Download Diapositiva 1 - ASCRS/ASOA 2009

Department of Ophthalmology
University of Siena, Italy
PTERYGIUM PROGRESSION
DETECTED BY IN VIVO
CONFOCAL MICROSCOPY
Martone Gianluca, Malandrini Alex,
Balestrazzi Angelo, Tosi Gian Marco,
Pichierri Patrizia , Caporossi Aldo
No author has a financial
or proprietary interest in
any material or method
mentioned
Introduction
Pterygium is a benign growth of the conjunctiva from
the nasal side of the sclera towards the centre of the
cornea. It is associated with, and thought to be caused
by ultraviolet-light exposure. The pathogenesis is still
debated (1). The histopathology is characterized by
basophilic degenerative fibrovascular tissue invading
the superficial cornea with destruction of the
underlying Bowman’s membrane.
IVCM is becoming a useful diagnostic tool for ocular
surface imaging to describe limbus and corneal
diseases (2). It can provide details of ocular structures
at the cellular level . In some studies, IVCM was used to
examine the typical structure of pterygium (3-4).
Purpose
To perform a qualitative assessment of
anatomical and pathological changes in
the cornea and conjunctiva of patients
affected by pterygium and to describe the
typical components of progressive and
not-progressive pterygium by IVCM.
Methods
40 eyes of 32 patients with primary pterygium was examined
by slit lamp examination and IVCM in a prospective
randomized double blind study.
IVCM (Heidelberg Retina Tomograph II with the Rostock
Cornea Module) analysis was performed in two different
corneal areas, in the central and peripheral pterygium
zone. The IVCM images (400 µm x 400 µm) were acquired
from the periphery to central pterygium areas. During the
examination, all subjects were asked to fixate external light
target in order to good visualization of the pterygium. All
eyes were evaluated at baseline, after 6 and 12 months. After
12 months they were classified in two groups:
progressive and non-progressive group.
Results: Progressive group
Actvated keratocytes and stromal
edema at body of pterygium
Cloudy and hyperreflective
margin of the apex head
Irregular corneal
epithelium adjacent to
the pterygium head
and not well defined
transfer zone
Many capillaries and an important infiltration
of dendritic cells in pterygium head
Hyperreflective formations as scars that
could be Bowman’s membrane breaks
Results: Not progressive group
Reduction of stromal edema with low
activated keratocytes and low
inflammatory cells and vessels
Many irregular hypereflective areas were
also present between the head of pterygium
and adjacent cornea (Fuchs' dots)
Irregular epithelium morphology adjacent to
the head of the pterygium but the margins are
well defined
Bright intracellular inclusions in the basal
epithelial cell layer (Stoker’ s line) and the
surrounding epithelium appears absolutely normal
Discussion
In this study, IVCM was used to examine the typical structure of
primary pterygium. The body and the head of the pterygium and the
corneal epithelium and stroma adjacent to the pterygium head were
characterized by the presence of different findings between the
progressive and not-progressive groups.
Significant correlations were found between clinical progression of
the pterygium and IVCM parameters.
Furthermore, the findings obtained by IVCM suggest that it may be
helpful as a non-invasive and uncomplicated method to study the
anatomical structural corneal and conjunctival changes in
patients with pterygium and understanding its condition of
progression.
Larger studies should be carried out to understand further the
changes at the level of the cornea induced by the pterygium and
correlate them with signs of clinical progression to plan the surgery.
References
1. Hill JC & Maske R. Pathogenesis of pterygium. Eye
1989;3:218–226.
2. Cavanagh HD, Petroll WM, Alizadeh H et al. Clinical and
diagnostic use of in vivo confocal microscopy in patients
with corneal disease. Ophthalmology 1993;100:1444-54
3. Papadia M, Barabino S, Valente C, Rolando M. Anatomical
and immunological changes of the cornea in patients with
pterygium. Curr Eye Res 2008;33:429-34.
4. Gheck L, Dupas B, Denion E, Amar N, Baudouin C.
Advantages of in vivo confocal microscopy for investigation
of the pterygium. J Fr Ophtalmol 2007;30:703-10.