Outcomes of Subthreshold Laser Versus Intravitreal Injection of Ranibizumab in Diabetic Macular Edema

Study Overview
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Brief Summary
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The aim of this study is To compare the anatomical and functional results of intravitreal( IV) injection of ranibizumab with sub threshold micropulse laser ( SML) in treatment of Diabetic macular edema (DME) both anatomically by spectral domain optical coherence tomography (SD OCT) and functionally by best-corrected visual acuity (BCVA) and multifocal electroretinogram (mfERG).

Detailed Description
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Diabetic macular edema (DME) causes significant visual loss in diabetic patients. About 20% and 40% of patients with Type 1 and Type 2 diabetes mellitus (DM), respectively, develop DME. One-third of diabetic patients who have had DM for more than twenty years will develop DME . Early impairment in the function of the middle and inner layers of the retina has been reported in diabetic patients before appearance of vascular complications . A good independent guide of macular function in patients with DME is multifocal electroretinogram (mfERG) readings from the macular area, which strongly associate with morphologic alterations in the macula. Some investigators suggested that temporal characteristic (implicit time) of mfERG waves are more important than amplitudes for evaluation of retinal function in diabetic patients. They concluded that patients with DM show temporal changes indicating delayed neural transmission due to local impairment of blood glucose metabolism. In contrast, others emphasize the importance of both parameters (implicit time and amplitude) in identifying retinal affection in DM. Intravitreal (IV) injections of anti-vascular endothelial growth factor (VEGF) agents provided good visual outcomes in treatment of DME. However, IV anti-VEGF injections are expensive, need to be repeated many times and have the potential risk of causing endophthalmitis . Subthreshold micropulse laser (SML) treatment of DME has the same effect as conventional laser treatment, nonetheless, there is less damage to adjacent tissues of the burn area in the retinal pigment epithelium (RPE). SML allows laser emission to be divided into bursts of short cyclic pulses that remain for microseconds permitting substantial cooling amid these short pulses .

Official Title
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Anatomical and Functional Outcomes of Subthreshold Micropulse Laser Versus Intravitreal Ranibizumab Injection in Treatment of Diabetic Macular Edema

Conditions
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Diabetic Macular Edema

Intervention / Treatment
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* Procedure: laser interference,INTRAVITREAL INJECTION


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: DME with BCVA<0.5 decimal Snellen acuity. Controlled blood glucose (HbA1c) <6.5%. Exclusion Criteria: History of previous intraocular surgery, History of previous laser treatment, History of previous IV injection, Macular disease or ischemia, Proliferative diabetic retinopathy, Vitreoretinal traction, Interruption of external limiting membrane (ELM) or ellipsoid zone (EZ). Dense media opacity, Optic disc pathology History of strokes or ischaemic heart diseases. patients with (CST) > 400 µm on OCT .
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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: group 1<br>group 1 of DME which treated by SML | Procedure: laser interference,INTRAVITREAL INJECTION<br>* sub threshold micro pulse laser for DME for group 1 and intravitreal injection of Ranibizumab for group 2<br>|
| Active Comparator: group 2<br>Group 2 of DME which treated by intravitreal injection of Ranibizumab | Procedure: laser interference,INTRAVITREAL INJECTION<br>* sub threshold micro pulse laser for DME for group 1 and intravitreal injection of Ranibizumab for group 2<br>|
| No Intervention: group 3<br>control group of diabetic patients received no treatment | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| central subfield thickness in micrometer | OCT for the macular area with measuring CST in micron | 6 months | 
| p1 amplitude of mfERG | p1 amplitude of multifocal ERG measured in nv/deg2 | 6mnths | 
| BCVA | BCVA is measured in decimal of Snellen visual acuity | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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DME, mfERG, SML, ranibizumab,IV.injection