Contents
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
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
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
