Canadian Ophthalmological Society Evidence-based Clinical Practice Guidelines for the Management of Glaucoma in the Adult Eye

Angle-closure Glaucomas

Angle-closure glaucomas The most useful classification for angle-closure glaucoma is based upon etiology. The most important criterion is the presence or absence of pupil block, with further sub- classification into primary and secondary mechanisms. The prevalence of PACG varies significantly among different ethnic groups. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Angle-closure glaucomas Patients with PACG commonly present with 1 of 3 possible scenarios: –acute angle closure, –narrow angle at risk of acute closure with normal IOP, or –creeping angle closure with or without elevated IOP. Patients may present with what appears to be chronic OAG, but angle closure is subsequently discovered on gonioscopy. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

PupilPrimaryExamples of secondary Pupil blockPrimary acute or chronic angle closure Posterior synechiae Silicone oil AC IOL without iridectomy Lens subluxation or lens swelling Non-pupil block Plateau iris syndrome Posterior mechanisms −Choroidal tumour −Choroidal effusion o medication-induced (sulfonamides) o spontaneous −Ciliary block −Lens-induced Anterior mechanism −Angle neovascularization −Iritis −ICE syndrome −Epithelial down growth Classification of angle closure based on functional cause Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Risk factors for development of primary angle closure Axial hyperopia Family history of angle closure Advancing age Female gender East Asian ethnicity Inuit ethnicity Latino ethnicity Shallow peripheral anterior chamber Short axial length eyes Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Acute angle closure: Signs and symptoms Symptoms include:Severe pain Headache Nausea and vomiting Blurred vision Halos around lights Conjunctival injection Signs include:Ciliary flush Corneal edema Fixed mid-dilated pupil Shallow anterior chamber Elevated IOP Sometimes glaukomflecken The angle is observed to be closed on gonioscopic examination Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Narrow angle at risk of closure (angle-closure suspect) A patient would be considered an angle-closure suspect if he or she had iridotrabecular contact on gonioscopy without PAS, and without GON and VF damage. There are usually no symptoms associated with a narrow angle; however, intermittent angle closure is possible. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Narrow angle at risk of closure (angle-closure suspect) (cont’d) Signs of narrow angle at risk of closure include: –Shallow peripheral anterior chamber and an open angle on gonioscopy. –Trabecular meshwork, while still visible, is almost or partially occluded. The IOP is not elevated. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Creeping angle closure There are no symptoms associated with creeping angle closure. Signs include: –normal or elevated IOP, –PAS in portions of the angle, –possible optic disc damage, and –possible glaucomatous VF defects. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Diagnosis of Angle Closure Glaucomas

Diagnosis of angle closure glaucoma Diagnosis requires a detailed history and physical exam. History must include: –whether the pupil has ever been pharmacologically dilated, –medication history to elicit the use of medications that may dilate the pupil, such as those: o with anticholinergic effects/side effects o that counteract the iris sphincter muscle o with sympathomimetic effects that work on the iris dilator muscle, o that may cause anterior movement of the lens iris diaphragm (e.g., sulfonamides) –family history of acute glaucoma or previous laser iridotomy in a first-degree relative, and –personal history indicative of symptoms of previous intermittent attacks of angle closure. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Diagnosis of angle closure glaucoma On examination, it is important to note: –visual acuity –refractive error –pupil size and reaction –presence of corneal edema –anterior chamber depth centrally and peripherally –presence of iris or angle new vessels indicative of neovascularization –presence of anterior chamber inflammation –IOP –lens appearance Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Diagnosis of angle closure glaucoma Gonioscopy of both eyes is mandatory to assess the depth of the anterior chamber and the presence of PAS (compression gonioscopy with a Zeiss-type lens is very useful in differentiating PAS from apposition). Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Gonioscopy technique in narrow angles Recommendation Careful gonioscopy, performed under ideal conditions (dim ambient light, narrow light beam from the slit lamp, use of compression gonioscopy) is fundamental to assess the presence of angle closure in patients suspected of having narrow angles [Consensus]. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of Angle-Closure Glaucomas

Treatment of angle-closure glaucoma Treatment should be based on the type and cause of the angle closure, i.e.: –primary acute angle closure, –narrow angle with normal IOP, –chronic angle closure, or –secondary angle closure (which will further depend upon the particular underlying mechanism). Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of primary acute angle closure Upon diagnosis, agents to lower IOP are indicated, including: –topical beta blockers –topical miotics –topical alpha-2 adrenergic agents –topical and (or) systemic carbonic anhydrase inhibitors –prostaglandins –systemic hyperosmotics Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of primary acute angle closure (cont’d) Topical glycerol 100% (to achieve temporary clearing of the cornea when edema is present) may be useful. Corneal indentation (Anderson manoeuvre) 1 with the tip of the Goldmann tonometer or Zeiss 4- mirror lens may be useful. Laser iridotomy should be performed when the cornea is clear. 1. Anderson DR. Am J Ophthalmol 1979;88:1091–3. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of primary acute angle closure (cont’d) In some instances, when the acute attack cannot be broken, peripheral laser iridoplasty may be helpful. 1 In some instances, anterior chamber paracentesis, 2 lens extraction, 3 or surgical iridectomy 4 may be useful. Laser iridotomy to the fellow eye is indicated to prevent an attack in the fellow eye (if it is similarly predisposed) Lai JSM, et al. J Glaucoma 2002;11:484–7. 2. Lam DSC, et al. Ophthalmology 2002;109:64– Greve EL. Int Ophthalmol 1988;12:157– Schwartz GF, et al. Ophthalmic Surg 1992;23:108– Ang LP, et al. Ophthalmology 2000;107:2092–6. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of narrow angle with normal IOP Laser iridotomy is effective as a preventive measure in patients at moderate to high risk of experiencing an angle closure attack. 1,2 An occludable angle would include: –those with any degree of appositional closure, or –when more than 180° of trabecular meshwork cannot be visualized with proper gonioscopic maneuvers. When the trabecular meshwork can be visualized for 360°, but the approach is very narrow and therefore felt to be at risk for closure, consideration should also be given to performing an iridotomy. 1. Ang LP, et al. Ophthalmology 2000;107:2092–6. 2. Friedman DS, et al. Ophthalmology 2006;113:1087–91. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Laser iridotomy — prophylaxis against acute angle closure Recommendation Laser peripheral iridotomy should be performed in patients with narrow angles at risk for an attack of acute angle closure [Level 1B 1,2 ]. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S Ang LP, et al. Ophthalmology 2000;107:2092–6. 2. Friedman DS, et al. Ophthalmology 2006;113:1087–91.

Treatment of chronic angle closure Angle closure becomes chronic when permanent PAS develop. Once the pupil block component has been resolved by laser iridotomy, the IOP control is achieved by the same protocol as with chronic open-angle glaucoma. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of secondary angle closure Treatment is aimed at the specific etiology, e.g.: –In lens-induced mechanisms, lensectomy may be indicated. –In neovascularization, intravitreal anti-VEGF medication may help cause regression of the fibrovascular membrane. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Laser iridotomy — suspected pupillary block Recommendation Laser peripheral iridotomy should almost always be considered to remove the pupil block component in angle closure. It is even indicated in suspected cases of angle closure due to posterior mechanisms or plateau iris appearance in order to eliminate any possible pupillary block component. It is not indicated in cases secondary to anterior mechanisms such as angle neovascularization, iritis with PAS, iridocorneal-endothelial syndrome or epithelial down growth, as pupil block is not typically a factor in these situations [Consensus]. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Neovascular Glaucoma

Neovascular glaucoma Neovascular glaucoma is a common form of secondary non-pupil block anterior-mechanism glaucoma. The most common inciting factors are: –posterior segment ischemia due to central retinal vein occlusion, or –diabetes mellitus. These lead to anterior segment iris and angle new vessel formation. The angle new vessels form a fibrovascular membrane, which contracts to create PAS and angle closure. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of neovascular glaucoma Treatment is aimed at controlling the cause of the new vessels: –by PRP, and –possibly intraocular injection of anti-VEGF medication. IOP is controlled by the usual protocol as for open- angle glaucoma. If there is significant visual potential, filtering surgery is often required. If there is minimal visual potential, cycloablation is useful Iliev ME, et al. Br J Ophthalmol 2007;91:1631–5. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Ciliary Block Glaucoma

Ciliary block glaucoma Ciliary block glaucoma (malignant glaucoma or aqueous misdirection) is a rare cause of secondary non-pupil block posterior-mechanism glaucoma. It may occur after intraocular surgery of any kind, and may even occur after a laser iridotomy. It is likely due to ciliary body rotation and aqueous misdirection posteriorly. It may occur in phakic, pseudophakic or aphakic eyes. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of ciliary block glaucoma Initial treatment includes: –laser iridotomy to minimize any potential pupil block component, as well as –maximal cycloplegia with atropine. 1 Acute treatment includes: –topical beta blockers –topical and (or) systemic carbonic anhydrase inhibitors –prostaglandins, alpha-2 adrenergic agents –systemic hyperosmotics 1. Chandler PA, et al. Am J Ophthalmol 1968;66:2495–502. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Treatment of ciliary block glaucoma (cont’d) If the attack cannot be broken: –in phakic eyes: a vitrectomy is indicated –in pseudophakic or aphakic eyes: an attempt at Nd:YAG laser lysis of the anterior hyaloid and posterior capsule (hyaloidotomy or vitreolysis) may avoid a vitrectomy 1 1. Epstein DL, et al. Am J Ophthalmol 1984;98:137–43. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.

Aqueous misdirection syndrome Recommendation Ciliary block (aqueous misdirection syndrome) must be considered in any patient with postoperative shallow anterior chamber with elevated or normal IOP [Consensus]. Canadian Ophthalmological Society evidence-based clinical practice guidelines for the management of glaucoma in the adult eye. Can J Ophthalmol 2009;44(Suppl 1):S1  S93.