Morphological and Functional Retinal Changes Following Retinal Photocoagulation (pascal)

February 13, 2015 updated by: Katharina Kriechbaum, Medical University of Vienna

Morphological and Functional Retinal Changes Following Retinal Photocoagulation Using a Semiautomated Patterned Scanning Laser System in Proliferative Retinopathy or Macular Edema Secondary to Diabetes Mellitus or Retinal Vein Occlusion

Imaging of retinal morphological changes with time secondary to laser treatment as assessed with high definition optical coherence tomography (OCT). Furthermore changes in retinal function as an effect of treatment will be documented by visual acuity testing using ETDRS charts and microperimetry. The change in vascular leakage will be assessed by performing fluorescein angiography, flare counts will be performed monthly.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Hypertension and diabetes are widespread diseases in our modern society and due to the comfortable, but often unhealthy "western world" lifestyle, the population suffering from its consequences is constantly growing. Vascular pathologies affect the body's entire vascular system subsequently including the circulation and vessels in the eye. For these reasons, after diabetic retinopathy and vein occlusions rank among the most common vascular disorders of the retina, with the highest incidence in a population over the age of 60. As to prevent severe vision loss due to complications induced by these angiopathies, panretinal or segmental laser coagulation is recommended as standard treatment of proliferative retinopathy. So far patients who undergo panretinal coagulation typically receive between 1200 and 1500 lasers spots in two to four sessions over the course of 2 to 4 weeks. Clinical guidelines recommend not exceeding the number of more than 900 applied laser spots per session, due to the development of possible reversible exudative reaction e.g. macular edema. However, the performance of a panretinal photocoagulation is so far a time consuming procedure which is generally painful for the patient. For these reasons new laser systems were developed aiming to solve these obvious drawbacks. Main improvement of these systems is the reduction of the laser burn durations per spot and to enable therefore the rapid application of a large number of spots in a preset pattern. Treatment with reduced pulse duration is associated with less pain for the patient and, compared to several sessions requiring about 30 minutes each when using a conventional laser system, treatment time for a complete panretinal treatment could be significantly reduced. The PASCAL® Laser (Pattern Scan Laser, OptiMedica® Corporation, Santa Clara, CA, USA) is a new commercially available laser system confirming all these requirements.

As the first study part (group I and II) we propose a controlled randomized comparison of single session to conventional multisession panretinal laser treatment, using the Pascal laser system for the single-session protocol and the Pascal laser system or the conventional laser system for the multi-session protocol. Development and regression of a retinal exudative reaction and the eventual onset of transient macular edema will be observed and documented. The morphological changes within the retina induced by laser burns will be imaged mainly using optical coherence tomography techniques. In regard to determine the lowest laser intensity as possible to produce a visible morphologic effect within small retinal areas different laser intensities will be used for photocoagulation of retinal segments to show the effect of a "sub-threshold" and gentle laser burn.

As a second study part (group III), grid pattern laser coagulation will be performed in a conventional way using the Pascal laser system. In a small area of the retinal perifoveal zone showing macular edema, morphologic effects of photocoagulation using titrated low, sub threshold or threshold laser energy will be analyzed using OCT.

Study Type

Interventional

Enrollment (Actual)

64

Phase

  • Phase 4

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

  • Austria
      • Vienna, Austria, 1090
        • Dept. of Opthalmology, Medical University of Vienna

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 to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Signed informed consent
  • Age 18 years
  • Patients with either retinopathy/maculopathy secondary to diabetes mellitus type I or II with medical indication for segmental or panretinal laser coagulation or with necessity for completion of previous incomplete laser photocoagulation.
  • Patients with proliferative diabetic retinopathy requiring panretinal laser treatment (Group 1, 2 and 3)
  • Patients with macular edema requiring central focal or grid laser treatment (Group 4).

Exclusion criteria:

  • A condition that would preclude a patient for participation in the study in opinion of investigator, e.g., unstable medical status including glycemic control and blood pressure.

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

  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: group 3

Group 3: 20 patients with proliferative retinopathy secondary to diabetes mellitus or venous occlusion) with need for panretinal photocoagulation.

Intervention: All patients will receive a multi-session panretinal laser treatment according to the conventional protocol, using a conventional laser system.
Procedure: laser treatment with conventional laser system
panretinal laser treatment - multi-session according to the conventional protocol, using a conventional laser system
Active Comparator: group 2

Group 2: 20 patients with proliferative retinopathy secondary to diabetes mellitus or venous occlusion) with need for panretinal photocoagulation randomized into group 2.

Intervention: This group will receive multi-session panretinal laser treatment. The treatment will be performed using Pascal laser system.
Procedure: laser treatment with PASCAL®
panretinal laser treatment - single-session
Other Names:
  • PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)
Procedure: laser treatment with PASCAL®
panretinal laser treatment - multi-session
Other Names:
  • The PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)
Procedure: laser treatment with PASCAL®
grid / focal laser treatment
Other Names:
  • PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)
Active Comparator: group 1

Group 1: 20 patients with proliferative retinopathy secondary to diabetes mellitus or venous occlusion) with need for panretinal photocoagulation randomized into group1.

Intervention: One group will receive a single-session panretinal laser treatment, performed using Pascal laser system.
Procedure: laser treatment with PASCAL®
panretinal laser treatment - single-session
Other Names:
  • PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)
Procedure: laser treatment with PASCAL®
panretinal laser treatment - multi-session
Other Names:
  • The PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)
Procedure: laser treatment with PASCAL®
grid / focal laser treatment
Other Names:
  • PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)
Active Comparator: group 4

Group 4: 20 patients with persistent central or para-central diabetic macular edema receiving focal or grid laser treatment. As the treatment will be performed according to the conventional protocol (single spot), only the Pascal laser system will be used.

Intervention: focal or grid laser treatment
Procedure: laser treatment with PASCAL®
panretinal laser treatment - single-session
Other Names:
  • PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)
Procedure: laser treatment with PASCAL®
panretinal laser treatment - multi-session
Other Names:
  • The PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)
Procedure: laser treatment with PASCAL®
grid / focal laser treatment
Other Names:
  • PASCAL® (Pattern Scan Laser, OptiMedica ® Corporation)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Retinal morphological changes with time secondary to laser treatment as assessed with optical coherence tomography (OCT).
Time Frame: 2007-2014
2007-2014

Secondary Outcome Measures

Outcome Measure
Time Frame
changes in retinal function as an effect of treatment, documented by visual acuity testing and microperimetry. The change in vascular leakage will be assessed by performing fluorescein angiography, flare counts will be performed monthly.
Time Frame: 2007-2009
2007-2009

Collaborators and Investigators

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

Sponsor

Medical University of Vienna

Investigators

  • Study Chair: Ursula Schmidt-Erfurth, MD, Medial University of Vienna, Dept. of Ophthalmology
  • Principal Investigator: Katharina Kriechbaum, MD, Medical University of Vienna
  • Principal Investigator: Matthias Bolz, MD, Medical University of Vienna
  • Principal Investigator: Sonja Prager, MD, Medical University Vienna

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

October 1, 2007

Primary Completion (Actual)

February 1, 2014

Study Completion (Actual)

February 1, 2014

Study Registration Dates

First Submitted

May 20, 2008

First Submitted That Met QC Criteria

May 21, 2008

First Posted (Estimate)

May 22, 2008

Study Record Updates

Last Update Posted (Estimate)

February 16, 2015

Last Update Submitted That Met QC Criteria

February 13, 2015

Last Verified

February 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Pascal Study

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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