Department of
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OphthalmologyObjectives
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? At the end of this class the students shal be able
to :
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? Define primary angle closure glaucoma.? Understand the pathophysiology and the risk
factors.
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? Be able to classify primary angle closure
glaucoma.
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? Understand the fundamentals of managingprimary angle closure glaucoma
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DEFINITION? Primary angle closure glaucoma is a type of
primary glaucoma(with no obvious systemic or
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ocular cause) characterized by
occludable/closed angles leading to
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obstruction of aqueous outflow resulting inrise of intra ocular pressure, optic nerve
damage and visual field defects.
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ANGLE OF ANTERIOR CHAMBER
? STRUCTURES
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? Schwalbe's line? Trabecular meshwork
? Scleral spur
? Ciliary body band
? Root of iris
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DRAINAGE OF AQUEOUS HUMOR
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PRIMARY ANGLE CLOSURE
GLAUCOMA
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EPIDEMIOLOGY? PACG is the major cause of glaucoma blindness
worldwide.
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? Age :- Average age at presentation 50-60 yrs
? Gender :- F > M, 4 : 1
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? Race :-seen commonly in South-East Asianpopulation, Chinese and Eskimos
? Heredity :- mostly sporadic but may be inherited
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AD/AR
? first degree relatives are at increased risk.
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? Refractive error :- more common inhypermetropes
Ocular risk factors
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1. Shallow anterior chamber bothcentrally and peripherally.
2. Decreased anterior chamber volume.
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3. Short axial length of the globe.
4. Small corneal diameter.
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Ocular risk factors5.Decreased posterior corneal radius of
curvature
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6.Anterior position of the lens with respect to
the ciliary body.
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7.Increased curvature of the anterior surface &thickness of lens
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PATHOGENESIS? It is incompletely understood.
? a. Iris?pupil obstruction (e.g., `pupil ary block')
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? b. Ciliary body anomalies (e.g., `plateau iris syndrome')? c. Lens?pupil block (e.g., `phacomorphic block' (swollen
lens or microspherophakia))
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? Relative Pupillary block? Normal y the pressure in the post. chamber exceeds that in the ant.
chamber due to physiological degree of resistance at the pupil ,since the
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iris rests posteriorly on the anterior lens capsule.Anterior Iris Bowing
Simultaneous dilatation of the pupil renders the peripheral
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iris more flaccid. The pupil block causes the pressure in the
Posterior Chamber to increase & peripheral iris bows
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anteriorlyIridocorneal contact
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Eventually the iris touches the posterior corneal surface,obstructing the angle and the IOP rises.
(Figures and photographs- Courtesy : Kanski's Clinical Ophthalmology)
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Precipitating factors
1. Factors that produce mydriasis
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? Dim illumination? Emotional stress(due to increased sympathetic tone)
? Drugs
? Mydriatic agents :
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? cyclopentolate, tropicamide, atropine, homatropine.
? Antipsychotic agents
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? Phenothiazines: e.g., perphenazine ,fluphenazine? Anticonvulsants e.g., Topiramate
? Antidepressants
? Tricyclic agents: amitriptylene ,imipramine
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? Non-tricyclic agents: fluoxetine? Antiparkinsonian agents : Trihexyphenidryl
? Antispasmolytics : Propantheline ,Dicyclomine
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? Sympathomimetic agents : Adrenaline (epinephrine),
ephedrine, phenylephrine.
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CLASSIFICATION
A. Primary angle-closure disease
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? Irido-trabecular contact is the final common pathway ofangle closure disease, obstructing aqueous outflow
1. New classification
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Primary angle closure suspect/PACSPrimary angle closure/PAC
Primary angle-closure glaucoma/PACG
2. Old classification
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Angle closure suspectIntermittent (sub acute) angle closure
Acute angle closure
Chronic angle closure
Absolute angle closure
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New classification of PACGqPrimary angle closure suspect/PACS
Has occludable/narrow angles
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qPrimary angle closure/PACHas occludable/narrow angles +
High IOP/Peripheral anterior synechiae/
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Excessive trabecular meshwork
pigmentation
qPrimary angle-closure glaucoma/PACG
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PAC+ Optic disc changes+ Visual field
defects
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Gonioscopic grading of Angleclosure
? Several grading systems :- Shaffer's, Spaeth's,
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Scheie's.
? Shaffer's grading
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Grade Angle width configurationChances of
Structures visible
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closure
IV
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35?-45?Wide open
Nil
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SL,TM,SS,CBB
I I
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20?-35?Open angle
Nil
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SL,TM,SS
I
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20?Moderately open Possible
SL,TM
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I
10?
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Very narrowHighly likely
SL only
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0
0?
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ClosedClosed
None
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---------
Grade
IV
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II
II
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I0
Van Herrick's grading
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Tests for Angle closure
? Eclipse test : uses flash light to make a rough
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assessment of angle depth? Provocative tests for PAC suspects
?Prone- darkroom test: An increase in IOP of more
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than 8mm Hg after one hour suggests PAC?Mydriatic provocative test: Not preferred now
qFincham's Test: Also known as stenopaeic-slit test.
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Glaucomatous halos remain intact , whereas
halos due to cataract are broken up into segments
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PRIMARY ANGLE CLOSURE GLAUCOMA SUSPECT
? Also known as Latent PACG
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? Essentially, the term impliesan anatomically predisposed
eye.
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? Symptoms :- absent
? Signs :
? Axial AC depth is < normal
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& iris lens diaphragm is
convex
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? Close proximity of the iristo the cornea
? Gonioscopy :- occludable
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angle(grade 1 or 0)
without indentation in at
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least 3 quadrants.?Clinical course without
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treatment may be:IOP may remain normal
Acute or sub acute angle
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closure may ensue
Chronic angle closure may
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develop, without acute orsub acute stages.
? Treatment
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? Without treatment , risk of an acute pressure rise during the next5 years is about 50 %.
? The need to treat is based on following criteria:-
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? If one eye has had acute or subacute angle closure, then
fellow eye should undergo prophylactic peripheral laser
iridotomy (Laser PI)
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? If both eyes have occludable angles, laser PI may be done
INTERMITTENT(SUBACUTE)PRIMARY ANGLE CLOSURE
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GLAUCOMA
? A form of pupillary block glaucoma, which may not have
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any recognizable symptoms.? Occurs in a predisposed eye with an occludable angle in
association with intermittent pupillary block.
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? Precipitating factors :- physiological mydriasis , or
physiological shallowing of AC when patient assumes a
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prone or semi prone position ;emotional stress.? Symptoms
? Characteristic h/o transient blurring of vision with haloes
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around lights
? Ocular discomfort or frontal headache
? Attacks are recurrent and are usually broken after 1-2 hrs by
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physiological miosis.
? Signs
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? During an attack , eye is usually white? In between attacks, eye looks normal although the angle is
narrow.
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? Clinical course? Without treatment is variable
? Some eyes develop an acute attack
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? Others chronic angle closure? Treatment:- Prophylactic laser PeripheraI Iridotomy(PI)
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ACUTE PRIMARY ANGLE CLOSURE GLAUCOMA? Sight threatening emergency
? Painful loss of vision due to sudden and total
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closure of the angle.? VA usually 6/60-Hand Movements.
? IOP is usually very high (40?70 mmHg).
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Findings during an acute attack of angle-closure glaucoma? Two of the following symptom sets:
? Periorbital or ocular pain
? Diminished vision
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? Specific history of rainbow haloes with blurred vision? IOP > 21 mmHg plus three of the following
findings:
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? Ciliary flush (perilimbal conjunctival hyperemia)
? Corneal edema (epithelial,stromal)
? Shallow anterior chamber
Findings during an acute attack of angle-closure glaucoma
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? Anterior chamber cell and flare
? Mid-dilated ,vertically oval and sluggishly reactive
pupil
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? Closed angle on gonioscopy
? Hyperemic and swollen optic disc(due to
decreased axoplasmic outflow)
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? Constricted visual fields
? MANAGEMENT
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? Patient comfort ,lowering of the IOP and to break acuteattack-- main priorities.
? A. Immediate medical treatment
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1. Patient should lie supine to allow the lens to shift
posteriorly.
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2. Acetazolamide 500 mg orally(if there is no vomiting).or I.V Mannitol 20% 1-2 g/kg over 1 hour (rule out
contraindications)
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3.Topical
Prednisolone or dexamethasone q.i.d (if AC reaction)
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Timolol (if there is no contraindication).4. Analgesia and emetics as required.
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? B. Subsequent medical treatmentPilocarpine 2% q.i.d. to the affected eye and 1% q.i.d. to the
fellow eye.
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Topical steroids (prednisolone 1% or dexamethasone 0.1%)
q.i.d. if the eye is acutely inflamed.
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Timolol 0.5% b.d.,and oral acetazolamide 250 mg q.i.d. may be required.
? If the above measures fail:
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? Laser iridotomy or iridoplasty after clearing corneal oedema with
glycerol.
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? Surgical options in resistant cases include lens extraction,goniosynechiolysis, trabeculectomy and cycloablation.
? Findings suggestive of previous episodes of acute
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angle closure glaucoma
? Descemets Membrane folds
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? Fine pigment granules on corneal endothelium? Peripheral anterior synechiae
? Posterior synechiae
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? Glaucomflecken
? Sectoral/generalized iris atrophy
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? Fixed and semi dilated pupil? Optic nerve cupping &/or pallor
? Gonioscopy shows narrow angle
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or PAS
? Visual field loss
Chronic angle closure glaucoma
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? Visual Acuity is normal unless damage is
advanced.
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? Anterior chamber is shal ower in pupil aryblock than non-pupil ary block.
? Optic nerve signs depend on severity of
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damage.
? IOP elevation may be only intermittent.
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? Gonioscopic abnormalities-PeripheralAnterior Synechiae, narrow angle,
pigmentation of Schwalbe's line.
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Treatment of chronic angle closure
? Medical treatment is similar to that of POAG
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? Prostaglandin/ProstamidesLatanoprost, Bimatoprost, Travoprost
? Beta blockers
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Timolol maleate, Betaxolol
? Carbonic anhydrase inhibitors
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Dorzolamide, Brinzolamide? Sympathomimetics
Brimonidine, Apraclonidine
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? Parasmpathomimetics
Pilocarpine
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? Oral carbonic anhydrase inhibitorsAcetazolamide, Methazolamide
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Treatment of chronic angle closure? Laser Peripheral Iridotomy (PI) in affected eye
along with Prophylactic PI in fellow eye
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Laser Peripheral Iridotomy
? Complications of laser therapy
1. Bleeding
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2. IOP elevation3. Iritis
4. Corneal burns
5. Lens opacities
6. Glare and diplopia
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? Surgical treatmentTrabeculectomy (filtering surgery) is the
surgical procedure of choice
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? Success:- 87- 100 % with multiple operations
? Complications:-
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? Flat AC, hypotony? Bleb related infections
? Cyclodialysis
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? PATIENTS REQUIRE REGULAR AND LIFE LONG
FOLLOW UP
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Absolute glaucoma? Is the final/last stage of PACG
? Clinical features:
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? Painful blind eye?Perilimbal reddish blue zone, due to dilated
anterior ciliary veins
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?Cornea gradually becomes hazy, insensitivewith bullous keratopathy and filamentary
keratitis
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?Anterior chamber is very shallow/flat
Clinical features of absolute glaucoma
? Iris is usually atrophic
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?Pupil is fixed and dilated?Glaucomatous optic atrophy of the optic disc
?High IOP
Management of absolute glaucoma
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? Cycloablation/destruction of the secretory
ciliary epithelium
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q Cyclophotocoagulationq Cyclocryotherapy
q Cyclodiathermy
? Rarely
? Retrobulbar alcohol injection
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? Enucleation of eyeballComplications
? Corneal ulceration
? Staphyloma formation (Ciliary/Equatorial)
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? Atrophic bulbi (Shrunken eye)Conclusion
? Primary angle closure glaucoma is a
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potentially sight threatening condition,
characterized by occludable anterior chamber
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angles.? Obstruction of aqueous outflow results in rise
of intra ocular pressure, optic nerve damage
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and visual field defects.
? Management may include medical, laser
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and/or surgical modalities.