Malignant Glaucoma

Presenter: Dr.Niket Gandhi

Moderator: Dr.Vijay Shetty

Introduction

Albrecht von Graefe in 1869

It is characterized by normal or increased IOP associated with axial shallowing of the entire anterior chamber in the presence of a patent peripheral iridotomy

After surgery in patients with primary angle closure and primary angle-closure glaucoma

Synonyms:

1. Ciliary block glaucoma

2. Aqueous misdirection syndrome

3. Direct lens-block glaucoma

Prevalence

2% to 4% - h/o of acute or chronic angle-closure glaucoma that have undergone filtration surgery

1.3 % - glaucoma surgery alone or combined with cataracts

2.3%- Penetrating surgery

Women are three times more likely than men

Predisposing Factors

Axial hyperopia

Nanophthalmos

Disorders of anatomical proportions in the anterior chamber

chronic angle closure with plateau iris configuration

History of malignant glaucoma in the fellow eye.

Risk Factors

Filtration surgeries: Trabeculectomy

Penetrating Keratoplasty

Laser treatment :

1. Peripheral laser iridotomy

2. trabeculectomy scleral flap suture lysis

3. cyclophotocoagulation

use of miotics

trabeculectomy bleb needling

Infection

Retinopathy of prematurity

Retinal detachment

retinal vein occlusion

trauma

Preoperative IOP is not a good indicator

Unlike in pupillary block angle closure, miotics can exacerbate malignant glaucoma.

Theories

Theories

Shaffer and

Hoskins

Epstein et all

Chandler et all

Quigley et all

Shaffer and Hoskins

Posterior diversion of aqueous flow causes accumulation of aqueous behind a posterior vitreous detachment with secondary forward movement of the iris-lens diaphragm

Collections of fluid behind the vitreous gel, which also seemed more dense than normal, and believed that this prevented forward flow of aqueous

They postulated a valve-like mechanism by which aqueous humourwas “misdirected” posteriorly.

Epstein and colleagues

Anterior displacement of the vitreous due to posterior diversion of aqueous

Associated thickening of the anterior hyaloid, and they were able to demonstrate an impedance to flow across the intact anterior hyaloid

The accumulation of aqueous within the posterior segment forces the ciliary body and the anterior hyaloid face forward, shallowing the anterior chamber and causing secondary angle closure

Chandler et all

Laxity of lens zonules coupled with pressure from the vitreous leads to forward lens movement

A vicious circle is set up in that the higher the pressure in the posterior segment, the more firmly the lens is held forward

Quigley et al.

Proposed that the precipitating event which increases vitreous pressure is choroidal expansion

Initial compensatory outflow of aqueous along the posteroanteriorpressure gradient causes shallowing of the anterior chamber.

Choroidal expansion has been detected on UBM in eyes with malignant glaucoma, and choroidal effusion secondary to angio-oedema has also been reported to result in malignant glaucoma

Predisposing Anatomical features

Incorrect anatomical relationships lead to disruptions in the direction of aqueous humour flow

The place of increased resistance may be located at the level of the iris-lens, ciliary-lens, iris-hyaloid, and ciliary-hyaloid block

Structures that are particularly related to the development of malignant glaucoma and its clinical picture:

1. Sclera

2. Lens

3. Choroid

4. Vitreous body

Sclera– a thick sclera may lead to partial stenosis of the vortex veins, impairing normal venous outflow and causing overfilling of the choroid

Lens –Disproportions between its volume and the volume of the entire eyeball

Choroid – the choroid has a lobular structure with a tendency for accumulation of blood and thickening when outflow is impaired.

Secondary, ciliary body and iris rotate to the front in patients with malignant glaucoma closing access to the filtration angle from the back.

Vitreous body –optically clear areas within the vitreous body –reservoirs of aqueous humour trapped in its gel structure

In aphakic eyes, the anterior surface of the vitreous body may directly adhere to the ciliary processes

Highly resistant anterior hyaloid membrane may be observed in aphakic and pseudophakic eyes

Clinical Features

Myopic shift - Anterior dislocation of the iris-lens diaphragm with secondary improvement of near vision

Narrowing or shallowing of the circumferential and central part of the anterior chamber even if patent iridotomy or iridectomy is present.

Persistent symptoms - Anterior adhesions due to the long-lasting shallowingof the anterior chamber

Increased IOP

No decrease of IOP in response to conventional antiglaucoma treatment

Examination

Medical history

1. Determination of predisposing factors

2. Symptoms

Slit lamp examination

1. ACD - axial (central and peripheral) shallowing of the anterior chamber

2. Patency of the iridotomy

3. Seidel test should be performed to exclude filtering bleb leaking after filtration surgery.

4. Posterior segment : Ruling out choroidal detachment or suprachoroidalhemorrhage

Tonometry – usually reveals increased IOP

DDx

Glaucoma with pupillary block

Closure of anterior chamber angle

Laser peripheral iridotomy is the treatment of choice

Unlike malignant glaucoma the anterior chamber usually remains deeper in the center than on its circumference

Angle closure glaucoma

Shallowing of the anterior chamber occurs symmetrically

Sudden increase in IOP

Microcystic edema of the cornea

Conjunctival injection

Choroidal effusion

Cause:

1. inflammatory (trauma and intraocular surgery, scleritis, following cryocoagulation and photocoagulation, chronic uveitis, Vogt-Koyanagi-Harada disease)

2. Hydrostatic causes (hypotony and wound leak, dural arteriovenousfistula, abnormally thick sclera in nanophthalmos)

IOP may be normal but is often reduced in uveal effusion secondary to inflammatory factors.

Abnormal amounts of fluid in the

choroid

Thickening of the choroid

accumulation of fluid in the suprachoroid

space

Suprachoroidal hemorrhage

Shallowing of the anterior chamber coexists with increased IOP, sudden pain, and the presence of a haemorrhagic, non-serous detachment of the choroid in biomicroscopic and ultrasonographic examination.

It occurs most often within 1 week after surgery, rarely later

may be also related to postoperative hypotony

Ultrabiomicroscopy (UBM)

The rotation of the ciliary body to the front and shallowing of the anterior chamber

Marked displacement of the structures of the anterior segment

Peripheral irido-corneal touch

Forward shift of the lens may be noted

Treatment

Medical

Cycloplegia

Mydriatics (atropine and phenylephrine) should be given immediately in

order to tighten the lens zonules and pull the anteriorly displaced lens backwards

In some cases, Atropine is needed upto one year to avoid recurrence.

MIOTICS – CONTRAINDICATED promoting zonular relaxation and encourage forward lens movement.

Anti-Inflammatory Medication :

Topical steroids can help to reduce inflammation

Intraocular Pressure Reduction

Oral acetazolamide and topical beta-blockers and alpha agonists are used to reduce aqueous production.

Reduction of Vitreous Volume.

Osmotic agents (mannitol or glycerol) are used to reduce vitreous volume, deepen the anterior chamber, and possibly increase vitreous permeability

Laser

AIM: to restore a normal aqueous flow pattern by establishing a direct communication between the vitreous cavity and anterior chamber.

Disruption of Anterior Hyaloid Face

Laser of Ciliary Processes.

The successful use of transscleral cyclodiode laser photocoagulation in pseudophakic patients can help eliminate an abnormal vitreociliaryrelationship by posterior rotation of the ciliary processes secondary to coagulative shrinkage

Often a single session of therapy is sufficient over 1-2 quadrants

Cyclocryotherapy has been used in the past but no longer has a place in modern management

Surgical

The purpose of the vitrectomy is again to disrupt the anterior hyaloidface and release fluid trapped within the vitreous

Anterior vitrectomy via pars plana approach and/or in

combination with reformation of the anterior chamber with

air +/- lens extraction

Iridectomy-hyaloido-zonulectomy + anterior

vitrectomy ( anteriorly via the iridectomy or pars plana )

In phakic patients:

phacoemulsification-vitrectomy (with zonulo-

hyaloidectomy-iridectomy)

In refractory cases:

Complete pars planavitrectomy along with lens

+removal of the entire hyaloidface as well as creation of

vitrectomy tunnel

Conclusion

Malignant glaucoma – Therapeutic challenge

Patients with h/o MG in fellow and PACG should be closely followed in after glaucoma filtration surgeries

Good prognosis with current treatment modalities

Thank You