Glaucoma. A lecture from Dr. Lee from Penang Medical College
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Language: en
Added: Aug 18, 2014
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GlaucomaGlaucoma
Dr Lee Ming YuehDr Lee Ming Yueh
Ophthalmology UnitOphthalmology Unit
Penang HospitalPenang Hospital
Glaucoma is a sight threatening disease Glaucoma is a sight threatening disease
which can cause irreversible visual losswhich can cause irreversible visual loss
Baltimore Eye Survey:Baltimore Eye Survey:
- - by the year 2000 by the year 2000 > 66.8 million primary glaucoma > 66.8 million primary glaucoma
> 6.7 million bilateral blindness > 6.7 million bilateral blindness
DefinitionDefinition
A spectrum of disease characterized byA spectrum of disease characterized by
- progressive optic neuropathy- progressive optic neuropathy
- visual field loss- visual field loss
**IOP is an important risk factor. IOP is an important risk factor.
Optic NeuropathyOptic Neuropathy
Progression of
Glaucomatous
Optic Neuropathy
Visual Field Visual Field
LossLoss
Classification:Classification:
Open Angle GlaucomaOpen Angle Glaucoma
Close Angle GlaucomaClose Angle Glaucoma
Congenital GlaucomaCongenital Glaucoma
Trabecular meshwork acts like a sieve…Trabecular meshwork acts like a sieve…
Open Angle GlaucomaOpen Angle Glaucoma
Clinical features:Clinical features:
- ‘silent thief of sight’- ‘silent thief of sight’
- Painless gradual loss of vision; loss of - Painless gradual loss of vision; loss of
visual field follows by impairment of visual visual field follows by impairment of visual
acuity.acuity.
- Intraocular pressure (IOP) rise gradually, - Intraocular pressure (IOP) rise gradually,
usually asymptomatic, till significant visual usually asymptomatic, till significant visual
impairment occurs.impairment occurs.
This is what a glaucoma patient This is what a glaucoma patient
sees….sees….
4.4.Optic nerve head & retinal nerve fibre layer Optic nerve head & retinal nerve fibre layer
assessmentassessment
- vertical cup-disc ratio (CDR) > 0.7- vertical cup-disc ratio (CDR) > 0.7
- Asymmetry of CDR > 0.2- Asymmetry of CDR > 0.2
- thinning & notching of neuroretinal rim, - thinning & notching of neuroretinal rim,
nasalization & bayonetting of retinal vessels.. nasalization & bayonetting of retinal vessels..
(Normal NRR follow ‘ISNT rule’).(Normal NRR follow ‘ISNT rule’).
- Laminar dots sign- Laminar dots sign
- optic disc haemorrhage- optic disc haemorrhage
5. Evaluation of the angle5. Evaluation of the angle
GonioscopyGonioscopy
- open or close ?- open or close ?
- to exclude secondary cause of glaucoma- to exclude secondary cause of glaucoma
Angle StructureAngle Structure
Grading for Gonioscopy findingGrading for Gonioscopy finding
GradeGrade00 II IIII IIIIII IVIV
ShafferShafferclosedclosed1010°° 2020°° 3030°° 4040°°
ModifieModifie
ShafferShaffer
Schwalbe Schwalbe
lineline
Not seenNot seen
SchwalbeSchwalbe
Line Line
visiblevisible
TrabTrab
MeshworkMeshwork
visiblevisible
Scleral Scleral
spurspur
visiblevisible
Ciliary Ciliary
Body Body
visiblevisible
6.6.Visual Field TestVisual Field Test
- Humphrey visual field is gold standard- Humphrey visual field is gold standard
- classical VF defects are - classical VF defects are
: : paracentral scotomaparacentral scotoma
nasal stepnasal step
Arcuate scotomaArcuate scotoma
Temporal wedgeTemporal wedge
Humprey Humprey
Visual FieldVisual Field
Optic disc photographOptic disc photograph showing thinning of the inferior showing thinning of the inferior
neuroretinal rim and increased cupping, consistent with neuroretinal rim and increased cupping, consistent with
glaucoma.glaucoma.
Humphrey visual fieldHumphrey visual field showing showing superior arcuatesuperior arcuate defect defect
and and nasal stepnasal step corresponding to the glaucomatous optic corresponding to the glaucomatous optic
nerve changes on the left.nerve changes on the left.
Indications for surgery:Indications for surgery:
1.1.Failed medical therapyFailed medical therapy
2.2.Disease progression despite maximun Disease progression despite maximun
medical therapymedical therapy
3.3.Anticipated fast progressionAnticipated fast progression
4.4.Combined cataract & trabeculectomy Combined cataract & trabeculectomy
surgerysurgery
Primary Angle Closure GlaucomaPrimary Angle Closure Glaucoma
Risk Factors:Risk Factors:
- - age, average 60 y-oldage, average 60 y-old
- female more common 4:1- female more common 4:1
- race: more common in SEA, Chinese, - race: more common in SEA, Chinese,
Eskimos.Eskimos.
- Family: 1- Family: 1
stst
degree relatives increased risk . degree relatives increased risk .
Anatomical predisposing factorsAnatomical predisposing factors
1.1.Relatively anterior location of iris-lens Relatively anterior location of iris-lens
diaphragm.diaphragm.
2.2.Shallow anterior chamberShallow anterior chamber
3.3.Narrow entrance to the chamber angleNarrow entrance to the chamber angle
Eyes with PACGEyes with PACG have have
-corneal diameter 0.25mm smaller than normal -corneal diameter 0.25mm smaller than normal
eyeseyes
- shallower anterior chamber (1.8mm)- shallower anterior chamber (1.8mm)
- hypermetropic eyes- hypermetropic eyes
Secondary- Pupillary Block GlaucomaSecondary- Pupillary Block Glaucoma
Inflammatory with occlusio or seclusio Inflammatory with occlusio or seclusio
pupillaepupillae
PhacomorphicPhacomorphic
Vitreous blocVitreous bloc
Silicone oilSilicone oil
Clinical Features:Clinical Features:
Rapidly progressive blurring of visionRapidly progressive blurring of vision
Periocular pain and congestionPeriocular pain and congestion
Nausea and vomiting in severe cases.Nausea and vomiting in severe cases.
Slit-lamp exam:Slit-lamp exam:
- ciliary flush/circumcornea injection- ciliary flush/circumcornea injection
- high IOP (50 -100mmHg)- high IOP (50 -100mmHg)
- cornea oedema w epithelial cysts- cornea oedema w epithelial cysts
- shallow anterior chamber.- shallow anterior chamber.
Acute Management ofAcute Management of
Angle Closure GlaucomaAngle Closure Glaucoma
To lower the IOP fastTo lower the IOP fast
- IV Diamox 500mg /IV Mannitol- IV Diamox 500mg /IV Mannitol
- Topical antiglaucoma- Topical antiglaucoma> pilocarpine 2%> pilocarpine 2%
> timolol 0.5%> timolol 0.5%
> prostaglandin analog > prostaglandin analog
Definitive treatmentDefinitive treatment
- laser peripheral iridectomy/ surgical - laser peripheral iridectomy/ surgical
Further managementFurther management
To To control IOPcontrol IOP to to stop disease progressionstop disease progression
- IOP, optic nerve changes, visual field- IOP, optic nerve changes, visual field
MedicalMedical
- - ββ blocker, prostaglandin analog carbonic blocker, prostaglandin analog carbonic
anhydrace inhibitor, anhydrace inhibitor, αα agonist agonist
SurgicalSurgical
- Trabeculectomy- Trabeculectomy
- Shunt/valve surgery- Shunt/valve surgery