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Title:
ULTRASOUND APPARATUS AND SYSTEM
Document Type and Number:
WIPO Patent Application WO/2018/039729
Kind Code:
A1
Abstract:
An apparatus or system for use proximate an area of an eyelid in the treatment of eye conditions, comprising an ultrasound transducer configured for supplying low-frequency 5 ultrasound waves to cause cavitation of an obstructed gland in the eyelid area in use; and a heating element configured for providing heat to the obstructed gland such that an obstruction in the gland is softened.

Inventors:
HE MINGGUANG (AU)
YAN WILLIAM (AU)
Application Number:
PCT/AU2017/050935
Publication Date:
March 08, 2018
Filing Date:
August 31, 2017
Export Citation:
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Assignee:
CENTRE FOR EYE RES AUSTRALIA LIMITED (AU)
International Classes:
A61F7/00; A61F9/007; A61N7/00
Domestic Patent References:
WO2016070134A12016-05-06
Foreign References:
US20070016254A12007-01-18
US20150057701A12015-02-26
US20150148711A12015-05-28
US20130053733A12013-02-28
US20110319794A12011-12-29
US20120136281A12012-05-31
US20140343432A12014-11-20
Attorney, Agent or Firm:
DAVIES COLLISON CAVE PTY LTD (Melbourne, Victoria 3000, AU)
Download PDF:
Claims:
THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. An apparatus for use proximate an area of an eyelid in the treatment of eye conditions, comprising:

an ultrasound transducer configured for supplying low-frequency ultrasound waves to cause cavitation of an obstructed gland in the eyelid area in use; and

a heating element configured for providing heat to the obstructed gland such that an obstruction in the gland is softened. 2. An apparatus according to claim 1, wherein the frequency range of the ultrasound waves is between 20 to 100 KHz.

3. An apparatus according to either claim 1 or claim 2, wherein the frequency range of the ultrasound waves is between 40 to 80 KHz.

4. An apparatus according to any one of the preceding claims, wherein the frequency range of the ultrasound waves is about 40 KHz.

5. An apparatus according to either claim 1 or claim 2, wherein the frequency range of the ultrasound waves is about 20 KHz.

6. An apparatus according to any one of the preceding claims, wherein the heating element is a heater wire. 7. An apparatus according to any one of claims 1 to 5, wherein the heating element is a water-heated radiator.

8. An apparatus according to any one of the preceding claims, further comprising an applicator operatively coupled to the ultrasound transducer for contacting and transmitting low-frequency ultrasound waves to the eyelid area.

9. An apparatus according to claim 8, wherein the applicator is shaped in the form of a dome in which an apex of the dome is adapted to contact the eyelid area.

10. An apparatus according to claim 8, wherein the applicator is of a concavity shape to complement a contour of the eyelid.

11. An apparatus according to claim 8, wherein the applicator is of an ellipsoid shape to complement a contour of the eyelid. 12. An apparatus according to any one of the preceding claims, further comprising a temperature sensor configured to output a surface temperature of the eyelid area.

13. An apparatus according to claim 12, further comprising a controller configured to receive output from the temperature sensor and determine treatment parameter inputs for the ultrasound transducer and the heating element such that the surface temperature of the eyelid area remains under a predetermined temperature threshold.

14. An apparatus according to claim 13, wherein the treatment parameter includes any one or more of the following parameters: ultrasound frequency; ultrasound amplitude; pulse width modulation; heating element temperature; and treatment duration.

15. An apparatus according to claim 13, wherein the predetermined temperature threshold is between 38 and 43 degrees Celsius. 16. An apparatus according to any one of the preceding claims, further comprising a display for visually outputting a treatment parameter to a user.

17. An apparatus for use proximate an area of an eyelid in the treatment of eye conditions, comprising:

an ultrasound transducer configured for supplying low-frequency ultrasound waves to cause cavitation of an obstructed gland in the eyelid area in use, wherein the frequency range of the ultrasound waves is between 20 to 100 KHz.

18. An apparatus according to claim 17, further comprising a heating element configured for providing heat to the obstructed gland such that an obstruction in the gland is softened.

19. A system for use in the treatment of eye conditions, comprising:

an ultrasound transducer configured for supplying low-frequency ultrasound waves proximate an area of an eyelid to cause cavitation of an obstructed gland in the eyelid area in use; and

a heating element configured for providing heat to the obstructed gland such that an obstruction in the gland is softened.

20. A system according to claim 19, further comprising a lens adapted for use underneath the eyelid to reduce irritation effects of heat and/or ultrasound waves to an eye.

21. A system according to claim 20, wherein the lens is in the form of an air- filled hollow lens. 22. A system according to any one of claims 19 to 21, further comprising a topical cream adapted for use between the eyelid and the ultrasound transducer to facilitate transdermal delivery of the cream.

23. A system according to any one of claims 19 to 22, wherein the frequency range of the ultrasound waves is between 20 to 100 KHz.

24. A system according to any one of claims 19 to 23, wherein the frequency range of the ultrasound waves is between 40 to 80 KHz. 25. A system according to any one of claims 19 to 24, wherein the frequency range of the ultrasound waves is about 40 KHz.

26. A system according to any one of claims 19 to 22, wherein the frequency range of the ultrasound waves is about 20 KHz.

27. A system according to any one of claims 19 to 26, wherein the heating element is a heater wire.

28. A system according to any one of claims 19 to 26, wherein the heating element is a water-heated radiator. 29. A system according to any one of claims 19 to 28, further comprising an applicator operatively coupled to the ultrasound transducer for contacting and transmitting low- frequency ultrasound waves to the eyelid area.

30. A system according to claim 29, wherein the applicator is shaped in the form of a dome in which an apex of the dome is adapted to contact the eyelid area.

31. A system according to claim 29, wherein the applicator is of a concavity shape to complement a contour of the eyelid. 32. A system according to claim 29, wherein the applicator is of an ellipsoid shape to complement a contour of the eyelid.

33. A system according to any one of claims 19 to 32, further comprising a temperature sensor configured to output a surface temperature of the eyelid area.

34. A system according to claim 33, further comprising a controller configured to receive output from the temperature sensor and determine treatment parameter inputs for the ultrasound transducer and the heating element such that the surface temperature of the eyelid area remains under a predetermined temperature threshold.

35. A system according to claim 34, wherein the treatment parameter includes any one or more of the following parameters: ultrasound frequency; ultrasound amplitude; pulse width modulation; heating element temperature; and treatment duration.

36. A system according to claims 34, wherein the predetermined temperature threshold is between 38 and 43 degrees Celsius.

37. A system according to any one of claims 19 to 36, further comprising a display for visually outputting a treatment parameter to a user. 38. A method for use in the treatment of Meibomian gland dysfunction, the method comprising the steps of:

transmitting low-frequency ultrasound waves using an ultrasound transducer to cause cavitation of an obstruction in a Meibomian gland in a treatment area proximate an eyelid, wherein the frequency range of the ultrasound wave is between 20 to 100 KHz; heating the Meibomian gland in the treatment area using a heating element such that the obstruction in the gland can be softened; and

reducing the obstruction from the gland by expressing the obstruction from the eyelid using force.

Description:
Ultrasound Apparatus and System

Field of the invention

The invention relates to ultrasound apparatus and system for use in the treatment of eye conditions, and particularly for use in the treatment of Dry-Eye Disease and Meibomian Gland Dysfunction.

Background of the invention

Dry-Eye Disease (DED) is a common condition in the general population and is responsible for a majority of symptomatic presentations to specialist eye clinics. Meibomian Gland Dysfunction (MGD) is a subset of this disease, which concerns a deficient protective lipid tear layer resulting from gland disruption and loss. MGD is the attributed underlying cause for up to 80% of DED cases, and chronic inflammation of the Meibomian gland could lead to damage of the corneal epithelium and other adverse eye conditions, including Meibomian cyst formation, hordeolum or stye, chalazion and blepharitis.

Conventional methods for treating MGD revolve around the application of heat to the affected area in a clinical setting as well as good eyelid hygiene. However, conventional clinical treatment sessions for MGD require significant on-going compliance requirements with heat application, which can be expensive, time-intensive and thus out of reach for many patients. Accordingly, compliance and treatment satisfaction for conventional treatment methods of MGD are generally poor. The applicant has determined that it would be advantageous to provide an improved apparatus and system that is suitable for use in the treatment of eye conditions. The present invention seeks to at least in part alleviate the problems identified above.

Summary of the invention

According to an aspect of the invention, there is provided an apparatus for use proximate an area of an eyelid in the treatment of eye conditions, the apparatus comprising an ultrasound transducer configured for supplying low-frequency ultrasound waves to cause cavitation of an obstructed gland in the eyelid area in use; and a heating element configured for providing heat to the obstructed gland such that an obstruction in the gland is softened.

Preferably, the frequency range of the ultrasound waves is between 20 to 100 KHz. Preferably, the frequency range of the ultrasound waves is between 40 to 80 KHz. More preferably, the frequency range of the ultrasound waves is about 40 KHz. Preferably, the frequency range of the ultrasound waves is about 20 KHz.

Preferably, the heating element is a heater wire. Preferably, the heating element is a water- heated radiator.

Preferably, the apparatus further comprises an applicator operatively coupled to the ultrasound transducer for contacting and transmitting low-frequency ultrasound waves to the eyelid area. Preferably, the applicator is shaped in the form of a dome in which an apex of the dome is adapted to contact the eyelid area. Alternatively, the applicator is of a concavity shape to complement a contour of the eyelid. Alternatively, the applicator is of an ellipsoid shape to complement a contour of the eyelid.

Preferably, the apparatus further comprises a temperature sensor configured to output a surface temperature of the eyelid area.

Preferably, the apparatus further comprises a controller configured to receive output from the temperature sensor and determine treatment parameter inputs for the ultrasound transducer and the heating element such that the surface temperature of the eyelid area remains under a predetermined temperature threshold. Preferably, the predetermined temperature threshold is between 38 and 43 degrees Celsius. Preferably, the treatment parameter includes any one or more of the following parameters: ultrasound frequency; ultrasound amplitude; pulse width modulation; heating element temperature; and treatment duration.

Preferably, the apparatus further comprises a display for visually outputting a treatment parameter to a user.

According to another aspect of the present invention, there is provided an apparatus for use proximate an area of an eyelid in the treatment of eye conditions, comprising an ultrasound transducer configured for supplying low -frequency ultrasound waves to cause cavitation of an obstructed gland in the eyelid area in use, wherein the frequency range of the ultrasound waves is between 20 to 100 KHz.

Preferably, the apparatus further comprises a heating element configured for providing heat to the obstructed gland such that an obstruction in the gland is softened. According to another aspect of the present invention, there is provided a system for use in the treatment of eye conditions, comprising an ultrasound transducer configured for supplying low-frequency ultrasound waves proximate an area of an eyelid to cause cavitation of an obstructed gland in the eyelid area in use; and a heating element configured for providing heat to the obstructed gland such that an obstruction in the gland is softened.

Preferably, the system further comprises a lens adapted for use underneath the eyelid to reduce irritation effects of heat and/or ultrasound waves to an eye. Preferably, the lens is in the form of an air-filled hollow lens.

Preferably, the system further comprises a topical cream adapted for use between the eyelid and the ultrasound transducer to facilitate transdermal delivery of the cream.

Preferably, the frequency range of the ultrasound waves is between 20 to 100 KHz. Preferably, the frequency range of the ultrasound waves is between 40 to 80 KHz. More preferably, the frequency range of the ultrasound waves is about 40 KHz. Preferably, the frequency range of the ultrasound waves is about 20 KHz.

Preferably, the heating element is a heater wire. Preferably, the heating element is a water- heated radiator.

Preferably, the system further comprises an applicator operatively coupled to the ultrasound transducer for contacting and transmitting low-frequency ultrasound waves to the eyelid area. Preferably, the applicator is shaped in the form of a dome in which an apex of the dome is adapted to contact the eyelid area. Alternatively, the applicator is of a concavity shape to complement a contour of the eyelid. Alternatively, the applicator is of an ellipsoid shape to complement a contour of the eyelid.

Preferably, the system further comprises a temperature sensor configured to output a surface temperature of the eyelid area.

Preferably, the system further comprises a controller configured to receive output from the temperature sensor and determine treatment parameter inputs for the ultrasound transducer and the heating element such that the surface temperature of the eyelid area remains under a predetermined temperature threshold. Preferably, the predetermined temperature threshold is between 38 and 43 degrees Celsius.

Preferably, the treatment parameter includes any one or more of the following parameters: ultrasound frequency; ultrasound amplitude; pulse width modulation; heating element temperature; and treatment duration.

Preferably, the system further comprises a display for visually outputting a treatment parameter to a user. According to another aspect of the present invention, there is provided a method for use in the treatment of Meibomian gland dysfunction, the method comprising the steps of: transmitting low-frequency ultrasound waves using an ultrasound transducer to cause cavitation of an obstruction in a Meibomian gland in a treatment area proximate an eyelid, wherein the frequency range of the ultrasound wave is between 20 to 100 KHz; heating the Meibomian gland in the treatment area using a heating element such that the obstruction in the gland can be softened; and reducing the obstruction from the gland by expressing the obstruction from the eyelid using force.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Brief description of the drawings

Further aspects of the present invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description. The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic view showing an apparatus in use with an eye for treating an eye condition according to an embodiment of the present invention;

Figure 2 is a cross- sectional schematic view showing the eye and the apparatus of

Figure 1;

Figure 3 is a flow chart showing a method of treating an eye condition according to an embodiment of the present invention;

Figure 4 is a schematic perspective view showing an apparatus in accordance with another embodiment of the present invention;

Figure 5 is a cross-sectional schematic view showing an eye and the apparatus of Figure 4;

Figure 6 is a schematic perspective view showing an apparatus in accordance with another embodiment of the present invention;

Figure 7 is a schematic side view of the apparatus of Figure 6;

Figure 8 is a cross-sectional schematic view showing an eye and the apparatus of Figure 6; and

Figure 9 is a cross-sectional schematic view showing an eye with application of topical cream and the apparatus of Figure 6. Detailed description

Preferred embodiments of the present invention seek to provide apparatus and systems that allow trained eye specialists to perform treatment of eye conditions in a clinical setting, including Dry-Eye Disease (DED) and Meibomian Gland Dysfunction (MGD). Embodiments of the present invention use low-frequency ultrasound to generate heat, cavitation effects and promote molecular exchange in eyelid tissues containing the Meibomian glands so that an obstruction of lipids within the Meibomian gland of an affected eye can be extracted and subsequently reduced. The reduction of obstruction within the Meibomian gland leads to improved production and flow of a protective lipid layer which preserves tears by reducing the effect of evaporation and thus alleviates dry- eye conditions.

Figures 1 and 2 show a preferred embodiment of a treatment device 100 in the form of a probe for use in the treatment of eye conditions as described above. The probe 100 has a housing which comprises an ultrasound transducer 110 adapted for use proximate the upper and lower eyelids 20, 30 of an affected eye 10 (also referred to as the treatment area). The ultrasound transducer 110 is configured to produce and supply safe levels of low-frequency ultrasound waves to the eyelid tissues of the treatment area 20, 30, and in particular to any obstruction, such as obstructed or solidified lipids, within a Meibomian gland 22, 32 to cause cavitation of said obstruction. The low-frequency range of the ultrasound wave being supplied can be in the order of between 20 and 100 KHz, or more preferably, between 40 and 80 KHz. In some configurations, the frequency range of the ultrasound wave being supplied is about 40 KHz. In other configurations, the frequency range of the ultrasound wave being supplied is about 20KHz. Low-frequency ultrasound wave ranges as described herein (below 100 KHz) are unique and differ to ultrasound at other ranges due to its effect on stimulating cells and increasing cell membrane permeability (also known as cavitation). In particular, it is understood that ultrasound waves below the frequency of 100 KHz, advantageously, exhibit unique properties independent to thermal effects such as cavitation, micro-cavitation, formation of microjets and acoustic streaming effects on treated cells. These effects help break up clogged or solidified lipid obstructions within the Meibomian gland 22, 32.

In one embodiment and with reference to Figure 2, the probe 100 is further provided with a heating element 120 configured for providing supplemental heating to the treatment area 20, 30. The heating element 120 can be in the form of a heater wire. In some configurations, the heating element 120 is in the form of a water-heated radiator. In other configurations, the heating element 120 is configured to provide heating in the form of a heated air stream. The heating element 120 advantageously provides heating to the treatment area (in addition to any heat generated by the ultrasound waves), in particular to the obstructed Meibomian gland 22, 32 such that the obstruction or cavitated obstruction in the Meibomian gland 22, 32 and its duct excretion pathways can be softened or loosened so as to facilitate free flow of the obstruction through the gland.

A proposed pathophysiology for MGD is the obstruction of secretory ductules due to hyperkeratinisation, which over time affects the function of secretory cells, and consequently, the composition of meibum. The melting point is increased to approximately 40 degrees Celsius and therefore cannot be dissolved at body temperature of the eyelids, causing further obstruction and resuming the cycle of obstruction build-up. Heat generated by the ultrasound waves and the heating element 120 is proposed to gently heat the meibum within the ductules and to break this cycle. The cavitation and acoustic streaming effects of low-frequency ultrasound mobilise the lipid and keratin deposits within the ductules, as well as encourage molecular exchange to occur at a cellular level to promote acinar cell viability, differentiation, and to break down scarring. The practice of fat-cavitation and drug-delivery sonophoresis in dermatology follows these principles, and the treatment is intended to have a progressive redundancy following restoration of functional acinar cells and meibum secretion pathways.

It is understood however that low-frequency ultrasound waves below the 100 KHz frequency may not provide adequate heating to the treatment area to soften or loosen obstructions within the Meibomian gland 22, 32. It has been discovered by the inventors that a combination of low-frequency ultrasound waves and supplementary heating by the heating element 120 provides the desired synergetic effect in effectively breaking down and softening obstructions within the Meibomian glands 22, 32 for ease of subsequent extraction.

It is to be appreciated that, in one embodiment, the ultrasound transducer 110 is combined with the heating element 120 to form an integrated apparatus. In an alternative embodiment, the ultrasound transducer 110 and the heating element 120 are separate devices to be used as part of a system.

Referring to the embodiment as shown in Figure 2, a probe 100 has a cylindrical housing for incorporating the ultrasound transducer 110 and the heating element 120. The probe 100 can also be provided with a temperature sensor configured to detect and output a parameter representing a surface temperature of the treatment area in use. The probe 100 is connected to a power source and/or controller 300 via suitable power and/or data connection cables 102. In one embodiment, the power source and controller 300 is incorporated within the probe 100 housing. The controller 300 is configured to regulate treatment parameters and hence ultrasound and heat outputs of the probe 100. In one configuration, the controller 300 is connected to: a display 310 for visually outputting a treatment parameter to a user; a temperature regulator 320 for regulating the temperature of the heating element 120; and an ultrasound regulator 330 for regulating parameters relating to the ultrasound transducer. It is to be understood that non-limiting examples of treatment parameters may include any one or more of the following parameters: ultrasound frequency; ultrasound amplitude; ultrasound energy (intensity); pulse width modulation durations (on/off cycle durations); heating element temperature; maximum treatment temperature; overheating temperature; surface temperature of the treatment area and treatment duration/period.

In one embodiment, the probe 100, the power source and/or the controller 300 is configured with user input mechanisms such as buttons and dials for actuating/powering on/off the device as well as receiving input and/or changing treatment parameters. For example, the user can adjust the ultrasound wave frequency supplied by the ultrasound transducer 110 and/or temperature of the heating element 120 by manipulating the input mechanisms. In another embodiment, the display 310 can be configured with a suitable input mechanism such as a touch screen for a user to input and monitor the treatment parameters.

In some configurations, the controller 300 is configured to receive one or more output(s) from the temperature sensor, the ultrasound transducer 110 and/or the heating element 120 to determine a suitable treatment parameter for the ultrasound transducer 110 and/or the heating element 120. One example of a suitable treatment parameter to be controlled by the controller 300 is the surface temperature of the treatment area such that the surface temperature of the treatment area remains below a safe predetermined temperature threshold. The safe predetermined temperature threshold can be between 38 and 43 degrees Celsius. In one configuration, the controller 300 is configured to shut down the ultrasound transducer 110 and/or the heating element 120 if the surface temperature of the treatment area exceeds the overheating temperature. It is to be appreciated that the ultrasound transducer 110 and the heating element 120 can be considered to form part of a system for use in the treatment of DED conditions such as MGD and lipid deficiency in a supervised clinical setting. Such treatments may be administered independently or as an adjunct to existing therapies including medications, lid hygiene and/or lubricant eye drops, if necessary. Additional components of the system will be described in further details below.

In one embodiment, the system incorporates the use of an eye shield or lens 200, for example in the form of a contact lens, adapted for use underneath the eyelids 20, 30 (on the posterior eyelid surface) of the affected eye 10. The lens 200 serves the purpose of a barrier to heat and/or ultrasound waves, thereby protecting the anterior ocular surface, the underlying sclera and cornea of the affected eye 10 from any thermal or ultrasonic irritation. In some embodiments, the lens 200 is temperature sensitive and capable of providing feedback information to the probe 100 and/or the controller 300 before any critical temperatures are reached at the sclera and corneal surface. The lens 200 is shaped in the form of a contact lens and constructed from the same polymer as commercially available contact lenses. Suitable polymer materials include fluoro-silicone/acrylate, polymathy methacrylate (PMMA) and silicone hydrogel. In some configurations the lens 200 covers a substantial section of the iris. In an alternative embodiment, the lens 200 is in the form of a hollow lens having a cavity filled with air. The advantage of the air-filled hollow lens 200 is that densities at the air/tissue interface are very different and thus the hollow lens would provide the additional effect of reflecting waves entering the eye externally and directing more energy to the glands and protecting the posterior segment of the affected eye 10.

The system may also incorporate a temperature calibration unit (not shown) which can be placed onto the external eyelid 20, 30 surfaces prior to treatment. The temperature calibration unit can be configured to provide a reference estimate for the controller 300 to determine suitable treatment parameters such as ultrasound intensity and pulse width modulation. Referring to Figures 5 and 9, the system can also be used to administer topical cream 132 adapted for use between the eyelids 20, 30 and the ultrasound transducer 110 and/or the heating element 120 to facilitate transdermal delivery of the cream 132. It is understood that this is an effective form of cream or medicinal drug delivery through the outer eyelid skin 20, 30 to the Meibomian glands 22, 32. It is also to be appreciated that effective delivery of transdermal cream through the skin using the ultrasound transducer 110 and/or the heating element 120 is not limited to applications relating to the treatment of MGD or Meibomian glands.

Referring now to Figures 2, and 4 to 9, the probe 100 may be provided with an applicator 114 for contacting and transmitting ultrasound waves to the eyelid areas 20, 30. The applicator 114 is operatively coupled to the ultrasound transducer 110. In one embodiment, the applicator 114 is in the form of a dome in which an apex of the dome is adapted to be in contact with the eyelid area 20, 30 in use. In another embodiment, the applicator 114 is in the form of a thin, truncated tip. In yet another embodiment, the applicator 114 is in the form of a concave shaped to complement a contour of the eyelid 20, 30 in the direction of the eye so that ultrasound wave energy is delivered to a greater surface area surrounding the eyelid 20, 30 towards the orbital septum. Such applicators may be applied to the entirety of either the superior or inferior external eyelids 20, 30 concurrently. Similarly, the applicator 114 may also be in an ellipsoid shape to complement a contour of the eyelid 20, 30 across the longitudinal length of the affected eye 10.

Referring to Figure 3, methods of use will now be described in relation to the apparatus and the system for the treatment of MGD. The method generally includes the following steps to be administered generally by a trained eye specialist in a clinical setting. First, a measurement of eye size is optionally performed and the protective lens 200 is optionally provided to a patient underneath the eyelid treatment area 20, 30 in a similar fashion to contact lens, with the patient asked to close his/her eyes. Topical cream 132 is also optionally provided to the patient on the outer surface of the eyelid treatment area 20, 30. The ultrasound transducer 110 is configured with treatment parameters suitable for the patient, including ultrasound wave frequency, intensity, pulse duration and treatment duration. The treatment duration is estimated based on the chronicity of symptoms and severity or refractory degree of symptoms. Typical treatment duration is between two to ten minutes. In some arrangement, the treatment duration is between two to five minutes. The ultrasound transducer 110 may be configured to provide ultrasound wave energy either in a steady on state or pulsed with on and off cycles (pulse width modulation) depending on the requirement of the treatment. A temperature calibration unit is optionally coupled to the eyelid treatment area 20, 30 to provide a reference estimate for the controller 300 to determine suitable treatment parameters such as ultrasound intensity and reference temperatures.

The applicator 114 of the ultrasound transducer 110 is placed in contact with the external eyelid treatment area 20, 30, and preferably proximate the Meibomian glands 22, 32. Low frequency ultrasound waves (in the order of between 20 to 100 KHz) are then transmitted by the ultrasound transducer 110 to the treatment areas 20, 30 to cause cavitation of an obstruction in the Meibomian glands 22, 32 for the treatment duration. The applicator 114 may be placed onto the external eyelid margin and applied along the palpebral fissure one eyelid 20, 30 at a time to generate molecular effects as described above. Supplementary heating is optionally provided to the eyelid treatment area 20, 30 using the heating element 120 for period of time sufficient to soften the obstruction in the Meibomian glands. If the controller 300 senses at any point during the treatment that the surface treatment area has reached a predetermined temperature, it will regulate the ultrasound transducer 110 and/or the heating element 120 to avoid overheating. Any dissolved blockages of the obstruction within the Meibomian glands 22, 32 are then reduced/removed from the glands 22, 32 by expressing the treated Meibomian glands 22, 32. Expressing the Meibomian glands 22, 32 can be achieved by application of pressure to the eyelid margin using forceps to remove any dissolved blockages, and therefore reducing the obstruction in the glands to allow free passage of lipids through the gland ducts.

Although the steps described above are provided in a specific order, it can be performed in any variation of this order and additional steps may be executed between the steps described above.

A clinical example is also provided for the treatment of a patient with MGD using the apparatus and/or system as described above. A clinician (for example an ophthalmologist, optometrist, or trained assistant) operates the system as a day procedure following a calibration of the ultrasound intensity settings. Once the preliminary history, examination and investigations have confirmed MGD as the cause for a patient's dry eye symptoms, a review of their management to date including medications, exposures, as well as symptom severity is used to guide the initial treatment parameters including duration, intensity and pulse. A patient may be asked to remove any contact lens or prosthesis and an optional scleral shield is placed while the patient is positioned supine or reclined. A temperature calibration unit initially calibrates the intensity that is needed to generate a temperature increase at the surface of the treatment area 20, 30, so that a safety threshold is determined. Alternatively, the intensity is pre-set by the clinician and titrated/switched off based on the temperature changes. Following treatment duration of a maximum of ten minutes, or as tolerated by the patient, the patient is observed for a period of time and then tested for intraocular pressure (IOP) and visual acuity before being discharged. The patient is followed up after two weeks to measure any objective improvements, such as tear film break-up time, lipid layer thickness, as well as any improvement of symptoms. The response to treatment is assessed and a subsequent treatment at the fourth week is scheduled, with further treatments guided by ongoing or plateauing response.

It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

In the description and drawings of this embodiment, same reference numerals are used as have been used in respect of the first embodiment, to denote and refer to corresponding features. While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.