Short-pulse Subthreshold vs Infrared Micropulse for Diabetic Macular Edema

NCT ID: NCT04505306

Last Updated: 2020-08-10

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 113 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2015-01-01
• Study Completion Date: 2017-01-01

Brief Summary

When applied according to manufacturer recommendations, short-pulse system may yield more temporary reduction in edema while infrared micropulse system may yield slightly better functional outcomes.

Detailed Description

Purpose: To assess both anatomic and functional outcomes between short-pulse continuous wavelength and infrared micropulse lasers in the treatment of DME.

Materials and Methods: A prospective interventional study from tertiary care eye hospital - King Khaled Eye Specialist Hospital (Riyadh, Saudi Arabia). Patients with center-involving diabetic macular edema were treated with subthreshold laser therapy. Patients in the micropulse group were treated with the 810-nm diode micropulse scanning laser TxCell™ (IRIDEX Corporation, Mountain View, CA, USA). Laser was applied according to manufacturer recommendations for MicroPulseTM in a confluent mode (low intensity/high density) to the entire area of the macular edema. Patients in the short-pulse group were treated with grid pattern laser with 20ms pulse PASCAL laser 532nm (TopCon Medical Laser Systems, Tokyo, Japan) with EndPoint algorithm, which was either 30% or 50% of testing burn. Main outcome measures included best-corrected visual acuity (BCVA) and foveal thickness at baseline and the last follow-up visit.

Conditions

Diabetic Macular Edema

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Subthreshold Laser 30%

Patients in the SPCW group were treated with grid pattern laser with 20ms pulse PASCAL laser 532nm (TopCon Medical Laser Systems, Tokyo, Japan) with 30% EndPoint algorithm.

Group Type: ACTIVE_COMPARATOR

Macular Laser

Intervention Type: PROCEDURE

All treatments were performed using SPCW EndPoint 30% and 50% protocols and STMP laser. Patients in the STMP group were treated with the 810-nm diode micropulse scanning laser TxCell™ (IRIDEX Corporation, Mountain View, CA, USA) at 15% duty cycle. Laser was applied in the confluent mode (low intensity/high density) to cover the entire area of the macular edema and leakage as imaged by OCT and/or fundus fluorescein angiography. Patients in the SPCW group were treated with grid pattern laser with 20ms pulse PASCAL laser 532nm (TopCon Medical Laser Systems, Tokyo, Japan) with EndPoint algorithm, which was either 30% or 50% of testing burn with one burn width apart. In both groups, subthreshold power was determined by titrating burn to light (barely visible) burn and switching to either micropulse mode with 15% duty cycle or 30% and 50% EndPoint value.

Subtreshold Laser 50%

Patients in the SPCW group were treated with grid pattern laser with 20ms pulse PASCAL laser 532nm (TopCon Medical Laser Systems, Tokyo, Japan) with 50% EndPoint algorithm.

Group Type: ACTIVE_COMPARATOR

Macular Laser

Intervention Type: PROCEDURE

All treatments were performed using SPCW EndPoint 30% and 50% protocols and STMP laser. Patients in the STMP group were treated with the 810-nm diode micropulse scanning laser TxCell™ (IRIDEX Corporation, Mountain View, CA, USA) at 15% duty cycle. Laser was applied in the confluent mode (low intensity/high density) to cover the entire area of the macular edema and leakage as imaged by OCT and/or fundus fluorescein angiography. Patients in the SPCW group were treated with grid pattern laser with 20ms pulse PASCAL laser 532nm (TopCon Medical Laser Systems, Tokyo, Japan) with EndPoint algorithm, which was either 30% or 50% of testing burn with one burn width apart. In both groups, subthreshold power was determined by titrating burn to light (barely visible) burn and switching to either micropulse mode with 15% duty cycle or 30% and 50% EndPoint value.

Micropulse Laser

Patients in the STMP group were treated with the 810-nm diode micropulse scanning laser TxCell™ (IRIDEX Corporation, Mountain View, CA, USA) at 15% duty cycle.

Group Type: ACTIVE_COMPARATOR

Macular Laser

Intervention Type: PROCEDURE

All treatments were performed using SPCW EndPoint 30% and 50% protocols and STMP laser. Patients in the STMP group were treated with the 810-nm diode micropulse scanning laser TxCell™ (IRIDEX Corporation, Mountain View, CA, USA) at 15% duty cycle. Laser was applied in the confluent mode (low intensity/high density) to cover the entire area of the macular edema and leakage as imaged by OCT and/or fundus fluorescein angiography. Patients in the SPCW group were treated with grid pattern laser with 20ms pulse PASCAL laser 532nm (TopCon Medical Laser Systems, Tokyo, Japan) with EndPoint algorithm, which was either 30% or 50% of testing burn with one burn width apart. In both groups, subthreshold power was determined by titrating burn to light (barely visible) burn and switching to either micropulse mode with 15% duty cycle or 30% and 50% EndPoint value.

Interventions

Macular Laser

All treatments were performed using SPCW EndPoint 30% and 50% protocols and STMP laser. Patients in the STMP group were treated with the 810-nm diode micropulse scanning laser TxCell™ (IRIDEX Corporation, Mountain View, CA, USA) at 15% duty cycle. Laser was applied in the confluent mode (low intensity/high density) to cover the entire area of the macular edema and leakage as imaged by OCT and/or fundus fluorescein angiography. Patients in the SPCW group were treated with grid pattern laser with 20ms pulse PASCAL laser 532nm (TopCon Medical Laser Systems, Tokyo, Japan) with EndPoint algorithm, which was either 30% or 50% of testing burn with one burn width apart. In both groups, subthreshold power was determined by titrating burn to light (barely visible) burn and switching to either micropulse mode with 15% duty cycle or 30% and 50% EndPoint value.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• center-involving clinically significant macular edema due to diabetic retinopathy (>300 microns)
• clear ocular media
• ETDRS visual acuity >29 letters (Snellen equivalent of 20/150) or better
• treatment naïve eyes or previously treated with antiangiogenic intravitreal agent(s) more than 6 months ago to allow for long wash-out period

Exclusion Criteria

• non-center involving diabetic macular edema
• previous retinal laser or surgery
• intravitreal steroid use
• any condition that may be associated with a risk of macular edema such as age-related macular degeneration, retinal vein occlusion, vitreomacular traction, epiretinal membrane and others.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

King Khaled Eye Specialist Hospital

OTHER_GOV

Sponsor Role: collaborator

University of Nebraska

OTHER

Sponsor Role: collaborator

Moorfields Eye Hospital Centre Abu Dhabi

OTHER

Sponsor Role: lead

Responsible Party

Igor Kozak

Consultant Vitreoretinal Surgeon/Clinical Lead

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Moorfields Eye Hospital Centre

Abu Dhabi, , United Arab Emirates

Countries

United Arab Emirates

Other Identifiers

Moorfields Eye Abu Dhabi

Identifier Type: -

Identifier Source: org_study_id