12.3  Glaucoma Procedures

12.3.1 Laser Peripheral Iridotomy (LPI)

Y (Why Have the Procedure)

“You have / or are at risk of sudden, painful vision loss from raised pressure inside your eye (acute angle closure glaucoma). If left untreated you will lose vision (or are at risk of an angle closure attack).”

Aims:

  1. Decrease the pressure inside the eye (IOP)
  2. Decrease risk of a future acute angle closure event occurring
  3. Maintain / return your vision

M (Mechanism, What is the Procedure)

“A laser will be used to create a tiny hole in the coloured part of your eye (iris)”

  • “This aims to allow blocked fluid from behind the iris to escape, It is performed on a laser “slit-lamp”. You will be given anaesthetic drops and a contact lens is placed on your eye during the procedure. It can be uncomfortable if the eye is already inflamed from high pressure but is usually well tolerated. Sometimes two different types of lasers are used in succession to decrease the laser energy used and chance of bleeding. In most cases the other eye will also need to be done same. The pressure lowering effects are quite rapid but initially your normal glaucoma medication should be continued after the laser”

C (Complications)

Although LPI has a good success rate, complications may occur:

Iris / AC Bleed

Small chance and easily managed with gentle pressure on globe

Inflammation

Raised IOP, mild AC reaction, corneal oedema, macula oedema

Further Laser Sessions

Iridotomy closure

Retinal Tear / Detachment

Monocular Diplopia / Glare

Stress close follow-up and IOP checks, need for urgent review if develops reduced vision, pain / redness.

A (Alternatives)

Observation

Very high risk of permanent vision loss

Addition of glaucoma drops

Potential for issues with compliance and tolerance of medication, does not treat cause

Oral Aqueous Suppressants

Effective but poorly tolerated long term due to side effects and renal complications

Glaucoma Surgery

Risks associated with surgery and need for close follow up

Confirm that the patient understands. Any questions?

12.3.2 Selective Laser Trabeculoplasty (SLT)

Y (Why Have the Procedure)

“You have raised pressure inside your eye (“glaucoma”) or are intolerant of drops. If left untreated over a period of time this raised pressure can lead to permanent vision loss”

Aims:

  1. Decrease the pressure inside the eye (IOP) and hopefully reduce the need for additional pressure lowering drops
  2. Maintain your vision

M (Mechanism, What is the Procedure)

“SLT involves a gentle laser aimed at improving drainage of fluid out of your eye”

  • “It is performed on a laser “slit-lamp”. You will be given anaesthetic drops and a contact lens is placed on your eye during the procedure. You should not feel pain. Only half the eye will be lasered in one sitting. There is the potential to laser the other half (180 degrees) of drainage structures if the pressure does not reduce appropriately. The pressure lowering effects are rarely permanent and may “wear off” over time but the procedure can be repeated if required”

C (Complications)

Although SLT has a good success rate, complications may occur:

Temporary Raised IOP

~5% of patients, usually transient within 24hrs

Inflammation

Mild AC reaction, corneal oedema, macula oedema

Further Laser Sessions / Surgery

Pressure may not decrease or glaucoma may continue to progress

Stress close follow-up and IOP checks, need for urgent review if develops reduced vision.

A (Alternatives)

Observation

Higher risk of vision loss

Addition of glaucoma drops

Potential for issues with compliance and tolerance of medication

Oral Aqueous Suppressants

Effective but poorly tolerated long term due to side effects and renal complications

Glaucoma Surgery

Risks associated with surgery and need for close follow up

Confirm that the patient understands. Any questions?

12.3.3 Trabeculectomy

Y (Why Have the Procedure)

“You have glaucoma. Left untreated this can lead to progressive blindness by damaging the nerve (“electrical cabling” analogy) at the back of the eye. We want to perform an operation called a trabeculectomy to lower the pressure in your eye and thereby slow the progression of glaucoma.”

Aim:

  • Lower eye pressure to slow glaucoma progression and prevent (further) visual loss. The operation will not improve vision.

12.3.4 Glaucoma Drainage Tube

Y (Why Have the Procedure)

“You have glaucoma. Left untreated this can lead to progressive blindness by damaging the nerve (“electrical cabling” analogy) at the back of the eye. We want to perform an operation called a trabeculectomy to lower the pressure in your eye and thereby slow the progression of glaucoma.”

Aim:

  • Lower eye pressure to slow glaucoma progression and prevent (further) visual loss. The operation will not improve vision

M (Mechanism, What is the Procedure)

“A glaucoma drainage tube operation creates a new drainage pathway for fluid to exit the eye (draw a diagram, use sink analogy- make the drain larger)”

  • “The tube is attached to a plate which is hidden under the top eyelid. The plate will allow the formation a small blister or “bleb” where the fluid will drain in to. You cannot feel the bleb and tube, and you cannot feel the fluid flowing through them. Fluid does not drip out of your eye or onto your face”
  • “To keep the drainage pathway open we may choose to use medications (antimetabolites) that prevent scarring (avoid in pregnancy) (You may require an operation to remove the jelly of your eye (vitrectomy - if AC placement)) We operate on one eye at a time (if bilateral surgery is required). The operation takes about 60 minutes, during which time you have to lie still under a surgical drape (blanket). The operation is usually performed under a LA (small injection around your eye)- your anaesthetist will explain this further”
  • Pre-operation: Fasting, stop anticoagulants
  • Post-operation: Often admitted, patch, drops, close review during early post-operative period

C (Complications)

Although glaucoma drainage tubes have very good success rates, complications may occur:

More Common

Pressure hard to control

  1. Too low: May need injection of some gel in the front of the eye, another operation
  2. Too high: May need additional drops / tablets. May need bleb manipulation (needling / injections / laser of sutures), another operation.

Less Common (May Need Further Surgery)

  1. Infection: Risk is lifelong. Potential for vision loss or loss of eye.
  2. Bleeding (suprachoroidal haemorrhage)
  3. Cataract
  4. Diplopia
  5. Tube erosion
  6. Dysaesthesia
  7. Corneal damage (endothelial loss with an AC tube)
  8. Anaesthetic risks

Stress compliance, close follow-up, need for urgent review if develops a sore red eye or reduced vision.

A (Alternatives)

  1. Observation- but will get worse
  2. Medical therapy (but probably has already failed)
  3. Laser therapy (less effective)
  4. Cataract surgery
  5. Minimally invasive glaucoma surgery
  6. Trabeculectomy

Confirm that the patient understands. Any questions?

          

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