2. Introduction
Definition:
Primary open-angle glaucoma (POAG) is a commonly disease of adult
onset.
It is characterized by:
• IOP >21 mmHg at some stage.
• Glaucomatous optic nerve damage.
• An open anterior chamber angle.
3. Introduction Cont..
• Characteristic visual field loss as damage progresses.
• Absence of signs of secondary glaucoma or a non-
glaucomatous cause for the optic neuropathy.
4. Risk factors
• The higher the IOP, the greater the likelihood of
glaucoma.
• POAG is more common in older individuals.
• More common in black individuals.
• Family history of POAG
• Diabetes mellitus
• Myopia
5. Risk factors Cont..
• Contraceptive pill.
• Vascular disease.
• Translaminar pressure gradient.
• Large discs may be more vulnerable to damage
• Ocular perfusion pressure
6. Pathogenesis of glaucomatous
optic neuropathy
• Direct mechanical damage
damage to retinal nerve fibres at the
optic nerve head, perhaps as they pass through the lamina
Cribrosa.
• Ischaemic damage
due to compression of blood
vessels supplying the optic nerve head.
7. Changes in glaucoma
(a) the optic nerve head
(b) the peripapillary area and
(c) the retinal nerve fibre layer
9. Non-specific signs of glaucomatous damage
• Disc haemorrhages
• Baring of circumlinear blood vessels
• Bayoneting
• Collaterals between two veins
• Loss of nasal NRR
• The laminar dot sign
• ‘Sharpened edge’ or ‘sharpened rim’
16. Treatment goals
1. Target pressure: IOP level is identified below which further damage
is considered unlikely.
2. Proportional reduction in IOP by a certain percentage – often 30%
and then monitor, aiming for a further reduction if progression
occurs.
3.Response to progression.
17. Treatment goals
Target IOP depend upon
• IOP at which damage has occurred.
• Severity of visual field damage.
• Rate of progression of damage.
• Age and Life expectancy.
18. Management
The primary aim of treatment is to prevent functional
impairment of vision within the patient’s lifetime by slowing
the rate of ganglion cell loss.
Currently the only proven method of achieving this is the
lowering of IOP.
22. Medical therapy
• 1. Commencing medical therapy
Initial treatment is usually with one drug in its lowest
concentration with the desired therapeutic effect & fewest
potential side effects .
2.Review:
• Response to the drug is assessed against the target IOP.
• If the response is satisfactory subsequent assessment is
generally done for a further 3-4 months.
23. Medical therapy(contd)
• If there has been little or no response the initial drug is
withdrawn and another substituted.
• If there has been an apparently incomplete response another
drug may be added or a fixed combination substituted.
• When two separate drugs are used the patient should be
instructed to wait five minutes before instilling the second
drug to prevent washout of the first.
24. Medical therapy(contd)
3. If IOP control is good and glaucomatous damage mild or
moderate with no substantial threat to central vision, annual
perimetry is generally sufficient.
4. Gonioscopy should be performed annually because anterior
chamber angle tends to narrow with age.
5. Optic disc examination
25. Surgical treatment
• Trabeculectomy is the surgical procedure most commonly
performed for POAG.
• Phacoemulsification alone is frequently associated with a
significant fall in IOP, but is generally only offered to patients in
whom significant lens opacity is present.
26. Surgical treatment cont..
Indications Of Surgery
1. Progressive deterioration despite maximum medical therapy
2. Avoidance of excessive polypharmacy and drug intolerance
3. Primary therapy- advanced disease requiring very low target
pressure
4. Patient preference
27. Laser Treatment
Indication of Laser trabeculoplasty
• Intolerance to topical medication
• Failure of medical therapy
• Avoidance of polypharmacy
• Avoidance of Surgery
• Primary therapy
28. Patient counselling
Full informations regarding the disease
Informations regarding the medications.
Mode of administering the drug.
Informations regarding expected side effects
29. Prognosis
• The great majority of patients diagnosed with POAG will not be
blind in their lifetime but the incidence of blindness varies
considerably.
• Bad prognostic factors are:
Advance damage at diagnosis
Non-compliance with treatment
Ethnic origin-black patients.
30. Take home message
Glaucoma is the second leading cause of blindness .
Glaucoma is a treatable disease, if detected earlier & treated
properly we can stop the progression of glaucomatous
damage.
By making good awareness about glaucoma
we can minimize family, socio-economic & as a whole
national burden.
