The document outlines essential aspects of refractive surgery, including preoperative evaluations and the surgical procedure using both traditional microkeratomes and the all-laser intralase method. It highlights the importance of assessing individual patient needs, managing potential complications, and ensuring proper postoperative care. Key considerations include pupil size, ablation zone, and the management of various eye health issues and systemic diseases that could affect surgical outcomes.

1. “REFRACTIVE SURGERY
BASICS”
Michael Duplessie, MD

2. The Preoperative Visit
• REFRACTION:
–Manifest with binocular balance
–Cycloplegic Refraction
• Tropicamide vs. cyclogel

3. Keratometry/Topography
• Not to flat and not to steep
• Plan: MR*0.6 = anticipated change in
myopic refraction with excimer treatment
(less than 36 is contraindication)
• Plan: MR*1.0 = anticipated change in
hyperopic excimer treatment (more than 50
is contraindication)
• Rule out corneal distortion/KC/CL warpage

4. Topography

5. Pupils
• Historically, smaller ablation zones resulted
in significant spherical aberration following
surgery
Ablation Zone
6.0 mm
Pupil Size
7 mm

6. Pupils
• Current technology reduces the problems
associated with pupil size
– larger ablation zones
– blend zones
a. 8 mm with myopes on VISX
b. 9 mm with hyperopes on VISX
• Glare/halos results from induced HOA’s
regardless of pupil size
• Still considered standard of care

7. Pachymetry
• Ultrasound is standard
–Central readings necessary
–Utilize intraoperative stromal bed
measurements
• Orbscan tends to be thinner

8. Munnerlyn’s Formula
• 11 microns*MR (at 6 mm) = ablation depth
• Pachymetry – ablation depth – flap
thickness = GREATER THAN 250
MICRONS
• Larger ablation zones (6.5 or 7 mm) will
remove MORE tissue

9. General eye health
• Dry eye
• Lid disease: Blepharitis, Meibomian gland
dysfunction
• Corneal scars/ABMD/neovascularization
• Acne Rosecea
• Glaucoma with or without field defects

10. Systemic Disease
• Diabetes with or without DR
• Arthritis
• Thyroid (tendancy for dry eye)
• Medications: more than one psychiatric
med? Watch out
• Personality: more than two drug allergies
or more than three rings

11. Consent form
• Legal document which describes risks and
benefits of the procedure.
• We do this for all patients at the
preoperative visit.

12. Day of surgery
• Bring meds: Antibiotic, Steriod and
Valium
• Valium (0.5 mg PO taken 30 minutes prior
to surgery)
• Dress in layers (Suite is cold)
• No perfume or scented lotion
• Testing performed: Machines, consent
discussion and meet with Dr. Duplessie

13. Making the flap
• Microkeratomes have come a long way
since the ACS
– 3 parts
– Track
• Problematic incision
– Blind incision (some exceptions)

14. Disadvantages to Traditional
Microkeratomes
• Irregular flap thickness
• Irregular flap diameter
• Free flaps
• “Track marks” in stromal bed
• Epithelial ingrowth

15. Flap Tear

16. Superficial Scarring

17. Flap complications Using
Traditional Microkeratomes
• Button-hole flaps
• Thin flaps
• Torn flaps
• Decentered flaps
• Incomplete flaps

18. The All-Laser Method
• The Intralase FS laser combined with
excimer laser
• CDRH CFR1040 class IIIb ophthalmic laser
• Long wavelength 1053 nm not absorbed by
tissue
• Indicated for the use in patient’s requiring
lamellar resection of the cornea

19. Mechanism of Action
• The laser defines resection
planes through femtosecond
laser pulses that photodisrupt
tissue with micron-scale
precision.
• Resection is achieved by precise
placement of
microphotodisruptions scanned
at high repetition rates controlled
by computer.

20. Tailoring the flap to each patient
• Unlike traditional
microkeratomes,
the Intralase allows
the surgeon to
specify the
architecture of the
flap

21. Tailoring the flap to each patient
• Flap diameter: range of 0.1-10.00 mm
• Flap thickness: range of 0-400 µm
• Hinge angle: 45-90 degrees
• Hinge position: 360 degrees
• Side cut angle: 30-90 degrees

22. Complications using Intralase
• Thin flaps
• Torn flaps; flaps are incompletely cut by
laser on every case
• Decentered flaps
• Incomplete flaps
• Prolonged vacuum time

23. Resurface the eye
• Typical limits :
– Myopia 10D
– Hyperopia 4D
– Astigmatism 4D
• Wavefront or no wavefront????

24. Custom Parameters
WaveScan Hyperopia Myopia
Sphere +3.75 -6.50
Cyl +2.75 -3.50
WaveScan
SE
+3.75 -6.50

25. Review Post-op instructions
• Steriod/Antibiotic: Tobradex 4x/day x 5
days
– Artificial tears FREQUENTLY – Q15min
while awake week #1, Q30 min week#2 then
hourly
• Gel QHS as needed for AM dryness

26. Common Side Effects
• Dry eye
• Night glare (warn Custom patients)
• Hyperopia treatment within first month:
• Soft CL EW with Acular (NOT Acular LS)
QID
– RTO 2 weeks

27. Light Sensitivity
• Onset: first weeks to several months later
• It will resolve with further healing but if
patient complain, treat it
• Topical steroids “4/3/2/1 x 1 week”
• Acular QID x 1 week

28. Slow healing/Persistent Edema
• Steroids 4/3/2/1 x 1 week
– Maxidex (Dex
– Pred Forte (prednisilone acetate)
– Lotemax (loteprednal acetate)
• Muro 128 solution QID
• Acular LS QID x 1 week

29. Flap Dislocation

30. Fibers

31. Diffuse lamellar keratitits
• Typically at edge, moves centrally
• Treat immediately! Heavy steroids – Pred
preferred
• May require relifting and cleaning
• If stria develop, long term visual importance
1. Tissue destruction
2. Distortion of vison and loss of BVA
3. Hyperopia shift
• Monitor closely in patients with abrasions, flap
trauma

32. DLK

33. Central DLK

34. Epithelial Ingrowth

35. Epithelial Ingrowth

36. Epithelial Ingrowth

37. Enhancements
“Touch ups”
• 20/40 or less
• Significant improvement subjectively?
• Warn low myopes about loss of vision at
near if over 40
• Rule out ectasia in high myopes/thin
pachemetry
• Warn patient they may be more
uncomfortable after numbing drops wear off

38. Custom Enhancements
WaveScan Hyperopia Myopia
Sphere +1.00 +1.00
Cyl -1.00 -1.00
WaveScan SE +1.00 +1.00

39. Monovision
• Patients who have worn it in the past are
most successful
• Trial frame: if like trial, will be successful
• If don’t like TF, go distance OU
• Deep monovison causes anisometropia in
spectacles