1. Refractive Surgery COmplications Lecture 3
Liana Al-Labadi, O.D.

2. Postoperative LASIK Complications
Early
Late
Normal healing Sx:
*Over-correction of RE- 1 month p.o.
*Induced astigmatism d/t corneal remolding or tear film disruption
*Central Islands- after 1 month p.o.
- Central steepening greater than 1.50 D
- Causes sx such as ghosting & monocular DIPL
Neurotrophic Keratitis- extremely rare severe dry eye effect or keratitis d/t microkeratome transection of the long ciliary nerve
*Epithelial Ingrowth
- 1 month visit
- White, milky deposits at the level of interface
- Observe if not obstructing visual axis, not inducing irregular
astigmatism or if progressive
- Aggressive complications: corneal melt or RCE
*Diffused lamellar keratitis (DLK)
- AKA “Sands of the Sahara”
- Signs of multiple fine inflammatory infiltrates in the flap
interface
- Usually occurs within 5 days of surgery. But can occur
weeks to years after LASIK in response to any K insult
- Must be aggressively treated with steroids
*Persistant stromal or flap edema
- Rare beyond 1-wk p.o.
- Occurs in patients with Fuch’s, high IOP
* Progressive corneal ectasia
-keratoconus-like condition that either was there pre-op and
has worsened or that has developed after the surgery
- Due to weakened K tissue or to not maintaining 250 microns
of tissue under the flap after ablation
*Irregular astigmatism induced by:
- Irregular flap cut or misalignment, epithelial ingrowth or
from laser ablation irregularities
* Large epithelial defects
*Flap folds, dislocation or lost K flap
*Regression Effect:
- Undercorrection or overcorrection or regular astigmatism
- Tx with spectacles initially
- Recommended 3months
*K ulcers &/or infection in the flap interface 35

3. Postoperative PRK Complications
Early
Late
Normal healing Sx:
* Dislodged BCL
*Over-correction of RE- 1 month p.o.
*Induced astigmatism d/t corneal remolding or tear film disruption
*Central Islands- after 1 month p.o. (aka “higher order aberrations)
- Central steepening greater than 1.50 D
- Causes sx such as ghosting & monocular DIPL
Neurotrophic Keratitis- extremely rare severe dry eye effect
- Rare with PRK- insults only the most anterior layer of the
K, affecting only buds of corneal nerves & causing
temporary loss of sensation
*Persistant K edema or K haze
- Rare beyond 1-wk p.o.
- Occurs in patients with:
** Fuch’s Dystrophy
** High IOP (steroid responder)
** Medications that slow endothelial bump function
i.e. CAI
* Large epithelial defects
*K ulcers
*K infection- Noticed mostly 2nd day p.o,
* Steroid-induced glaucoma
* K Ectasia
*Irregular astigmatism induced or higher-order uncx astigmatism
- Most common complication of refractive surgery
- causes: irreg of laser ablation (decentration), pre-op K
irregularity and healing response
*Medcation allergy
*Regression Effect:
- Undercorrection or overcorrection or regular astigmatism
- Tx temp with spectacles; RE 6 months
- Recommended 3months 35

4. SIDE EFFECTS

5. SIDE EFFECTS

6. SIDE EFFECTS

7. SIDE EFFECTS

8. SIDE EFFECTS

9. SIDE EFFECTS

10. SIDE EFFECTS DRY EYES: d/2:
Optical Aberrations:
Traditional objective refraction measures sphere, cylinder and axis (lower orders aberrations)
Ignores HOA such as coma, spherical aberration & quadrafoil
Effects of HOA on vision include: ghost images, haloes, shadows
Decrease optical quality
These effects are not compensated for with traditional spectacles & CLs
Optimal visual performance requires the simultaneous compensation of both lower and higher-order aberrations
Most likely eliminated with wave-front technology
DRY EYES: d/2:
conjunctival goblet cell damage / disruption of feedback loop from lacrimal gland to brainstem (neurotrophic theory)
cut corneal nerves ↓ sensitivity => ↓ CSF and optical quality

11. HOA- Different Views

12. SIDE EFFECTS Dry Eyes: Conjunctival goblet cell damage
Disruption of feedback loop from lacrimal gland to brainstem (Neurotrophic theory)
Cut K nerves ==> decreased K sensitivity --> decreased tear production = poor optical quality

13. SIDE EFFECTS starbursts Haloes Night Vision Problems
Opt zone diam < pupil diam
Residual Rx / irregular astig => haloes and decr vision.
Often require night driving Rx
starbursts
Haloes

14. SIDE EFFECTS Discomfort Photophobia: Conjunctival Heme
First 24 hrs for LASIK
d/t speculum => orbital ache
Not as painful as PRK
Photophobia:
Related to optical quality and scattering, healing or haze
Conjunctival Heme
Application of suction ring

15. P.O. Clinical Implications for O.D.
1. ↓ in BCVA
d/t irregular astigmatism & HOA which decreases optical quality
Optical quality is important for artists, architects, draftsmen who require good contrast sensitivity
Solution:
Eliminated with Wavefront guided ablations targeted beam - sent through eye - focused on retina.
Allows customized reshaping of cornea during refractive surgery procedure
P.O. Clinical Implications for O.D.

16. P.O. Clinical Implications for O.D.
2. ↓ NIGHT VISION
Residual Rx
Irregular astigm
Pupil diam > corrected optic zone diam
Solution:
Rx for driving
GP C/L
Miotic drops
Wavefront Rx

17. P.O. Clinical Implications for O.D.
3. UNDERESTIMATION OF IOP
Appl tono => underestimates IOP
Flattened and thinned central cornea
Implication: Delay diagnosis of glaucoma
Solution: IOP’s > 17mmHG should be investigated further

18. P.O. Clinical Implications for O.D.
4. DRY EYES
Conjunctival goblet cell damage
Disruption of feedback loop from lacrimal gland to brainstem
Implications: ↓ optical quality & discomfort
Solution:
Tear supplements
Punctal occlusion
Mild steroid/ Restasis

19. P.O. Clinical Implications for O.D.
5. Corneal Ectasia
Bowing forward of post cornea thro weakened ant cornea
Implication: Astigmatism & keratoconus
Solution:
Monitor post-refractive surgery patients closely with K topography
Tx RE with GP C/L’s
P.O. Clinical Implications for O.D.

20. P.O. Clinical Implications for O.D.
6. DONOR CORNEAS
Post- refractive surgery corneas cannot be used for penetrating keratoplasty (corneal transplants)
Concern – negative impact on availability of donor corneas

21. Summary Unbiased advise to make an informed decision
Requires practitioner education and familiarity with different aspects of refractive surgery
Interdisciplinary collaboration: pre-op, post-op management in conjunction with ophthalmologist
Research – long term effects remain unknown ??
Summary