|
Post LaserVisionCorrection
Ectasia
Literature review has
pointed out the most common
risk factors for post-LASIK
ectasia:
Preoperative corneal
topographic abnormalities
Residual stromal bed
thickness bellow 300 µm
High myopia and myopic
astigmatism
Patient age (below 25 years
old)
Preoperative corneal
thickness (less than 500 µm)
Unpublished observations
collected from our personal
files (9800 patients)
include some additional
potential risk factors:
Familiar history of
keratoconus
Increased amount of
higher-order aberrations
BCVA less than 20/25
Topographic and refractive
instability
-
High myopia
-
Residual stromal bed <
250
-
Preoperative pachymetry
< 500
-
Steep keratometry (47-50
D)
-
Abnormal topography
a. Inferior steepening
b. Irregular astigmatism
c. Asymmetric
astigmatism
d. Abnormal posterior
float
-
Enhancements
-
Younger age
Treatments
-
Reduce IOP
-
Riboflavin crosslinking
-
Intracorneal ring
-
Keratoplasty
E. Prevention
-
Avoid LASIK in
"borderline" cases
-
Surface ablation
procedures
-
Intraoperative
pachymetry
-
Second opinion for
patients that are not
ideal candidates
|