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CompletedNCT02995629Updated Dec 16, 2016

Patient Comfort Using Green vs. Yellow Pan Retinal Photocoagulation

An interventional study of laser indirect ophthalmoscopy pan retinal photocoagulation in Proliferative Diabetic Retinopathy - High Risk, sponsored by Wills Eye. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2016-12-16.

Sponsored by Wills Eye · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
40
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

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.

Read the 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.

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Conditions studied

  • Proliferative Diabetic Retinopathy - High Risk
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In context

Retinal Diseases

815 studies on the registry are indexed under Retinal Diseases; 105 are open to participants now.

This study's enrollment of 40 is below the median of 60 across 500 interventional studies indexed under Retinal Diseases.

Browse Retinal Diseases studies →

Lead sponsor

Wills Eye is the lead sponsor of 74 studies on the registry; 3 are open to participants now.

Of its 12 completed or terminated interventional studies of FDA-regulated products, 10 (83%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

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

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
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Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Single (Participant)
Enrollment
40 participants (actual)

Study arms

  • Experimental
    green (532 nm) laser

    scatter laser indirect ophthalmoscopy pan retinal photocoagulation

    Procedure: laser indirect ophthalmoscopy pan retinal photocoagulation

  • Experimental
    yellow (577 nm) laser

    scatter laser indirect ophthalmoscopy pan retinal photocoagulation

    Procedure: laser indirect ophthalmoscopy pan retinal photocoagulation

Interventions

  • Procedurelaser 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

    Also known as: PRP laser

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What researchers measure

Primary outcomes

  1. Perceived patient pain assessment

    Assessed using a standardized Wong-Baker faces pain scale

    Time frame: a single time point within 2 minutes of completing laser treatment

Secondary outcomes

  1. Minimum power requirement to achieve moderate gray-white retinal burns

    Time frame: During treatment

  2. Time of treatment

    Time required to treat with each laser

    Time frame: During treatment

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Study locations

1 site
  • Mid Atlantic Retina- Wills Eye Institute
    Philadelphia, Pennsylvania 19107, United States
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References and documents

Publications

  • Photocoagulation treatment of proliferative diabetic retinopathy. Clinical application of Diabetic Retinopathy Study (DRS) findings, DRS Report Number 8. The Diabetic Retinopathy Study Research Group. Ophthalmology. 1981 Jul;88(7):583-600. PubMed 7196564 ↗
  • Richardson C, Waterman H. Pain relief during panretinal photocoagulation for diabetic retinopathy: a national survey. Eye (Lond). 2009 Dec;23(12):2233-7. doi: 10.1038/eye.2008.421. PubMed 19169228 ↗
  • Alvarez-Verduzco O, Garcia-Aguirre G, Lopez-Ramos Mde L, Vera-Rodriguez S, Guerrero-Naranjo JL, Morales-Canton V. Reduction of fluence to decrease pain during panretinal photocoagulation in diabetic patients. Ophthalmic Surg Lasers Imaging. 2010 Jul-Aug;41(4):432-6. doi: 10.3928/15428877-20100525-02. Epub 2010 May 28. PubMed 20608612 ↗
  • Mirshahi A, Lashay A, Roozbahani M, Fard MA, Molaie S, Mireshghi M, Zaferani MM. Pain score of patients undergoing single spot, short pulse laser versus conventional laser for diabetic retinopathy. Graefes Arch Clin Exp Ophthalmol. 2013 Apr;251(4):1103-7. doi: 10.1007/s00417-012-2167-5. Epub 2012 Oct 11. PubMed 23052718 ↗
  • Wu WC, Hsu KH, Chen TL, Hwang YS, Lin KK, Li LM, Shih CP, Lai CC. Interventions for relieving pain associated with panretinal photocoagulation: a prospective randomized trial. Eye (Lond). 2006 Jun;20(6):712-9. doi: 10.1038/sj.eye.6701989. Epub 2005 Jul 8. PubMed 16021194 ↗
  • Ko BW, Shim JH, Lee BR, Cho HY. Analgesic effects of tramadol during panretinal photocoagulation. Korean J Ophthalmol. 2009 Dec;23(4):273-6. doi: 10.3341/kjo.2009.23.4.273. Epub 2009 Dec 4. PubMed 20046687 ↗
  • Zakrzewski PA, O'Donnell HL, Lam WC. Oral versus topical diclofenac for pain prevention during panretinal photocoagulation. Ophthalmology. 2009 Jun;116(6):1168-74. doi: 10.1016/j.ophtha.2009.01.022. Epub 2009 Apr 19. PubMed 19376588 ↗
  • Tesha PE, Giavedoni LR, Berger AR, Altomare F, Chow DR, Navajas EV, Yoganathan P, Wong DT, Principe A. Subconjunctival lidocaine before laser treatment: a randomized trial. Ophthalmology. 2010 Sep;117(9):1810-4. doi: 10.1016/j.ophtha.2010.01.036. Epub 2010 Jun 8. PubMed 20570360 ↗
  • Chiu HH, Wu PC. Manual acupuncture for relieving pain associated with panretinal photocoagulation. J Altern Complement Med. 2011 Oct;17(10):915-21. doi: 10.1089/acm.2010.0082. Epub 2011 Oct 6. PubMed 21978192 ↗
  • Vujosevic S, Martini F, Longhin E, Convento E, Cavarzeran F, Midena E. SUBTHRESHOLD MICROPULSE YELLOW LASER VERSUS SUBTHRESHOLD MICROPULSE INFRARED LASER IN CENTER-INVOLVING DIABETIC MACULAR EDEMA: Morphologic and Functional Safety. Retina. 2015 Aug;35(8):1594-603. doi: 10.1097/IAE.0000000000000521. PubMed 25719988 ↗
  • Yadav NK, Jayadev C, Mohan A, Vijayan P, Battu R, Dabir S, Shetty B, Shetty R; Medscape. Subthreshold micropulse yellow laser (577 nm) in chronic central serous chorioretinopathy: safety profile and treatment outcome. Eye (Lond). 2015 Feb;29(2):258-64; quiz 265. doi: 10.1038/eye.2014.315. Epub 2015 Jan 23. PubMed 25613846 ↗
  • Mainster MA. Wavelength selection in macular photocoagulation. Tissue optics, thermal effects, and laser systems. Ophthalmology. 1986 Jul;93(7):952-8. doi: 10.1016/s0161-6420(86)33637-6. PubMed 3763141 ↗

Individual participant data

Plan to share: Yes — Manuscript is under development.

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Dec 16, 2016, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT02995629
Lead sponsor
Wills Eye
Collaborators
Mid Atlantic Retina
Responsible party
MidAtlantic Retina (Dr. Allen Chiang, MD, Wills Eye) — Principal investigator
First posted
Dec 16, 2016
Start date
Mar 2016
Primary completion
Oct 2016
Completion
Oct 2016
Last update
Dec 16, 2016

Study contacts

Allen Chiang, MD
principal investigator · Mid Atlantic Retina

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Dec 2016. You cannot join it, but the record below documents what was studied.

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