Panretinal Photocoagulation for Diabetic Retinopathy With PASCAL Laser

Panretinal Photocoagulation for Diabetic Retinopathy With PASCAL Laser - an Anatomic and Functional Evaluation of Different Treatment Strategies

This study will investigate the clinical efficacy and safety of the PASCAL laser (PAttern SCAn Laser) for diabetic retinopathy. Patients with proliferative or severe nonproliferative retinopathy will be treated with panretinal photocoagulation utilizing different treatment strategies. The investigators believe that using "lower" laser parameters, the clinical response may be equivalent with less adverse effects.

Study Overview

• Status: Unknown
• Conditions: Diabetic Retinopathy
• Intervention / Treatment: Procedure: Panretinal photocoagulation; Procedure: Panretinal photocoagulation; Procedure: Panretinal photocoagulation

• Study Type: Interventional
• Enrollment (Anticipated): 60
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Renato M Passos, MD; Phone Number: 55 11 50852043; Email: renatompassos@yahoo.com.br

Study Locations

• Brazil
  • SP
    • São Paulo, SP, Brazil, 04023062
      • Recruiting
      • Department of Ophthalmology, Federal University of São Paulo

Participation Criteria

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:

• proliferative or severe nonproliferative diabetic retinopathy (type 1 or type 2)
• best corrected visual acuity of 20/50 or better
• capability to read and follow instructions
• capability to sign the consignment term

Exclusion Criteria:

• best corrected visual acuity worse than 20/50
• significant macular edema responsible for visual acuity lower than 20/50
• media opacities (includes vitreous hemorrhage in the visual axis, but not a reabsorbing inferior vitreous hemorrhage)
• previous laser treatment (PRP, focal or macular grid)
• glaucoma (confirmed or suspicious)
• other diseases of the retina and optic nerve
• previous ocular surgery in the last 6 months
• impossibility to obtain good quality images of retinography, angiography or OCT

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 100ms single-shot; Panretinal photocoagulation utilizing 100ms pulse duration, moderate intensity burns, in a single-shot fashion	Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 100ms pulse duration, moderate intensity burns, in a single-shot fashion; Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 20ms pulse duration, moderate intensity burns, in a multiple-shot fashion; Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 20ms pulse duration, barely visible intensity burns, in a multiple-shot fashion
Experimental: 20ms multiple-shot; Panretinal photocoagulation utilizing 20ms pulse duration, moderate intensity burns, in a multiple-shot fashion	Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 100ms pulse duration, moderate intensity burns, in a single-shot fashion; Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 20ms pulse duration, moderate intensity burns, in a multiple-shot fashion; Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 20ms pulse duration, barely visible intensity burns, in a multiple-shot fashion
Experimental: 20ms multiple-shot, barely visible; Panretinal photocoagulation utilizing 20ms pulse duration, barely visible intensity burns, in a multiple-shot fashion	Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 100ms pulse duration, moderate intensity burns, in a single-shot fashion; Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 20ms pulse duration, moderate intensity burns, in a multiple-shot fashion; Procedure: Panretinal photocoagulation; Panretinal photocoagulation utilizing 20ms pulse duration, barely visible intensity burns, in a multiple-shot fashion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of severe visual loss after 1 year	Severe visual loss is defined as visual acuity worse or equal to 5/200 in two consecutive visits (DRS/ETDRS primary outcome)	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical involution of retinal new vessels	Clinical involution of retinal new vessels will be evaluated with retinography and fluorescein angiography	1 year
Nerve fiber layer thickness	Nerve fiber layer thickness will be evaluated with Spectral Domain OCT	1 year
Retinal sensitivity	Retinal sensitivity will be evaluated with Humphrey computerized perimetry and FDT (Frequency Doubling Technology)	1 year

Collaborators and Investigators

• Sponsor: Federal University of São Paulo

Publications and helpful links

General Publications

• Modi D, Chiranand P, Akduman L. Efficacy of patterned scan laser in treatment of macular edema and retinal neovascularization. Clin Ophthalmol. 2009;3:465-70. doi: 10.2147/opth.s6486. Epub 2009 Aug 20.
• Muqit MM, Gray JC, Marcellino GR, Henson DB, Young LB, Patton N, Charles SJ, Turner GS, Dick AD, Stanga PE. In vivo laser-tissue interactions and healing responses from 20- vs 100-millisecond pulse Pascal photocoagulation burns. Arch Ophthalmol. 2010 Apr;128(4):448-55. doi: 10.1001/archophthalmol.2010.36.
• Muqit MM, Marcellino GR, Henson DB, Young LB, Patton N, Charles SJ, Turner GS, Stanga PE. Single-session vs multiple-session pattern scanning laser panretinal photocoagulation in proliferative diabetic retinopathy: The Manchester Pascal Study. Arch Ophthalmol. 2010 May;128(5):525-33. doi: 10.1001/archophthalmol.2010.60.
• Nagpal M, Marlecha S, Nagpal K. Comparison of laser photocoagulation for diabetic retinopathy using 532-nm standard laser versus multispot pattern scan laser. Retina. 2010 Mar;30(3):452-8. doi: 10.1097/IAE.0b013e3181c70127.

Study record dates

Study Major Dates

• Study Start: September 1, 2010
• Primary Completion (Anticipated): March 1, 2012
• Study Completion (Anticipated): March 1, 2013

Study Registration Dates

• First Submitted: February 24, 2011
• First Submitted That Met QC Criteria: February 24, 2011
• First Posted (Estimate): February 25, 2011

Study Record Updates

• Last Update Posted (Estimate): February 25, 2011
• Last Update Submitted That Met QC Criteria: February 24, 2011
• Last Verified: February 1, 2011

More Information

Terms related to this study

• Keywords: diabetic retinopathy; photocoagulation; PASCAL laser
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Eye Diseases; Endocrine System Diseases; Diabetic Angiopathies; Diabetes Complications; Diabetes Mellitus; Retinal Diseases; Diabetic Retinopathy
• Other Study ID Numbers: PASCAL-001