Introduction:
Glaucoma is a condition referring to a group of eye disorders affecting or harming the optic nerve. The optic nerve transmits images from the eyes to the brain. Glaucoma is typically caused by increased eye pressure called intraocular pressure (IOP). Glaucoma can result in permanent (vision impairment) vision loss and blindness if left unaddressed.
What Is Malignant Glaucoma?
Malignant glaucoma was previously described as an elevated intraocular pressure (IOP) associated with a flat or shallow anterior chamber that occurs generally as a result of any ocular surgery. This condition is considered one of the most complex and severe glaucomas to manage. This is so serious that it can progress, resulting in complete vision loss or blindness without appropriate treatment. Malignant glaucoma is called ciliary block glaucoma, aqueous misdirection, and lens block angle closure.
What Causes Malignant Glaucoma?
Malignant glaucoma is known to occur in about two to four percent of the people who have undergone eye surgery for angle closure glaucoma (a condition in which the part of the angle with the trabecular meshwork is obstructed or occluded by peripheral iris). It might occur any day following the ocular surgery, from the very first postoperative time to many times later. This condition might result in phakic (implanted lens), pseudophakic (false lens), or aphakic (no lens) eyes. It commonly occurs after filtration surgery in individuals with angle closure but might also occur following the laser iridotomy or cataract surgical treatment. Certain clinical findings suggest that this condition can occur following laser cyclophotocoagulation because of being influenced by the usage of large optic intraocular lenses.
The exact cause and mechanism of this condition are still unclear. Nevertheless, a blockage or obstruction of the normal aqueous (fluid of the eye) flow at the level of the lens, ciliary body, and anterior vitreous face is considered to cause malignant glaucoma. So, anatomical interaction within the lens, anterior vitreous, and ciliary processes could divert the aqueous back to the vitreous cavity. One theory says that misdirection of aqueous into the vitreous or around them can contribute to malignant glaucoma. This is because the backward misdirection of aqueous humor into its vitreous cavity could result in continuous expansion, increasing the pressure at the backward portion.
What Are the Risk Factors for Malignant Glaucoma?
The risk factors of malignant glaucoma include the following.
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Ocular surgery for angle closure glaucoma.
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This condition can result after incisional surgery in most cases.
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Following iatrogenic causes, including cataract extraction with or without intraocular lens implantation and trabeculectomy.
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Intravitreal Injection.
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Needling of the filtering trap-door called blebs.
What Are the Signs and Symptoms of Malignant Glaucoma?
The common symptoms of malignant glaucoma include:
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Infection of the eye structures.
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Inflammatory condition of the eyes.
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Retinal detachment (an emergency circumstance in which the sensitive thin layer of tissue called the retinal present at the back of the eye is pulled or detached away from its actual position).
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Trauma.
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Retinopathy of prematurity.
How Is Malignant Glaucoma Diagnosed?
It is challenging to diagnose and treat malignant glaucoma. Slit lamp examination helps identify the frontward displacement of the lens and iris diaphragm in phakic (implantable lens) and pseudophakic (false lens) individuals. Most cases report the presence of a peripheral iridotomy. Some cases have been reported with the absence of iridotomy. The doctors perform an extensive eye examination and look for the physical findings. The physical findings of the diagnosis of malignant glaucoma include increased myopia (a condition in which the nearby things appear clearly while the fat away objects seem to be unclear), discrepancies in the anterior chamber depths, and chronic shallowing of the anterior chamber.
The doctors might consider creating an iridotomy when there is no previous iridotomy or when potency is in doubt. Suprachoroidal hemorrhage and choroidal detachment will be eliminated clinically or using ultrasound biomicroscopy (UBM) when there is increased intraocular pressure and patent iridotomy.
What Is the Management Option for Malignant Glaucoma?
The management of malignant glaucoma is quite challenging. However, the healthcare providers and ophthalmologists perform one or a combination of the following treatment options for favorable outcomes.
Medical Therapy:
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The doctors prescribe an initial medical treatment including aqueous suppressants with lower intraocular pressure, hyperosmotic agents to shrink the vitreous, and strong cycloplegic agents like Atropine to enunciate backward displacement of the lens-iris diaphragm.
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A laser iridotomy might be performed if any is present or when the patency of a past iridotomy cannot be determined.
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The effect of medical therapy is not acute in most cases. However, about 59 percent of patients could be relieved in about five to eight days.
Laser Treatment:
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Nd: YAG laser treatment is suggested if medical therapy is unsuccessful or if any lens-cornea contact occurs. This is used to influence the posterior portion and other states.
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Argon laser in conjugation with peripheral iridectomy might also be done to shrink the ciliary processes. This also helps relieve the blockage of the flow of the aqueous.
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Posterior vitrectomy can be performed if the laser treatment is unsuccessful or not possible to be done.
The medical treatment is usually withdrawn at gradual rates once the anterior chamber's deepening and the intraocular pressure's normalization is achieved. Some cases might need indefinite treatment with cycloplegic agents for the prevention of recurrence of malignant glaucoma if vitrectomy was not done.
Conclusion:
Malignant glaucoma is otherwise called aqueous misdirection syndrome. Here, the aqueous flow is disrupted due to the blockage. Malignant glaucoma is a rare and severe complication of glaucoma that occurs often following certain types of ocular surface surgery and glaucoma surgery. With early recognition, appropriate treatment, and care, this condition can be treated effectively, though challenging.
