ESASO, Rozzano 29-30 aprile 2016 Astigmatism, tear … · ESASO, Rozzano 29-30 aprile 2016 Paolo...
Transcript of ESASO, Rozzano 29-30 aprile 2016 Astigmatism, tear … · ESASO, Rozzano 29-30 aprile 2016 Paolo...
ESASO, Rozzano 29-30 aprile 2016
Paolo Vinciguerra, M.D.1, 2
Riccardo Vinciguerra M.D.4
Silvia Trazza, orth3
1Associate Professor Ophtalmology, Department of Biomedical
Sciences-Humanitas University.
Director Eye Centre- Humanitas Research Hospital 2 Visiting Professor Columbus, Ohio State University 3 Eye Centre- Humanitas Research Hospital 4 Varese Insubria University, Humanitas Mater Domini
Astigmatism, tear
film and epithelium
Dry eye induces…
Surface irregularities
Epithelium irregular layering
H.O.A.
Astigmatism
Visual loss
H.O.A.
Surface irregularities
Low contrast images
Dry eye induces…
Ring
•Undefined
•Broken
Epithelium
irregular
layering
Irregular Astigmatism
How to diagnosis astigmatism coming
from dry from regular astigmatism?
Look at:
Dellen in slit lamp
Tear film in dynamic keratoscopy
Dynamic tear film observation
Keratoscopy images
Evaluate corneal H.O.A.
OCT of anterior segment Epithelial
maps
Local dehydration of the cornea
Dellen at Corneal limbus at slit
lamp
Despite this ‘’thinning’’ none of the cornea is lost; It’s just dehydrated
Dynamic tear film (TF)observation:
TF-Scan
Quality evaluation and quantity tear
film evaluation
Good view of tear film flow
Dynamic keratoscopy
Non-invasive exams
Does not alter corneal surface or tear
film as other examination methods
Different observations pattern
Mucin layer
Acqueous layer
Lipid layer
Microvilli
Corneal
Epithelium
Microplates
Large network pattern
~13 - 50nm
~13 - 50nm
~50 - 70nm
~>200nm
~90-180nm
~80 - 90nm
Lipid droplet
Coloured
interference
pattern
Amorphous pattern
Waved pattern (
LIPID)
Irregular network
pattern
15 %
14 %
29 %
6 %
17 %
19 %
Ocular Tear film
TF-Scan Makes the Tear Film Visible
In cases of dry eye patients the tear film should be examined carefully.
This software shows the quality and quantity of the tear film.
measures the tear film breakup time non-invasively (quality assessment).
Shows tear film quality using the colour maps
The graph shows % of the examined area that is affected during the measuring period
Tear film break-up time (NIKBUT) in seconds The break-up areas detected by the
software are highlighted accordingly.
Quantity and Quality of the Tear Film
Tear Meniscus Height
It’s possible to evaluate the course of the tear
meniscus along the eyelid by means of the infrared
illumination; it measures the tear meniscus height with
the built-in ruler
Evaluation of Lipid Layer: Record a video.
Distribution characteristics, morphology and
thickness of the lipid film can be continuously
evaluated
Tear film Dynamics:
Evaluate the quantity and movement of particles
on tear film
Dry eye and Meibography The dysfunction of meiboniam glands is the most
frequent cause of dry eye. Morphological
changes in the gland tissue are visible
Keratoscopy
Rings are:
Broken
Undefined
Low contrast images
Floating particles on tear film (this causes
processing errors)
Low tear flow on corneal surface
Keratoscopy
Corneal HOA dry eye pre vs post
teraphy
Epiyhelium map Cheratoscopy
Min 47-max 70 µ
Min 52-max 54 µ
OCT and epithelial maps
Useful to differentiate:
Epithelial damage coming from dry
eye, warpage, true astigmatism
Hidden old sub epithelial scars
Epithelium as an indicator of normal
tear film
Warpage
Epithelium map 6 mm
Min 45-max 61 µ
Warpage: compare 2 examination
Epithelium as an indicator of normal tear film
Hidden old subepithelial scars
Epithelium map 6 mm
Min 38-max 53 µ
Dry eye and OCT epithelial maps 1°
Thin epithelium is a sign of suffering
Sometimes epithelium can be thick
and fluffy as sign of suffering
When is thin nerve layer are closer to
surface and this can explain typical
dry eye symptoms
Even if abnormally thick and fluffy the
epithelial layer is not well attached
and can explain the same symptoms
The epithelial layer is not well attached …
Min 40-max 57 µ
Dry eye and OCT epithelial maps 2°
We can use epithelial maps to follow dry
eye therapy and obtain a objective
evaluation of the outcome
More repeatable, sensitive, linked to
symptoms even when other sign does not
show any evidence
Always link epithelial maps to keratoscopy
rings
Sub epithelial membrane
Normal epithelium
Irregular layering
Bumpy epithelium
Epithelial maps & keratoscopy rings
Post therapy
Pre Post
Rings show the surface regularization
Min 41 µ
Max 48 µ Min 45 µ
Max 51 µ
Dry eye, OCT epithelial maps and rings
Rings normalizations show the surface
regularization
OCT maps shows when an efficient
layer is rebuilt
Usually the first sign of normalization is
rings quality
Normal epithelial pachymetry follows
OCT maps : layer is rebuilt
Pre tp
Post tp
Maps change post refractive
surgery overtime Epithelium map Pachymetry map Pacido image Instantaneus map
Pre
Post
What to look in OCT epithelial maps
Homogeneous pachymetry
The max difference between thinnest
and thickest point
Local thinning
Where abnormalities are
Look where abnormalities are present
if in the same area stromal defects are
present
Homogeneous pachymetry and
epithelium map
• Irregularities are present in the epithelium map
Pachymetry map 6 mm Stroma map 6 mm Epithelium map 6 mm
• Irregularities are present in the pachymetry,
stroma and epithelium map
Pachymetry map 6 mm Stroma map 6 mm Epithelium map 6 mm
Dry eye and therapy follow up
A single map can not explain a lot
Look the maps change overtime
Relate the maps change to pts symptoms
Relate to rings change
Usually pts respond very well to specific
therapeutic prescription and not to others
Use this sign to adjust prescription change
overtime
epithelial maps & topographic maps :follow up Dry eye therapy
First observation 1 mos 2 mos
When suspect dry eye from
topography maps
“Noisy maps”
High change of corneal curvature in a
small area
Important changes between two
maps taken sequentially
During acquisition rings appear to
change constantly
Floating particle ( if not make up)
Dry eye and refractive or lens
surgery
Dry eye is a contraindication to
refractive surgery
Always fix the pathology before surgery
Dry eye induces surface , corneal
curvature and H.O.A. changes
Planning any surgery in this conditions
leads to unpredictable outcome
Dry eye is a contraindication to refractive surgery
Pachymetry map Epithelium map
Astigmatism coming from dry eye OSV 0,8 +1,25(-1,25)170
Modalities of Therapy Selection
From dynamic tear film observation try
to defines the ”weak layer”
Use eye drops that can restore the
weak layer
Follow up with the appropriate
diagnostic tools
New pharmaceutical substance have
reached the market
1Associate Professor Ophtalmology, Department of
Biomedical Sciences-Humanitas University.
Director Eye Centre- Humanitas Research Hospital 2 Visiting Professor Columbus, Ohio State University
3 Eye Centre- Humanitas Research Hospital
Thank you for your attention