GB2619264A - Device for measuring the function of a Schlemm's canal - Google Patents
Device for measuring the function of a Schlemm's canal Download PDFInfo
- Publication number
- GB2619264A GB2619264A GB2205315.1A GB202205315A GB2619264A GB 2619264 A GB2619264 A GB 2619264A GB 202205315 A GB202205315 A GB 202205315A GB 2619264 A GB2619264 A GB 2619264A
- Authority
- GB
- United Kingdom
- Prior art keywords
- schlemm
- canal
- ultrasonic
- function
- cornea
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 210000004087 cornea Anatomy 0.000 claims abstract description 13
- 230000002792 vascular Effects 0.000 claims abstract description 12
- 238000006073 displacement reaction Methods 0.000 claims abstract 2
- 210000002159 anterior chamber Anatomy 0.000 abstract description 4
- 208000010412 Glaucoma Diseases 0.000 abstract description 3
- 210000001742 aqueous humor Anatomy 0.000 abstract description 3
- 239000012530 fluid Substances 0.000 abstract description 2
- 230000013632 homeostatic process Effects 0.000 abstract description 2
- 230000004410 intraocular pressure Effects 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 5
- 239000004020 conductor Substances 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 201000010099 disease Diseases 0.000 description 2
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 238000009530 blood pressure measurement Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011207 functional examination Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 210000001519 tissue Anatomy 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
- A61B3/16—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for measuring intraocular pressure, e.g. tonometers
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
- A61B3/107—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for determining the shape or measuring the curvature of the cornea
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/18—Arrangement of plural eye-testing or -examining apparatus
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/10—Eye inspection
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Surgery (AREA)
- Biophysics (AREA)
- Ophthalmology & Optometry (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Physics & Mathematics (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Pathology (AREA)
- Radiology & Medical Imaging (AREA)
- Eye Examination Apparatus (AREA)
- Ultra Sonic Daignosis Equipment (AREA)
Abstract
A device for non-invasive determination of the function of the Schlemm’s canal, the device comprising an ultrasonic emitter 1 and an ultrasonic receiver 2, both directed at the cornea (11, Fig 3) for detecting corneal displacement. The angular position and distance of the ultrasonic emitter 1 and ultrasonic receiver 2 from the cornea (11, Fig 3) may be adjustable. Signals from the ultrasonic receiver 2 are compared with signals from a vascular pressure sensor 6 by means of an electronic device, for determination of a lag between the two sets of signals. Such a lag can indicate a blockage of the Schlemm’s canal, which acts to maintain fluid homeostasis by drainage of the aqueous humor from the anterior chamber of the eye. A blockage of the Schlemm’s canal can thus lead to the development of high intraocular pressure, which is a primary cause for the development of glaucoma.
Description
Device for Examination of the Schlemm's canal The invention relates to a device for determination of the function of Schlemm's canal, which regulates the Inter Ocular Pressure of the eye.
Measurement and detection of elevated Infra ocular pressures (10P) is a prime method for early detection of the onset of glaucoma. By preliminary functional examination of the Schlemm's canal, it is possible to determine whether a subject is likely to develop high 10P and initiate corrective treatment for prevention of the disease.
Current methods for detection of intra ocular pressures include the Goldman Applanation method that involves the use of a probe, subjected to a known force, in contact with the cornea. The extent of applanation is then indicative of the 10P. Other methods involve the use of a jet of air for measuring the resulting corneal deformation. Recently, the use of contact lenses equipped with strain gauges that measure the diurnal strains of the cornea have also been used for determination of 10P.
The main errors of these methods arise from inaccuracies due to membrane stresses which arise due to contact between the measuring device and the cornea. In addition, variations of the corneal stiffness and geometrical and material elasticity variations of the various tissues from which the eye is composed, introduce additional errors. Therefore, a fixed 10P threshold will differ across a population.
Such constraints are known to have generated false negative or false positive pressure measurement, with an error rate greater than approximately 60% within the ocular region of the eye.
From the above, it is evident that precise 10P measurement does not enable a safe tool for prediction of the onset of Glaucoma. Instead, a means for examination of the mechanism by which 10P is regulated, -2 -namely the function of the Schlemm's canal, should provide a safer means of assessment for the likelihood of high 10P and consequent development of the disease.
High 10P occurs due to blockage of the Schlemm's canal, which acts to maintain fluid homeostasis by drainage of the aqueous humor from the anterior chamber of the eye.
Hence, it is an aim of the present invention to provide a device for measuring the function of Schlemm's canal and provide a solution of a type that is not io made in a conventional manner and that will overcome the limitations mentioned above.
The invention provides for a device for measuring the function of Schlemm's canal as defined by claim 1 of the set of claims following this description.
Preferred and / or optional features of the invention are the subject of other claims of the set of claims.
An alternative solution for measuring the function of Schlemm's canal that overcomes the above-mentioned constraints is the main aim of this invention and will hereby be described by means of a non-limited example.
Accordingly, this invention provides for a device for non-invasive and contactless measurement of corneal deflection, characterized in that it has an ultrasonic emitter (UE) directed at the cornea and an ultrasonic receiver (UR) for receiving the reflected ultrasonic wave, both of which are placed at a known angle and distance in front of the cornea of the eye.
The UE emits an ultrasonic signal, of known frequency, which is deflected by the cornea and picked up by the UR. With naturally occurring vascular pressure variations (VPV), the 10P also varies, and these variations result in corresponding deflections of the cornea. Comparison between the UR signal returns, with a range of VPV enables to detect the corresponding lag of 10P variations and thus the function of the Schlemm's canal. -3 -
Since 10P is dependent on VPV, a comparison between the UR signal and the WV will enable to determine a potential blockage within the anterior chamber. This will be manifested by a prolonged period of elevated 10P before return to a lower 10P. In essence, a blocked or partially blocked Schlemm's canal acts as a restrictor to the aqueous humor from exiting the anterior chamber Hence, over a range of vascular pressures, a prolonged lag in 10P response, characterised by an elevated UR signal, would indicate that a blockage of the Schlemm's canal exists and hence a potential for increased 10P.
In one preferred embodiment of a device for measuring the function of the Schlemm's canal, a UE and a UR are placed withing a spherical carrier, which is situated in a spectacle frame. The UE and UR are situated at angle to an eye, such that the emitted ultrasonic signal from the UE, is reflected and transmitted by the UR to a suitable electronic device, where signal comparisons can be made. Concurrently, the vascular pressure variations are also measured by frame mounted ultrasonic sensors placed on the spectacle arms and near the temple.
Comparison between the vascular pressure variations and the associated diurnal corneal deflections will reveal the rate of 10P decay and whether a blockage of the Schlemm's canal exists.
One embodiment of the invention will be described solely by way of non-limited example and with reference to the accompanying drawings in which: Fig. 1 shows a general external view of a device for determination of the function of Schlemm's canal.
Fig. 2 shows a top view of a device for determination of the function of Schlemm's canal. -4 -
Fig. 3 shows a vertical sectional view of device for determination of the function of Schlemm's canal near the eye.
Fig. 1 shows an assembly of a device for determination of the function of Schlemm's canal. The assembly consists of a spherical carrier (5), frame (3), ultrasonic emitter (1), ultrasonic receiver (2) frame arms (7), eyes (8) and vascular pressure sensors (6).
Fig. 2 shows a plan view of an assembly of a device for determination of the function of Schlemm's canal. The assembly view shows a spherical carrier (5), ultrasonic emitter (1), ultrasonic emitter conductors (la), ultrasonic receiver (2), ultrasonic receiver conductors (2a) frame arms (7), eyes (8) and vascular pressure sensors (6).
Fig.3 shows a vertical sectional view of a device for determination of the function of Schlemm's canal. The assembly view shows a spherical carrier (5), ultrasonic receiver (2) ultrasonic receiver conductors (2a) spectacle frame (7), eye (8), posterior chamber (9), lens (10) cornea (11) frame arms (7) and vascular pressure sensors mount (4). With vascular pressure variations, signal returns from the ultrasonic receiver (2) will be deflected at varying angles due to the expansion of the cornea (11) and transmitted to an electronic device where these signals will be compared to the vascular pressure signals picked up by vascular sensors (6) and thus enable to determine whether a lag exists in the response of the 10P and therefore indicative of a potential blockage of the Schlemm's canal. -5 -
Claims (2)
- Claims 1. A device for non-invasive determination of the function of Schlemm's canal, characterized in that it comprises of at least one ultrasonic emitter (1) and one ultrasonic receiver (2), both pointed at the cornea (11) for detecting corneal (11) displacements wherein the signals from the ultrasonic receiver (2) are compared with signals of the vascular pressure sensors (6) by means of an electronic device for determination of a lag between the two sets of signals.
- 2. A device assembly according to claim 1, characterised in that the angular position and distance of the ultrasonic emitter (1) and ultrasonic receiver (2) from cornea (11) can be adjusted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2205315.1A GB2619264A (en) | 2022-04-11 | 2022-04-11 | Device for measuring the function of a Schlemm's canal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2205315.1A GB2619264A (en) | 2022-04-11 | 2022-04-11 | Device for measuring the function of a Schlemm's canal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB202205315D0 GB202205315D0 (en) | 2022-05-25 |
| GB2619264A true GB2619264A (en) | 2023-12-06 |
Family
ID=81653137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2205315.1A Pending GB2619264A (en) | 2022-04-11 | 2022-04-11 | Device for measuring the function of a Schlemm's canal |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2619264A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130329187A1 (en) * | 2012-06-08 | 2013-12-12 | Oculus Optikgeraete Gmbh | Method and Analysis Apparatus For Measuring A Cornea |
| WO2021024764A1 (en) * | 2019-08-05 | 2021-02-11 | 株式会社ニデック | Ultrasonic ophthalmotonometer |
| US20210177657A1 (en) * | 2018-09-04 | 2021-06-17 | University Hospitals Health System, Inc. | Ocular device for treating glaucoma and related minimally invasive glaucoma surgery method |
-
2022
- 2022-04-11 GB GB2205315.1A patent/GB2619264A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130329187A1 (en) * | 2012-06-08 | 2013-12-12 | Oculus Optikgeraete Gmbh | Method and Analysis Apparatus For Measuring A Cornea |
| US20210177657A1 (en) * | 2018-09-04 | 2021-06-17 | University Hospitals Health System, Inc. | Ocular device for treating glaucoma and related minimally invasive glaucoma surgery method |
| WO2021024764A1 (en) * | 2019-08-05 | 2021-02-11 | 株式会社ニデック | Ultrasonic ophthalmotonometer |
Also Published As
| Publication number | Publication date |
|---|---|
| GB202205315D0 (en) | 2022-05-25 |
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