6. First: Why doctors return again to Surface
ablation?
Easy technique
No flap related complications
Less liability for future ectasia
Less cost
7. Second: Is LASIK hazardous technique ?
Hazardous in the following conditions
1. Long-term safety (in border line corneas)
2. Flap related complications
3. Suction high pressure effect on posterior segment
8. Third: What are the advantages of Surface
ablation over LASIK?
More safe → No flap → No damaging effect in
corneal architecture → Maintained corneal
stability → Less liability for ectasia
Less thinning → More residual bed
Can be done for border line corneas
No effect on posterior segment
less dry eye
11. However, after answering the previous
questions
The last question is:
• Why great evolution had occurred from
surface ablation to LASIK in the beginning of
excimer laser corneal refractive surgeries
12. Surface ablation is not a completely safe
technique, it has its own problems.
13. Problems of Surface ablation
1. Haze:
• Early: Due to early removal of therapeutic
contact lens (bad healing)
• Late: Subepithelial fibroblasts proliferation:
• UVA exposure
• High error correction
23. Advanced Surface Ablation
1. LASEK, in which the epithelium is
removed with alcohol
2. Epi-LASIK, in which the epithelium is
mechanically lifted without adjunctive
agents.
In both procedures, laser photoablation is
performed just above the Bowman layer
24. Advantages
1. Done in high myopes (–6.00 to –10.00 D).
2. Avoids all the flap-related complications
seen in LASIK, including incomplete flaps,
free caps, buttonhole flaps, flap striae,
dislocated flaps, flap melts, epithelial
ingrowth, and DLK.
3. Safety in posterior segment.
27. Surface ablation is a good alternative
to LASIK as regard safety and corneal
stability, however it carries some
problems especially haze and
epithelial healing problems.
LASIK is better in straight forward
cases especially with ultrathin flaps.
28.
29. Femtosecond laser in ophthalmology
Uses:
•Femtolasik
•Femtosecond cataract surgery
•Femtokeratoplasty
•Femtosecond laser in
keratoconus
33. Advantages:
Optimal safety
No flap related complications e.g.: free cap, button
holes, incomplete cuts
- Thinner flap:
Uniform thin flaps with no liability of complications
Thin flaps leads to large stromal bed with less liability
for ectasia
- Precise depth
35. Advantages:
Flap Design
Large flap diameter : in HMT, in custom
ablation
Hinge : superior or nasal if there is cylinder
Hinge angle can be also modified
38. Flap edge
Flap edge :
Femtosecond laser can create
a corneal flap that has edges
that enable the flap to fit
more securely in place,
(inverted Side cut) > 90
degree “ beveled edge”
Better Biomechanics
M2 flap : 40: 70 degree