Observational Study of DME Following Scatter Laser Photocoagulation (PRP)
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|ClinicalTrials.gov Identifier: NCT00687154|
Recruitment Status : Completed
First Posted : May 30, 2008
Last Update Posted : August 26, 2016
The development or worsening of macular edema following full scatter photocoagulation is a well recognized occurrence. However, there is limited literature in this regard.
The purpose of this study is to determine the incidence and extent of macular edema following scatter laser photocoagulation surgery using optical coherence tomography (OCT) in eyes without macular edema prior to scatter laser photocoagulation and to explore whether the incidence and extent of macular edema varies according to the number of sittings included in the treatment regimen.
Study eyes will receive one of two types of scatter photocoagulation with results compared through use of OCT and photography images, as well as visual acuity testing.
|Condition or disease||Intervention/treatment||Phase|
|Diabetic Macular Edema||Procedure: Scatter Laser Photocoagulation in 1 Sitting Procedure: Scatter Laser Photocoagulation in 4 Sittings||Not Applicable|
Study eyes will receive scatter photocoagulation given by one of the following two regimens. To reduce selection bias, investigators will be required, prior to study initiation, to indicate which treatment (1 PRP sitting or 4 PRP sittings) they will administer. Only the selected treatment will be performed by a given investigator on study eyes.
- 1 sitting with a minimum of 1200 to a maximum of 1600 burns, with one burn width separation of burns and scatter extending from the peripheral arcades to beyond the equator.
- 4 sittings, each separated by four weeks (+4 days), with approximately 300 burns in each of the first two sittings and investigator judgment for number of burns for the third and fourth sittings as long as the total for the four sittings is between 1200 and 1600 burns.
Both of these regimens conform with usual clinical practice.
The study aims to enroll 150 eyes. At least 40 eyes will be enrolled with prior focal laser photocoagulation and at least 40 eyes without prior focal laser treatment. After enrollment of 80 eyes (40 with prior treatment and 40 without prior treatment), an interim analysis will be conducted so that focused enrollment strategies can be implemented if the analysis suggests that more subjects in a subgroup should be entered. Approximately half of the eyes will receive each scatter treatment regimen.
The following procedures will be done on the study eye at baseline and at each scheduled visit (except 8 and 12 weeks at which exam data are not collected) unless otherwise specified:
- E-ETDRS visual acuity in both eyes (refraction in the study eye at baseline, 17 weeks, and 34 weeks)
- Fundus photographs (7-fields at baseline and 3-fields at 34 weeks only)
- Photographs to document the scatter photocoagulation (day of the first PRP sitting only)
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||155 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||None (Open Label)|
|Official Title:||An Observational Study of the Development of Diabetic Macular Edema Following Scatter Laser Photocoagulation|
|Study Start Date :||September 2005|
|Actual Primary Completion Date :||January 2008|
|Actual Study Completion Date :||January 2008|
Active Comparator: 1 Sitting
Subjects with (1) OCT central subfield thickness ≤ 299 microns and (2) early proliferative or severe nonproliferative diabetic retinopathy for which investigator intends to perform full scatter photocoagulation in 1 sitting
Procedure: Scatter Laser Photocoagulation in 1 Sitting
1 sitting with a minimum of 1200 to a maximum of 1600 burns, with one burn width separation of burns and scatter extending from the peripheral arcades to beyond the equator.
Other Name: PRP
Active Comparator: 4 Sittings
Subjects with (1) OCT central subfield thickness ≤ 299 microns and (2) early proliferative or severe nonproliferative diabetic retinopathy for which investigator intends to perform full scatter photocoagulation in 4 sittings.
Procedure: Scatter Laser Photocoagulation in 4 Sittings
4 sittings, each separated by four weeks (+4 days), with approximately 300 burns in each of the first two sittings and investigator judgment for number of burns for the third and fourth sittings as long as the total for the four sittings is between 1200 and 1600 burns.
Other Name: PRP
- Retinal thickening (measured with OCT) [ Time Frame: 34 weeks ]
- Visual Acuity (measured with E-ETDRS) [ Time Frame: 2 days, 4 weeks, 17, and 34 weeks ]
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00687154
|Study Chair:||Alexander J. Brucker, M.D.||Scheie Eye Institute|