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Ocular System

Malignant glaucoma (MG)

Rare condition involving acute shallowing of the anterior chamber (AC), usually accompanied by ocular hypertension, refractive to treatment, typically following ocular surgeries.

Rare condition involving acute shallowing of the anterior chamber (AC), usually accompanied by ocular hypertension, refractive to treatment, typically following ocular surgeries.

  • Very rare complication of all kind of ocular surgeries with an incidence of 2-4%

History:

The term “malignant glaucoma” was coined by von Graefe in 1869 to describe an aggressive form of postoperative glaucoma that was resistant to treatment and resulted in blindness. It is alternatively known by names relating to the proposed pathogenic mechanisms of this condition, such as ciliary block glaucoma, aqueous misdirection syndrome, and direct lens-block glaucoma.


Aetiology

Typically follows surgery in patients with primary angle closure and primary angle-closure glaucoma.


Clinical features

  • Improvement in near vision (secondary to a myopic shift in refraction as the lens-iris diaphragm moves forward)
  • Red, painful eye with decreased vision (↑ IOP)
  • Associated headache with nausea and vomiting

Diagnosis

Malignant glaucoma is diagnosed when there is shallowing of the central (axial) anterior chamber in association with increased intraocular pressure (IOP) and normal posterior segment anatomy.

Fundus examination:

  • Corneal oedema
  • Absence of forward bowing of the iris
  • Axial flattening of the anterior chamber with anterior displacement of the lens
  • Intraocular implant, or vitreous face, depending on the lenticular status of the eye in the presence of elevated IOP

Ultrasound biomicroscopy (UBM):

Aids in both diagnosis and monitoring therapeutic response in eyes with malignant glaucoma
Ultrasound biomicroscopy (UBM) of malignant glaucoma. (a) The patient with a history of angle closure glaucoma and a patent laser iridotomy presented after glaucoma filtration surgery with elevated intraocular pressure. UBM showed shallow anterior chamber and anterior rotation of the ciliary body. (b) After treatment with cycloplegic medication and topical steroids, the anterior chamber deepened and the ciliary body returned to normal position. C, cornea; I, iris; B, ciliary body; and M, hyaloid membrane | Quigley H. A. Angle-closure glaucoma-simpler answers to complex mechanisms: LXVI Edward Jackson Memorial Lecture. American Journal of Ophthalmology. 2009;148(5):657.e1–669.e1. doi: 10.1016/j.ajo.2009.08.009.

Optical coherence tomography (OCT):

Noninvasive technique for monitoring anterior chamber narrowing in affected eyes
  • Qualitative and quantitative marked shallowing of the anterior chamber depth during the acute presentation and resolution of these findings after pars plana vitrectomy and deepening of the anterior chamber with viscoelastic agents.

Management

Management pathway for malignant glaucoma | Shahid, H., & Salmon, J. F. (2012). Malignant glaucoma: a review of the modern literature. Journal of ophthalmology, 2012, 852659. https://doi.org/10.1155/2012/852659

Medical management:

  • Cycloplegia:
    • Mydriatics (atropine and phenylephrine)
  • ↓ IOP:
    • Oral acetazolamide
    • Topical β-blockers
    • α agonists
  • Reduction of Vitreous Volume:
    • Osmotic agents (mannitol or glycerol)
  • Anti-inflammatory medications:
    • Topical steroids

Laser therapy

Aims to restore a normal aqueous flow pattern by establishing a direct communication between the vitreous cavity and anterior chamber.
  • Nd:YAG laser capsulotomy with disruption of the anterior hyaloid face
  • Transscleral cyclodiode laser photocoagulation

Surgical management:

In malignant glaucoma that is refractory to medical and laser therapy, surgical intervention to remove the vitreous is necessary to increase aqueous flow into the anterior chamber
  • Pars plana vitrectomy surgery techniques
Malignant glaucoma treatment. (a) The patient presented after glaucoma filtration surgery with a shallow chamber and markedly elevated intraocular pressure, not responding to initial treatment with cycloplegia and laser. (b) After pars plana vitrectomy, the anterior chamber was deep and the intraocular pressure was normalized. | Foreman-Larkin, J., Netland, P. A., & Salim, S. (2015). Clinical Management of Malignant Glaucoma. Journal of ophthalmology, 2015, 283707. https://doi.org/10.1155/2015/283707

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