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Basics in Glaucoma
Dr. SharmilaGlaucoma clinic
Glaucoma Glaucoma is an
optic neuropathy with characteristic appearance of the optic disc and specific pattern of visual field defects that is associated frequently but not invariably with raised IOP
POAG
Adult onset IOP > 21mm Hg Open Angles Glaucomatous nerve damage Visual field loss
Risk factors
Age > 65Black racePositive family historyMyopiaThin Corneas
Pathogenesis Increased resistance to aqueous
outflow Ischaemic Theory Mechanical theory
pathogenesisPathogenesis
Symptoms
Usually asymtomatic Rarely decreased visual
fields
Diagnosis of glaucoma
History taking Visual acuity and refractive state Tonometry Gonioscopy Ophthalmoscopy Perimetry
Tonometry Indentation tonometry-schiotz
tonometer Applanation tonometry
variable force-goldmann Tonopen
variable area- maklakov Non contact tonometer
Schiotz indentation Tonometry
Body –footplate-rests on the cornea
Plunger Weights-
5.5gm –permanently fixed.
additional weights-7.5g.10g,15g
Technique of schiotz tonometry
Anaesthetise cornea Patient in supine position Fixes on the target Eyelids gently separated Plunger rests on cornea. Look for movement of the needle Additional weights –if reading is <4 IOP derived from conversion table
Sources of error
Ocular rigidity
High ocular rigidity-high hyperopia,long standing glaucoma,ARMD
Low ocular rigidity –high myopia,osteogenesis imperfecta,miotic therapy,retinal surgeries
Thick cornea-high value
Othertonometers
TONOPEN
GOLDMAN APPLANATION
PERKINS TONOMETER
PNEUMOTONOMETER
Gonioscopy
Goniolens[direct]
Koeppe, layden, barken
Gonioprism
Goldman single mirror, two mirror, three mirror
Zeiss four mirror
Posner four mirror
Normal angle structures
Ciliary body band
Scleral spur Trabecular
meshwork Schwalbe’s line
Ophthalmoscopy Disc
Focal atropy
Concentric atrophy
Deepening of the cup Advanced glaucomatous cupping
Vascular changes
Haemorrhage,baring of vessels, bayonetting
Retinal nerve fiber layer changes
Peripapillary atrophy
Perimetry Kinetic Static Visual fied defects
Paracentral scotoma
Seidel scotoma Arcuate scotoma Double arcuate
scotoma Nasal step
Angle Closure Glaucoma With pupillary
block Without pupillary
block
Diagnosis depends on : Anterior segment
examination Gonioscopy
Risk factors Age Gender Asians, Chinese, Eskimos Family history Hypermetropia
PathogenesisIncreased opposition between iris and lens
enhance the degree of pupillary block
Increased pressure in posterior chamber
Increased peripheral iris bowing
Iris Bombe
High IOP
Types Latent Subacute Acute congestive Post congestive Chronic Absolute
Acute Congestive Glaucoma
SymptomsSevere pain and vomitingUnilateral visual losscoloured haloesHeadache and vomiting
Signs
Shallow AC Corneal edema Semi dilated pupil High IOP Closed angles
Treatment
Immediately 2% Pilocarpine Steroid eye drops Β blockers Analgesics and antiemetics Lie in supine position I.V. Mannitol + Oral T. Diamox
Treatment
MEDICAL
AFTER CORNEA CLEARS
LASER PI
IF NOT POSSIBLE
TRABECULECTOMY
Cont.d… After 1 hr:
Pilocarpine 2% Yag PI
After 11/2 hr: If IOP is still high 50% oral glycerol 20% Mannitol (1-2g/kg) I.V. over
45minutes
Laser Iridotomy
Clear corneas Less than 1800 of
angle by PAS Surgery:
Trabeculectomy
Congenital Glaucoma
1:10,000 births 65% are boys Pathogenesis:Maldevelopment
of the angle of anterior chamber
Classification
Congenital Glaucoma
Infantile Glaucoma
Juvenile Glaucoma
Clinical Features
Corneal edema Buphthalmos Breaks in DM Optic disc cupping
Diagnosis
Increased IOP Increased Corneal diameter > 11mm at 1yr
> 13mm Treatment:
Goniotomy Trabeculotomy trabeculectomy
Lens related Glaucomas
Phacolytic:
Hyper mature cataract
Corneal edema AC reaction –
psuedo hypopyon Open angles
Treatment
Anti glaucoma drugs
Topical antibiotic steroids
surgery
Phacomorphic Galucoma
Intumscent cataractous lens
Shallow anterior chamber
Treatment: Antiglaucoma drugs Laser iridotomy surgery
Neo vascular Glaucoma
Retinal ischaemia
NVI NVA
OPEN ANGLE ANGLE CLOSURE
Causes Ischeamic CRVO Diabetes Mellitus Miscellaneous
Carotid disease Intra ocular tumor Long standing RD
Symptoms & Signs
Decreased visual acuity Congestion of Globe Very high IOP and corneal edema Severe pain Aqueous flare NVI Gonioscopy - NVA
Treatment
Medical – topical Atropine & steroids Retinal ablation / - DIODE CPC Surgery:
Trab with MMC Aqueous drainage shunts
Retrobulbar alcohol injection Enucleation
Treatment Modalities in glaucoma
MedicalLaserSurgery – Trabeculectomy
combined surgery
Anti Glaucoma Drugs Β blockers
Decreases IOP by decreasing aqueous secretion
Contra indications: Congestive cardiac
failure Heart block Bradycardia Bronchial asthma
Side effects
Iotim, Nyolol, Glucomol 0.5% bd Ocular Systemic
allergy Bradycardia, Hypotention
SPK’s Broncho spasm
tear secretion Hallucination, head ache
nausea, dizziness
Alpha 2 Agonists Brimonidine,
apraclonidine Mechanism:
Decreases aqueous secretion
Increases uveo scleral outflow
Side Effects: Allergic
conjunctiviti s Xerostomia Drowsiness and
headache
PROSTAGLANDIN ANALOGUES
Mechanism Decreases IOP by
increasing uveoscleral outflow
Latanoprost F2 α analogue.005%
Travoprost 0.004% Bimatorpost 0.3% Unoprostone 0.15%
BD
Side Effects Conjunctival hypereamia Eye lash growth and hyperpigmentation of
periorbital skin Anterior uveitis Cystoid macular edema
MIOTICS
Pilocarpine 1% 2% 3% 4% QID Parasympathomimetic stimulates
muscarinic receptors in sphincter pupillae & ciliary body
In POAG – increases aqueous outflow In PACG – opens the angles
Side Effects
Miosis Browache Myopic shift Visual field defect
Carbonic Anhydrase Inhibitors
Inhibits aqueous secretion
Topical CAI Dorzolamide (Trusopt) Brinzolamide (Azopt)
Systemic CAI Acetazolamide
250mg BD
Side Effect
Parasthesia Malaise GI upset Renal Stone Blood dyscrasias
Hyper Osmotic Agents
Glycerol 1g / kg in 50% solution Mannitol 1-2g/kg in 20% solution Side Effects:
Cardiac or renal failure Urinary retention Head ache, nausea
Lasers in Glaucoma
Laser Iridotomy: Indications:
PACG Occludable angles SACG with pupillary block Combined mechanism glaucoma
Laser PI
prerequisites Instil 1% Apraclonidine Miotic pupil Laser settings 4-8 mJ Post laser steroid eye
drops Abraham lens
Complications
Bleeding Iritis Corneal burn Glare Diplopia
Surgery Trabeculectomy:
A conventional filtering procedure creates a new channel for aqueous outflow between the anterior chamber and subtenons space without the use of an artificial device
Partial thickness Full thickness
Management of coexistent cataract and glaucoma
Complications
Wound leak Excessive filteration Pupillary block Malignant glaucoma Hypotony Choroidal detachment
Failing bleb
SIGNS• Injection• Vascularisation• Thickening• Localization• High domed Bleb• Normal / High IOP• Low IOP
Initial few weeks critical
Failing filtration
Frame work for Classification
• IOP
• Bleb
Failing filter – High IOP
Low localized Bleb
External - Subconjunctival fibrosis
- Tight scleral flap sutures
Internal - Sclerectomy obstruction
Failing filter – High IOP
High domed bleb – encapsulated bleb or Tenon’s cyst
Failing filter - Low IOP
Low bleb - Bleb leakElevated diffuse bleb - Over
Filtration hypotony
Bleb Failure
Argon laser suturolysis 0.2sec 50µ 500-700mw
Digital massage Topical steroids 5FU injection DF Nd yag laser Needling of tenons cyst
REFRACTORY GLAUCOMA
AQUEOUS DRAINAGE IMPLANTS
Refractory glaucomas
Cyclo destructive procedures
New diagnostic and surgical procedures
Central corneal thickness assessment
OPTICAL COHERENCE TOMOGRAPHY
ULTRASOUND BIOMICROSCOPY