(CXL) in Post-LASIK Ectasia
Download
Report
Transcript (CXL) in Post-LASIK Ectasia
Topography-Guided Photorefractive Keratectomy
(TG-PRK) and Simultaneous collagen crosslinking (CXL) in Post-LASIK Ectasia Using 2
High-Resolution Excimer Lasers
Simon Holland
David TC Lin
ASCRS, Chicago, Illinois 2012
No financial interests
Purpose
To evaluate the early efficacy and safety of
TG-PRK combined with simultaneous CXL
in post-LASIK ectasia for correction of
irregular astigmatism using the IVIS and
Allegretto platforms
Methods
Using 2 high-resolution excimer lasers for TG-PRK, modified
by TNT (topographical neutralization)
- trans epithelial technique (n=17)
Riboflavin 0.1% in dextran, until aqueous staining
UV irradiation with riboflavin (up to 20 minutes)
UV 370 um, 3mW/cm2 - 5.4 J/m2
Hypotonic dextran if <400 um
Bandage contact lens, standard post PRK
management
Symptom scor -pre and post-operative
uncorrected visual acuity (UVA), best corrected visual acuity
(BCVA), manifest refraction (MR)
predictability, safety
TG-PRK with CXL for ECTASIA
Original Topography:
UCVA: 20/100
Pre-op: -2.00sph
BSCVA: 20/20
CT: 553
TG-PRK with CXL for ECTASIA
4.5 years post LASIK
UCVA: 20/200
MR: -1.50-1.25x100 20/30
CT: 500
8 months post-op
UCVA: 20/20
MR: PL-0.25X180 20/20
TG PRK CXL for ECTASIA
UCVA: 20/400
Pre-op: -6.25-3.50x100
BSCVA: 20/80
12 month post-op
UCVA: 20/30RX: +0.50-0.50 x 160 20/30-
TG CXL PRK for Ectasia
26 years old male
LASIK x 5 years
UCVA : 20/60
MR:+1.00-2.75x125 20/30
CT : 552
3 months post-op
UCVA: 20/30MR:Pl-0.75x180 20/25+
CT : 544
Results
17 patients completed ≥ 6 months post-operatively
12/17 (71%) had UVA of ≥20/40
9 (53%) gained 2 lines or more BCVA; 1 (6%) lost 2
lines or more
Mean reduction of astigmatism 2.56D
All but two symptomatically improved
Complications included delayed epithelialization
No progression of ectasia noted up to 18 mth
No significant differences in the small sample sizes
iVIS central corneal regularization does not induce as
much myopia as the Allegretto when used with TNT
iVIS - less gain in BSCVA
Conclusions
Early results of TG-PRK with simultaneous CXL
using two laser platforms shows promise as an
effective treatment for highly symptomatic
patients with post-LASIK ectasia
All but two had improved symptoms
71% of patients had 20/40 or better UVA
More than half gained ≥2 lines of BSCVA
TG PRK-CXL Summary –
2 platforms, 2 conditions
KC
with Allegretto
KC
with iVIS
Ectasia
with both lasers
99
43
17
UVA ≥20/40
54%
42%
71%
Gained 2 lines or
more BCVA
32%
9%
53%
1.63D
1.17D
2.56D
Analysis
Patients completed 6
months post-op
Average reduction of
astigmatism
TG CXL PRK for KERATOCONUS
Pre-op: +1.75-4.00x060
BSCVA: 20/30-
12 months post-op
UCVA: 20/30
RX: +0.25-0.75x170 20/25
iVIS TG-PRK with CXL for KC
Pre-op
6 months post-op
UCVA: CF
UCVA: 20/50MR: -6.50-4.75X110 20/60+ MR: -1.00-1.25x180 20/40-
TG PRK CXL for ECTASIA
UCVA: 20/400
Pre-op: -6.25-3.50x100
BSCVA: 20/80
12 month post-op
UCVA: 20/30RX: +0.50-0.50 x 160 20/30-
KC – Allegretto
PreOp:
+1.75-4.00x060 20/3012 months PostOp:
+0.25-0.75x170 20/25
KC – iVIS
PreOp:
-0.50-3.75x050 20/60
6 months PostOp:
-1.00sph
20/40
Ectasia
PreOp:
-6.25-3.50x100
20/80
12 months PostOp:
+0.50-0.50 x 160
20/30
Allegretto vs iVIS
Induced myopia , larger optical zone
Mixed cylinder - smaller optical zone
TG PRK with Cross-linking
for Keratoconus and Ectasia:
Concerns
Thinning an already thin cornea - long term
stability unknown
Predictability - hyperopic surprises - less
than expected even with -1.25 target
Endothelial damage , delayed
epithelialization
TG PRK with Cross Linking:
Impressions
Effective in both KC and Ectasia in early
studies for highly symptomatic CL
intolerant patients
Reduce nomogram for TNT in ectasia
Topograpgical neutralization techniques
mostly effective for correcting for induced
refractive error from TG PRK – across
platforms and for both KC and ectasia