The facts are that people loss vision with glaucoma because of problems with optic neuropathy, but t

1

• The facts are that people loss vision with
  glaucoma because of problems with optic
  neuropathy, but they develop the optic neuropathy
  because of the elevated IOP. For clinicians, the
  most important fact is that by controlling the
  pressure, we currently have the best way of
  preventing the blindness.
• Ref http//www.ophthalmologytimes.com

2
RELATIONSHIP BETWEEN INTRAOCULAR PRESSURE AND
VISUAL FIELD LOSS

• The Australian Blue Mountain study found the odds
  ratio of developing glaucoma was 4.7 times higher
  in patients with a screening IOP of greater than
  21 mmHg than in patients with lower IOP.
• Ref Surveys of Ophthalmology 2003 48 (Suppl
  1) 53-57

3
RELATIONSHIP BETWEEN INTRAOCULAR PRESSURE AND
VISUAL FIELD LOSS

• According to the AGIS study, reducing IOP in
• glaucoma patients limits disease progression
• and slows visual field loss.
• 
  Ref Surveys of Ophthalmology
  2003 48 (suppl 1) 53-57

4
RELATIONSHIP BETWEEN INTRAOCULAR PRESSURE AND
VISUAL FIELD LOSS

• According to the EMGT study, for every 1
• mm drop in IOP, a 10 reduction in risk of
• glaucomatous progression was observed.
• Ref Surveys of ophthalmology 2003 48 (suppl
  1) 53-57

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• Thus lowering IOP to an appropriate level reduces
  the risk of further visual loss
• It is now agreed that using a number (e.g. lt 21
  mmHg) is obsolete, because it does not take into
  account the individual variability for each
  patient
• Ref1. Surveys of Ophthalmology 2003 48
  (suppl 1) 53-57
• 2. Bull. Soc. Belge
  Ophthalmol 1999 274 61-65

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THE TARGET PRESSURE CONCEPT

• A target pressure should be set as a goal of
  long term therapy it should be chosen on an
  individual basis, weighing potential benefits and
  risks of treatment for each patient.
• Ref Surveys of Ophthalmology 2003 48 (suppl
  1) 53-57

7
TARGET IOP

• The goal of the clinician while treating patients
  with glaucoma should be to lower the
  intraocular pressure to a level that is
  safe for that particular eye.
• Ref Surveys of Ophthalmology 2003 48 (suppl
  1) 53-57

8
TARGET IOP DEFINITION

• Target IOP may be defined as a pressure, rather a
  range of intraocular pressure levels within which
  the progression of glaucoma and visual field loss
  will be delayed or halted
• Ref Surveys of Ophthalmology 2003 48 (suppl 1)
  53-57

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SETTING TARGET IOP FACTORS TO BE CONSIDERED

• IOP level at which optic nerve damage occurred
• Extent and rate of progression of glaucomatous
  damage, if known
• Presence of other risk factors
• Patients age
• Expected life span
• Medical history
• Ref Surveys of Ophthalmology 2003 48 (suppl 1)
  53-57

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HOW TO CALCULATE TARGET IOP

• Target IOP Maximum IOP Maximum IOP - Z
• Z is an optic nerve damage severity factor.
• Z Optic Nerve damage
• 0 ? Normal disc and Normal visual field
• 1 ? Abnormal Disc and Normal visual field
• ? Visual field loss not
  threatening
• fixation
• 3 ? Visual field loss threatening or
  involving fixation
• Ref Bull Soc. Belge Ophthalmol 274, 61-65, 1999

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HOW TO CALCULATE TARGET IOP

• For e.g. An eye with a maximum IOP of 30 mmHg,
  optic nerve damage and visual field loss not
  threatening fixation would have a target set at
  19 mmHg (30-30-2)
• Ref Bull. Soc. Belge Ophthalmol 274, 61-65, 1999

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AAO GUIDELINES TARGET IOP

• Glaucoma patients with mild damage (optic disc
  cupping but no visual field loss)
• ? Reduction of 20-30 from baseline
• Glaucoma patients with advance damage
• ? Reduction of 40 or more from baseline
• Normal pressure glaucoma
• ? Reduction of 30 from baseline
• Ocular hypertension
• ? Reduction of 20 from baseline
• Surveys of Ophthalmology 2003 48 (suppl 1)
  53-57

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AAO GUIDELINES TARGET IOP

• Open angle glaucoma with IOP in the mid to high
  20s? Target IOP range 14-18 mmHg
• Advanced Glaucoma ? Target IOP lt 15 mmHg
• OHT whose IOP gt 30 mmHg with no sign of optic
  nerve damage ? Target IOP lt 20 mmHg
• Ref Surveys of Ophthalmology 2003 48 (suppl 1)
  53-57

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HOW TO USE A TARGET IOP

• Recommended to record and highlight the target
  pressure in the chart of a patient
• Draw an IOP curve for each glaucomatous patient
  and to highlight the target pressure on the curve
• Ref Bull. Soc. Belge Ophthalmol 274 61-65, 1999

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HOW TO USE A TARGET IOP

• Target pressures should be reevaluated
  periodically. This is because a target IOP that
  is appropriate when you first see a patient may
  not be safe pressure 10 years later when he or
  she may have developed systemic hypertension,
  diabetes, or some other condition that may affect
  the patients susceptibility to glaucomatous
  progression
• Ref Surv. Of Ophthalmology 2003 48 (suppl 1)
  53-57

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• Youre not going to have one target pressure
  thats appropriate for every patient. It is a
  dynamic process and you always have to be alert
  and open to modification.
• L. Jay Katz,
• Professor of Ophthalmology
• Jefferson Medical College

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• Patients should be followed closely over time
  and their target pressures should be adjusted,
  depending upon how the patient is doing. If the
  patient progresses, the target pressure should be
  lowered. If the patient does very well, the
  target pressure should be lowered. If the
  patient does very well, the target might be
  raised.
• Stevens Simmons,
• Associate Clinical Professor,
• Albany Medical College

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TARGET IOP SUMMARY AND RECOMMENDATIONS

• Target IOP should be individualized as per
  patient and should be a flexible ever changing
  variable varying with the progression of the
  disease
• The concept of a target IOP should be a part of
  the standard of care for physicians who treat
  glaucoma patients
• The methods used to maintain the target pressure
  should be sustainable over the long term with
  minimal adverse effects