U.S. patent application number 12/691208 was filed with the patent office on 2010-05-13 for system and methods for the treatment of retinal diseases.
This patent application is currently assigned to NovaVision, Inc.. Invention is credited to Bernhard Sabel.
Application Number | 20100118264 12/691208 |
Document ID | / |
Family ID | 38066642 |
Filed Date | 2010-05-13 |
United States Patent
Application |
20100118264 |
Kind Code |
A1 |
Sabel; Bernhard |
May 13, 2010 |
System and Methods for the Treatment of Retinal Diseases
Abstract
Systems and methods for treating a retinal disease in a human
include locating and defining one or more zones of vision within
the human's visual system and defining a treatment area which is
located within at least one of the zones. The method of this
embodiment may also include treating the human's retinal disease by
presenting visual stimuli to the treatment area at a specified
location and with a specified definition and recording changes in
specified characteristics of the human's visual system. The method
of this embodiment may also include reiterating the previous steps
so as to improve the human's overall visual system.
Inventors: |
Sabel; Bernhard; (Berlin,
DE) |
Correspondence
Address: |
Sunstein Kann Murphy & Timbers LLP
125 SUMMER STREET
BOSTON
MA
02110-1618
US
|
Assignee: |
NovaVision, Inc.
Boca Raton
FL
|
Family ID: |
38066642 |
Appl. No.: |
12/691208 |
Filed: |
January 21, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11343960 |
Jan 31, 2006 |
7682021 |
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12691208 |
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10503869 |
May 18, 2005 |
7367671 |
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PCT/EP02/01339 |
Feb 8, 2002 |
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11343960 |
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Current U.S.
Class: |
351/203 |
Current CPC
Class: |
A61H 5/00 20130101; A61B
3/024 20130101 |
Class at
Publication: |
351/203 |
International
Class: |
A61H 5/00 20060101
A61H005/00; A61B 3/00 20060101 A61B003/00; A61B 3/02 20060101
A61B003/02 |
Claims
1. A method for treating a retinal disease in a human comprising:
locating and defining one or more zones of vision within the
human's visual system; defining a treatment area which is located
within at least one of the zones; treating the human's retinal
disease by presenting visual stimuli to the treatment area at a
specified location and with a specified definition; recording
changes in specified characteristics of the human's visual system;
and reiterating the previous steps so as to improve the human's
overall visual system.
2. The method of claim 1, wherein reiterating includes adapting the
location and definition of the stimulus presentation to the
treatment area, according to the changes.
3. The method of claim 1, wherein the visual system of the human
includes an intact visual field and only the intact visual field is
treated.
4. The method of claim 1, wherein the visual system of the human
includes a zone outside intact visual field that may include: a
zone of deteriorated vision, a zone of residual vision, a zone of
partial vision function, and a zone of partial visual function
injury; and wherein at least one of the zones outside the intact
visual field is treated.
5. The method of claim 1, wherein the visual system of the human
includes a blind zone and at least the blind zone is treated.
6. The method of claim 1, wherein the size, location and kind of
said treatment area are selected in accordance with the size,
location and kind at least one of the intact zone of vision, zone
of partial visual system injury, zone of residual visual function
and zone visual deficit of said human.
7. The method of claim 1, wherein light stimuli are presented to
the human's visual system as the visual stimuli.
8. The method of claim 7, wherein the light stimuli are light
stimuli of at least one of different color, luminance, intensity,
and shape.
9. The method of claim 1, wherein the step of presenting visual
stimuli to the human's visual system comprises presenting at least
one fixation point to the human's visual field allowing a control
of the human's angle of view.
10. The method of any of claim 1, wherein substantially all visual
stimuli are presented to the human's visual system in or
immediately adjacent to the zone of intact vision.
11. The method of claim 1, wherein the step of presenting visual
stimuli to the human's visual system is conducted on a screen.
12. The method of claim 11, wherein the screen may include a
computer screen, a video screen, or a projection screen.
13. The method of claim 1, wherein the step of presenting visual
stimuli to the human's visual system is conducted on a visual
projection device.
14. The method of claim 13, where in the visual projection device
includes virtual reality goggles or a helmet.
15. The method of any claim 1, wherein the recording of changes in
the characteristics of the human's visual system comprises a
recording of at least one of responsiveness, color recognition,
shape recognition, and localization of the visual stimuli by the
human.
16. The method of claim 1, wherein the steps of locating and
defining said at least one zone, defining said treatment area,
presenting visual stimuli, recording changes in the characteristics
of the human's visual performance, adapting the location and
definition of the treatment area and reiterating the previous steps
are controlled by a central data processing means.
17. The method of any of claim 1, wherein the step of recording
changes in the human's performance includes a step of recording
changes in the human's ability to react on time-connected signal
discrimination.
18. The method of claim 17, wherein the step of recording changes
in the human's ability to react on time-connected signal
discrimination includes at least one step of recording changes in
the human's ability to change reaction time after appearance of a
stimulus, to estimate time intervals between the appearance of two
stimuli, and to discriminate time-connected patterns of
stimuli.
19. The method of claim 1, wherein the human's visual system
includes the visual system of humans operating at least one of
technical machines, weapon systems, land vehicles, water vehicles
and air vehicles.
20. The method of claim 1, wherein the retinal disease is
glaucoma.
21. The method of claim 1, wherein the retinal disease is retinitis
pigmentosa.
22. A device for treating a retinal disease in a human comprising:
at least one optical stimuli presenting means; a fixation point
means allowing the fixation of the human's view; means for entering
the human's response on optical stimuli perceived; means for
allowing a control of the at least one optical stimuli presenting
means in accordance with the performance of the human responding to
optical stimuli perceived; and a central data processing means for
recording, storing, processing and emitting data from the optical
stimuli presenting means, the fixation point means, the means for
entering the human's response, and the means for allowing a control
of said at least one optical stimuli presenting means.
23. The device of claim 22, the device further comprising: means
for locating and defining one or more zones of vision within the
human's visual system that include a zone of intact vision and zone
outside the visual region; means for defining a treatment area
which is located within at least one of said zones; means for
treating the human's visual system by presenting optical stimuli to
the human's visual system; means for recording changes in the
characteristics of the human's visual system; means for adapting
the location and definition of the stimulus presentation to said at
least one zone, according to said changes; and means for
reiterating the previous steps continuously so as to improve the
human's overall visual system.
24. The device of claim 23, wherein only the zone of intact vision
is treated.
25. The device of claim 23, wherein the zone of intact vision and
at least one zone of deteriorated vision, residual vision function,
and partial visual function injury are treated.
26. The device of claim 22, additionally comprising means for at
least one of fixing and supporting the head of the human.
27. The device of claim 22, wherein said optical stimuli-emitting
means are light emitting means.
28. The device of claim 27, wherein the light emitting means are
light emitting means for light of at least one of variable color,
luminance, intensity, and shape.
29. The device of claim 27, wherein said light emitting means
includes a screen.
30. The device of claim 29, wherein the screen may include a
computer screen, a video screen, or a projection screen.
31. The device of claim 27, wherein said light emitting means
includes a visual projection device.
32. The device of claim 31, wherein the projection device includes
virtual reality goggles or a helmet.
33. The device of claim 22, wherein said fixation point means
allowing the fixation of the human's view is a colored mark.
34. The device of claim 33, wherein said colored mark is of
variable color, allowing a control of the human's angle of
view.
35. The device of claim 22, wherein said control means allows a
control of said at least one optical stimuli presenting means in
accordance with the quality of the response on said optical
stimuli.
36. The device of claim 22, wherein said means for entering the
human's response on optical stimuli perceived includes a means for
recording changes in the human's ability to react on time-connected
signal discrimination.
37. The device of claim 36, wherein the means for recording changes
in the human's ability to react on time-connected signal
discrimination includes at least one of an ability to change
reaction time after appearance of a stimulus, to estimate time
intervals between the appearance of two stimuli, and to
discriminate time-connected patterns of stimuli.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/343,960, filed Jan. 31, 2006, which is a
continuation-in-part of U.S. patent application Ser. No.
10/503,869, filed May 18, 2005 in the United States claiming
priority from PCT Patent Application No. PCT/EP02/01339, which was
filed in English on Feb. 8, 2002, all of which are hereby
incorporated by reference herein in their entirety.
TECHNICAL FIELD AND BACKGROUND ART
[0002] The present invention relates to the treatment of retinal
diseases, and in particular, to the treatment of retinal diseases
using vision restoration therapy (VRT).
[0003] Damage to the visual system, as used herein, is defined as
impairment of any structure (or of all structures) involved in the
processing of vision. These structures include, but are not
restricted to, the nervous system tissue from the level of the
retina, including the retina up to the optic nerve and all brain
structures involved in process of vision. Such damage leads to
visual deficits or even a loss of visual functions which may lead
to partial or more or less complete blindness. This damage may come
from many sources and may include damage to the retina. Damage to
the retina may be caused by various diseases including, but not
limited to, retinal diseases such as glaucoma, age related macula
degeneration, or retinitis pigmentosa. The retina may also be
damaged by retinal detachment or laser damage. In addition, the
retinal may become or originate damaged based on inflammation,
inherited genetic defects, metabolic issues or other causes. Damage
to the retina shall be referred to herein as "retinopathies."
[0004] Retinopathies in general have not been deemed amenable to
reversal using the inherent plasticity of the central nervous
system (CNS), and only surgical or pharmacological interventions
have been considered. That is, damage to the retina, either by
disease or other means, typically requires surgery for the patient
to have any restoration of vision that may have been lost.
SUMMARY OF THE INVENTION
[0005] Embodiments of the present invention may utilize a
behavioral training of patients, such as a VRT, to treat damage to
the retina and restore at least some (if not all) of a patient's
vision. This may be accomplished by presenting visual stimuli on a
simple device for emitting optical stimuli to the visual system of
a human in such a way that target stimuli may be presented to
various zones of the visual field: the intact sector of the visual
field, to partly damages zones, or to blind regions, or all of
them. Clinical tests suggest that treatment as described below may
improve the vision of patients having retinal damage.
[0006] In one embodiment there is provided a method for treating a
retinal disease in a human. The method of this embodiment may
include locating and defining one or more zones of vision within
the human's visual system and defining a treatment area which is
located within at least one of the zones. The method of this
embodiment may also include treating the human's retinal disease by
presenting visual stimuli to the treatment area at a specified
location and with a specified definition and recording changes in
specified characteristics of the human's visual system. This method
may also include reiterating the previous steps so as to improve
the human's overall visual system.
[0007] In another embodiment there is provided a device for
treating a retinal disease in a human. In this embodiment the
device may include at least one optical stimuli presenting means
and a fixation point means allowing the fixation of the human's
view. The device of this embodiment may also include means for
entering the human's response to optical stimuli perceived and
means for allowing a control of the at least one optical stimuli
presenting means in accordance with the performance of the human
responding on optical stimuli perceived. The device of this
embodiment may also include a central data processing means for
recording, storing, processing and emitting data from the optical
stimuli presenting means, the fixation point means, the means for
entering the human's response, and the means for allowing a control
of said at least one optical stimuli presenting means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing features of the invention will be more readily
understood by reference to the following detailed description,
taken with reference to the accompanying drawings, in which:
[0009] FIG. 1 represents vision in a normal visual field;
[0010] FIG. 2 represents a visual field where one hemisphere does
not function;
[0011] FIG. 3 represents a visual field where the central area of
the visual field is injured;
[0012] FIG. 4 shows the presentation of two stimuli in sequence;
and
[0013] FIG. 5 shows another presentation of two stimuli in
sequence.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0014] The invention relates, generally, to a process for treating
retinal diseases in a human by presenting optical stimuli to the
human. The stimuli may be presented to either a zone within the
intact visual field of the person or a zone outside the intact
visual field of the human, or both. One of these zones is a zone to
be treated, thereby allowing an improvement of the vision in
general.
[0015] One feature of the present invention is that the treatment
by stimulus presentation may predominantly occur in or near the
zone of intact vision, but optionally also in the zone of
deteriorated vision or in the zone of residual visual function or
in the zone of partial visual system injury, i.e. in the transition
zone. Yet another alternative would be to treat the blind region or
a combination of all zones. The treatment, by presenting visual
stimuli, occurs preferably only in the zone of intact vision,
although a parallel or consecutive presentation of optical stimuli
to at least one other zone, e.g. to the so-called "transition zone"
or the blind field may occur, in addition to the presentation of
stimuli to the zone of intact vision. In other embodiments, visual
stimuli may only be presented to the zone outside the intact visual
field.
[0016] The term "zone of intact vision" as used herein means the
zone of the visual field (or brain area) which is substantially not
injured or influenced by the events resulting into an impairment of
the visual system, i.e. shows more or less normal visual
performance when receiving optical stimuli. In contrast, the term
"zone of deteriorated vision" (which is used in a similar sense as
the term "zone of residual visual function" or the term "zone of
partial visual system injury") is defined to mean the zone where
events like accidents, stroke, degenerative diseases, or retinal
diseases such as glaucoma or retinitis pigmentosa caused damages of
the brain regions or the retina influencing the visual capabilities
of the human so that the vision is at least partly deteriorated or
even partly or completely lost. The term "blind zone" is meant to
indicate those regions where a patient does not respond to stimuli
at all.
[0017] Zones of intact vision, on the one hand, and zones of
deteriorated or even lost vision ("blindness"), on the other hand,
may be shaped continuously, i.e. as zones of a certain (e.g. round)
shape, wherein the zone of said shape has more or less identical
visual capabilities, as, for example intact visual capabilities.
Such continuous zones may be adjacent to another (optionally
similarly shaped) zone having a different visual capability as, for
example, a zone of deteriorated vision, which, in turn, may be
followed by a zone where the vision was completely lost. However,
it may also be possible that several zones of intact vision are
surrounded, in a discontinuous manner, by zones of deteriorated or
lost vision. When the visual field is lost, for example, following
glaucoma, a typical regional field loss (scotoma) occurs. Often,
the person having experienced said event can still fixate, and the
region of intact vision is in one specific area of the visual
field. In the case of macula degeneration diseases or other
diseases that lead to a loss of fixation ability due to loss of the
function of the fovea, there may be a circular visual field that is
donut-shaped, with a deficit region in the centre of the visual
field (damaging the fovea) and with intact (or partially damaged)
areas surrounding it (see FIG. 3).
[0018] In another embodiment the zones of intact vision are
located, defined and characterized, instead of (or optionally
together with) zones of impaired, i.e. deteriorated vision or
residual visual function or partial visual system injury. The zones
of deteriorated vision or impaired vision or partial visual system
injury are hereinafter shortly referred to as "transition zones"
(see FIG. 2), while the zones of intact vision are simply referred
to as "zones of intact vision". Such transition zones may, for
example, be found with aged people whose vision, for example
peripheral vision, becomes more and more restricted. Transition
zones may also be found with people whose visual system was
influenced as a result of a brain injury, stroke or similar event.
Another example are transition zones between zones of completely
maintained and wholly lost ability to visually discriminate between
colours, shapes or movements. However, in one embodiment the
predominant treatment areas or treatment zones may be located in
the intact vision zones.
[0019] In one embodiment, the size and location of the treatment
area or areas within the intact vision zone(s) may be selected in
accordance with the size, location and kind of the zone of partial
visual system deterioration, of residual visual function or visual
deficit of the human. In other words, it may be beneficial to check
which parts of the visual system of said human offer the greatest
chance for improving the overall vision by the subsequent treatment
by presenting optical stimuli. In one embodiment the transition
zones may be treated together with the zones of intact vision.
[0020] Based on the individual person's performance, which may be
determined continuously or intermittently during the treatment,
treatment stimuli may be presented in those zones of intact vision.
The type, shape, intensity, duration and time sequence of the
treatment stimuli is not restricted; there may be used one type of
treatment stimuli or several types of treatment stimuli. In the
latter case, several types may be used simultaneously or in a time
sequence. In some embodiments of the invention, optical or light
stimuli are presented to the person's visual system. In some
embodiments the light stimuli of different colour, luminance,
intensity and/or shape may be presented to the visual system of the
person being treated. Such light stimuli can be presented as static
light stimuli or a series of light stimuli in a sequence generating
an impression of a moving object. In another embodiment, stimuli in
the form of simple or more differentiated pictures of articles of
daily life may be presented to the intact vision zone of the person
to be treated. Such pictures may be static or moving (dynamic),
according to the needs. In one embodiment of the invention optical
stimuli are presented to the intact vision zone of the person to be
treated, which have the form of letters, ciphers or even words or
sentences. The invention, however, is not at all restricted to the
above preferred embodiments of stimuli to be presented.
[0021] In a first process step, the person's visual field defect is
measured. This includes the step of establishing a zone of intact
visual field. The measurement is done by methods which are, as
such, known from the prior art. In one embodiment of the invention,
standard perimetry devices may be used, i.e. those devices, which
are commonly used in the opthalmological practice. In a preferred
embodiment of the invention, a computer-based campimetric
measurement is conducted. With such a device, blind, partially
injured and intact sectors of the visual field can be defined.
[0022] The definition of what comprises the border between the
intact zone and the partially injured zone or the intact zone and
the blind zone may vary. Its position will depend on what kind of
stimuli are used to define the visual function, i.e. large or small
stimuli, bright or less bright stimuli, etc., the nature of the
background, i.e. cluttered or simple backgrounds, and/or the timing
of the stimulus, i.e. short or long presentation times.
[0023] In the second step, the zone or area of intact vision is
defined, based on the measurement of the first step. The definition
of the intact visual field depends on the nature of the visual
stimulation selected for said definition. Stimuli which are seen
more easily by the person to be treated will produce a larger
apparent visual field, while stimuli which are responded to less
will produce smaller apparent visual fields. Whatever method is
selected to define the visual field or intact visual zone, the
result of this step is a clear zone or area of vision that is
defined to be intact. The shape of the intact visual field is not
restricted. It may be one large area, usually round in shape, but
may also consist of several intact regions which are not connected
to each other.
[0024] In the third treatment step, a sequence of visual stimuli is
presented to the intact visual zone of the person to be treated.
The task the person to be treated has to perform is to respond, as
in the prior art, to the stimulus presentation by a reaction which
may be a step of pressing a key or any other input device in order
to demonstrate that the stimulus--or a sequence of stimuli--was
seen and recognized.
[0025] One embodiment of the present invention includes the
presentation of the target stimulus to the intact vision zone(s) of
the person to be treated, whereby the stimulus is selected from a
library of visual objects exemplified above. The transition
zone(s), near the border of blindness, may be treated in addition
consecutively or may be treated in parallel. The same applies to
the blind zones, which can also be selected and stimulated by
presenting visual stimuli.
[0026] As the size and shape and optionally also the number of the
intact vision zones may vary, the presentation of the stimuli is
adjusted in such a way that the location and size of the objects
fits within the boundaries of the intact vision zone(s) according
to the above measurements. Of course, the "intact regions" used in
this example embodiment disclosed herein could be replaced with
transition zones on the blind zones. That is, the transition zones
or the blind zones could be the zones being treated.
[0027] The target stimulus may be presented, for example, on a
computer monitor. It could be any type of a single stimulus, or
there may be selected several or many stimuli together or
successively with or without different types of background. For
example, useful target stimuli could be letters, words, sentences,
meaningful objects (drawings, faces, photographs etc.) or objects
without meaning (dots, a line pattern etc.) moving or not moving on
the screen. As long as the presentation is occurring in the intact
vision zone, defined as the position of the field in relation to a
fixation point, and as long as the blind zone of the visual field
of the person to be treated is not stimulated, any stimulus or
combination of stimuli may be used.
[0028] By presenting the stimuli in the above-described way to the
intact vision zone of the person to be treated, the intact vision
zone is treated, and the treatment steps are repeated for treatment
purposes.
[0029] In some embodiments algorithms may be used to follow the
above presentation strategy, which algorithms allow the highly
efficient treatment of zones or areas of visual system function
(and, optionally, also dysfunction or malfunction in parallel or
consecutively) and blind regions as well. The detailed steps of the
treatment procedure are described below with respect to stimulating
specific areas or zones of the human visual system by optical
stimuli.
[0030] During the treatment step, changes in the characteristics of
the visual system of the human treated are recorded. In other
words: The performance of the person treated in view of visually
recognizing the optical stimuli presented and himself/herself
presenting the desired reaction on said visual recognition step is
recorded by the system/device of the present invention. To give
just one example: The reaction time of the treated person on an
optical stimulus presented to the intact zone of his/her visual
system is measured, and the time elapsed between the emission of
the optical stimulus and the reaction given (for example by
pressing a button of the device), relative to an average time value
measured before for the treated person as a base line value, is
taken as the performance of the person with respect to the treated
area of the intact zone. However, this example is not to be
considered as limiting the invention; any other appropriate step
may be taken, too, in order to continuously or intermittently
record changes in the characteristics of the human's visual
system.
[0031] In one embodiment, the reaction of the person to be treated
upon the presentation of one stimulus or several or many stimuli is
measured, and the performance of the person is rewarded. This may
happen in a way that reward points are added to a "reward account"
when the responses fulfill a predetermined criterion. For example,
when the person to be treated is instructed to perform as fast as
possible, reward points are added to the reward account only in
those cases where the response is recorded within a predetermined
time delay (reaction time). Alternatively, reward points could be
assigned to the reward account when a discrimination is properly
made (e.g. correct form; correct colour; time discrimination).
Based on the continuous recordal of the changes in the
characteristics as described above, the location and definition of
the intact zone is adapted to said changes. This may also be
conducted continuously or intermittently. In a preferred embodiment
of the invention, the number of reward points is used to
automatically increase the difficulty of the next task. In this
way, a means to increase the treatment difficulty is provided,
depending upon the recordal of the reaction/response shown by the
person to be treated. In other words: depending upon the
performance of the treated person in processing the presented
optical stimuli by the visual system, the intact visual zone is
newly defined. Without wanting to be bound by the explanation, it
can be assumed that, due to the effective treatment of the defined
intact visual zone, the vision of the treated person is improved in
said intact vision zone, specifically, and in general, for example
by improving any function of the visual system (e.g. peripheral
vision, visual acuity, ability to discriminate between different
colours, shapes, movement; reduction of squinting; increase of the
visual angle) or improving visual functions in general or removing
partial visual system injuries. As a result thereof, the intact
vision zone is enlarged or at least improved with respect to its
contribution to the person's vision. As found in practice, the
person to be treated experienced an improvement of the overall
vision subjectively and due to a better performance in the
treatment.
[0032] By reiterating the above-described steps, the human's intact
visual field is continuously extended into zones which were
previously located and defined to be transition zones.
[0033] Treatment may be carried out with a personal computer for
use at home where persons to be treated practiced on a regular
basis. In one embodiment daily treatment for 1 hr in a darkened
room for an extended time period may be performed, as for example a
6-months period as employed in this test. However, any other
treatment period may also prove efficacious.
[0034] One algorithm produces on a monitor an emission of light
stimuli effecting a repetitive visual stimulation of the zone to be
treated. In a first step, the zone was located, defined and
characterized, i.e. there occurred a determination of the exact
visual function in the zone with respect to location, size and
kind.
[0035] Then there was defined a treatment area which is located
within the zone. Said treatment area is a region within the zone
where a regeneration of the neuronal structures of the person's
visual system could be expected due to the results of the
definition and characterization of the intact vision zone in the
first step, e.g. due to the presence of a certain number of
remaining neuronal structures.
[0036] In a subsequent step, there was conducted a stimulation of
the zone based on the performance determined in the first and
second steps.
[0037] Also, unlike prior art devices in which the program only
stores the data for a later analysis, the present invention adapts,
on a continuous or intermittent basis, treatment algorithms to the
visual system performance in or near the zone being trained.
[0038] In addition, daily therapy results can be stored on suitable
storing media like a tape or a disc which permits monitoring of
compliance and which allows the therapy strategy to be adapted to
the progress of the person.
[0039] The invention is hereinafter described in detail with
reference to the Figures. While the description of the invention
mainly relates to treating persons whose visual system is severely
damaged, all details of the invention, i.e. the process and the
apparatus, can be applied mutatis mutandis by a skilled person to
the treatment of persons whose visual system deteriorates smoothly
due to an ageing of said person and also to persons whose regular
vision is to be treated in order to maintain the quality of the
vision on a high level. Insofar, the description of the treatment
procedure in connection to persons with a severely damaged visual
system, and particularly a damaged retina, but having intact vision
areas is not to be construed as a limitation of the invention.
[0040] In the Figures,
[0041] FIG. 1 shows the case of visual field treatment in a normal
case where the intact vision zone has been defined to have a
circular shape at least covering or even overlapping the field of
the monitor frame where the target stimulus is presented. The
fixation point for fixing the eyes of the person to be treated is
presented in the middle of the intact vision zone, as is the target
stimulus to be recognized by the person.
[0042] FIG. 2 shows the case where the visual system in one
hemisphere does not function; the fixation point is presented in
the intact vision zone, as is the target stimulus "TS1", i.e. the
stimulus treatment the intact vision field, while another target
stimulus "TS2" is presented partly in the intact and partly in the
injured field, independently.
[0043] FIG. 3 shows the case where the central area of the visual
system (e.g. where the fovea is located) is injured ("donut-shaped
visual field"). In such a case, the fixation point cannot be
presented in the central area (due to the injury, it would not be
recognized), but so-called "fixation ankers" are presented in the
peripheral part of the blind region where the intact vision zone is
located and defined. Then, a visual stimulus is presented in the
intact vision zone, in this case in the form of a word.
[0044] FIG. 4 shows the case of a presentation of two stimuli in
sequence (T1 and thereafter T2). In the same way as in FIG. 2, the
visual field is intact in one part (I=intact visual field sector)
and partially blind in another part (B=blind region). A priming
stimulus (P) is preceding the target stimulus (TS1) in order to
increase the probability of detecting and recognizing the
target.
[0045] FIG. 5 shows another case of a presentation of two stimuli
in sequence (T1 and thereafter T2). In the same way as in FIG. 2,
the visual field is intact in one sector (I=intact visual field
sector) and partially blind in another sector (B=blind region). One
of two priming stimuli P1 and P2 is presented to the person to be
treated, and thereafter, one target stimulus (TS1) is presented to
the intact zone of the visual field. The person will have to
respond by discriminating whether a target stimulus were presented
to the intact vision field in the area of the priming stimulus.
[0046] The invention is explained in further detail with reference
to the Figures and the preferred embodiments of Examples 1 to 5
without being restricted to these preferred embodiments.
[0047] The computer algorithms for the step of presenting visual
stimuli to the human's visual system are such that the monitor
presents a fixation point, which can be presented in any part of
the monitor. The fixation point serves to a fixation of the
person's view to a certain point in order to allow an adjustment of
the person's angle of view. In succession, additional visual
stimuli are presented in or immediately adjacent to the intact
vision zone, the location of which is determined in the previous
step and changed in accordance with the person's performance. In
the prior art device published by Kasten et al., the visual stimuli
were presented independent of the persons' actual progress and were
therefore inefficient and laborious. In contrast thereto, the
visual stimuli are presented in the present invention predominantly
in or adjacent to the intact vision zone, i.e. an area with almost
no or only slight visual system injury or deteriorated vision.
Example 1
[0048] One preferred embodiment is intended for persons to be
treated having a damage of the brain's visual system. For example,
when the visual system in one hemisphere does not function, the
opposite sector of the visual field is lost ("hemianopsia"); see
FIG. 2. In this case, the device of the present invention would
present target stimuli only in the intact vision field and not in
the deficient half field. Depending upon responses to the
presentation of the stimuli, increasingly more difficult target
stimuli are selected to which the person to be treated has to
respond until no further progress in performance can be
achieved.
Example 2
[0049] Another embodiment of the invention is useful in cases where
the central area of the visual system, where the fovea is located,
is injured; see FIG. 3. This may occur after retinal damages such
as age-related macular degeneration. The person to be treated sees
little of nothing centrally, but has a donut-like visual field with
no vision in the centre but intact vision in the peripheral part of
the visual system. The device of the present invention generates
target stimuli (in this case letters or words) in the intact vision
zone near the visual field border, i.e. above or below the damaged
region and positioned near the border. The letters or words may be
stationary or moving, depending, e.g. upon the difficulty of the
response requested.
Example 3
[0050] In another embodiment of the present invention (exemplified
in FIG. 4), a target stimulus is preceded by a priming stimulus.
This could be a priming stimulus with an emotional content (e.g. a
"Smiley" or "Happy Face"), which preceding priming stimulus could
increase the probability of detecting the subsequent target
stimulus. Both stimuli are presented to the intact vision zone of
the person to be treated. In one embodiment, the priming stimulus
could be presented in a very short time so that it cannot be seen
consciously by the person to be treated. The person would not be
asked to respond to the priming stimulus. As could be found, the
presentation of a priming stimulus influences the person's ability
of detection of the target stimulus.
Example 4
[0051] Another embodiment of the invention is directed to a case
where two target stimuli are presented either in rapid succession
or simultaneously. The response requested from the person to be
treated is a discrimination whether one or several target stimuli
were presented. The person would receive award points only when the
discrimination problem was responded to correctly.
Example 5
[0052] In yet another embodiment of the invention, reward points
are entered into the treatment person's reward account only for
responses which fulfill a predetermined criterion. For example,
reward points could be given only if a response is recorded by the
computer within a predetermined reaction time or following the
correct response to a discrimination task. Preferably, the target
stimulus/stimuli is/are presented to the intact vision zone,
although a simultaneous or consecutive presentation of one or more
than one stimulus/stimuli to the intact vision zone and the
transition zone may be possible and also in the frame of the
present invention.
Example 6
[0053] In another embodiment of the invention (see FIG. 5), the
priming stimulus (P1, P2) may be an attention cue such as a window
frame or another object which is located at the identical position
as the subsequent target stimulus (TS1) presented to the intact
vision zone. In this case (or also other cases), the fixation point
(F in FIG. 5) may be presented to the intact vision zone or the
transition zone, i.e. in a zone where the person to be treated has
at least sufficient vision capability to recognize the fixation
point for a fixation of his eyes or to the blind zone.
[0054] It should be apparent from this disclosure that it is
beneficial treatment to those parts or the visual field which are
injured or deteriorated based on damage to the retina. Of course,
the actual stimulus presented can vary in size, luminance, shape or
color and it can be presented by various means, such as a
projection screen, a simple computer monitor or other visual
projection devices such as virtual reality goggles or helmet. The
type of stimulus as well as the way by which it is presented is not
limited.
[0055] Although the above discussion disclosed various exemplary
embodiments of the invention, it should be apparent that those
skilled in the art can make various modifications that will achieve
some of the advantages of the invention without departing from the
true scope of the invention.
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