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[Eye Reports 2012; 2:e2] [page 7]

Eye Reports 2012; volume 2:e2

Late onset post-LASIK
keratectasia with reversal
and stabilization after use
of latanoprost and corneal
collagen cross-linking 
Aleksandar Stojanovic,1,2 Xiangjun Chen,2
Linyan Zheng,3 Yile Xu,3
Filip Stojanovic,2 Tor Paaske Utheim2

1Eye Department, University Hospital of
North Norway, Tromsø, Norway;
2SynsLaser Kirurgi AS, Tromsø/Oslo,
Norway; 3School of Ophthalmology and
Optometry and Eye Hospital, Wenzhou
Medical College, Wenzhou, Zhejiang,
China

Abstract 

We report a case of late onset keratectasia
after laser in situ keratomileusis (LASIK) and
its quick reversal and stabilization after use of
latanoprost and riboflavin/ultraviolet-A corneal
collagen cross-linking (CXL). A 39-year-old man
with normal intraocular pressure developed a
rapid deterioration of vision in his left eye 6
years after LASIK-retreatment for high myopic
astigmatism. Keratectasia was diagnosed by
corneal topography and ultrasound pachymetry.
After two months of treatment with latanoprost
and a minor intraocular pressure reduction,
uncorrected distance visual acuity improved
from 20/100 to 20/20 and corneal topography
showed reversal of keratectasia. CXL was per-
formed after the reversal to achieve long-term
stabilization. At 1, 3, 6, 13 and 39 months follow-
up exams after the CXL, stable vision, refrac-
tion, and topography were registered. This case
shows that keratectasia may rapidly occur sev-
eral years after LASIK and that a quick reversal
and stabilization may be achieved by use of
latanoprost followed by CXL.

Introduction

Although several risk factors for keratecta-
sia after laser in situ keratomileusis (LASIK)
have been identified and screening techniques
continue to improve, post-LASIK keratectasia
still occurs.1 A case of transient post-LASIK
keratectasia associated with a marked eleva-
tion of intraocular pressure (IOP), where the
keratectasia subsided promptly after IOP nor-
malization, has previously been reported.2 The
current study reports a case of late onset post-
LASIK-keratectasia associated with normal
IOP, where reversal of keratectasia occurred

after only minor IOP reduction after use of
latanoprost. Collagen cross-linking (CXL) was
subsequently used to successfully stabilize the
result. 

Case Report

A 39-year-old male truck driver underwent
uneventful bilateral LASIK in October 2001.
The patient had no previous history of eye rub-
bing, trauma, atopy, or any eye disease. No
family history of keratoconus was reported. His
corrected distance visual acuity (CDVA) before
LASIK was 20/16 in both eyes. For the right and
the left eye the preoperative manifest refrac-
tion was -6.75-3.50¥156 and -6.75-5.00¥4, ker-
atometry at orthogonal meridians within the
central 3 mm was 44.40D /41.90D¥165° and
44.60D /41.20D¥7°. Preoperative IOP (mea-
sured by Goldmann applanation tonometry,
corrected for pachymetry) was 14 mmHg in
both eyes. Orbscan II (B&L, Rochester, NY,
USA) corneal topography showed no morpho-
logical signs of increased risk for ectasia. The
orthogonal asymmetry within the central 3 mm
was 1.3D and 1.4 D and the highest point on
posterior floating elevation map was 35 and 37
microns for the right and left eye, respectively.
Central corneal thickness measured by ultra-
sonic pachymetry (Corneo-Gage Plus,
Sonogage Inc., Cleveland, OH, USA) was 586
microns and 593 microns, and the planned
ablation depth was 128 microns and 135
microns, for the right and the left eye respec-
tively. Emmetropia within the optical zone of
5.5 mm, and transition zone of 6.5 mm was

attempted. The planned flap thickness was 160
microns, leaving the minimal planned residual
stroma at 298 microns in both eyes.
Hansatome (B&L, Rochester, NY, USA) micro-
keratome with a 160-micron head and an 8.5
mm ring was used on both eyes. Intraoperative
flap thickness, as measured by subtraction
pachymetry, was 146 and 158 microns in the
right and the left eye, respectively. LaserSight,
Astrascan (LaserSight, Orlando, FL, USA), 200
Hz, 1 mm flying-spot laser was used for the
ablation. 

Correspondence: Aleksandar Stojanovic, Fløyvn.
32, 9020 Tromsdalen, Norway.
Tel. + 47.9069.3319 - Fax: + 47.7764.7929.
E-mail: aleks@online.no

Key words: keratectasia, LASIK complication,
CXL.

Contributions: the authors contributed equally.

Conflicts of interests: the authors have no poten-
tial conflicts of interests.

Received for publication: 1 January 2012.
Revision received: 1 January 2012.
Accepted for publication: 14 January 2012.

This work is licensed under a Creative Commons
Attribution NonCommercial 3.0 License (CC BY-
NC 3.0).

©Copyright A. Stojanovic et al., 2012
Licensee PAGEPress, Italy
Eye Reports 2012; 2:e2
doi:10.4081/eye.2012.e2

Figure 1. Anterior surface elevation map after the LASIK-retreatment in 2002 (left), after
the acute visual deterioration in 2007 (center) and the difference between the two, show-
ing the anterior surface protrusion (right).

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After the initial surgery, the patient’s uncor-
rected distance visual acuity (UDVA) was
20/65 in both eyes, with CDVA of 20/20 in both
eyes, corrected with -2.00-1.25¥175 and -1.50-
1.00¥170. The central ultrasound pachymetry
was 505 and 502 microns for the right and the
left eye, respectively. Retreatment using the
flap re-lift technique aiming at emmetropia
was performed in January 2002. The ablation
depth of the retreatment was 49 and 39
microns and the calculated minimal residual
stromal thickness was 296 and 303 microns for
the right and the left eye, respectively. After
the retreatment, the patient achieved UDVA of
20/20 in both eyes and there were no signs of
keratectasia on Orbscan II topography at the
follow-up exam 3 months after the surgery. At
that point the ultrasound central corneal
pachymetry was 463 and 470 microns, and the
highest point on the posterior floating eleva-
tion map was 43 and 45 microns for the right
and left eye, respectively.

The patient reported five years of stable and
good vision until November 2007, at which
point he experienced an acute and progressive
worsening in his left eye, which could not be
corrected with spectacle glasses or soft contact
lenses. On examination performed on
December 12, 2007, UDVA was 20/25 and
20/100, with CDVA 20/20 and 20/60, corrected
with -0.25-0.50¥180 and -1.00-1.50¥145, for
the right and the left eye respectively. Right
eye showed unremarkable clinical and topog-
raphy findings. Orbscan II topography analysis
of the left eye revealed signs of keratectasia,
showing protrusion on the anterior elevation
map (Figure 1), as well as the maximum
height on the posterior floating elevation map
of 85 microns (Figure 2, center), coinciding
with the point of the minimal corneal thick-
ness of 410 microns. 
Keratometric map showed an irregular

astigmatism with 3.1 D of asymmetry within
the central 3 mm. IOP (corrected for pachyme-

try) was 14 mmHg. Central ultrasound
pachymetry was 435 microns. Treatment with
latanoprost (Xalatan®, Pfizer Inc, New York,
NY, USA) once daily was initiated at this time. 
According to the patient and the local

optometrist, his UDVA improved dramatically
within the following two weeks. At the follow-
up examination 2 months after the onset of
treatment with latanoprost (February 11,
2008), UDVA and CDVA of the left eye
improved to 20/20 and only a minor manifest
refractive error remained. Orbscan II anterior
surface analysis showed the regression of the
protrusion (Figure 3), while the posterior ele-
vation decreased to 55 microns (Figure 2,
right). Keratometric map showed a decrease of
the irregular astigmatism within the central 3
mm to 1.5 D. The IOP showed a slight decrease
to 11 mmHg. 
On the same day, latanoprost was discontin-

ued and CXL, with 0.1% riboflavin/dextran
solution and 365 nm ultraviolet-A (UVA) irradi-
ation with UVA-illuminator (UV-X, IROC,
Zurich, Switzerland), was performed according
to the standard protocol.3 The 1-, 3-, 6-, 13- and
39-months follow-up exams after CXL showed
consistently stable UDVA of 20/20, stable
refraction and no topographic signs of ectasia. 

Discussion

High-grade myopia and astigmatism as well
as a history of retreatment are identified risk
factors for post LASIK keratectasia.4 In the cur-
rent case keratectasia was topographically
diagnosed by moderate protrusion of the ante-
rior surface, marked increase of the height of
the posterior elevation and increased asymme-
try. The concurrent corneal thinning on ultra-
sound pachymetry followed the finding. 
Guirao and colleagues explained the mecha-

nism of keratectasia as the action of the IOP
on the weakened cornea.4,5 In our case, in con-
trast with the previously published case report
where the keratectasia reversal occurred with
reduction of elevated IOP,2 the reversal coin-
cided with only a minor reduction of normal

Case Report

[page 8] [Eye Reports 2012; 2:e2]

Figure 2. Posterior floating elevation after the LASIK-retreatment in 2002 (left) (45 microns), after the acute visual deterioration in 2007
(center) (85 microns) and after the treatment with latanoprost and collagen cross-linking (right) (55 microns).

Figure 3. Anterior surface elevation map at the acute visual deterioration (left), after the
treatment with latanoprost (center) and the difference between the two, showing the
regression of the anterior surface protrusion (right).

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[Eye Reports 2012; 2:e2] [page 9]

IOP after use of latanoprost. 
Atmospheric pressure, IOP, and corneal bio-

mechanical strength are factors known to
affect the corneal shape and optics. The
dynamic balance between these factors seems
to be robust in healthy virgin corneas, unaf-
fected by IOP fluctuation in a relatively wide
range.2 However, one may speculate that a sud-
den occurrence of keratectasia in the current
case, followed by its reversal coinciding with
use of latanoprost and a minor decrease of IOP,
may imply that the factors keeping the post-
LASIK cornea stable may not be in a robustly
balanced continuum, but rather in a fragile
balance. 
Hiatt and colleagues6 reported a case where

IOP reduction was used for reversal of LASIK-
induced keratectasia, but the ectasia recurred
3 months after discontinuation of the IOP-
reducing medication. We chose to treat our
patient with CXL rather than continuing the

latanoprost, primarily to avoid the need for
long-term medication. 
Although a certain causality between the use

of latanoprost and reversal of post-LASIK kera-
tectasia in the current case cannot be estab-
lished, and the IOP reduction may not always
be effective, it shows that latanoprost may be
used in an initial attempt to reverse keratecta-
sia even in normotensive eyes, and that the
reversal can be stabilized by use of CXL.

References

1. Binder PS, Lindstrom RL, Stulting RD, et
al. Keratoconus and corneal ectasia after
LASIK. J Cataract Refract Surg 2005;31:
2035-8.

2. Toshino A, Uno T, Ohashi Y, et al.
Transient keratectasia caused by intraocu-

lar pressure elevation after laser in situ
keratomileusis. J Cataract Refract Surg
2005;31: 202-4.

3. Wollensak G, Spoerl E, Seiler T. Ribo-
flavin/ultraviolet-a-induced collagen cross-
linking for the treatment of keratoconus.
Am J Ophthalmol 2003;135:620-7.

4. Guirao A. Theoretical elastic response of
the cornea to refractive surgery: risk fac-
tors for keratectasia. J Refract Surg  2005;
21:176-85.

5. Comaish IF, Lawless MA. Progressive post-
LASIK keratectasia; biomechanical insta-
bility or chronic disease process? J
Cataract Refract Surg 2002;28:2206-13.

6. Hiatt JA, Wachler BS, Grant C. Reversal of
laser in situ keratomileusis-induced ecta-
sia with intraocular pressure reduction. J
Cataract Refract Surg 2005;31:1652-5.

Case Report

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