Effect of Intraoperative Dexamethasone Implant in Taut Posterior Hyaloid Removal in Diabetic Macular Edema
Condition: Diabetic Macular Edema; Vision Disorders
MeSH terms: Vision Disorders; Macular Edema; Edema
Study type: Interventional

Summary: 
      This study is undertaken to determine effect of sustained release dexamethasone
      implant,Ozurdex in improving outcome of taut posterior hyaloid removal in patients with
      diabetic macular edema

      Diabetic macular edema constitute important cause of visual impairment in patients with
      diabetes.Focal/ grid laser photocoagulation is the standard of care in the management .
      Several adjuncts including intravitreal corticosteroids, Pegaptanib Sodium , Ranibizumab ,
      Bevacizumab are also been tried.In some patients inspite of multiple lasers or injections
      macular edema persists as a consequence overlying taut posterior hyaloid membrane which needs
      to be removed by vitrectomy. Visual improvement after vitrectomy is related to the duration
      of edema, as well as the extent of intraretinal lipid and vascular nonperfusion.Even after
      surgery some patients might need repeat intravitreal bevacizumab or triamcinolone injections
      to take care of residual macular edema.Intravitreal Triamcinolone Acetonide (TA), a water
      insoluble steroid, has been shown to reduce the retinal thickness and improve the visual
      acuity. However, recurrence of macular edema in patients who receive intravitreal TA is a
      major concern because of its short half life . In search for the ideal corticosteroid
      preparation, a Dexamethasone Posterior Segment Drug Delivery System (Dexamethasone DDS -
      Ozurdex®, Allergan Inc, Irvine, California) was recently developed which has generated new
      interest in this molecule. It is a sustained release intravitreal implant containing 700µg
      dexamethasone has been approved by the US-FDA (Food and Drug Administration) for treatment of
      macular edema in retinal vein occlusions. The present study introduces a novel concept of
      using intraoperative Ozurdex ® implant during taut posterior hyaloid removal and its effect
      in improving the surgical outcome
    

Detailed description: 
      This study is undertaken to determine effect of sustained release dexamethasone
      implant,Ozurdex in improving outcome of taut posterior hyaloid removal in patients with
      diabetic macular edema

      Diabetic macular edema constitute important cause of visual impairment in patients with
      diabetes.Focal/ grid laser photocoagulation is the standard of care in the management
      .Several adjuncts including intravitreal corticosteroids, Pegaptanib Sodium , Ranibizumab ,
      Bevacizumab are also been tried.In some patients inspite of multiple lasers or injections
      macular edema persists as a consequence overlying taut posterior hyaloid membrane which needs
      to be removed by vitrectomy. The exact role of vitreous in the pathogenesis of diabetic
      maculopathy remains unclear although it has been implicated as a cause of macular edema via
      several mechanical and physiologic mechanisms, which include the following (1)
      destabilization of the vitreous by abnormal glycation and crosslinking of vitreal collagen,
      leading to traction on the macula, (2) accumulation and concentration of factors causing
      vasopermeability in the premacular vitreous gel and (3) accumulation of chemoattractant
      factors in the vitreous, leading to cellular migration to the posterior hyaloid, contraction
      and macular traction. The observation that release of mechanical traction on the macula with
      subsequent reduction in DME, either by spontaneous posterior vitreous detachment or with
      vitrectomy, lends support to this line of reasoning. Furthermore, the evidence that
      vitrectomy produces improved retinal oxygenation taken together with the evidence that
      increased oxygenation can reduce DME, suggests an additional physiologic advantage but
      determination of which eyes might benefit from vitrectomy is the most challenging aspect in
      the treatment of this condition. Fluorescein angiography, B-scan ultrasonography, and optical
      coherence tomography may be helpful in this regard. Most often, vitreous surgery is performed
      when diabetic macular edema persists despite multiple laser treatments. All reports published
      to date regarding vitrectomy for diabetic macular edema are uncontrolled and nonrandomized
      patient series. Visual improvement after vitrectomy is related to the duration of edema, as
      well as the extent of intraretinal lipid and vascular nonperfusion.Even after surgery some
      patients might need repeat intravitreal bevacizumab or triamcinolone injections to take care
      of residual macular edema.Intravitreal Triamcinolone Acetonide (TA), a water insoluble
      steroid, has been shown to reduce the retinal thickness and improve the visual acuity.
      However, recurrence of macular edema in patients who receive intravitreal TA is a major
      concern because of its short half life . In search for the ideal corticosteroid preparation,
      a Dexamethasone Posterior Segment Drug Delivery System (Dexamethasone DDS - Ozurdex®,
      Allergan Inc, Irvine, California) was recently developed which has generated new interest in
      this molecule. It is a sustained release intravitreal implant containing 700µg dexamethasone
      has been approved by the US-FDA (Food and Drug Administration) for treatment of macular edema
      in retinal vein occlusions. The present study introduces a novel concept of using
      intraoperative Ozurdex ® implant during taut posterior hyaloid removal and its effect in
      improving the surgical outcome
    

Intervention name(s): Dexamethasone Drug delivery system (Ozurdex)
Intervention type(s): Drug
Intervention description(s): It is a sustained release intravitreal implant containing 700µg dexamethasone
Other intervention name(s): OZURDEX
Intervention MeSH terms: Dexamethasone; Dexamethasone acetate; BB 1101
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: diabetic macular edema; taut posterior hyaloid membrane; ozurdex