

Principal Investigator

Ophthalmology Department, Centre Hospitalier de l'Université de Montreal

Eligibility Criteria

This trial is for adults who need a Boston keratoprosthesis (KPro) to replace their cornea and can follow the study's procedures. It excludes those under 18 or over 80, with severe ocular surface disease, terminal glaucoma, intra-ocular tumors, recent glaucoma surgery, or certain other conditions.

Inclusion Criteria

Able to give an informed consent

I am 18 years old or older.

Candidate for the Boston keratoprosthesis type I

Exclusion Criteria

I have ocular albinism.

I have a tumor inside my eye.

I am unable to understand and agree to the study's details on my own.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Prophylactic Treatment

Participants receive prophylactic transscleral cyclophotocoagulation treatment 4-8 weeks before Boston keratoprosthesis surgery

4-8 weeks

1 visit (in-person)

Post-Treatment Follow-up

Participants are examined by a glaucoma specialist 1 week following the laser treatment

1 week

1 visit (in-person)

Postoperative Follow-up

Participants are monitored for safety and effectiveness after Boston keratoprosthesis surgery

5 years

Day-1, weeks 1 and 2, months 1 and 3, then every 4-6 months

Treatment Details

Interventions

• G-Probe transscleral cyclphophotocoagulation
• Transscleral cyclphophotocoagulation using the Micropulse system

Trial Overview The study tests if using transscleral cyclophotocoagulation (TS-CPC) before KPro surgery helps control eye pressure and prevent glaucoma. Participants are randomly assigned to receive either G-Probe TS-CPC or Micropulse TS-CPC from a specialist.

Participant Groups

Group I: MicroPulse Treatment Experimental Treatment 1 Intervention

Prophylactic transscleral cyclophotocoagulation treatment, delivered by micropulse waves will be given 4-8 weeks before the Boston keratoprosthesis surgery.

Group II: G-Probe Treatment Experimental Treatment 1 Intervention

Prophylactic transscleral cyclophotocoagulation treatment, delivered with a diode laser using the G-Probe device, will be given 4-8 weeks before the Boston keratoprosthesis surgery.

Group III: Historical Cohort Active Control 1 Intervention

An historical cohort composed of patients who received a Boston keratoprosthesis between january 2017 and january 2019 will be included. Only patients who did not receive any glaucoma treatment 3 months before their surgery will be included. A total of 10 patients will be selected with the goal of matching the preoperative characteristics of the interventional patients. This group will serve as the control group in our study. Retrospective chart review will be performed for this branch.

Who Is Running the Clinical Trial?

Centre hospitalier de l'Université de Montréal (CHUM)

Lead Sponsor

Trials

389

Recruited

143,000+

Fonds de recherche en ophtalmologie de l'Université de Montréal

Collaborator

Trials

6

Recruited

160+

Findings from Research

Micropulse transscleral cyclophotocoagulation (MP-TSCPC) effectively reduced intraocular pressure (IOP) in patients with uncontrolled glaucoma, achieving a mean reduction of 41.2% at one month and continuing to lower IOP over a 12-month follow-up period.

While MP-TSCPC decreased the need for ocular antihypertensive medications, it was associated with complications such as inflammation and vision loss in some patients, indicating the need for careful patient selection and monitoring.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Micropulse Cyclophotocoagulation: Initial Results in Refractory Glaucoma. Emanuel, ME., Grover, DS., Fellman, RL., et al.[2022]

Micropulse cyclophotocoagulation (MP CPC) demonstrated a 30% or greater reduction in intraocular pressure (IOP) in 53.4% of treated eyes among a cohort of 47 patients with various types of glaucoma, indicating its efficacy as a treatment option.

The procedure is non-incisional with a high safety profile and minimal complications, making it suitable for patients with different stages and types of glaucoma, and it can be repeated if necessary.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Our experience with micropulse cyclophotocoagulation in the therapy of glaucoma. Nutterová, E., Pitrová, Š., Lešták, J.[2020]

MicroPulse transscleral laser therapy (MP-TLT) is as effective as continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) in lowering intraocular pressure (IOP) in glaucoma patients, with success rates of 87.5% for MP-TLT and 88.6% for CW-TSCPC after 12 months.

MP-TLT has a better safety profile, allowing it to be used in earlier stages of glaucoma and in patients with good central vision, making it a promising option for broader treatment applications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

MicroPulse Transscleral Laser Therapy Demonstrates Similar Efficacy with a Superior and More Favorable Safety Profile Compared to Continuous-Wave Transscleral Cyclophotocoagulation. Bernardi, E., Töteberg-Harms, M.[2022]

In a study of 37 patients who underwent micropulse transscleral cyclophotocoagulation (MP-CPC) for glaucoma, a significant correlation was found between reduced intraocular pressure (IOP) and increased anterior chamber flare at 1 and 4 weeks post-surgery.

The results suggest that while MP-CPC effectively lowers IOP, it also causes anterior chamber inflammation, indicating a complex relationship that may need further investigation to understand the implications for patient safety and treatment outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Correlation between intraocular pressure reduction and anterior chamber aqueous flare after micropulse transscleral cyclophotocoagulation. Kimura, A., Nakashima, KI., Inoue, T.[2021]

Micropulse transscleral cyclophotocoagulation (MP-CPC) effectively reduced intraocular pressure (IOP) by an average of 51% in patients with refractory glaucoma, with treatment success rates of 75% at 3 months and 67% at the last follow-up (mean follow-up of 7.8 months).

While MP-CPC showed promising efficacy, it was associated with complications in some patients, including hypotony (8.8%), prolonged inflammation (26%), and vision loss (17%), suggesting careful monitoring and consideration of treatment frequency is necessary.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical Efficacy and Safety Profile of Micropulse Transscleral Cyclophotocoagulation in Refractory Glaucoma. Williams, AL., Moster, MR., Rahmatnejad, K., et al.[2022]

MicroPulse® transscleral cyclophotocoagulation (µP-TSCPC) was found to be effective in reducing intraocular pressure (IOP) by an average of 52% after 12 months in 71 eyes of patients with various types of glaucoma, with no significant change in visual acuity.

The procedure demonstrated a high surgical success rate of 90% to 95.7% within the first six months, and importantly, no significant adverse events or complications were reported, indicating a strong safety profile.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Outcome Of MicroPulse® Transscleral Photocoagulation In Different Types Of Glaucoma. Al Habash, A., AlAhmadi, AS.[2022]

Micropulse Transscleral Cyclophotocoagulation (MP-TSCPC) effectively reduced intraocular pressure (IOP) in patients with advanced and refractory glaucoma, showing significant reductions at 1, 3, and 6 months post-treatment for both primary and additional therapy groups.

The success rates for controlling IOP were high for both groups, with 87% for primary therapy and 91% for additional therapy at 1 month, indicating that MP-TSCPC is a viable option for patients at high risk for invasive surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Short-term outcomes of micropulse transscleral cyclophotocoagulation as a primary versus additional therapy in eyes with uncontrolled glaucoma. Rajendrababu, S., Senthilkumar, VA., Tara, TD., et al.[2023]

Micropulse trans-scleral cyclophotocoagulation (TSCPC) effectively lowers intraocular pressure (IOP) in glaucoma patients, with mean IOP decreasing from 23.5 mm Hg preoperatively to around 16.8 mm Hg at 24 months post-treatment, based on a study of 141 eyes over two years.

The treatment is also associated with a reduction in the number of IOP-lowering medications needed, from an average of 3.3 preoperatively to 2.2 at 24 months, and has a favorable safety profile with mostly reversible complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Micropulse Trans-scleral Cyclophotocoagulation in Patients With Glaucoma: 1- and 2-Year Treatment Outcomes. de Crom, RMPC., Slangen, CGMM., Kujovic-Aleksov, S., et al.[2021]

Micropulse transscleral diode laser cyclophotocoagulation (TSCPC) effectively reduced intraocular pressure (IOP) in patients with refractory glaucoma, with significant decreases observed at multiple follow-up points over 18 months.

The procedure demonstrated a high success rate of 72.7% without any cases of hypotony or loss of best-corrected visual acuity, indicating it is a safe alternative to conventional TSCPC.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Micropulse transscleral diode laser cyclophotocoagulation in the treatment of refractory glaucoma. Tan, AM., Chockalingam, M., Aquino, MC., et al.[2022]

Micropulse transscleral cyclophotocoagulation is a new technique that uses repetitive micropulses of laser energy to treat glaucoma, showing promise in managing intraocular pressure.

Current research highlights gaps in understanding the exact mechanism of action and optimal laser settings, indicating that further studies are needed to refine this treatment approach.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Update on Micropulse Transscleral Cyclophotocoagulation. Sanchez, FG., Peirano-Bonomi, JC., Brossard Barbosa, N., et al.[2021]

References

1. United States pubmed.ncbi.nlm.nih.gov

Micropulse Cyclophotocoagulation: Initial Results in Refractory Glaucoma. [2022]

2. Czech Republic pubmed.ncbi.nlm.nih.gov

Our experience with micropulse cyclophotocoagulation in the therapy of glaucoma. [2020]

3. United States pubmed.ncbi.nlm.nih.gov

MicroPulse Transscleral Laser Therapy Demonstrates Similar Efficacy with a Superior and More Favorable Safety Profile Compared to Continuous-Wave Transscleral Cyclophotocoagulation. [2022]

4. England pubmed.ncbi.nlm.nih.gov

Correlation between intraocular pressure reduction and anterior chamber aqueous flare after micropulse transscleral cyclophotocoagulation. [2021]

5. United States pubmed.ncbi.nlm.nih.gov

Clinical Efficacy and Safety Profile of Micropulse Transscleral Cyclophotocoagulation in Refractory Glaucoma. [2022]

6. New Zealand pubmed.ncbi.nlm.nih.gov

Outcome Of MicroPulse® Transscleral Photocoagulation In Different Types Of Glaucoma. [2022]

7. India pubmed.ncbi.nlm.nih.gov

Short-term outcomes of micropulse transscleral cyclophotocoagulation as a primary versus additional therapy in eyes with uncontrolled glaucoma. [2023]

8. United States pubmed.ncbi.nlm.nih.gov

Micropulse Trans-scleral Cyclophotocoagulation in Patients With Glaucoma: 1- and 2-Year Treatment Outcomes. [2021]

9. Australia pubmed.ncbi.nlm.nih.gov

Micropulse transscleral diode laser cyclophotocoagulation in the treatment of refractory glaucoma. [2022]

10. United States pubmed.ncbi.nlm.nih.gov

Update on Micropulse Transscleral Cyclophotocoagulation. [2021]