Primary Angle Closure Glaucoma

Dr AR Rajalakshmi

• PACG definition• Stages• Clinical presentation• Management• Red eye D/D

Angle closure glaucomasPrimary angle- closure glaucoma (PACG) with pupillary block

Movement of aqueous humor from posterior chamber to anterior chamber restricted at the point of irido lenticular contact; resulting in anterior iris bowing and contact with trabecular meshwork

Acute angle closure glaucoma

Occurs when I O P rises rapidly as a result of relatively sudden blockage of the trabecular meshwork

Subacute angle closure( intermittent angle closure ) glaucoma

Repeated, brief episodes of angle closure with mild symptoms and elevated I O P, often a prelude to acute angle closure

Chronic angle closure glaucoma

I O P elevation caused by variable portions of anterior chamber angle being permanently closed by peripheral anterior synechiae

Secondary angle closure glaucomawith pupillaryblock

Pupillary block occurs as a result of a mechanism other than the anatomical configuration of the anterior segment (eg, an intumescent lens or a secluded pupil ) .

Secondary angle closure glaucomawithout pupillaryblock

Posterior pushing mechanism: lens-iris interface pushed forward (eg, posterior segment tumor, scleral buckling procedure, uveal effusion )

Anterior pulling mechanism : anterior segment process pulling iris forward to form peripheral anterior synechiae ( e g , iridocorneal endothelial syndrome, neovascular glaucoma, inflammation)

Plateau iris syndrome

An anatomical variation in the iris root in which narrowing of the angle occurs independent of pupillary block

Risk Factors• Age. 60 years at presentation. • Gender. Females > males. • Race Far Eastern and Indian Asians. • Family history. Genetic factors are important ; increased

prevalence of angle closure in family members. • Refraction. Eyes with ‘pure’ pupillary block are typically

hypermetropic, • hypermetropia of one dioptre or more are primary

angle closure suspects, so routine gonioscopy should be considered in all hypermetropes.

• Axial length. Short eyes tend to have a shallow AC.

Precipitating factors include: • watching television in a darkened room, • pharmacological mydriasis • adoption of a semi-prone position (e.g. reading), • acute emotional stress and • systemic medication:

– parasympathetic antagonists or sympathetic agonists including inhalers, motion sickness patches and cold/flu remedies (mydriatic effect),

– topiramate and other sulfa derivatives (ciliary body effusion).

Symptoms

Intermittent mild symptoms • blurring (‘smoke-filled room’)• haloes (‘rainbow around lights’) due to corneal epithelial

oedema, Acute symptoms• markedly decreased vision,• redness and • ocular/periocular pain and headache; • abdominal pain and other gastrointestinal symptoms may

occur.

Chronic presentation • intraocular pressure is chronically raised • synechial closure over at least 180°. • Changes in the optic nerve head and visual field may

or may not be present

• repeated subacute attacks of PACG• acute PACG persisting for more than a few hours• asymptomatic or 'creeping' angle closure

Clinical Presentation

Acute primary angle closure (APAC) • VA is usually 6/60 to HM. • IOP is usually very high (> 50 mmHg). • Conjunctival hyperaemia

with violaceous circumcorneal injection.

• Corneal epithelial oedema

• The AC is shallow, and aqueous flare present.

• An unreactive mid-dilated vertically oval pupil is classic

Red, teary eyeCorneal edemaClosed angleShallow ACMid-dilated,Fixed pupil“Glaucomflecken”Iris atrophyAC inflammation

• The fellow eye typically shows an occludable angle; if not present, secondary causes should be considered

Treatment

PACS • Laser iridotomy • If significant ITC persists after iridotomy,

options include • observation (most),• laser iridoplasty, and • If symptomatic cataract is present, lens

extraction usually definitively opens the angle

APAC Initial treatment

• Supine position to encourage the lens to shift posteriorly under the influence of gravity.

• Acetazolamide 500 mg is given intravenously if IOP >50 mmHg, – (Contraindications include sulfonamide allergy and

angle closure secondary to topiramate/other sulfa derivatives).

• IV mannitol 20% 1 gm/kg body weight• Timolol 0.5%, and prednisolone 1% or dexamethasone

0.1% to the affected eye, leaving 5 minutes between each.

• Pilocarpine 2–4% one drop to the affected eye, repeated after half an hour;

• one drop of 1% into the fellow eye. • omit pilocarpine until a significant IOP fall, as when

IOP is high ischaemia may compromise its action, • Analgesia and an antiemetic may be required.

• Assess the other eye

Laser iridotomyLaser iridotomy: creates a small hole in the iris toimprove flow of aqueous humor into drainage angle.

Narrow Angle GlaucomaTreatment: Peripheral Iridotomy

Trabeculectomy

Combined mechanism glaucoma

• A patient who has been successfully treated for a narrow angle but who continues to demonstrate reduced outflow facility and elevated IOP in the absence of peripheral anterior synechiae (PAS).

• the intrinsic resistance of the trabecular meshwork to aqueous outflow in open - angle glaucoma

• A patient who has open-angle glaucoma but develops secondary angle closure from other causes

• the direct anatomical obstruction of the filtering meshwork by synechiae in angle closure glaucoma

Red eye

Differential diagnosis

• Conjunctivitis• Acute uveitis• Acute attack of angle closure glaucoma• Corneal ulcer• Scleritis• Episcleritis• Trauma• Subconjunctival hemorrhage

Features Acute conjunctivitis Acute anterior uveitis

Acute congestive glaucoma

Onset Acute Rapid, over few days

Sudden

Vision Normal Slightly impaired Grossly impaired

Pain Mild Moderate, along 1st divn of Vth nerve

Severe

Discharge Mucopurulent Watery Watery

Coloured halos Occationally present

Absent Present

Injection Superficial conjunctival

Deep ciliary Deep ciliary

Anterior chamber depth

Normal May be deep Shallow

Iris Normal Muddy Edematous

Features Acute conjunctivitis Acute anterior uveitis

Acute congestive glaucoma

Pupil Normal size, brisk reaction

Small, irregular, sluggish reaction

Vertically oval,non reacting

IOP Normal Normal, raised, low Markedly raised

Ciliary tenderness Absent Marked Marked

Cornea Clear KPs Edema, haze

Aqueous Clear Flare & cells Flare

Lens Transparent Transparent Opacities occationally

Vitreous Clear Hazy ant vitr Clear

Constitutional symptoms

Absent Mild Prostration, vomitting

• Stages of PACG• Clinical presentation• Management• Red eye D/D