Comparing the Effectiveness of Phacoemulsification + ECP Laser and Phacoemulsification Alone for Glaucoma Patients

Summary

Laser endoscopic cyclophotocoagulation (ECP) has been in use for the treatment of glaucoma for over 20 years and is usually used in conjunction with cataract surgery. In the US it is one of the most commonly performed cataract 'plus' surgeries. The take-up of ECP laser has been much lower in the UK and Europe. This is partly due to the lack of robust clinical evidence from randomised controlled trials to justify its use in routine practice. More recently the advent of minimally invasive glaucoma surgery techniques (MIGS) has increased the options available for cataract 'plus' surgery. Without any randomised controlled trial data for the use of ECP laser in this context the increasingly popular use of MIGS devices, such as iStent (the current market leader) may further marginalise the use of ECP laser for cataract 'plus' surgery in patients with Primary Open Angle Glaucoma (POAG) and visually significant cataract.

To further evaluate the use of ECP laser for the treatment of glaucoma in patients with glaucoma and cataract, investigators plan to conduct a randomised controlled trial comparing cataract surgery alone versus cataract surgery plus ECP laser surgery. Investigators will compare the efficacy of these interventions for the treatment of glaucoma based on clinical outcomes and also undertake a cost-benefit analysis, taking into account the cost of surgery, any reduction in clinical time allocation for procedures, the frequency of intra- and post-operative complications, and any reduction in the need for topical glaucoma treatments post-surgery, as well as the frequency with which further glaucoma filtering surgery is needed for patients in each group.

Investigators anticipate that a total number of 160 patients (80 in each arm) will be adequate to detect whether there is any difference in efficacy between cataract surgery + ECP versus cataract surgery alone. Recruitment is expected to take around 9-12 months. Participants will undergo treatment wash-out (28 days minimum) of any eye drops they use for their glaucoma prior to data collection at baseline (before surgery) and prior to data collection at one-year and at two-years post-surgery. Results will be reviewed during an interim analysis at 6 months once 50 patients have reached that time point.

Conditions

• Glaucoma Open-Angle Primary
• Cataract

Interventions

DEVICE

Phacoemulsification+ Endoscopic cyclophotocoagulation (ECP) laser

A clear corneal incision should be used for instrumentation. The choice of viscoelastics to maintain the anterior chamber is left to the surgeon's discretion. Phacoemulsification energy used during the cataract surgery will be recorded. If the patient has been randomised to ECP laser, the viscoelastic will be washed-out of the capsular bag. Further cohesive viscoelastic material will be injected through the main wound between the anterior capsule and iris, until the iris is close to or touching the cornea. A curved ECP probe will be inserted through the corneal incision wound/wounds and 360° of the anterior section of the ciliary processes will be treated. The power setting will be varied according to tissue response (starting power of 250 mW with continuous setting). 'Pops' should be avoided (but recorded) but no indentation used during treatment. Final power used and duration of surgery will be recorded.

Sponsors & Collaborators

• King's College London

  collaborator OTHER

• Imperial College London

  collaborator OTHER

• Guy's and St Thomas' NHS Foundation Trust

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

40 Years

Max Age

85 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-03-15

Primary Completion

2022-03-14

Completion

2023-03-14