Malignant Glaucoma Presenter: Dr.Niket Gandhi Moderator: Dr.Vijay Shetty
Jul 08, 2015
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