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

info@vincieye.it

Thank you for your attention