Optics: Retinal Prosthesis

Question 1

About _______ % of retinal area encodes large portion of information

Answer 1

0.01%

Question 2

In the early stages of RP, are rods or cones more severely affected?

Answer 2

Rods

Question 3

People with RP experience ________ blindness and a progressive loss of __________

Answer 3

Night blindness and a progressive loss of the visual field

Question 4

In the late stages of RP, cones die which affects the VF in what way?

Answer 4

Loss of more visual field leading to tunnel vision

Question 5

Both AMD and RP are characterized by a significant loss in ___________ or ___________

Answer 5

Spatial resolution or visual acuity

Question 6

What conditions are the criteria for being able to use visual prosthetics, bionic eye or artificial vision?

Answer 6

Conditions where blindness is due to a disease in the photoreceptors in the retina like RP or AMD wherein the neural connections are intact

Question 7

The implantable miniature telescope is an ophthalmic device developed to improve vision in individuals who have lost vision due to __________

Answer 7

AMD

Question 8

The IMT is used to _________ objects in the central visual field

Answer 8

Enlarge

Question 9

The IMT focuses the image onto what areas of the retina?

Answer 9

Healthy areas that are not affected by AMD

Question 10

IMT is a telescopic prosthesis that combined with the optics of the cornea constitutes an ___________ magnifying system

Answer 10

Intraocular

Question 11

Is the IMT telescope prosthesis implanted in both eyes?

Answer 11

No, just one

Question 12

The implanted eye provides __________ and the non-implanted eye provides __________

Answer 12

Improved visual acuity

Peripheral vision

Question 13

Supra-choroid implants are positioned between the ________ and the _______

Answer 13

Sclera and the choroid

Question 14

What condition is treated with Supra-choroidal implants?

Answer 14

Retinitis pigmentosa

Question 15

How do Supra-choroidal implants work?

Answer 15

Electrode array gets preprocessed signals from head worn video camera and sends signals to brain

Question 16

Do Supra-choroidal implants provide a safety benefit?

Answer 16

Yes

Question 17

How many channels is the wearable vision processor used with Supra-choroidal implants?

Answer 17

24-channel

Question 18

Sub-retinal chip is implanted where?

Answer 18

Beneath retinal surface

Question 19

Sub-retinal chip contains amplifier pixels that replace the ______________

Answer 19

Photoreceptor function in the eye

Question 20

What condition does sub-retinal chip treat?

Answer 20

Retinitis pigmentosa

Question 21

How does a sub-retinal chip work?

Answer 21

Photo-diode amplifier array replaces function of damaged outer-retinal photoreceptors. Leveraging un-damaged inner retinal cells

Question 22

Sub-retinal chip implant area corresponds to only _____º of the retina

Answer 22

15º

Question 23

Sub-retinal implant provides VA of ________ for Landolt C and _________ for grating acuity

Answer 23

20/546

20/200

Question 24

Is color discrimination possible with a sub-retinal implant?

Answer 24

No, only brightness contrast is possible

Question 25

With a sub-retinal implant, is it possible to adapt to ambient brightness?

Answer 25

No

Question 26

Alpha subretinal implant has enabled visual acuity of up to _________

Answer 26

20/546

Question 27

Patients with severe blindness from RP that have used the sub-retinal implant have shown improved ________ and ________

Answer 27

Object detection and identification

Question 28

Subretinal electronic chips allow blind patients to read __________ and combine them to __________

Answer 28

Letters ## Footnote Words

Question 29

Where is an epi-retinal prosthetic implanted?

Answer 29

On the retinal surface

Question 30

What condition does an epi-retinal prosthetic treat?

Answer 30

Retinitis Pigmentosa

Question 31

Epiretinal implants rely on imaging devices such as a camera and then transform _________ information to __________ stimulation patterns to excite remaining viable neurons

Answer 31

Visual information to electrical stimulation patterns

Question 32

Optogenics aims to restore vision by replacing lost or dysfunctional photoreceptors by inserting __________ into the downstream retinal neurons that have no intrinsic light sensitivity

Answer 32

Opsins or light sensitive proteins

Question 33

With optogenetic therapy through gene transfer techniques, what cells can be converted into artificial photoreceptors to help those with retinal degenerative diseases?

Answer 33

Bipolar and RGCs can be converted

Question 34

Optogenetic tools: Opsin Type 1

Answer 34

Microbial type (plant origin)

Question 35

Optogenetic tools: Opsin Type 2

Answer 35

Animal type and origin

Question 36

How is stimulation of the optic nerve realized?

Answer 36

By using a cuff electrode encircling it

Question 37

Since the electrodes are outside the very densely packed optic nerve, what is hard to achieve?

Answer 37

Focal stimulation

Question 38

What benefits does optic nerve stimulation provide compared to retinal approaches?

Answer 38

Relatively safer and easier implantation procedure

Question 39

Deep brain stimulation creates the possibility of implanting stimulating electrodes at what structure?

Answer 39

LGN

Question 40

Cortical stimulation is stimulation of the _____________

Answer 40

Visual cortex

Question 41

Cortical stimulation is for those with _______________

Answer 41

Profound blindness

Question 42

Cortical stimulation could restore vision even if damage to both _________ and ___________ was present

Answer 42

Retina and optic nerve

Question 43

Disadvantages to cortical stimulation

Answer 43

High surgical risk

Question 44

Advantages to cortical stimulation

Answer 44

Reduced power requirements ## Footnote Most predictable signal generation Increased resolution

Question 45

What are the 6 locations for possible visual prosthetics to be implanted/stimulated?

Answer 45

1. Lens 2. Choroid 3. Retina 4. Optic nerve 5. Thalamus (LGN) 6. Cortical Stimulation (Primary Visual Cortex)