Neovascular Glaucoma _NVG_.ppt by shensengvf

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									Neovascular Glaucoma
       (NVG)

  Saleh A. Al-Obeidan, MD
   Department of Ophthalmology
       College of Medicine
      King Saud University
        Neovascular Glaucoma
               (NVG)
Neovascular Glaucoma is one of the most
Challenging forms of secondary glaucomas. It
occurs when the fibrovascular tissue proliferates
onto the chamber angle, obstructs the trabecular
meshwork, and produces peripheral anterior
synechiae and progressive angle closure. The
elevated intraocular pressure is often difficult to
control and frequently results in loss of vision.
               NVG

1871   Pagenstetcher Hemorrhagic


1963   Weiss, et al.   NVG
                 NVG
              Pathogenesis
Leading causes:

 Retinal   Ischemia Responsible for 97%
   - Diabetic Retinopathy
   - Central Retinal Vein Occlusion
                  Brown GC et al. Ophthalmology 1984
                NVG
             Pathogenesis
 X-Factor
 VEGF
 - Vascular Endothelial Growth Factor
 1 of 9 non polypeptide growth factors
 Specific for endothelial cells (EC)
 Causes EC migration and mitosis
 Increases EC permeability
             NVG
          Pathogenesis
 VEGF   (source in the eye)
 Expressed and produced by: Corneal
 endothelium, Iris pigment epithelium,
 RPE, Ganglion cells, Astrocytes,
 Muller cells, Uveal melanocyte, and
 Choroidal fibroblasts.
                   J Glaucoma 2002
             NVG
          Pathogenesis

 VEGF
 Markedly elevated in aqueous
 humor of patients with NVG.
               Diabetes Care Nov. 1996
               Ophthalmology 1998
               J Glaucoma 2002
                NVG
             Pathogenesis
   VEGF       (210 Vitrectomy samples)
      - Vitreous (VEGF) PDR 36x NPDR
      - Vitreous (VEGF) > Aqueous (VEGF)
      - (VEGF) 75% post PRP
   VEGF plays a major part in mediating
    active intraocular neovascularization
    in patients with ischemic retinal
    diseases.
                    N Engl J Med 1994;331:1480-7
               NVG
            Pathogenesis

Anti Angiogenic Therapy:
 Intravitreal injection of crystalline
 cortisone causes regression of iris
 neovascularization

                Jonas et al. J Glaucoma 2001
               NVG
            Pathogenesis
Anti-Angiogenic Therapy:
Anti VEGF (Ranibizumab, Lucentis)
  Intravitreal injection prevented
     formation of CNV in monkeys and
     decreased leakage of already formed
     CNV with no significant toxic effects
                      Arch Ophthalmol 2002
                      Kim, et al. Invest Ophthalmol. Vis Sci 2006
               NVG
            Pathogenesis
Anti Angiogenic Therapy:
   Anti VEGF    [SU 5416 (Semaxinib)]
   Durable and rapid recovery of
   visual functions in a patient with
   von Hippel-Lindau syndrome
                 Ophthalmology, Feb 2002
                 J Clin Oncol. May 2005
               NVG
            Pathogenesis
Anti Angiogenic Therapy:
   Anti VEGF [Aptamer (Macugen)]
   Remarkable reduction in the size of
    CNV
   Remarkable visual improvement
    “26.7% gained 3 lines or more”
              The Eye Tech Study Group, Retina 2002
              Exp Eye Res. May 2006
              Ophthalmology. Apr 2006
           NVG
        Pathogenesis

Anti Angiogenic Therapy:

    Bevacizumab [Avastatin]

         Davidorf, et al. Retina 2006
         Kehook, et al. Ophtha Surg 2006
              NVG
           Pathogenesis
Panretinal Photocoagulation and
Ocular Neovascularization
   PRP upregulate expression of
     transforming growth factor-
     (TGF- )
   TGF-  is a powerful vascular
     endothelial cell proliferation
     inhibitor.
                   Invest Ophthalmol Vis Sci 1998
               NVG
            Pathogenesis
Panretinal Photocoagulation and
Ocular Neovascularization
   Photo coagulated cultured human
     RPE & rat retinas upregulate
     expression of high level of Pigment
     Epithelium Derived Factor (PEDF)
   PEDF has been shown to be a potent
     inhibitor of ocular angiogenesis
                      Am J Ophthalmol, Sep 2001
                      Am J Ophthalmol Aug 2002
                      Invest Ophthalmol Vis Sci 2002
            NVG
         Pathogenesis
Panretinal Photocoagulation and
Ocular Neovascularization
   Major benefit of PRP may be
   destruction of VEGF source.
                NVG
        Clinical Presentation
   Reduced vision
   Injected eye
   A/C reaction
   Elevated IOP < 40 mmHg
   Middilated, non reactive pupil
   Rubeosis irides (NVI)
   Neovascularization of the angle (NVA)
                   NVG
 Enucleation   is only practical treatment
                        Duke Elder, 1969



 No   means are known to prevent NVG
                         Grant, 1974



 The   treatment of NVG is disheartening
                        Hoskins, 1974
             NVG
 Outcomeshave improved
 dramatically.
 Newmedical and surgical
 approaches.
       understanding and
 Better
 control of angiogenesis.
               NVG

“If the neovascular element can be
removed and further neovascularisation
prevented, then we are left with an
uncomplicated angle-closure problem
which should be amenable to classical
drainage surgery.”

                   Flanagan D.W. & Blach R.K.
                   Br J. Ophtamol 1983;67,526-8
             NVG
           Management
 Recognition of patients at HIGH RISK
 Recognition of NVI before angle
  closure is critical
 Treatment
                NVG
              Management
 Prevention:
    Recognition high risk patients
      Correction of the underlying pathology
      Close observation (NVI & NVA)
      Efficient & sufficient PRP

 Treatment
          NVG
        Treatment
Determinants

   Visual potential
   Clarity of the media
            NVG
       Treatment (cont.)
Medical Therapy

   Control inflammation & pain
     Cycloplegia
     Steroids
            NVG
       Treatment (cont.)
Medical Therapy

   Control IOP
     Aqueous suppressants
     Avoid miotics & prostaglandines
                NVG
           Treatment (cont.)
Laser Therapy
   Panretinal photocoagulation (PRP)
     1st line of therapy (if possible)
     Reduces & can eliminate
      ant. seg. neovascularization.
Cryo Therapy
   Panretinal cryoablation
               NVG
          Treatment (cont.)
Conventional Surgery
   Filteration surgery
   Tube surgery
   Cyclodystructive procedures
   Others
                        NVG
                   Treatment
Cyclodestructive procedures:
High rate of serious complications and visual loss
 Cyclophotocoagulation
  Visual loss up to 46.6%
              Shields & Shields 1994

   Cyclocryotherapy
    Visual loss of up to 70%
              Caprioli et al. Ophthalmology 1985

   Phthisis Bulbi 34%
              Krupin T et al. Am J Ophthalmol 1978;86:24-6
                    NVG
                  Treatment
Tube shunts:
   Variable success rates
   Probably more suitable
    for previously operated
    eyes (e.g. failed filter
    proced. Aphakia)
   High rate of visual loss
    (19-48%) and phthisis
    bulbi (11-25%)
                       Mermoud et al. Ophthalmology 1993
          NVG
     Treatment (cont.)

 Filteration surgery
  Full PRP Improves the Outcome
    of Trabeculectomy in NVG
          Surgical Technique

Procedure - Standard Trabeculectomy
           - Mitomycin “C” 0.2mg/ml/2mins.
Precautions - Gradual decompression
            of the eye
Full PRP Improves the Outcome
  of Trabeculectomy in NVG
 Short Term Complications:
    - Transient hypotony - 14/23        (61%)
    - Hyphema - 8/23                    (35%)
    - Choroidal Detachment - 2/23       (9%)
    - Leaking Bleb - 1/23               (4%)
 Long Term Complications:
   - Cataract prog. – 2/23              (9%)
    - NLP
    - Hypotony Maculopathy        Non
    - Phthisis Bulbi
 Full PRP Improves the Outcome
   of Trabeculectomy in NVG

                Results

Complete Success    20/23   (87%)
Qualified Success    3/23   (13%)
                     Treatment
                          NVG

                                                  NLP
             Seeing eye
                                             - Medical Rx
                                             - Cyclodestructive
                                             procedure
Clear         Poor media      Vitreous hge
media PRP     Cryoablation    Vitrectomy+
                              endolaser



       Trabeculectomy & Mitomycin

            Tube shunts
            cyclophotocoagulation
           NVG
   Points to Remember


It is a preventable condition.
           NVG
   Points to Remember




It is a treatable condition.

								
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