Malignant Glaucoma / Aqueous Misdirection Syndrome Definition Von Graefe 1869 A shallow or flat anterior chamber with an inappropriately high intraocular pressure despite a patent iridectomy European Glaucoma Society; II edition Secondary angle closure glaucoma with ‘’posterior’’ pushing mechanism, without pupillary block, caused by the ciliary body and iris rotating forward
Malignant Glaucoma – Aetiology Surgery for angle-closure glaucoma Spontaneously Cessation of topical cycloplegic therapy Initiation of topical miotic therapy Laser iridotomy Laser capsulotomy Laser cyclophotocoagulation
Malignant Glaucoma – Aetiology Cataract extraction Seton implantation Central retinal vein occlusion Argon laser suture lysis Hyperopia Short axial lengths, or nanophthalmos . [4]
Pathogenesis
Malignant glaucoma: cilio-lenticular block
Malignant glaucoma: cilio-vitrean block
Clinical Presentation High index of suspicion - necessary A red, painful eye is surgery for acute angle-closure glaucoma Immediately after surgery , may occur during surgery or months to years later Cessation of cycloplegic therapy or the institution of miotic drops
Clinical Presentation Slit-lamp Shallow or flat anterior chamber both centrally and peripherally No iris bombé to make the appropriate diagnosis IOP is elevated and the anterior chamber is axially shallow Attempt to reform the anterior chamber postoperatively through the paracentesis site with viscoelastic substance, Great posterior resistance may be noted Anterior chamber may not deepen IOP may rise substantially.
Trigger factors Small, crowded anterior segment Angle closure Swelling and inflammation of the ciliary processes Anterior rotation of the ciliary body Forward movement of the lens-iris diaphragm
DIFFERENTIAL DIAGNOSIS Criterion Aqueous Misdirection Pupillary Block Suprachoroidal Hemorrhage Serous Choroidal Effusions Intraocular pressure Normal or elevated Elevated Normal or elevated Low Anterior chamber depth Shallow; flat centrally and peripherally Shallow; flat peripherally, but deeper centrally Shallow; flat centrally and peripherally Shallow; flat centrally and peripherally Relief by iridectomy No Yes No No Ophthalmoscopy Choroid and retina flat Choroid and retina flat Bullous light brown choroidal elevations Bullous dark brown or dark red choroidal elevations Ultrasound biomicroscopy Anterior rotation of ciliary body and lens Iris bombé with lens in normal position - -
DIFFERENTIAL DIAGNOSIS Criterion Aqueous Misdirection Pupillary Block Suprachoroidal Hemorrhage Serous Choroidal Effusions B-scan ultrasound - - Smooth, thick, dome-shaped movement with little after-movement Smooth, thick, dome-shaped membrane with little after- membrane Heterogeneous echogenic space Echolucent suprachoroidal space Onset Intraoperative or early postoperative period. Early postoperative period Intraoperative or early postoperative period Intraoperative or early postoperative period Occasionally months to years later
Pupilary block v/s Malignant Glaucoma
Investigationes Ultrasound A scan: axial length Ultrasound B scan: exclude other pathologies Ultrasound biomicroscoscopy
Ultrasound biomicroscopy Confirm the diagnosis by the visualitation of the anterior segment structures: Irido-corneal touch Appositional angle closure Anterior rotation of the ciliary body Apposition to the iris
MANAGEMENT Medical therapy Laser therapy Pars plana vitrectomy
Medical treatment Fi rst step (good results in 50% of cases) C ycloplegia with atropin 1%x 4-6/d M ydriasis with ph enile ph rin 2,5%x 4-6/d Mechanism of action posterior push of the irido-cristalinian diaphragm cilliary muscles relaxation Long time treatment with atropin required recurences (sometime for several years) β bloc kers, AIC , α agonists Hyperosmotics agents: Glycerol ( po ), Manitol (2g/kg iv) Miotics Are Contraindicated
Laser Therapy The second line of treatment Neodymium:yttrium -aluminum-garnet ( Nd:YAG ) laser - aphakic and pseudophakic Large peripheral iridectomy Anterior hyaloid rupture to release the trapped aqueous from the vitreous Several openings are made peripherally Placement of the iridectomies should be peripheral Peripheral placement will enable anterior migration of the aqueous
Laser Therapy Corneal- lenticular contact Risk of corneal decompensation Chamber should be reformed following Nd:YAG laser hyaloidotomy Slit lamp Viscoelastic substance via a 30-gauge cannula Through the original paracentesis
Pars plana vitrectomy MECHANISM To debulk the vitreous To disrupt the anterior hyaloid face. NEEDED Medical or or laser therapy fails Phakic eyes for which laser treatment is not a good option,
Pars plana vitrectomy Pseudo ph akic vitrectom y + anterior hialoidotomy P h akic P ars plana vitrectomy ± lensectom y Lensectom y : - corneal oedema - dens cataract - no anterior chamber formation during vitrectomy
Fellow eye Narrow angle is present The laser peripheral iridectomy is performed before Risk of aqueous misdirection may be reduced after iridectomy if the angle remains open and the IOP is normal Failure to provide prompt therapy to the fellow - bilateral blindness. [2]
Conclusion The prognosis depends of the severity and the anterior situation Malignant glaucoma remains a most difficult clinical problem in terms of diagnosis and management The precise mechanism remains unclear and that why the management is controversial