Retinitis Pigmentosa
Conditions
Keywords
retinitis pigmentosa, acoustic radiation force ultrasound, RP, visual field loss, Photoreceptor, Vision loss, retina, progressive vision loss, ultrasound
Brief summary
Retinitis pigmentosa (RP) is the name given to a group of inherited eye diseases that affect the retina (the light-sensitive part of the eye). RP causes the breakdown of photoreceptor cells (cells in the retina that detect light). Photoreceptor cells capture and process light helping us to see. As these cells breakdown and die, people experience progressive vision loss. There is no known cure for retinitis pigmentosa. The investigators have observed that short pulses of focused ultrasound can cause perception of light when directed to spots on the retinal surface. The investigators propose to conduct a study to determine if pulsed ultrasound will stimulate the perception of light in the absence of functional photoreceptors in people with RP
Detailed description
Patients affected by retinitis pigmentosa (RP) and related diseases suffer loss of vision due to death of photoreceptor cells. The investigators have observed that short pulses of focused ultrasound can cause perception of light (phosphenes) when directed to spots on the retinal surface. If this phenomenon is caused by direct stimulation of the retinal nerves, which seems probable, then it might be possible to use this phenomenon to produce a form of vision in such patients. The investigators propose to conduct a study of a small cohort of patients affected by RP to determine if pulsed ultrasound will evoke a perception of light in the absence of functional photoreceptors.
Interventions
PROCEDUREUltrasound Stimulus
Short pulses of focused ultrasound will be directed at spots on the retinal surface.
Sponsors
Columbia University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* retinitis pigmentosa * legally blind in at least one eye
Exclusion criteria
* unable to lay down on an exam table
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Phosphene Perception in Response to Ultrasound Pulse. | Subjects will undergo a single examination of approximately 15 minute duration during which they will report perception of phosphenes during ultrasound exposure. | The investigators will test the hypothesis that compression of retinal nerves by ultrasound force will cause perception of light (phosphenes) in blind subjects lacking functioning photoreceptors (retinitis pigmentosa). With each of two 5 msec ARFI exposures, if the subject either perceived the spark of light (phosphene), then it was documented as a positive response; if they did not, it was marked as a negative response. |
Countries
United States
Participant flow
Recruitment details
Recruitment occurred at the Department of Ophthalmology, Columbia University Medical Center from July 2011 to June 2012.
Pre-assignment details
No significant events followed enrollment prior to group assignment. There was only one group in this study: people with retinitis pigmentosa who were legally blind.
Participants by arm
| Arm | Count |
|---|---|
| Retinitis Pigmentosa Subject will have retinitis pigmentosa and will be legally blind in one or both eyes | 1 |
| Total | 1 |
Baseline characteristics
| Characteristic | Retinitis Pigmentosa |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 1 Participants |
| Age, Categorical Between 18 and 65 years | 0 Participants |
| Region of Enrollment United States | 1 participants |
| Sex: Female, Male Female | 1 Participants |
| Sex: Female, Male Male | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 1 |
| serious Total, serious adverse events | 0 / 1 |
Outcome results
Primary
Phosphene Perception in Response to Ultrasound Pulse.
The investigators will test the hypothesis that compression of retinal nerves by ultrasound force will cause perception of light (phosphenes) in blind subjects lacking functioning photoreceptors (retinitis pigmentosa). With each of two 5 msec ARFI exposures, if the subject either perceived the spark of light (phosphene), then it was documented as a positive response; if they did not, it was marked as a negative response.
Time frame: Subjects will undergo a single examination of approximately 15 minute duration during which they will report perception of phosphenes during ultrasound exposure.
Population: Only one subject was examined.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Retinitis Pigmentosa | Phosphene Perception in Response to Ultrasound Pulse. | Positive Evoked Response | 0 participants |
| Retinitis Pigmentosa | Phosphene Perception in Response to Ultrasound Pulse. | Negative Evoked Response | 1 participants |