maia new clinical presentation

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Confocal Microperimetry:

Macular function &

Visual Rehabilitation

Marco U. Morales Chief Scientific Officer

Ophthalmology & Visual Science PhD Program University of Nottingham

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Microperimetry Scope: To analyse vision

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Microperimetry Scope: To analyse vision

In patients with macular pathologies

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Dry AMD

Wet AMD

Vitelliform Dystrophy Myopic Macular degeneration

CENTRAL VISION LOSS

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RETINAL IMAGING

( SLO )

SENSITIVITY TEST

EYE TRACKING

-eye movement

-fixation information

(PRL)

Micro-Perimetry Concept

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RETINAL IMAGING

( SLO )

SENSITIVITY TEST

EYE TRACKING

-eye movement

-fixation information

(PRL)

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RETINAL IMAGING

( SLO )

SENSITIVITY TEST

FIXATION ANALYSIS

Fixation Location

&

Fixation Quality

PRL (Preferred Retinal Locus)

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Function of the Healthy Macula

Fixation STABLE

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Function of the Healthy Macula

Sensitivity Avg > 25 dB

#

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Function of the Unhealthy Macula

Sensitivity Avg. < 25 dB

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% Reduced Threshold to measure localized defects

(maia Integrity Index)

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Fixation UNSTABLE

PRL

PRL

PRL

PRL

Different PRL location during the same fixation attempt.

PRL on patients with loss of central vision

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Estimated foveal location

Fixation Drift indicates abnormal macular function

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Wet AMD Patient

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Wet AMD Patient

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Fixation points (ploted by the Eye Tracker)

Sensitivity points (dB) (Goldman III stimuli test)

Sensitivity points (dB) (Goldman III stimuli test)

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Fixation = Stable If P1 and P2 > 75 % Fixation = Relatively Unstable If P1<75% but P2> 75%, Fixation = Unstable If both P1 and P2 < 75%

Fixation stability is classified as:

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During the examination, patients are asked to look at the central fixation target in the MAIA microperimetry (1° red circle)

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Estimated fovea location

If the fovea is not in good conditions, patients use an extra foveal locus to perceive the fixation target.

PRL initially used to “see” the fixation target

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MAIA use the initial PRL ( 10 initial seconds of examination) to automatically center the stimuli grid map on it

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During the whole examination the cloud of fixation points are identified and measured by the area known as the Bivariate Contour Ellipse Area (BCEA)

BCEA

6/17/2015 29

PRL_initial

PRL_ final


At the end of the examination it is easy to recognise both, the initial and the final PRL

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Macula Clinic

Eccentric Viewing

Rehabilitation

Cataract Surgery

CLINICAL APPLICATIONS

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Macula Clinic

Eccentric Viewing

Rehabilitation

Cataract Surgery


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Wet AMD Patient

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PRL_initial = Foveal

PRL_final = 3.5° Superior

Avg sensitivity central 10° = 14.1 dB

Avg perifoveal sensitivity = 11.4 dB

Is ∆PRLi-f an important prognosis factor?

Morales et al: “PRL profile during prolonged fixation attempt”

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Macula Clinic

Eccentric Viewing

Rehabilitation

Cataract Surgery


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Macular integrity assessment prior cataract surgery

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With a slit lamp and fundus camera, it may be difficult to see specific retinal details in presence of cataract.

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Thanks to the Scanning Laser Ophthalmoscope confocal technology, early cataracts can be seen reflected as dark shadows over the retina image.

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… and in the case of dense cataracts, the SLO confocal technology is able to “see” the retina even up to grade 3+ opacity.

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Confocal technology

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Confocal technology

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Macular Integrity Assessment

in patients with cataract.

Case reports

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CASE 2: Male, 80 years old, OD - IOL OS - cataract

MAIA helps with the decision of performing cataract surgery on the fellow eye.

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The SLO image on OS shows signs of cataract

OD - IOL OS cataract

CASE 2: Male, 80 years old, OD IOL OS cataract

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MAIA shows considerable reduced average macular sensitivity on the IOL-eye (5.7db), although fixation (represented by the blue dots) is highly stable and central.


OD - IOL

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The sensitivity detail shows low sensitivity on the perifoveal area with dense RING-scotoma on the perimacular area


OD - IOL

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The MAIA test on the cataract eye (OS) shows higher

macular average sensitivity (16.3 dB) than the fellow

eye, with stable and central fixation (good foveal

function).


OS - cataract

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The MAIA information helped the surgeon and his patient in the decision to proceed with the cataract surgery on OS.


OS - cataract

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CASE 3: Female, 81 years old, OD cataract, OS cataract with Geographic Atrophy (GA)

MAIA helps in the decision to perform cataract surgery.

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The MAIA test on OD showed relatively good average sensitivity (yellow area) and excellent fixation stability suggesting good prognosis after cataract surgery. In contrary, OS has low retina sensitivity and very unstable fixation suggesting poor BCVA prognosis after surgery.

Fixation stability

Retina sensibility Avg threshold = 11.3dB Retina sensibility Avg. threshold = 20.4 dB

Fixation stability

CASE 3: Female, 81 years old, OD cataract OS cataract + GA

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Macula Clinic

Eccentric Viewing

Rehabilitation

Cataract Surgery


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MAIA in the Low Vision practice is used to

“Relocate PRL with Biofeedback techniques”

The aim is to gain control involuntary bodily function.

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What is BioFeedback ?

Biofeedback is a treatment technique in which patients are trained to improve their health by using signals from their own bodies.

Instruments measure physiological activities and “feed-back” such information in real time to create a awareness of their body condition.

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The MAIA Biofeedback training

A beep sound guides the patient during the eye movement control exercises.

= patient fixation

= target fixation

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PRL OD Before Rehabilitation V.A. = 1.0 LogMAR

(6/60 – 20/200 – 0.10)

PRL OD After Rehabilitation V.A. = 0.60 LogMAR (6/24 – 20/80 – 0.25)

Examples of PRL training with Biofeedback

Severe vision loss Moderate vision loss

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Examples of PRL training with Biofeedback

PRL OD Before Rehabilitation V.A. = 0.8 LogMAR

(6/38 – 20/125 – 0.16)

PRL OD After Rehabilitation V.A. = 0.5 LogMAR (6/19 – 20/63 – 0.32)

Moderate vision loss Mild vision loss

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Binocular Analysis for PRL rehabilitation

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http://casereports.bmj.com/content/2015/bcr-2014-207969.abstract

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XV Congresso Nazionale della Low Vision Academy, MILANO, 2014 61

VA = 1.0 LogMAR (OO)


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Analysis of both eyes

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XV Congresso Nazionale della Low Vision Academy, MILANO, 2014

OCT to determine the foveal location

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Definition of the best PRL Target

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Reading Reading

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Reading Reading

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CONCLUSIONS Confocal Microperimetry may be considered as a valuable tool in the evaluation of retinal function, particularly in cases with central scotoma. Microperimetry values of localized retinal sensitivity, fixation stability and fixation location are precise parameters to monitor pathologies progression and may be considered as important prognosis factor for visual therapies. 70

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GRACIAS [email protected]

[email protected]

mailto:[email protected]

mailto:[email protected]

maia new clinical presentation

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