1st EuCornea Congress

1st EuCornea Congress venice, 17-19 june 2010
INVITED SPEAKERS
Hannush, Sadeer B.
The new corneal triple procedure: EK/CE/IOL,
simultaneous or sequential
S Hannush
Pennsylvania, USA
This lecture will discuss indications for endothelial keratoplasty (EK) and
cataract surgery with particular emphasis on the advantages and limitations
of combined vs sequential surgery
Kaminski, Stephan
Eye banking in Europe. Past, present and future
S. Kaminski
Eye Bank Vienna, Dept. of Ophthalmology, Medical University of Vienna,
Austria
Galen (AD 130-200) suggested the concepts of restoring the transparency
of an opaque cornea, but it took until 1905 for the first successful transplant
in human (Zirm). In 1910 Magitot began research on preservation of human
corneal tissue in Paris- the birth of eye banking. Nowadays the European
Eye Bank Association (EEBA) has 83 member banks from 22 European
countries. The vast majority is using organ culture at 31°C. Approximately
28.000 corneas were stored (data EEBA, 2007) and approximately
18000 corneas were transplanted (including lamellar techniques). In
2004 the European Union tissues and cells Directives were implemented.
This directive sets standards for the quality and safety for the donation,
procurement, testing, processing, preservation, storage, and distribution
of human tissues and cells. On one hand this directive should assure
the quality of corneas throughout Europe, on the other hand corneas will
become more expensive due to adaption of the eye banks. Whether the
directive will improve the overall quality and safety of corneas is unclear.
FINANCIAL DISCLOSURE: 0
Kanna, Ramesh
Corneal limbal stem cells: entity or function Fact or
fiction
K. Ramaesh
Gartnavel General Hospital, Glasgow, UK
Corneal epithelial maintenance has been attributed to a unique population.
A convincing and definitive marker to define the corneal limbal stem
cell as an entity has defied the investigators so far. Potten and Loeffler
defined stem cells by virtue of their functional attributes. ‘ stem cell are
undifferentiated cells capable of (a) proliferation, (b) self maintenance ,
(c) producing a large number of differentiated , functional progeny, (d)
regenerating the tissue after injury and (e) a flexibility in the use of these
options.1 This definition concept was rather arbitrary and was not based
on experiential evidence. Extrapolating this concept to explain corneal
epithelial maintenance developed into limbal stem cell concept. Corneal
epithelial homeostasis - stem cell Hypothesises 1. corneal epithelial
homeostasis depend on the peripheral epithelial proliferation and migration.
2. limbal stem cells: corneal limbus has stem cells that are responsible for
the epithelial cell maintenance 3. These stem cells are poorly differentiated
;the cytoplasm of SC appear primitive and contains if any differentiation
products 4. these cells have high capacity for self renewal with an
increased potential for error free proliferation and cell division. 5. SC have
long life span 6. stem cells have long cell cycle time . although stem cells
have high proliferative capacity under steady state conditions are in low
rates of proliferation. 7. cell division within stem cells can be intrinsically
asymmetric, asymmetric only with regress to daughter cell fate or
symmetric limbal stem cell is an entity many of the above features cannot
be proven and experimental evidence does not exist. . However it may be
possible to explain the corneal epithelial hypothesis based on conditional
speciation (during development), cell cycle and cell polarity regulation.
Corneal epithelial homeostasis- conditional specification, cell cycle and
cell polarity hypothesis 1. corneal epithelial homeostasis depend on the
peripheral epithelial proliferation and migration 2. during embryogenic
periods each cell originally has the ability to become any of the many
different cell type. However interaction of the cell with other cells restrict the
fate of the cell. This phenomenon is called conditional specification because
the fate of a cell depends upon the conditions in which the cells finds
itself. The cells at the limbus that maintain the homeostasis are specified
cells by the condition and the fate has been determined due to regulative
development. 3. Epithelial cells polarize along their apico-basal and planar
axes and separate apical from basolateral membrane compartments during
development. Mature epithelial cells are highly polarized with separate
apical and baso-lateral membrane compartments, each with a unique
composition of lipids and proteins. Within mature epithelial tissues, cell
polarity regulates cellular morphology, intracellular signaling, asymmetric
cell division, cell migration, cellular and tissue physiology as well as
complex organ morphogenesis. It is the capacity of the limbal basal
epithelial cells to mainatin cell polarity that mainatins corneal epithelial
homeostasis. 4. the cell at the limbus and peripheral cornea are at different
phase of cell cycle. Depending on which phase of the cell cycle the cell
may display different capacity to proliferate in vivo and in vitro. ( so called
colony forming efficiency) conclusion based on conditional specification,
cell cycle and cell polarity hypothesis: Corneal epithelial regulation is due
to functional interplay of cellular polarity and cell migration of condition
specified(during development) cells.
Katsanevaki, Vikentia
SubBowman’s keratomileusis for hyperopia and
hyperopic astigmatism
V. Katsanevaki
Orasis Eye Center Athens, Greece
Purpose:To present the clinical results of SubBowman’s keratomileusis
for hyperopia and hyperopic astigmatism
Methods: 146 eyes of 76 patients underwent hyperopic LASIK for the
correction of hyperopia and hyperopic astigmatism and the alleviation of
presbyopia Mean patients’ age was of 46,2 ± 10,8 ranging from 19 to 71
years. Mean attempted correction was of 2,87 ± 1,68 D ranging from 1
to 7,37 D and mean preoperative cylinder of 1,11 ±1,22 ranging from -1
to -6 D. All the operations were performed by a single surgeon using the
Wavelight Alegretto laser platform and a mechanical microkeratome for
the flap creation (Schwind , carriazo pendular). The enrolled patients were
followed @ 1 day, 1 week, 1,3,6 and 12 months post the surgery and yearly
thereafter
Results:1 year after the treatment the mean spherical equivalent was
of 0,052 with mean uncorrected visual acuity of 0,996. The efficacy index
(UCVA post surgery/ BCVA pre surgery) was 1 or higher in 76,99% of the
treated eyes with 85,71% of patients having binocular near vision of J4 or
better.
Conclusions:Hyperopic SBK is safe and effective treatment and
can substantially improve unaided near vision of presbyopic patients.
Realization of goals remains the mainstay of successful corrections and
happy patients
Koller, Tobias
Failure and complication rates of corneal
crosslinking (CXL)
T. Koller, T. Seiler
Zurich, Switzerland
So far, CXL has been heralded as a procedure attributed with nearly no
complications and success in all cases. However, reliable prospective data
are still missing. In a prospective trial with completed a 1 year follow-up
a complication was defined by a loss in BSCVA of 2 Snellen lines and a
failure by means of an increase of Kmax (Pentacam) by 1 D and more.
The study group included 117 eyes. The compliction rate was 2.8% and the
failure rate was 7.6%. When respecting the following risk factors : age>35
years, Kmax>58 D, and BSCVA>0.8 the complication rate drops to 1% and
the failure rate to 2.8% Based on this data CXL may be considered safe
and effective only if the inclusion criteria are respected.
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