Neovascular Glaucoma
What is Neovascular Glaucoma?
It is a type of glaucoma caused by a fibro vascular membrane, overgrowing the anterior-chamber angle structures. Initially, the angle may appear open, but blocked by the membrane. The fibro vascular membrane eventually contracts, causing peripheral anterior synechaie formation and secondary angle-closure glaucoma. Rarely, may have neovascularization of the angle without neovascularization of the iris at the pupillary margin. The etiology of the fibro vascular membrane is ischemia from a variety of causes.
What are the symptoms of Neovascular Glaucoma?
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May be asymptomatic
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Pain
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Red eye
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Photophobia
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Decreased vision
What are the different stages of Neovascular Glaucoma?
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Stage 1: Abnormal, nonradial, misdirected blood vessels along the pupillary margin, the trabecular meshwork, or both.
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Stage 2: Stage 1 plus increased intraocular pressure.
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Stage 3: Partial or complete angle-closure glaucoma caused by a fibro vascular membrane covering the trabecular meshwork.
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Other signs: Mild-anterior chamber cells and flare, conjunctiva injection, corneal edema when an acute increase in intraocular pressure occurs, hyphema, eversion of the pupillary margin allowing visualization of the iris pigment epithelium, optic nerve cupping, visual-field lost.
What is the workup for Neovascular Glaucoma?
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A complete ocular examination, including intraocular pressure measurement and gonioscopic evaluation of the anterior-chamber angle to determine what degree of the angle is closed. A dilated retinal evaluation is essential in determining the cause of the iris neovascularization.
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Fluorescein angiogram as needed to identify an underlying retinal abnormality or in preparation for retinal laser treatment.
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Carotid noninvasive studies to rule out carotid disease when no retinal pathology can be found accountable for the neovascularization.
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B-scan ultrasound is indicated when the retina cannot be visualized to rule out an intraocular tumor or retinal detachment.
How is Neovascular Glaucoma treated?
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Reduce inflammation and pain: Topical steroid (e.g., prednisolone acetate, 1%, q 1 to 6 h) and a cycloplegic (e.g., atropine, 1%, t.i.d.). Atropine may reduce IOP when the angle is closed by increasing uveoscleral outflow.
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Reduce the IOP if it is increased.
What is the follow-up plan for Neovascular Glaucoma?
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The presence of iris neovascularization, especially when accompanied by high intraocular pressure, requires urgent therapeutic intervention, usually within one to two days. Angle closure can proceed relatively rapidly (within days to weeks).