Post on 09-Jan-2017
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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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Micro-Perimetry Concept
RETINAL IMAGING
( SLO )
SENSITIVITY TEST
EYE TRACKING
-eye movement
-fixation information
(PRL)
#
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Micro-Perimetry Concept
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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Function of the Unhealthy Macula
% Reduced Threshold to measure localized defects
(maia Integrity Index)
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Function of the Unhealthy Macula
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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Estimated fovea location
MAIA use the initial PRL ( 10 initial seconds of examination) to automatically center the stimuli grid map on it
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Estimated fovea location
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
Estimated fovea location
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
CLINICAL APPLICATIONS
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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
CLINICAL APPLICATIONS
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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.
CASE 2: Male, 80 years old, OD IOL OS cataract
OD - IOL
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The sensitivity detail shows low sensitivity on the perifoveal area with dense RING-scotoma on the perimacular area
CASE 2: Male, 80 years old, OD IOL OS cataract
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).
CASE 2: Male, 80 years old, OD IOL OS cataract
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.
CASE 2: Male, 80 years old, OD IOL OS cataract
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
CLINICAL APPLICATIONS
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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)
VA = 0.5 LogMAR (OO)
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VA = 1.0 LogMAR (OO)
VA = 0.5 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 msxmum@nottingham.co.uk
marco.morales@centervue.com