WO2025158182A1

WO2025158182A1 - Digital exophthalmometer

Info

Publication number: WO2025158182A1
Application number: PCT/IB2024/051265
Authority: WO
Inventors: Naser OWJI; Maryam SAGHEB; Negar OWJI
Original assignee: Individual
Current assignee: Individual
Priority date: 2024-01-28
Filing date: 2024-02-11
Publication date: 2025-07-31
Anticipated expiration: 2026-07-28

Abstract

The invention discloses a digital exophthalmometer for depicting and measuring position of the eye globe relative to the lateral orbital margin. The device has two separate units at two end of a connecting plate. The photographer unit 102 is fixed at one end of connecting plate 106 and the movable unit 104 is in another end and sliding on the connecting plate. The foot plate 108 of photographer unit is placed on the lateral orbital rim 122 of targeted eyeball, and the foot 108 plate of the movable unit 104 rests on the fellow lateral orbital rim 122. The camera 126 take a picture of the targeted eye globe 124 against the viewing window containing transparent ruler 110. The image is displayed on the LCD monitor. The corneal apex on the millimeter scale of the transparent ruler 110 in the recorded image indicates the exophthalmometry value.

Description

DIGITAL EXOPHTHALMOMETER

FIELD OF THE INVENTION:

The invention related to the ophthalmology diagnostic devices to measure the anterior displacement of the eyeball about the cranium.

BACKGROUND:

Eyeball is in a bony orbit. Exophthalmos (or "proptosis") is the abnormal protrusion of the eyeball from the orbit (anterior displacement) due to exopthalmogenic diseases that cause the swelling of the orbital content, tumors, etc. resulting in the protrusion of the eyeball out of bony orbit. Enophthalmos is the backward (or posterior) displacement of the eyeball into the orbit, which may be caused by, for example, a fracture of the orbital walls.

Exophthalmometers are used to measure the amount of exophthalmia and enophthalmia in the patients.

In general, the eyeball position along the anterior-posterior axis of the eyeball is measured by the distance between the lateral orbital rim (the outer edge of the bony orbit) and the corneal apex (the front surface of the eyeball). That is, distance is measured from the lateral orbital rim to a vertical frontal facial plane (coronal plane), which is tangent to the corneal apex and perpendicular to the anterior-posterior axis.

It is possible to perform exopthalmometry to determine the exophthalmos and or the enophthalmos by using a transparent ruler. Luedde in 1983 presented his device for measuring eye bulging based on the simple measuring unit by the transparent ruler. The Luedde exophthalmometer is a thick transparent (rectangular cube) plastic ruler grooved at one end designed to fit on the lateral orbital margin. The distance from the lateral orbital margin to the apex of the cornea is measured using a scale marked on both sides of the instrument. This way, the line of sighting of the examiner would become perpendicular to the instrument. For correct reading, the foot plate should rest correctly on the lateral orbital rim, in other words, position perpendicular to the frontal plane. The measuring ruler should be in the sagittal plane parallel to the anterior-posterior axis of the eye globe. However, if the ruler is tilted inward or outward or the examiner moves or the line of sight of the examiner is not exactly perpendicular to the rule, the readings of the measured displacement of the eyeball would not be accurate. This produces an error commonly known as the parallax error, which is the apparent displacement, or difference in the apparent position of the eyeball, caused by the actual change (or difference) of the position of the point of observation (by the examiner). It offers a simpler but less accurate method of measuring exophthalmos. This type of exophthalmometry is less widely used today.

The most widely used method at present is Hertel exophthalmometry (Hertel E., Arch. F. Ophth. 60:171, 1905). Hertel exophthalmometry in which the position of the globe relative to the anterior lateral orbital margin is measured with the aid of a set of mirrors and prisms. It is a binocular instrument that rests on each lateral rim and allows an observer in front, with the aid of mirrors and prisms to view images of the corneal apex of the two eyes seen in profile superimposed upon a millimeter scale. In which estimates the distance from the apex of the cornea to the lateral orbital rim perpendicular to the frontal plane. This has become the standard technique in clinical and research publications for most of this century. There are three categories of exophthalmos:

(1) absolute, in which the eye protrudes beyond a given standard; (2) relative, an asymmetry of protrusion between the two eyes of the same person; and (3) comparative, a measurement of a person's eye position during a given interval.

Hertel's exophthalmometry difficulty is mainly caused by low sensitivity and reproducibility. Hertel himself questioned its ability to provide absolute measurements; Hertel stated that because of huge variations in absolute values, his exophthalmometer was not suitable for absolute exophthalmometry, but he found it entirely reliable for relative measurements. He advised physicians to use his exophthalmometer only as a tool for follow-up. Some investigators have questioned the reliability of the Hertel exophthalmometer for comparative exophthalmometry because of its low repeatability and high inter-observer variation.

Nowadays, a wide variety of Hertel-like exophthalmometer designs are in use. Several drawbacks and sources of error have been described over the years when using Hertel and other Hertel-like exophthalmometers. Some of these errors arise from the instrument itself, others from its use in practice. The first problem that is encountered in exophthalmometry is that readings from not completely identical instruments cannot be compared with each other. Instrument errors can be induced by the variety of commercially available exophthalmometers. Investigators found the inter-instrument variation of up to 4 mm between different models, and up to 2.9 mm between identical models from the same manufacturer.

Other major problems are the low repeatability of measurements and inter observer variation. There is a possibility that not only do the measurement values differ for each examiner, but also the measurement values differ each time the eye protrusion measurement is performed even by the same examiner. It is generally thought that a more stable design will minimize these errors. A reliable measurement is repeatable and reproducible. Any difference between or within observers (inter- or intra-observer variation) compromises the reliability. The inter observer disagreement has been reported at a frequency of 25% to 70%. In addition, the examination is difficult unless you are an experienced examiner, so only a skilled examiner such as a doctor who majored in plastic ophthalmology tends to perform the ocular protrusion measurement using an ocular protrusion.

Parallax error is other major problem. When using devices based on Hertel's design, movement of the examiner to the left or the right, while looking at the image of the apex of the cornea, introduces parallax error. Unfortunately, that is true only for the one reading position where there is no parallax. Exophthalmometers are most used when it is suspected that the eye is either exophthalmic or enophthalmic, and thus not at the instrument's no- parallax-alignment position. Due to parallax, prism-type exophthalmometers only yield adequate values within the normal range of eye position. This could be adjusted if the manufacturers would create a nonlinear ruler to compensate for the angle created by the need to adjust the pointer and the middle of the ruler in all examinations.

Unfortunately, devices based on Hertel's design do not provide particularly accurate exophthalmometry measurements (or readings) in that they depend on the position of the person using the instrument (the examiner), and indeed, any slight movement of the examiner, the patient, or the instrument itself can lead to the incorrect and unsafe examination of the eye bulging. Ensuring proper resting of the footplates on the lateral orbital rims, finding of parallax free line and adjusting to the reference line in the measuring mirror, finding and reading the corneal apex on the measuring ruler, and maintaining the instrument in the horizontal plane in the same time is difficult. The conventional exophthalmometer requires manual efforts to measure the reading and a long time to perform the measuring task usually leads to the unwished change of instrument position and error in reading.

Another source of error is the distance of the examiner from the exophthalmometer. The error at any exophthalmometry reading increases by about 20% when the distance from the examiner's eye to the reflecting surface decreases from 45 cm to 30 cm. Reading error is inversely proportional to this distance. It behooves the examiner to work consistently from the exophthalmometer and as far from the instrument as feasible to decrease the error associated with this distance.

In Hertel exophthalmometry, the globe position is measured simultaneously on both sides, and the measurements may not be independent of each other. This may reduce the reliability of the Hertel exophthalmometer for relative exophthalmometry. Because in relative exophthalmometry measurements of the right and left eyes are compared with each other, the ideal instrument should give an independent measurement of each side.

Other disadvantages of using the Hertel instrument include the difficulty of visualizing the scale under conditions of low illumination which may result in inaccurate readings.

Any instrument measuring proptosis must be portable, readily available, and quick to use. Any result must be reproducible between observers and over time. The quantitative assessment of the position of the globe in the orbit is an important clinical parameter, but in busy ophthalmic practice, exophthalmometry may not often be performed. The reasons for this may include the perceived difficulty of measurement in the clinical setting using the Hertel exophthalmometer. Variations of 1.5 to 2.0 mm could affect patient treatment when a difference in measurement of 2 mm is regarded as significant during serial or relative exophthalmometry.

Accurate measurement of physical parameters is essential for the practice of modern medicine and ophthalmology. Given the above-mentioned limitations in exophthalmometers, a simple, objective, available, and credible examination device for measuring eye bulging is needed. The object of the present invention is to provide a kind of portable exophthalmometry measuring instruments for a summary of the invention, to solve the prior art exophthalmometry instrument measures inaccurate problem as existing for by an artificial observer. This instruments for examining the eyes are independent of the observer's perceptions or reactions and has the advantages that measurement accuracy is high, easy to use, and digitally records the exophthalmometry.

OBJECTS:

It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.

The main object of the invention is to provide a newly designed exophthalmometer to measure the anterior or posterior displacement of the eyeball in the eye socket, independent of the observer's perceptions or reactions. It has the advantages that measurement accuracy is high, easy to use, and digitally records the exophthalmometry.

Another object of the invitation is a photographic recording of exophthalmos values. Saving the results provides new opportunities to collect measurements for each patient, perform image analysis, compare results of measurements, and monitor the progress of the disease, and dynamics of the changes after the treatment. The system gives us reproducibility and repeatability of the results. Availability, non-invasiveness, and ability to transfer and display make digital exophthalmometry a suitable method for clinical documentation and clinical trials, and scientific investigations. Digital photographs can also be easily stored and reemployed in future studies.

Another object of the invention is to allow operators to use the instrument easily. Exophthalmometry has become as easy as simple digital camera photography. Exophthalmometry with this device does not need special experience and could be learned easily, so it can be used in most ophthalmology and endocrinology clinics.

Another object of the invention is to provide the device with high sensitivity and reproducibility for measuring eye bulging. Another object of the invention is to minimize examinator errors in exophthamometry. The built-in camera acts as an artificial observer at the center of the measuring ruler with a fixed position and fixed distance from the ruler, so the recording of exophthalmometry is done by fixed observer on different exophthalmometry occasions.

Another object of the invention is to provide a device that measures exophthalmos separately on both sides. In contrast to Hertel exophthalmometry that the globe position is measured simultaneously on both sides, the exophthalmometry measurements by this device are independent of each other. Because in relative exophthalmometry measurements of the right and left eyes are compared with each other, the ideal instrument should give an independent measurement of each side. So, this device is a reliable instrument for relative exophthalmometry.

Another object of the invention is to provide a light source. It provides adequate reflected light from the cornea of sufficient intensity to illuminate the ruler measuring scale for easy reading in dim light.

Another object of this invention is a nonlinear ruler for measuring eye bulging. The clinician's exophthalmometry measuring equipment takes the form of a clear ruler with the ever-present possibility of inaccuracy from parallax and perspective. This device uses a nonlinear ruler to compensate for parallax and perspective. So, this instrument could be reliable for measuring exophthalmos values.

Another object of the invention is to provide a device that measures exophthalmos not only in upright position but also in supine position. Exophthalmometry measurement during orbital decompression surgery or orbital blow out fracture repair is important to compare eye bulging between operated side and fellow eye.

SUMMARY OF THE INVENTION

The present invention provides a new device for exophthalmometry through digital photography. It is an instrument with two separate units (one photographer unit and one movable unit) at two end of a connecting plate that rests on each lateral orbital rim and allows an observer in front, with the aid of a built-in digital camera to view image of the corneal apex of the eyeball seen in an picture superimposed upon a millimeter scale. It is an imaging system for imaging the eyeball before viewing the window of the camera, containing a transparent nonlinear ruler, onto the photographer unit. An imaging system comprising one focusing unit for setting a suitable focus. Photographer unit includes a foot plate, a light source, a nonlinear transparent ruler, an LCD monitor, and a camera.

In one embodiment footplate of the photographer unit (fixed part) is placed on the anterior lateral orbital margin of the targeted eyeball, the zero point for measuring exophthalmos, and the movable unit rest on the contralateral anterior margin of the lateral orbital rim. The eye should be in a primary position perpendicular to the frontal plane. The device should be kept in the horizontal plane. The ruler (viewing window of the photographer unit) should be in the sagittal plane parallel to the anterior-posterior axis of the eye. Inaccurate orientation in the sagittal plane is the source of error. The measuring scale should be as near as possible to the globe, in other words, the distance between two units of exophthalmometer (inter orbital distance) should be the least as possible. Fixing the distance between two ends of the exophthalmometer (inter orbital distance) minimizes error in reading on different exophthalmometry occasions and causes more precise measurements in relative and comparative exophthalmometry measurements. The light source illuminates the eye globe and receiving light passes into the device through a transparent ruler and the camera takes a picture of the eyeball against the ruler. The corneal apex on the millimeter scale of the ruler in the recorded image indicates the exophthalmometry in millimeters. The device is rotated 180 degrees and the photographer unit is placed on the lateral orbital rim of the other side and the movable unit is placed on the contralateral side, with inter orbital distance the same as when measuring was done for first eye, and records the eye bulging of the fellow eye.

BRIEF DESCRIPTION OF THE DRAWINGS

In the present invention, various modifications may be made, and various embodiment may be provided. Specific embodiment will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it is to be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention. Throughout the disclosure, the word "exemplary" is used exclusively to mean "serving as an example, instance, or illustration." Any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiment. The terms used in the present application are only used to describe specific embodiment and are not intended to limit the present invention.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms, as defined in a commonly used dictionary, should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application.

The invention will now be described concerning the drawings wherein:

FIG. 1 is an exemplary perspective illustration of the present invention according to an embodiment of the invention.

FIG. 2 is an exemplary illustration of the schematic cross-sectional top-view of the photographer unit of the present invention according to an embodiment of the invention in a typical position on the face of a patient.

FIG. 3 is an exemplary back-view illustration of the photographer unit of the present invention according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure. 1, shows an exemplary digital exophthalmometer. Device 100 comprises of a photographer unit 102, a movable unit 104, a connecting plate 106. The photographer unit 102 and movable unit 104 have footplates 108 for placing device 100 on the anterior lateral orbital margins of the patient as a zero point for exophthalmos measurement. Dash line 132 shows in the figure 1, at the inner side of footplates 108 on photographer unit 102 relative to the measuring ruler 110. It should be just at the zero point of the measuring ruler 110. The footplate 108 of this exophthalmometer is fitted with a rubber ring, allegedly to increase patient comfort. The photographer unit 102 has a viewing window 110 containing a nonlinear transparent ruler which the camera 126 (not visible in this view) can capture an image received through it. For compensation of the parallax and perspective in viewing and imaging of the eyeball by the recording camera 126 through a transparent ruler 110, the ruler is nonlinear. Furthermore, photographer unit 102 has a light source 114 for emitting light from the device. Light source 114 is configured to emit white light and serves for illumination of the eyeball to be imaged by the camera.

The photographer unit 102 comprises all the necessary components for the basic function of the camera 126, such as control electronics including the power supply and the communication means for connection to other devices such as mobile and PC.

The connecting plate 106 contains a millimeter scale for fixing the instrument in the same position in different exophthalmometry occasions. In another word, in different exophthalmometry occasions, inter orbital distance should maintain in the same scale on the connecting plate. The inner border of movable unit 104 on the scale of the connecting plate 106 shows inter orbital distance.

The inter orbital distance could be measured digitally. For this purpose, a number of rectangular capacitance sensors engraved or fixed onto a copper or glass strip, underneath the scale of the connecting plate 106. There is a circuit board on the underside of the movable unit 104. For digital displaying of inter orbital distance, movable unit 104 contains LCD monitor 118, chips, and battery. The whole series of capacitance sensors are connected to the chips (the coded data is stored in the chips) and then to the battery. When the movable unit 104 has to and fro motion, due to the connection and disconnections between the sensors the signals will pass to the chips then the chips will send the data and allows the LCD monitor 118 to display the inter orbital distance value.

Manual input elements 116 and 120 with the aid of which the device 100 can be operated, are located respectively on the photographer unit 102 and movable unit 104.

As shown in Figure. 2, footplates 108 of the device 100 is placed on the anterior lateral orbital margins 122 of the targeted eyeballs 124. The photographer unit 102 is configured for taking images. The photographer unit 102 has an internal camera 126 for receiving the image. Camera 126 is arranged such that it can capture an image received through the transparent ruler 110. Camera 126 has a light-sensing side with a focusing unit for producing an image from the light received through the transparent ruler 110. Provision is made for camera 126 to focus automatically. The optical axis 128 is shown by a dashed line. The optical axis 128 passes through the center of the transparent ruler 110. The image displays on the LCD monitor 112 and is saved on built-in device 100 memory.

In Figure. 3, shutter button 130 is used to automatically focus the image and take the image of the eyeball 124 against the measuring ruler 110.

In a further embodiment, the device is battery-powered. Therefore, the device 100 may comprise a rechargeable battery. The Device 100 could be charged directly by a power cord or could be charged by a wireless charging device included in the case when the device is placed into the case. Alternatively, device 100 could be charged directly via the USP port, and image information can also be transmitted from device 100 to the cellphone or PC.

In an embodiment, the device includes a Wi-Fi module which is configured to communicate by radio (for example by WLAN) to a cellphone or PC, and can store the result for documentation.

THE DIGITAL EXOPHTHALMOMETER FUNCTIONS AS FOLLOWS:

As indicated schematically in Figure. 2, the footplate 108 of the photographer unit 102 is placed on the anterior lateral orbital margin 122 of the right side, the zero point for measuring exophthalmos. The movable unit 104 is placed on the anterior lateral orbital margin 122 of the left side and slid on the connecting plate 106 to fix it in the proper position. The measuring ruler 110 (viewing window 110 of the photographer unit 102) should be as near as possible to the eyeball 124. In another word the distance between the two parts of the exophthalmometer should be as little as possible. The eyes should be in the primary position and the visual axis of the patient should be perpendicular to the coronal plane. The measuring scale or ruler 110 should be in the sagittal plane and parallel to the anterior-posterior axis of the targeted eyeball. In this manner, the camera 126 is arranged laterally to the eyeball 124 and the optical axis 128 of the camera 126 is perpendicular to the vertical plane passing through the anterior-posterior axis of the targeted eyeball. The position of the instrument is aligned in the horizontal position to place the anterior- posterior axis of the image of targeted eye parallel to the measuring ruler 110 in LCD monitor 112. For accurate measurement, the examiner sits at the same level in front of the patient. The light source 114 illuminates the eye globe and receiving light passes into the device through a transparent ruler and viewing window 110. With the shutter button 130, the image is focused automatically and camera 126 takes a picture of the globe against the transparent ruler 110. The camera 126 captures and saves the image of the targeted eyeball in front of the transparent ruler 110. The corneal apex on the millimeter scale of the ruler in the recorded image indicates the exophthalmometry in millimeters. The device is rotated 180 degrees and photographer unit 102 is placed on the lateral orbital rim of the other side position of the device 100 is correctly aligned against the patient's face as do in measuring of the right side in such a manner that foot plate 108 of movable unit 104 rest on the anterior lateral margin of the right side such a way that inter orbital distance on the connecting plate 106 is the same millimeter as when the right side was measured. Camera 126 captures the image of the left eye against the measuring ruler 110 in a position like the right side.

Device 100 could be placed on the image mode by manual input elements 120, and the examiner read the exophthalmometry again. The image could be sent to a cellphone or PC for documentation or sent to other clinicians or another clinical center.

In another embodiment, the device 100 may use an artificial intelligence assisted image processing algorithm to display exophthalmometry value on recorded image of the patient's eye against the ruler 110, numerically.

The instrument of the present invention is mainly described in relation to the measurement of the anterior posterior axial position of the eyeball using the lateral orbital rim as the reference, in another embodiment it would be apparent to those skilled in the art to modify and use the universal frame as the stabilizing base to measure the degree of exophthalmos using the superior and inferior orbital rims as the reference points. Measurements from exophthalmometer with fixation based on lateral orbital rim are inaccurate in patients with lateral orbital rim procedures and fracture, so in this situations the superior and inferior orbital rim based exophthalmometer may be more accurate.

It is to be understood that additional embodiment of the present invention described herein may be contemplated by one of the ordinary skills in the art and that the scope of the present invention is not limited to the embodiment disclosed. While specific embodiment of the present invention have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention. The invention defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as preferred forms of implementing the claimed invention.

TECHNICAL ADVANTAGES

The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a digital exophthalmometer, that:

Digitally measure the anterior or posterior displacement of the eye globe of a patient improves the accuracy of determining the magnitude of the displacement of the eye independent of the observer's perceptions or reactions.

Is portable and works as a digital camera and is to allow operators to use the instrument easily.

Digitalization of eye bulging measurements leads to accurate assessment of proptosis, comparing results of measurements, and monitoring the progress of the disease. Digital photographs can also be easily stored and reemployed in future studies.

Is to provide the device with high sensitivity and reproducibility for measuring eyeball bulging.

Is to provide the device with light source enable examiner to do exophthalmometry in dim light.

Digital exophthalmometer measures eye bulging not only in upright position but also in supine position. Exophthalmometry measurement during orbital decompression surgery or orbital blow out fracture repair is important to compare eyeball bulging between operated side and fellow eye.

ECONOMICAL SIGNIFICANCE

Since 1905 that the Hertel presented his invention, the most widely used and accurate method has been Hertel exophthalmometry. Hertel's exophthalmometry difficulty is mainly caused by low sensitivity and reproducibility. More than one century, there has not been any change in exophthalmometry instrument to produce more reliable and reproducible instrument to measure eye bulging.

The product in accordance with present invention will be in great demand worldwide due to novel technical features of a present invention that is a technical advancement in the field of exophthalmometer. Further by granting patent, the patentee can contribute in manufacturing the new product or new process of manufacturing by himself or by technology collaboration or through the licensing.

The product will contribute new concept in medical industry, wherein patented process/product will be used. The present device will replace the conventional exophthalmometer.

Exophthalmometry with this device does not need special experience and could be learned easily, so it can be used in most ophthalmology and endocrinology clinics.

Claims

WE CLAIM: l.The digital exophthalmometer , is an imaging system for imaging the eyeball before a viewing window (containing a nonlinear ruler) of a camera onto a photographer unit to measure exophthalmos relative to the lateral orbital rim. The digital exophthalmometer comprises: a: a fixed photographer unit for photography and recording the eye bulging, connecting to the movable unit by connecting plate. The photographer unit comprises: a foot plate to rest on the anterior lateral orbital rim of the targeted eye (in another embodiment the superior and inferior orbital rims) as the reference points; a camera to receive the image from the targeted eye; a viewing window comprising a nonlinear transparent ruler for measuring eyeball bulging in the recorded image by the photographer unit; a light source to emit white light and serves for illumination of the eyeball before the viewing window to capture the clear image of the targeted eye by the photographer unit; an LCD monitor for viewing the object during the shooting of the camera and to display captured image and a battery as powering source of the camera and LCD in the photographer unit . b: a movable unit sliding on the connecting plate to rest on the anterior lateral orbital margin of the fellow eye to keep the device in the horizontal plane and to position the measuring ruler of the photographer unit in the sagittal plane parallel to the anterior- posterior axis targeted eye. The movable unit comprises: a food plate to rest on the lateral orbital margin of the fellow eye (in another embodiment the superior and inferior orbital rims) as the reference points ; a LCD that receives data from the chips to display inter orbital value; chips that stored the coded data to process the received electrical signal from capacitance sensors of the connecting plate and send data to the LCD of movable unit; a battery as powering source of the chips and LCD in the movable unit; and a circuit board under side that with moving to and fro on the capacitance sensors of the connecting plate create electrical signal and send to the chips. c: a connecting plate contains a millimeter scale for fixing the instrument in the same position in different exophthalmometry occasions. There are a number of rectangular capacitance sensors engraved or fixed onto a copper or glass strip, underneath the scale of the connecting plate. The whole series of capacitance Sensors are connected to the chips and then to the battery in the movable unit. When the movable unit has to and fro motion, due to the connection and disconnections between the sensors, the signals will pass to the chip then the chip will send the data and allows the LCD of movable unit to display the interorbital value.

2.The digital exophthalmometer as claimed in claim 1, comprises a photographer unit configured to take a picture and display the image of the eye globe against the measuring ruler. The imaging system comprising one focusing unit for setting a suitable focus.

3.The digital exophthalmometer according to claim 2, wherein said photographer unit has a digital camera for receiving and recording the image of the targeted eyeball.

4.The digital exophthalmometer according to claim 3, wherein said camera takes an image of the eyeball through a viewing window.

5.The digital exophthalmometer according to claim 2, wherein said photographer unit has a viewing window comprises a transparent nonlinear ruler scaled in millimeters. A tangential line at the apex of the cornea against the measuring ruler scales in the imaged eye shows the value of exophthalmometry in millimeters.

6.The digital exophthalmometer according to claim 2, wherein said photographer unit has a light source comprised of LEDs which are configured to emit white light to illuminate the object (eyeball) before viewing window (transparent ruler).

7.The digital exophthalmometer according to claim 2, wherein said photographer unit has an LCD monitor for viewing the object during the shooting of the camera and displaying captured images. The examiner sees the image of the targeted eyeball on the LCD monitor to keep the position of the device in the horizontal plane such the eyeball image is correctly positioned on the measuring ruler in the viewing window to record the picture. The recorded picture of the patient's eye against the ruler by the camera is read by the examiner on the LCD monitor.

8. The digital exophthalmometer according to claim 2, wherein said photographer unit has an built-in memory that the image displays on the LCD monitor is saved on built-in device memory.

9.The digital exophthalmometer according to claim 2, wherein said photographer unit has a shutter button automatically activates the focusing and shooting of the digital camera.

10.The digital exophthalmometer according to claim 2, wherein said photographer unit has input elements for manually selecting digital camera functions.

11.The digital exophthalmometer according to claim 2, wherein said photographer unit has a foot plate to rest on the anterior lateral orbital rim of the targeted eye.

12.The digital exophthalmometer as claimed in claim 1, comprises a connecting plate, connecting the photographer unit to the movable unit for providing a stable base for ophthalmic measurements. The photographer unit is fixed on one end of the connecting plate and rests on the anterior lateral orbital rim of the targeted eyeball. The movable unit is on the other end of connecting plate and slides on the plate to adjust and rest on the lateral orbital rim of the fellow eyeball at a fixed inter orbital distance.

13.The digital exophthalmometer according to claim 12, wherein said connecting plate is scaled in millimeters to fix inter orbital distance in different exophthalmometry occasions.

14.The digital exophthalmometer according to claim 12, wherein said connecting plate contains a number of rectangular capacitance sensors engraved or fixed onto a copper or glass strip, underneath the scale. The whole series of capacitance Sensors are connected to the chips and then to the battery in the movable unit. When the movable unit has to and fro motion, due to the connection and disconnections between the sensors the signals will pass to the chip then the chip will send the data and allows the LCD monitor of movable unit to display the inter orbital value.

15.The digital exophthalmometer as claimed in claim 1, comprises a movable unit sliding on the connecting plate and rests on the anterior lateral orbital margin of the fellow eye to keep the device in the stable horizontal plane in front of the patient's face.

16.The digital exophthalmometer according to claim 15, wherein said movable unit has a foot plate to rest on the anterior lateral orbital rim of the fellow eye.

17- The digital exophthalmometer according to claim 15, wherein said movable unit has a circuit board under side that with moving to and fro on the capacitance sensors of the connecting plate create electrical signal and send to the chips.

18. The digital exophthalmometer according to claim 15, wherein said movable unit has chips that stored the coded data to process the received electrical signal from capacitance sensors of the connecting plate and send data to the LCD monitor of movable unit.

19. The digital exophthalmometer according to claim 15, wherein said movable unit has a

LCD monitor that receives data from the chips to display inter orbital value.

20.The digital exophthalmometer according to claiml5, wherein said movable unit has input elements for manually selecting digital ruler functions.

21. The digital exophthalmometer as claimed in claim 1, wherein the superior and inferior orbital rims could be used as the reference points for exophthalmometry measurement in another embodiment. Measurements from exophthalmometer with fixation based on lateral orbital rim are inaccurate in patients with lateral orbital rim procedures and fracture, so in this situations the superior and inferior orbital rim based exophthalmometer may be more accurate.

22.The digital exophthalmometer as claimed in claim 1, wherein exophthalmometry measurement could be displayed numerically by using artificial intelligence assisted image processing algorithm.

23.The digital exophthalmometer as claimed in claim 1, wherein said digital exophthalmometer includes a Wi-Fi module configured to communicate a cellphone or PC.

24.The digital exophthalmometer as claimed in claim 1, which said exophthalmometer unit includes at least one power source for supplying power to the camera, LCD monitors and the chips.

25.The digital exophthalmometer according to claim 24, wherein said power source is a rechargeable battery.