Transcript ALLEGRETTO

Collagen cross-linking (CXL) for
keratoconus (KC) with simultaneous
topographical-guided photorefractive
keratectomy (TG-PRK)
Simon Holland, MD, FRCSC, FRCS(Eng),
MRCP, FRC Oph
David TC Lin, MD, FRCSC
Pacific Laser Eye Centre
UBC Dept of Ophthalmology
ASCRS, San Diego 2011
*No financial interests
Purpose and Methods
 To evaluate early results of efficacy and safety of
simultaneous TG-PRK (Custom TNT) with CXL
in contact lens intolerant KC using the Wavelight
Allegretto laser
 105 eyes of 72 patients
 Target: -1.25 or maximum correction of
astigmatism if insufficient thickness
 Minimal predicted residual stromal depth
320microns
Methods
 Epithelial removal by trans-epithelial laser
 Topography-guided PRK with TCAT software (Custom
TNT), modified by refraction and proprietary protocol
 Riboflavin 0.1% in dextran, repeated drops until presence of
aqueous staining
 Hypotonic dextran if <400 um
 UV irradiation with additional drops of riboflavin (up to 20
minutes)
 UV 370 um, 3mW/cm2 - 5.4 J/m2
 Bandage contact lens, standard post PRK
management
TG PRK X-Linking for Keratoconus
20 year-old male
UCVA: 20/200
Pre-op: +4.00-4.00x075
BCVA: 20/30
CT: 486
11 months post-op
UCVA: 20/50
Rx: -0.25-1.25x080
BCVA: 20/30
CT: 412
TG PRK X-Linking for Keratoconus
19 year-old male
Pre-op: -1.75-0.75x075
BSCVA: 20/30
CT: 493
9 months post-op
UCVA: 20/25
Rx: -0.50-0.25x120
CT: 447
20/20
TG CXL PRK for KERATOCONUS
Pre-op: +1.75-4.00x060
BSCVA: 20/30-
6 months post-op
UCVA: 20/30
RX: +0.25-0.75x170 20/25
TG CXL PRK for KERATOCONUS
Pre-op: -2.75-2.25x010 12 months post-op
BSCVA: 20/20UCVA: 20/30RX: +0.50-0.50x020
20/30-
Results
 32 eyes completed 1yr follow up
 22 (70%) had ≥20/40 or better uncorrected vision
(UCVA) at six months; all had BSCVA of 20/40
better
 4 eyes lost two lines, six gained ≥2 lines
 Mean astigmatism ↓ from -2.60D pre-op to -1.05D
at 1 year
 5/22 using refractive correction at 1 year with
symptom improvement in 19/22
 Complications: 3 delayed epithelial healing beyond
one week, 1 herpetic keratitis = all 4 recovered preop BSCVA
Complications: HSV keratitis




20yr old male
RGP intolerant, KC OS>>OD
Pre-op, OS: +4.00-4.00x075 20/30
10 day post-op: remove BCL, photophobia,
dendrite – Valvocyclovir, Trifluridine
 18mth post-op: UVA 20/30
OS: -0.25/-1.25x115 20/25-
Conclusions: Simultaneous Topographyguided PRK with CXL
 Satisfactory early results were achieved with
simultaneous TG-PRK (Custom TNT) with CXL
 Degree of refractive correction limited by corneal
thickness although 70% were able to gain 20/40
or better UCVA at 12 months
 Simultaneous TG-PRK (Custom TNT) with CXL
is a novel technique with the ability to improve
both UCVA and BCVA in keratoconus
Thank-you