Download Fuchs` Endothelial Dystrophy in 830

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C A S E
Fuchs’ Endothelial Dystrophy
in 830-nm Spectral Domain
Optical Coherence Tomography
Bartlomiej J. Kaluzny, MD, PhD
Anna Szkulmowska, MSc
Maciej Szkulmowski, PhD
Tomasz Bajraszewski, PhD
Andrzej Kowalczyk, PhD
Maciej Wojtkowski, PhD
ABSTRACT
This article presents for the first time the potential
of 830-nm spectral domain optical coherence tomography (SD-OCT) in the evaluation of Fuchs’ endothelial dystrophy. SD-OCT is an imaging technique
that can be used for in vivo cross-sectional corneal
visualization. The important features of SD-OCT instruments include improved sensitivity and short acquisition time, which improves the quality of the tomograms compared with conventional time domain
OCT. Tomograms of the corneas of three patients in
different stages of Fuchs’ endothelial dystrophy are
presented. The authors conclude that 830-nm SDOCT provides clinically valuable cross-sectional assessment of pathomorphological changes in Fuchs’
endothelial dystrophy in vivo. [Ophthalmic Surg
Lasers Imaging 2008;39:S83-S85.]
From the Department of Ophthalmology, Collegium Medicum, Nicolaus
Copernicus University, Bydgoszcz (BJK); and the Institute of Physics, Nicolaus
Copernicus University, Torun, Poland (AS, MS, TB, AK, MW).
Accepted for publication April 17, 2008.
Supported by Polish Ministry of Science grants for 2006 to 2008. Dr.
Wojtkowski receives additional support from the Foundation for Polish Science (Homing project) and Rector of Nicolaus Copernicus University for the
scientific grant 504-F.
Address correspondence to Bartlomiej J. Kaluzny, MD, Department of
Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, CurieSklodowskiej 9, 85-094 Bydgoszcz, Poland.
CASE REPORT
R E P O R T
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INTRODUCTION
Cornea guttata corresponds to the presence of focal thickenings of Descemet’s membrane histologically
named “guttae.” These are mushroom-like formations
projecting into the anterior chamber. The endothelium
produces excessive amounts of basement membrane
material of an abnormal composition resulting in the
formation of a posterior collagenous layer. The endothelial cells are thinned over the guttae and degenerated, leading to endothelial disfunction and consequent
corneal edema. At this stage, the condition is called
Fuchs’ endothelial dystrophy, but some prefer to also
use this term for asymptomatic corneal guttae.1,2
Specular and confocal microscopy is currently used
for diagnosis and evaluation of Fuchs’ endothelial dystrophy. The recently introduced spectral domain optical
coherence tomography (SD-OCT) can also be used for
high-resolution corneal imaging.3,4 In this article, we present for the first time the potential of 830-nm SD-OCT in
the evaluation of Fuchs’ endothelial dystrophy.
CASE REPORTS
After slit-lamp examination, SD-OCT measurements of patients’ corneas were performed with the prototype instrument constructed at the Institute of Physics, Nicolaus Copernicus University, Torun, Poland. The
details of the SD-OCT instrument and its use for corneal imaging have been reported previously.5 The central
wavelength of the light source is 830 nm (⌬␭ = 70 nm),
and the axial and lateral resolutions of the instrument are
4.5 and 5 µm, respectively. The sensitivity of the prototype is 96 dB, and the scanning rate is 23 kHz per A-scan.
Finally, the diagnoses of Fuchs’ endothelial dystrophy
were confirmed by confocal microscopy with the use of
Confoscan 4 (Nidek Technologies; Gamagori, Japan).
Case 1
A 54-year-old woman with previously diagnosed
Fuchs’ endothelial dystrophy and moderate myopia
in both eyes was referred to the Department of Oph-
S83
Figure 1. Case 1. SD-OCT of the cornea with early Fuchs’ endothelial dystrophy. Arrow 1 points to guttae, arrow
2 to the area of intrastromal fluid. Bars
correspond to 100 µm.
Figure 2. Case 2. SD-OCT of the cornea with advanced Fuchs’ endothelial
dystrophy. Arrow points to thickened
Descemet’s membrane. Bars correspond to 100 µm.
thalmology, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland. She complained of
slightly decreased visual acuity without ocular pain. On
examination, her best-corrected visual acuity (BCVA)
was 0.9 in the right eye and 0.8 in the left eye. Her father had Fuchs’ endothelial dystrophy. Both slit-lamp
and confocal microscopy examinations confirmed the
diagnosis of early Fuchs’ endothelial dystrophy. SDOCT images of her left cornea showed highly reflective,
irregular posterior surface of the cornea with formations
protruding to the anterior chamber and corresponding
well with morphology of the guttae (Fig. 1). Moreover,
several small hyporeflective areas indicated the presence
of fluid, mostly in the posterior corneal stroma. Central
corneal thickness was 559 µm.
Case 2
A 79-year-old man, the father of the woman described as case 1, with Fuchs’ endothelial dystrophy in
both eyes observed decreased visual acuity in the 5th
decade of life. He underwent left corneal transplant
surgery in 1996. His BCVA was 0.4 in the right eye
and 0.8 in the left eye. The patient did not complain
of current major ocular discomfort or pain. Slit-lamp
and confocal microscopy examinations of the right eye
showed signs of Fuchs’ endothelial dystrophy with sig-
S84
nificant corneal edema. SD-OCT images showed features similar to those in case 1, but significant thickening of Descemet’s membrane (42 µm) was also detected
(Fig. 2). Numerous small hyporeflective areas are signs
of fluid within corneal stroma and epithelium. Central
corneal thickness was 593 µm.
Case 3
A 69-year-old woman with Fuchs’ endothelial
dystrophy in both eyes complained of decreased vision in the 6th decade of life. She had had several
episodes of ocular pain within the past 4 years. Her
BCVA was 0.3 in the right eye and 0.5 in the left eye.
Slit-lamp and confocal microscopy examinations confirmed the diagnosis of Fuchs’ endothelial dystrophy
with severe corneal edema. SD-OCT cross-sectional
images of the right cornea showed features similar to
those described in case 2, but also had two large hyporeflective areas beneath the epithelium and increased
epithelial thickness (86 µm) indicating serious edematous changes leading to early bullous keratopathy
(Fig. 3). Central corneal thickness was 668 µm.
DISCUSSION
Slit-lamp biomicroscopy is a standard technique
for cornea examination and it allows diagnosis of
OPHTHALMIC SURGERY, LASERS & IMAGING · JULY/AUGUST 2008 · VOL 39, NO 4 (SUPPLEMENT)
Figure 3. Case 3. SD-OCT of the cornea with advanced Fuchs’ endothelial
dystrophy with initial bullous keratopathy. Arrows point to bullae between
the epithelium and Bowman’s layer.
Bars correspond to 100 µm.
Fuchs’ endothelial dystrophy. However, it cannot
provide all of the information required for patient
treatment. It is necessary to check central corneal
thickness and to perform quantitative assessment of
endothelial cells. For this purpose, specular microscopy, scanning slit confocal optical system, or confocal laser microscopy are currently used.6,7 These techniques provide cellular level images and can be used
for en face imaging and histological investigation of
the cornea, including endothelium. Corneal thickness can also be measured.
SD-OCT, also known as Fourier domain, highspeed, or three-dimensional OCT, is a new imaging
technique that can be used for in vivo cross-sectional
corneal visualization.3,4 The important features of
SD-OCT instruments include increased sensitivity
and shorter acquisition time, which improves the quality of tomograms in comparison with conventional
time domain OCT. Moreover, three-dimensional and
real-time imaging are possible.8 The advantage of the
830-nm light source, used in our prototype, is an increased axial resolution of 4 µm compared with 18
µm achieved by the commercially available Visante
instrument (Carl Zeiss Meditec Inc., Dublin, CA)
with a 1,310-nm light source.
The 830-µm SD-OCT facilitates precise visualization of the pathological changes within the corneas
with Fuchs’ endothelial dystrophy. It can detect guttae,
thickening of Descemet’s membrane, and stromal and
epithelial edema at early stages. Moreover, this technology is capable of providing accurate measurements
of not only total corneal thickness but also Descemet’s
membrane and epithelial thickness. Thus, SD-OCT
appears to be useful for documentation and monitoring of the progression of Fuchs’ endothelial dystrophy.
Unfortunately, current SD-OCT prototypes cannot be
used for quantitative endothelium evaluation.
CASE REPORT
The 830-nm SD-OCT allows precise cross-sectional assessment of pathomorphological changes in Fuchs’
endothelial dystrophy in vivo. It has the potential to
improve evaluation, monitoring, and treatment of this
corneal disease.
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