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EPIDEMIOLOGY
In the world, glaucoma is the third
leading cause of blindness-
an estimated 13.5 million people
may have glaucoma and
5.2 million of those may be blind.
GLAUCOMA DEFINITION
Progressive optic neuropathy leading to
irreversible damage of optic nerve fibres,
thus to excavation of the optic disc and to
specific visual field impairment.
SUMMARY OF STEPS IN EYE EXAM
Visual Acuity
Pupillary examination
Visual fields by confrontation
Extraocular movements
Inspection of
– lid and surrounding tissue
– conjunctiva and sclera
– cornea and iris
Anterior chamber depth
Lens clarity
Tonometry
Fundus examination
– Disc
– Macula
– Vessels
GLAUCOMA
Physiology of aqueous circulation
Normal intraocular pressure = 10-22 mmHg
Balance of secretion and outflow
Higher IOP = decrease in ocular perfusion =
nerve damage
Visual acuity, visual field impairment
EXAMINATIONS IN GLAUCOMA
Slitlamp biomicroscopy (chamber depth, cells in
AC, iris atrophy, pupil shape, lens: glaucom flecken)
IOP control: 1: digital 2: impression (Schiötz)
3: applanation (Goldmann) 4. air push 5. ORA
6. CorVis etc.
Visual field testing (central 30° glaucoma program
perimetry)
Gonioscopy: angle anatomy
Fundus, optic nerve head screening (cup/disc ratio)
INTRAOCULAR PRESSURE
MEASUREMENT Range: 10 – 22 mmHg
NORMAL OPTIC NERVE HEAD „I.S.N.T” rule
Inferior > Superior > Nasal > Temporal
Neuroretinal rim
Excavation Elschnig ring
Superotemporal
Temporal Nasal
Inferotemporal
DIAGNOSTIC TOOLS
Mechanism Parameters
CSLO (HRT)
Surface topograph
Rim area
ONH shape
SLP (GDx)
RNFL thickness
RNFL thickness deviation map
Nerve fibre indicator (machine learning
classifier)
OCT
RNFL thickness
Rim area
Macular thickness
CSLO: confocal scanning laser ophthalmoscopy; HRT: Heidelberg Retinal Tomograph;
ONH: optic nerve head;
SLP: scanning laser polarimetry; RNFL: retinal nerve fiber layer
OCT: optical coherence tomography
IMAGING TECHNIQUES I.
Confocalis scanning laser
ophthalmoscope (CSLO)
– Heidelberg Retina Tomograph (HRT)
Scanning laser polarimetry (SLP)
– GDx VCC
Optical coherence tomograph (OCT)
CONFOCAL SCANNING
LASER OPHTHALMOSCOPE Heidelberg Retina Tomography* (HRT II / HRT3)
*Heidelberg Engineering GmbH, Germany. http://opt.pacificu.edu/ce/catalog/9451-GL/HRT-Kirstein.html. Accessed 10 September 2007.
TOPOGRAPHY CROSS-SECTION OF PAPILLA
STEREOMETRIC PARAMETERS
T N
EXCAVATION
REFERENCE
LEVEL
50 m
RIM
Stereometric results ONH 0°–360°
Disc area 1.978 mm2
Cup area 0.946 mm2
Cup/disc area ratio 0.478
Rim area 1.032 mm2
Height variation contour 0.193 mm
Cup volume 0.182 cmm
Rim volume 0.135 cmm
Mean cup depth 0.224 mm
Maximum cup depth 0.504 mm
Cup shape measure - 0.074
Mean RNFL thickness 0.117 mm
RNFL cross section area 0.586 mm2
IMAGING TECHNIQUES II.
Confocal scanning laser ophthalmoscope
(CSLO)
– Heidelberg Retina Tomograph (HRT)
Scanning laser polarimetry (SLP)
– GDx VCC
Optical coherence tomograph (OCT)
SCANNING LASER
POLARIMETRY (SLP)
GDx VCC (Carl Zeiss Meditec, Inc.)
Carl Zeiss. Structure and Function: An Integrated Approach for the Detection and Follow-up of Glaucoma. Module 3a--GDx.
http://www.zeiss.de/C125679E00525939/EmbedTitelIntern/GDxTechnologyDescription/$File/GDx_Technology_Description.pdf.
GDX VCC EXAMINATION CHART
TSNIT parameters
OD actual
value
OS actual
value
TSNIT average 39.99 43.10
Superior average 36.76 46.02
Inferior average 53.22 55.29
TSNIT std. dev 19.09 22.63
Inter-eye symmetry 0.93
Nerve fibre indicator 66 49
P>5% P<5% P<2% P<1% P<.5%
IMAGING TECHNIQUES III.
Confocalis scanning laser
ophthalmoscope (CSLO)
– Heidelberg Retina Tomograph (HRT)
Scanning laser polarimetry (SLP)
– GDx VCC
Optical coherence tomograph (OCT)
OCT „RNFL thickness”
OD (N=3) OS (N=0) OD-OS
Imax/Smax 0.69 0.00 0.69
Smax/Imax 1.46 0.00 1.46
Smax/Tavg 2.63 0.00 2.63
Imax/Tavg 1.81 0.00 1.81
Smax/Navg 2.15 0.00 2.15
Max-Min 95.00 0.00 95.00
Smax 128.00 0.00 128.00
Imax 88.00 0.00 88.00
Savg 96.00 0.00 96.00
Iavg 57.00 0.00 57.00
Avg. Thick 65.26 0.00 65.26
Carl Zeiss Meditec. http://www.zeiss.de/88256DE3007B916B/0/C26634D0CFF04511882571B1005DECFD/
$file/stratusoct_en.pdf.
PERIMETRY
Very important in the diagnosis and
management of glaucoma
Method: Static – kinetic
Goldmann – automated (suggested)
Humphrey automated perimeter
(Carl Zeiss Meditec) Octopus 900 automated perimeter
(Haag-Streit AG)
European Glaucoma Society. Terminology and Guidelines for Glaucoma. 3rd Edition.
PERIMETRIC ANALYSES
Numeric maps:
Total deviation
Variable maps:
Total deviation
Grey scale
Pattern deviation
Pattern deviation
Numeric threshold map
CLASSIFICATION OF GLAUCOMA Primary: etiology is unclear
1. Primary congenital glaucoma (goniodysgenesis, aniridia, megalocornea)
2. Primary open angle glaucoma=POAG (no pain, very slow visual impairment)
3. Primary angle closure glaucoma: PCAG
a.: acut attack (pain, redness, fast visual loss)
b.: chronic (less pain, not so fast visual loss)
4. Normal tension glaucoma
5. Ocular hypertension
Secondary: neovascular, traumatic, pseudoexfoliative, lens-related, etc.
PRIMARY CONGENITAL GLAUCOMA
Incidence: 1:10.000 live births
Etiology: trabeculodysgenesis, i.e. maldevelopment of the angle: flat/concave iris insertion
1. True primary congenital glaucoma: intrauterin IOP
2. Infantile glaucoma (onset before the 3rd birthday)
3. Juvenile glaucoma: 3-35 years
True PCG and
infantile glaucoma:
Buphthalmos
(large and cloudy
cornea, Haab-stria,
elevated IOP)
PRIMARY OPEN ANGLE
GLAUCOMA - Above 35 years
- Open angle on gonioscopic examination
- Glaucomatous damage of the optic nerve and/or visual
field
- Elevated IOP
Th.: IOP lowering eye drops, eye drop combinations,
laser treatment, filtration surgery
Follow up: IOP measurement every 3 months, visual
field testing every 6 months
PRIMARY ANGLE CLOSURE
GLAUCOMA
- Acute ACG
- Intermittent ACG
- Chronic ACG (creeping mehanism after acute ACG, periferal anterior synechiae)
plateau iris configuration: anterior iris insertion
plateau iris syndrome: anterior iris insertion + IOP
RISK FACTORS
Old age Myopia
African-American race Blood Hypertension
Family History Diabetes Mellitus
High IOP Smoking
PHARMACOLOGICAL
TREATMENT
BETA BLOCKERS (betaxolol, timolol, carteolol, levobunalol)
CARBONIC ANHYDRAZE INHIBITORS (acetazolamide*, dorzolamide, brinzolamide, methazolamide)
SYMPATHOMIMETICS (apraclonidine, brimonidine, epinephrine, dipivefrin)
CHOLINERGICS (pilocarpine, carbachol)
PROSTAGLANDIN DERIVATIVES = PGF2α analogues (latanoprost, travoprost, bimatoprost)
LASER TREATMENT
Trabeculoplasty (ALT, SLT)
Laser Peripheral Iridotomy (LPI)
Cyclophotocoagulation/cyclodestruction
SURGICAL TREATMENT
Goniotomy
congenital
Trabeculotomy
for congenital glaucoma's
Trabeculectomy
for adult glaucoma's
Implants
for difficult non responsive