Effect of Laser Treatment for Diabetic Retinopathy on the Optic Disc Topography

Study Overview
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Brief Summary
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This study analyzed diabetic patients without evidence of glaucoma who underwent panretinal photocoagulation to determine the effect on optic disc topographic parameters in non-glaucomatous patients with proliferative diabetic retinopathy (PDR).

Detailed Description
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Glaucoma and proliferative diabetic retinopathy (PDR) are two very prevalent diseases that often coexist. Previous literature suggest that panretinal photocoagulation may somehow lead to optic disk cupping. Therefore, evaluation of the optic disc cupping and of possible glaucomatous damage in patients with diabetic retinopathy can be difficult, especially after PRP treatment. The purpose of this study is to determine the long-term effect of PRP on optic disc topographic parameters in non-glaucomatous patients with PDR using Heidelberg retina tomograph (HRT) parameters and stereo photography. The Investigators found that PRP does not cause morphological optic disk changes in diabetic PDR patients after one year of follow-up.

Official Title
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Effect of Panretinal Photocoagulation on Confocal Laser Scanning Ophthalmoscopy and Stereo Photographic Parameters of the Optic Disc Topography in Diabetic Retinopathy Patients

Conditions
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Diabetic Retinopathy

Intervention / Treatment
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* Procedure: Panretinal photocoagulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: diagnosis of PDR (due to type 1 or 2 diabetes mellitus) intraocular pressure < 18 mmHg nonglaucomatous optic disc characteristics at fundus examination vertical cup-to-disc (C/D) ratio <0.7 absence of media opacities Exclusion Criteria: previous diagnosis of glaucoma family history of glaucoma neuroophthalmic disease uveitis retinal artery or vein occlusion optic disc neovascularization diabetic macular edema (DME) corneal opacity previous laser photocoagulation treatment
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pretreatment x Posttreatment<br>The group was evaluated through non-invasive complementary examinations before laser therapy and at the 1-year follow-up visit to analyze possible optical disc alterations that may occur after retinal panretinal photocoagulation in patients with proliferative diabetic retinopathy. | Procedure: Panretinal photocoagulation<br>* In cases of proliferative diabetic retinopathy (PDR), panretinal photocoagulation (PRP) is the first-line treatment. Although PRP reduces the risk of severe vision loss, it has been shown that laser energy can cause destruction to all layers of retina including the ganglion cells and the retinal nerve fiber layer (RNFL), and therefore generate visual field defects similar to that observed in glaucomatous damage. In such cases, visual field testing can be less helpful to evaluate glaucomatous damage in PDR patients treated with PRP.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cup area | Change in cup area (mm2) measured by Heidelberg retinal tomograph (HRT) before and one year after PRP | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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optic disc topography, panretinal photocoagulation, confocal scanning laser ophthalmoscopy, stereoscopic disc photographs, diabetic retinopathy, optic nerve head parameters