Download Neovascular Glaucoma (NVG)

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
 Outcomes
have improved
dramatically.
 New
medical and surgical
approaches.
 Better
understanding and
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
- Hyphema - 8/23
- Choroidal Detachment - 2/23
- Leaking Bleb - 1/23
 Long Term Complications:
- Cataract prog. – 2/23
- NLP
- Hypotony Maculopathy
Non
- Phthisis Bulbi
(61%)
(35%)
(9%)
(4%)
(9%)
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
Clear
media PRP
Poor media
Cryoablation
- Medical Rx
Vitreous hge
Vitrectomy+
endolaser
Trabeculectomy & Mitomycin
Tube shunts
cyclophotocoagulation
- Cyclodestructive
procedure
NVG
Points to Remember
It is a preventable condition.
NVG
Points to Remember
It is a treatable condition.