Topography-Guided Photorefractive Keratectomy (TG-PRK) for Keratoconus (KC) with
Simultaneous Collagen Cross-linking (CXL) Using High-Resolution Excimer Laser
Simon HollandDavid TC Lin
ASCRS, Chicago, Illinois 2012
*no financial interests*Purpose
To evaluate efficacy and safety of simultaneous TG-PRK with CXL using high-resolution excimer laser, iVIS
Methods 43 eyes keratoconus eyes underwent treatment with
high resolution excimer laser Trans-epithelial TG-PRK with iVIS using the
CIPTA program with simultaneous CXL (Dresden protocol)
Maximum refractive error corrected with minimal residual stromal depth 300microns
Data evaluated: pre-operative, 1, 2, 3 and 6 months:- uncorrected visual acuity (UVA), best corrected visual acuity (BCVA), topography, manifest refraction (MR), symptom score, topography
and keratometry
iVIS TG-PRK with CXL for KCPre-op 3 Months Post-op
UCVA:CF UCVA: 20/80
MR: -4.50-1.00x080 MR: -1.50-1.50x150 20/30+
Aim: –1.50
Pre-operative 4 months post-op
UCVA: CF UCVA: 20/50-
MR: -6.50-4.75X110 20/60+ MR: -1.00-1.25x180 20/40-
iVIS TG-PRK with CXL for KC
Results 43 eyes completed 6 months follow-up 18 (42%) had ≥20/40 or better uncorrected visual acuity
(UVA) 36 (84%) had ≥20/40 or better best corrected visual acuity
(BCVA) 16 (37%) had BCVA improved, 4 (9%) improved BCVA 2
lines or more, 15 (35%) no change, 2 (5%) lost 2 lines or more Mean astigmatism decreased -2.67D pre-op to
-1.50D 3 had delayed epithelial healing beyond 5 days with no
residual effects and no other complications Symptom scores at 3 months, n=20, improved in 11, no
change in 5 and worse in 4
Conclusions
Early results of simultaneous TG-PRK with CXL with
the high-resolution excimer laser, iVIS, shows
potential to improve both UCVA and BSCVA in CL
intolerant KC patients with good efficacy and safety
Advantages include central corneal regularization
possible with the iVIS CIPTA program but may be
offset by smaller treatment zones and less
reduction in symptoms