Refractive Surgery Complications

Question 1

What % of pxs who get laser vision correction will have serious complication?

Answer 1

Less than 1% of pxs will develop a serious complication

Question 2

Describe Diffuse Lamellar Keratitis (DLK) (LVC Complication)?

Answer 2

• Diffuse sterile inflammation
  o Characterised by inflammatory infiltrates beneath corneal flap interface
  o Characteristic accumulation of these fine, white infiltrates manifest clinically as grainy corneal opacification
• Occurs within 24-48hrs postoperatively – typically resolves 5-8 days after initiation of appropriate therapy e.g. steroid eye drops
• LASIK pxs only
• Non-specific inflammatory response
• 4 stages according to extent of corneal involvement
  o Stage 1 typically arises 1 to 2 days after LASIK refractive surgery – characterised by peripheral inflammatory infiltrates without central corneal involvement
  o Stage 2 typically arises on post-op days 3 to 4 when inflammatory cells begin migrating from periphery into central cornea, often compromising vision
  o Management of stage 1 & stage 2 is increase steroid drop (usually pred forte) to hourly & review within 24-48hrs
  o Stage 3 categorised as further migration of these cells & development of permanent corneal scarring
   Often referred to as the threshold because of likelihood of eyes in this stage of DLK will develop permanent scarring & resulting loss of vision
  o Stage 4 describes stage in which stroma begins to melt & further corneal scarring will occur – causes significant epithelial disruption that occurs during this stage often results in hyperopic shift
  o Management of stage 3 & 4 require urgent review with treating surgeon ophthalmologist

Question 3

Describe 2 LASIK Flap Complications?

Answer 3

• 1. Striae
     o Folds in the flap – if folds are large enough or lie in visual axis then can affect vision
     o Symptoms: reduced BCVA and affects quality of vision (e.g. glare, haloes)
     o Top pic: micro-striae – faint wrinkles seen on flap
     o Surgeon can correct these folds by lifting, stretching & repositioning flap – if detected at early post-op appt.
• 2. Dislodged flap
     o Causes: eye rubbing or squeezing, poorer epithelium, excessive dry eyes or bump to eye
     o Painful
     o Management: visually significant – refer to surgeon for repositioning of flap
     o Bottom pic: flap moved nasally

Question 4

Describe epithelial ingrowth (LASIK Complication)?

Answer 4

• Development of epithelial tissue underneath corneal flap
• Appearance sometimes described as visible nest of cells
• Symptoms:
  o Often asymptomatic but discomfort/light sensitivity & can sometimes effect vision
  o If progressive, induced astigmatism (cyl)
• Management: surgeon can correct this by lifting flap and removing ingrown tissue underneath

Question 5

Describe Slow Epithelial Healing (LASEK Complications)?

Answer 5

• Discomfort, lacrimation, vision can be affected
• Comfort usually aided by application of bandage contact lens
• Antibiotic eyedrops may also be prescribed
• Corneal haze (mostly associated with LASEK as laser energy is applied directly to surface of cornea)
  o Onset of haze is usually 1-3mths post-op
  o Will resolve naturally as healing completes
  o In more severe cases, ophthalmologist may prescribe eyedrop e.g. steroid to encourage the healing allowing haze to resolve quicker

Question 6

Describe Dry Eye as a LVC complication?

Answer 6

• Most common side-effect/risk of LVC
• Aetiology:
  o Suction effects on goblet cells/mucin layer
  o Alteration in corneal curvature with alteration in:
   Surface wetting
   Corneal denervation with flap creation
• All LVC pxs experience transient dry eye sxs, normally for around 1-3mths
  o In other cases it can require further on going tx
• Optom & ophthalmologist should screen for dry eye at pre-op consultation & treat to any surgical procedure using artifical tears/lubricants to reduce risk of dry eye post-op

Question 7

Describe Ectasia as a LVC complication?

Answer 7

• Thinning of cornea – post-LASIK is rare
• Signs & symptoms: can vary between pxs
  o Reduced vision
  o Quality of vision/induced astigmatism – may see more haloes, glare, starbursts around lights
• Timescale:
  o Months-years post-op
• Location:
  o Corneal, often inferiorly
• Appearance:
  o Often normal cornea/advanced: cone shape
  o Pentacam evidence
• Management:
  o Early intervention is critical/urgent surgeon referral
  o If increase in cyl &/or decrease in BCVA, capture pentacam (see pic – black arrow pointing to ectasia)
  o Cross-linking

Question 8

Describe Refractive Lens Exchange Complications?

Answer 8

• Infection occurs in less than ~1 in 1000 people (0.1%)
• Inflammation: endophthalmitis
  o Rare but severe sight-threatening complication of RLE surgery
  o URGENT surgeon review or HES emergency referral
• Cystoid Macular Oedema:
  o Fluid accumulates in centre of retina causing blurred vision
  o Usually occurs 2-8wks after surgery (both RLE and cataract surgery)
  o Reduced vision
  o Pre-existing conditions e.g. diabetes, uveitis as well as any intra-operative complication can raise risk of post-surgical cystoid macular oedema
  o First-line tx of postsurgical CMO can include topical eyedrops: pred forte, Acular & Acetazolamide
• Other complications:
  o Increased IOPs (steroid responder)
  o Retinal detachment
  o IOL displacement (top pic)
  o Posterior Capsular Opacification (YAG laser) (lower pic – beginning of it)