Patient Comfort Using Green vs. Yellow Pan Retinal Photocoagulation

December 13, 2016 updated by: MidAtlantic Retina, Wills Eye

Patient Comfort Using Green (532 nm) Versus Yellow (577 nm) Laser Indirect Ophthalmoscopy Panretinal Photocoagulation for Proliferative Diabetic Retinopathy

Our aim is to compare patient comfort when using the 532 nanometer (green) wavelength laser to the 577 nanometer (yellow) wavelength laser during pan retinal photocoagulation to treat patients with diabetic retinopathy. Secondary outcome measures will be power (mW) required to achieve gray-white retinal burns and duration of treatment.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

As demonstrated in the Diabetic Retinopathy Study (DRS), panretinal photocoagulation (PRP) reduces the risk of severe vision loss in patients with proliferative diabetic retinopathy. The DRS recommended that PRP treatment consist of 1,200 - 1,600 laser burns 500 µm in size, one half to one burn width apart, applied to the peripheral retina in a scatter fashion. Most patients who undergo PRP experience discomfort/pain during the procedure. Once present, pain can affect the number and quality of burns delivered and can indirectly increase the number of sessions required to complete the therapy.This may in turn adversely affect patient compliance. Although retrobulbar and peribulbar blocks can provide adequate anesthesia for PRP, these anesthetic methods carry rare but serious risks such as retrobulbar hemorrhage. Previous studies have explored other ways to reduce discomfort related to PRP, including optimization of laser settings, oral and topical analgesics, subconjunctival anesthesia, and even acupuncture.

Currently, green lasers (521 - 532 nm wavelength) are most commonly utilized for performing PRP in clinical practice. Yellow lasers (577 nm wavelength) have been of recent interest in treating diabetic macular edema with micropulse subthreshold grid photocoagulation, but have not been extensively studied in PRP for diabetic retinopathy. Compared to shorter wavelength laser, yellow laser comports high transmission through dense ocular media and less light scattering than shorter wavelengths which minimizes spot size and reduces thermal spread. The limited literature comparing green and yellow laser for PRP in diabetic retinopathy has shown that yellow laser requires less power to achieve a retinal burn. In theory this should translate into a reduction in perceived pain experienced during PRP, however a comparison of green and yellow lasers in this regard has not yet been directly examined and quantified.

Study Type

Interventional

Enrollment (Actual)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19107
        • Mid Atlantic Retina- Wills Eye Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • patient of Wills Eye Hospital Retina Service and/or Mid Atlantic Retina
  • volunteer patients age 18 years and older.
  • healthy enough to participate in the study.
  • willing and able to consent to participation in the study.
  • diagnosis of PDR with HRC based on clinical criteria outlined by the DRS.

Exclusion Criteria:

  • patient less than 18 years of age
  • institutionalized patient
  • prisoner
  • significant media opacity obscuring a view of the superior retina
  • history of intra-ocular surgery except cataract surgery
  • history of PRP laser within the last 30 days

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: green (532 nm) laser
scatter laser indirect ophthalmoscopy pan retinal photocoagulation
Procedure: laser indirect ophthalmoscopy pan retinal photocoagulation
  • Prior to procedure, eligible patient is dilated and a topical anesthesia is administered 3 to 5 minutes prior to treatment initiation
  • Treatment duration is fixed at 50 minutes and power is titrated until moderate gray-white burns are achieved, avoiding long ciliary nerves
  • Target treatment of 250 spots
  • Only one eye per eligible patient randomized with regard to whether green or yellow laser utilized first
  • After treatment,pain assessment conducted:spot count, laser parameters and treatment duration recorded for each respective laser wavelength
Other Names:
  • PRP laser
Experimental: yellow (577 nm) laser
scatter laser indirect ophthalmoscopy pan retinal photocoagulation
Procedure: laser indirect ophthalmoscopy pan retinal photocoagulation
  • Prior to procedure, eligible patient is dilated and a topical anesthesia is administered 3 to 5 minutes prior to treatment initiation
  • Treatment duration is fixed at 50 minutes and power is titrated until moderate gray-white burns are achieved, avoiding long ciliary nerves
  • Target treatment of 250 spots
  • Only one eye per eligible patient randomized with regard to whether green or yellow laser utilized first
  • After treatment,pain assessment conducted:spot count, laser parameters and treatment duration recorded for each respective laser wavelength
Other Names:
  • PRP laser

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Perceived patient pain assessment
Time Frame: a single time point within 2 minutes of completing laser treatment
Assessed using a standardized Wong-Baker faces pain scale
a single time point within 2 minutes of completing laser treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Minimum power requirement to achieve moderate gray-white retinal burns
Time Frame: During treatment
During treatment
Time of treatment
Time Frame: During treatment
Time required to treat with each laser
During treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Wills Eye

Collaborators

Mid Atlantic Retina

Investigators

  • Principal Investigator: Allen Chiang, MD, Mid Atlantic Retina

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

March 1, 2016

Primary Completion (Actual)

October 1, 2016

Study Completion (Actual)

October 1, 2016

Study Registration Dates

First Submitted

December 5, 2016

First Submitted That Met QC Criteria

December 13, 2016

First Posted (Estimate)

December 16, 2016

Study Record Updates

Last Update Posted (Estimate)

December 16, 2016

Last Update Submitted That Met QC Criteria

December 13, 2016

Last Verified

December 1, 2016

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 16-560

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Yes

IPD Plan Description

Manuscript is under development.

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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