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Argus 2: The Bionic Eye
Transcript of Argus 2: The Bionic Eye
Breakdown of Device
Active Implantable Device Surgically Implanted on & IN the eye
Interim Results From the International Trial of Second Sight's Visual Prosthesis
At the 2011 annual meeting of the Association for Research in Vision and Ophthalmology (ARVO), researchers presented data from a clinical trial of 30 people blinded by RP or other retinal disease who underwent implantation of the Argus II device at 10 eye surgery centers worldwide over a four-year period.
International Trials for Visual Prosthesis
Is viewed as a group of diseases affecting how light-sensitive cells in the back of the eye function
Overview of Retinitis Pigmentosa
Second Sight Medical Products has developed the Argus II Retinal Prosthesis System (“Argus II”). It is the world’s first and only approved device intended to restore some functional vision for people suffering from blindness due to severe to profound RP. Moreover, it offers the following benefits:
Improvements in ability to perform visual tasks demonstrated in many patients
Minimal time from implantation to first system use and use at home
by Second Sight
A little Terminology!
They actually studied this!!
Statement Of Compliance
30 Subjects had electrode array in macula region
All Patients had RP and One Patient had Choroideremia
They all had NO light Perception and history
of Useful form of Vision.
Some Exclusions are:
We even have a 'PenSoc'(penfight society)!
"The Bionic Eye"
I picked this topic because lets face it this is some cool stuff and the eyes are probably the most fascinating aspect of our body!
Argus 2 by Second Sight
Approved by the FDA Feb of last year
Medicare Provides Payment
Snippet From Media Article
The layer of tissue at the back of the inner eye
that contains photoreceptor cells
Group of inherited diseases that cause
retinal detachment in the eye
Why is this important?
It converts light images captured
from your visual fields
into nerve signals
& sends them back
to the brain
(via Optic Nerve)
When a portion of the retina comes loose from the back of the eye, the separation is called retinal detachment.
WHAT HAPPENS THEN?!
is usually lost first
and if the
all vision in that eye
may be completely lost.
Consisting of Rods (black and white vision) and Cones (color vision)
The Argus II system includes a tiny video camera that is built into a special pair of eyeglasses.
The camera is connected to a small, wireless device worn by the patient, which coverts the video input to electronic signals that are transmitted wirelessly to the implant in the eye.
The implant uses this information to stimulate remaining healthy cells in the retina, and visual information is thereby transmitted by the optic nerve to the brain, where it is perceived as patterns of light.
The patient learns to interpret these patterns so he or she can distinguish the outlines of objects.
OKAY, wait what?
What does this look like
only that it is inherited
The eye condition is associated with at least 32 different genes.
At times, the genetic trait is dominant and likely to be passed along to a child when a parent has RP.
At other times it is recessive and may be present for many generations before it appears in a family member.
The first signs usually occur in early childhood, when both eyes typically are affected.
Night vision can be poor, and the field of vision may begin to narrow.
Currently there is no cure, but several companies are developing retinal implants
NONE OTHER THEN...!!!!!
Complies with each countries National Regulations For Medical Device Clinical Trials
Approved by the National Ministries of Health
All Patients signed Informed consent to participate
~ 50 Years and older
Inability to implant the device physically
Complicating Ocular Pathology
Inability to commit to the expectations & duration of the study
*All subjects were followed for 6months-2.7years
Small camera + Transmitter mounted on glasses
Video Processor + Battery Worn on belt with Shoulder Strap
6x10 Electrode Array!!
8mg of Dexamethasone + 1g Cefazo
lens was removed via Clear cornea phacoemulsification
360* limbal conjunctival peritomy
Isolating the rectus muscle using 2-0 black silk
Coil placed temporally on the globe
Then centered on the Lateral Rectus Muscle
Electronic Package centered in Superior Temporal Quadrant
Implant was fixed on the eye via sutures passed through suture tabs (in both temporal quadrants)
Core & Peripheral Vitrectomies
Dissection of any Epiretinal Membrane surrounding area of the array
The micoelectrode array was insterted through temoral sclerotomy (5mm)
It was palced on the retina in the macula
Then tacked using retinal tack
The extraocular portion of cable was sutured to the sclera & all Sclerotomies were sutured
An Allograft was sutured and draped over electronic package to reduce likelihood of Conjunctival irritation
Finally the tenon's capsule and conjunctiva were sutured
500 mg Ciprofloxacin (2xday for 7-14 days)
1 drop Gatifloxacin (4xday for 7-14 days)
60 mg daily Prednisolone (orally 2 weeks)
Immediately followed by Methylprednisolone (medrol - 8 mg)
1 drop Pred Forte 1% (4xday for 2 weeks)
1 drop Atropine 1% (2weeks)
STEP BY STEP ACTIONS
The Latin word “Argus” refers to a giant in Greek mythology with 100 eyes, Argus Panoptes, who was considered all-seeing. Argus was the servant of Hera, goddess of women and marriage as well as the wife of Zeus. Zeus seduced the nymph Io who was also the priestess of Hera. In order to hide her from Zeus, Hera transformed her into a white heifer and asked Argus to watch over Io and protect her from Zeus.
Did You Know...?!?
For More Info
At the End of the Surgery
2mg of Dexamethasone
100 mg of Cefazolin
2 ml of Lidocaine
Injected under Conjunctiva
Subjects were evaluated on:
Weeks 1,2 and 4
Months 3,6,9,12,18,24,30 and 36
Subjects were allowed to use the system outside of clinic setting (aka in their daily lives) once it had been individually programmed & they had completed their training
Serious Device/ Surgery-Related events
Were reported to the relevant competent authorities & ethics committees
During each follow-up the following were performed:
Complete Eye Exams (Including IP)
Retinal Fundus Photography
Optical Coherence Tomography (OCT)
During trial all adverse events were subject to detailed review by independent medical safety monitor (IMSM)
as individual events
Full-Field Stimulus Light Threshold
In all Subjects measured there was no significant difference between threshold obtained before or after surgery
Outside Outpatient Clinical Use
Take Home: 1.4-3.7 months | Median 2.1 months
29/30 were using it at home on 03/01/2010
In use for: 4.2-28.8 months | Median 14.3 months
Rectangular Grid: 6x10
94.4% of electrode were enabled remained functional throughout study
Perception Threshold for Electrical Stimulation
All subjects (100%) were able to perceive light when their Systems were stimulated
Shows Mean Distance From the Center of the Target for System ON and OFF
Direction of Motion
Shows Mean Response Error With the system ON and OFF
Grating Visual Acuity
None of the Subjects have been able to score on the visual acuity scale in either eye with the systems OFF
Orientation & Mobility
Events related to device/surgery that did NOT require surgical intervention
A few More Methods...
The term "Subjects" instead of Patients
Explanation of some of the terms
Clarification of where the Patients/Clinics were located throughout the world
Elaboration of the Program used to measure thresholds
Full-Field Stimulus Light Threshold
Subjects "Residual Native Light Perception" was measure before & after implantation using the following protocol:
The Subjects' eyes were dilated & dark-adapted for 30 min
Outside Outpatient Clinic Use
Subjects were trained to independently set up and use the system & to respond to audible alarm states
Subjects were also trained to use the system to perform everyday tasks and activities
All Microelectrode Arrays includes 60 electrodes
Two Kinds of Test:
Subjects were asked to localize a white square on a black background
Direction of Motion:
Subject were asked to indicate the path of white line swept across a black background
Grating Visual Acuity:
Subjects were asked to differentiate the orientation of black & white bars of a range of widths
Real World Utility
Subject were asked to find a door across a room
Subjects were asked to follow a white line on the floor
The Median Number of enabled electrodes at the time of implant was 55 (46-60 due to conservative policy of shutting off electrodes that didn't meet stringent stimulation criteria)
Visual Acuity at Baseline
Unequal visual acuity:
Implantation was done in their worse eye
Equal Visual Acuity:
The right eye was selected for implantation
67% of subjects had their natural lens removed via clear cornea phacoemulsification
& they were left Aphakic
Most had allografts placed over extraocular portion of device
* The median implant surgery time was 4 hours and 4 minutes
Figures of Surgeries Provided by Article
26 were implanted in their right eye
4 were implanted in their left eye
*Patients with lens Pseudophakic did not undergo lens explantation
* France doesn't allow the use of allografts they received a PTFE Patch
(Range: 1:53 - 8:32)
The longest implant procedure was prolonged due to the fact that the patient had several previous surgeries on the implanted eye.
What were the adverse effects?!?
17 serious SAE's
High Intraocular Pressure
Mild Vitreous Hemorrhage
This study represents 45.6 cumulative subject-years in 30 Human Subject Implanted with Argus 2
Glaucoma Drainage Device
Rate of Conjunctival Erosion
NONE of the subjects implants had to be taken out -- ALL remained functional even with the cases with Endophthalmitis after they were treated with antibiotics
Rate of Retinal Detachment was 6.7% occurring in 2/30 of the subjects
High probability because subject had experienced blunt trauma to that eye.
Retinal Detachment reported between 8.5-9.5%
Reliability of Prosthesis
94.4% Remained Functional
96% can localize high-contrast on computer screen
57% can detect direction of motion of a high contrast bar
23% were able to score on the Grating Visual Acuity Test
Reliable over Long Term
Provided benefit to implanted Subjects
Prosthesis subjects improved visual acuity from light perception to at least hand motion
In our trial
Rate of Conjunctival Erosion