12.1 Anterior Segment Procedures

12.1.1 Cataract Surgery

Y (Why Have the Procedure)

“You have a cataract. This occurs when lens of the eye (that focuses light onto the back of the eye) becomes cloudy (it is normally clear like glass). Cataracts can cause blurred vision as well as glare.”

Aim: “Remove the cataract and replace it with a clear artificial lens to improve vision”.

NB: Cataract surgery is increasingly being undertaken as a refractive surgical procedure and community expectations of refractive outcomes are high. Expected refractive outcomes form an important part of the consent process for all cataract operations. The consent process is different depending on the patient’s current level of vision and desired refractive outcome. Patients requesting spectacle independence must be assessed fully from a refractive surgery perspective. Candidates must be clear with their patients pre-operatively about the expected refractive outcome and criteria for surgical “success”.

M (Mechanism, What is the Procedure)

“A cataract operation involves making a small incision in the front of the eye, taking out the lens with an ultrasound probe and inserting an artificial plastic lens that stays in for life. (Use a model or diagram).

  • “We operate on one eye at a time. The operation takes about 30 minutes, during which time you have to lie very 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, optimise diabetes
  • Post-operation: Usually day surgery, patch, drops, follow up

C (Complications)

“Although cataract surgery has excellent success rates, complications may occur that can leave you with vision worse than you have at present”:

More Common

Refractive Surprise

Many patients still require glasses after cataract surgery, particularly for reading. More common after previous refractive surgery. Clearly establish pre-operatively what refractive outcome is desired and guaranteed, and steps that can be undertaken if this is not achieved

Inflammation

e.g. Pseudophakic cystoid macula oedema. May need drops or another procedure

PCO

“Membrane growing on the back of the lens”. Treated with laser in clinic

Less Common

Difficulty Removing Lens

May need another operation

Infection in the Eye

1:1000 risk of endophthalmitis. Permanent loss of vision or eye is rare but possible

Bleeding

Very rare but can result in permanent loss of vision

Retinal Detachment

Especially if young, high myopes

Sympathetic Ophthalmia

Extremely rare but essential to mention

Anaesthetic Risks

Globe perforation

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

A (Alternatives)

  1. Observation – cataract will get inevitably get worse but the timing of this is uncertain
  2. If the refraction has changed, updated spectacles can improve vision but will not usually improve vision beyond what can be achieved with a pinhole
  3. There are no medical therapies for cataracts

Confirm that the patient understands. Any questions?

12.1.2 Corneal Graft

Y (Why Have the Procedure)

“Your cornea (the front “window” of the eye) has become cloudy (draw a diagram). A corneal graft is the only way to restore its clarity and improve your sight.”

Aims depending on indication:

  1. Restore vision loss caused by damaged cornea
  2. Reduce pain
  3. Preserve integrity of your eye
  4. Help control infection

M (Mechanism, What is the Procedure)

“A corneal graft is an operation where the damaged cornea is removed and replaced with a donor cornea. The donor cornea comes from someone who has died and has donated his or her eye (so the timing of the operation may depend on availability).”

Options for Fuchs’ Endothelial Dystrophy, Pseudophakic Bullous Keratopathy:

Penetrating Keratoplasty
(PK)

  1. Well established with long -term data
  2. Quicker

Endothelial Keratoplasty
e.g. Descemet’s Stripping Endothelial Keratoplasty (DSEK)

Benefits

  1. Less risk of traumatic rupture
  2. “No” suture problems (sutures can break, become infected, be a tract for vessels that stimulate rejection)
  3. Less risk of supra-choroidal haemorrhage
  4. Less astigmatism
  5. Faster rehabilitation
  6. Less surface related problems

Limitations

  1. May not be suitable if corneal scarring, phakic, anterior chamber IOL, filtering tube
  2. Technically difficult (especially if anterior chamber shallow)
  3. Risk of graft dislocation
  4. Greater loss of endothelial cells during procedure
  5. Induces ~0.5-1.0D hyperopia
Options for Keratoconus:

Penetrating Keratoplasty
(PK)

  1. Well established with long-term data
  2. Quicker
  3. Slightly better VA (no interface haze)

Deep Anterior Lamellar Keratoplasty (DALK)

  1. Less risk of traumatic rupture (for young patients)
  2. Less risk of intraoperative supra-choroidal haemorrhage
  3. No endothelial rejection (for patients living far away, atopic, eye-rubbers)
  4. Less astigmatism
  5. Less late endothelial failure
  • “We operate on one eye at a time, the operation takes about one hour, during which time you have to lie still under a surgical drape (blanket). The operation is usually performed under a GA - your anaesthetist will explain this further.”
  • Pre-operation: Fasting
  • Post-operation: Often admitted to hospital, patch, drops

C (Complications)

“Although corneal grafts have excellent success rates, complications may occur that can leave you with vision worse than you have at present”:

More Common

Suture Related

Break, infection

Rejection

May need admission, medications, another operation

Vision

Astigmatism is common
May need glasses / contact lenses / another operation
Takes time for good vision

Less Common

Infection

Can lead to permanent vision loss or loss of eye
All graft tissue is tested for HIV and hepatitis prior to release for transplantation

Bleeding

Intra-operative suprachoroidal haemorrhage (with PK)

Anaesthetic Risks

Globe perforation

  • 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. Depending on underlying pathology
  • Endothelial failure: Topical steroids / hypertonic saline.
  • Keratoconus: Contact lenses, intra-stromal corneal ring segments, collagen cross-linking.

Confirm that the patient understands. Any questions?

12.1.3 Pterygium Surgery

Y (Why Have the Procedure)

“You have a growth of tissue over your cornea caused by sun damage. If we leave it untreated, it could progress to distort your vision and possibly obstruct your visual axis.”

Pterygium surgery should always be done before cataract surgery.

Aim: Prevent progression of pterygium to obstruct the visual axis.

M (Mechanism, What is the Procedure)

Surgery consists of two parts:

  • Removing the pterygium and smoothing the affected cornea
  • Taking a conjunctival autograft and placing it at the site of the removed pterygium either by suturing or with a tissue glue


There will be discomfort post-operatively which will resolve over a few weeks as the eye heals.

C (Complications)

Pterygium surgery is generally a very safe operation. Major complications are rare but can be visually significant.

  1. Recurrence (5%)
  2. Most common: pain, bleeding
  3. Rare but sight threatening (globe perforation, infective scleritis)
  4. Damage to the medial rectus and diplopia

A (Alternatives)

  1. Observation
  2. Conservative: Topical lubricants / steroids
  3. Slowing Progression: Wrap-around sunglasses

Confirm that the patient understands. Any questions?

12.1.4 YAG Laser Capsulotomy

Y (Why Have the Procedure)

“After cataract surgery, some cataract cells are invariably left behind. These cells have grown over the back of your plastic intraocular lens to create a film which is clouding your vision. To restore your vision to its optimal state, we need to remove this film.”

Performed for visually significant posterior capsular opacification. Should not be performed immediately after cataract surgery (minimum 1 month, ideally 3 - 6 months).

M (Mechanism, What is the Procedure)

“A laser will be used to polish the film off behind your IOL”

  • “The procedure is quick and painless and is done on a slit lamp. Numbing drops will be instilled and a contact lens will be placed on your eye. After the procedure, your vision may be blurry and the eye may be light sensitive. It can take a few days for the vision to improve.”

C (Complications)

“YAG laser capsulotomy is safe and effective. There are a number of possible serious complications, but these are all extremely rare. Complications can include”:

  1. Inflammation at the front of the eye. Usually mild and treated with steroids
  2. A rise in IOP, that may require drops or extremely rarely surgery
  3. Cystoid macular oedema, the risk of which is highest if YAG is performed early after cataract surgery
  4. Pitting (“scratching”) of the lens resulting in small, permanent, blurry spots in the vision
  5. Subluxation or dislocation of the intraocular lens, which could at worst require further surgery (<1%)
  6. Retinal tear or detachment (1%, depending on a number of factors including refraction and ocular history)

A (Alternatives)

  1. Observation
  2. Conservative: Glasses, mitoics if par-axial

Confirm that the patient understands. Any questions?

          

All rights reserved. No part of this publication which includes all images and diagrams may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the authors, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law.

Vitreoretinal Surgery Online
This open-source textbook provides step-by-step instructions for the full spectrum of vitreoretinal surgical procedures. An international collaboration from over 90 authors worldwide, this text is rich in high quality videos and illustrations.

© 2021 WESTMEAD EYE MANUAL

Website by WebInjection