ES2685054A1 - Device for objective technique of estimation of accommodative delay (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Device for objective technique of accommodative delay estimation. The present invention describes an integral device capable of recording video images of the accommodation or ability of the eye to focus on objects at varying distances for the evaluation of accommodative delay and, therefore, the existence of an accommodative problem. The system allows to generate recordings in a short range of lens to store the information and obtain with objective precision the value of the accommodative delay, being the result less dependent of the person who makes the measurement. (Machine-translation by Google Translate, not legally binding)

Description

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DESCRIPTION

Device for objective technique of estimating accommodative delay SECTOR OF THE TECHNIQUE

The invention falls within the technical sector of Optometry, more specifically it relates to devices and procedures for objectively measuring accommodative delay.

BACKGROUND OF THE INVENTION

The accommodative delay is the difference between the position of the observed stimulus and the actual response of the accommodation. There are several techniques for measuring this difference using a strip or dot retinoscope (JP3095714). The main objective is to find the answer of the real accommodation or approach with respect to the chosen observation instrument. The retinoscope or schiascope consists of a set of main components such as the container that contains the batteries or energy accumulators and a head with a light bulb with a linear or circular signature (to obtain a strip or dot, respectively). The head has the option of varying the focus of the light it emits to observe the patient's eye.

The measurements are associated with the play of light and shadow in the pupil, which can be annulled with a point called "neutral point" or "neutralization point" where a total change of the pupil is observed with a slight rotational movement of the retinoscope in horizontal when passing from light throughout it to total darkness. Various techniques are used to locate this point, including dynamic retinoscopy and the monocular estimation method.

Dynamic retinoscopy can be started at 40 cm but, if shadows and lights appear simultaneously in the pupil and move in the direction in favor of the movement made with the instrument or in the reverse direction, the retinoscope moves backwards or forwards, respectively. , maintaining a fixed fixation point on which the patient keeps his eyes. When moving away or near, depending on the type of movement, the neutralization point must be achieved. This point has a distance from the observed eye that will be greater or less than the observation point. The inverse of this distance where the neutral point is seen, in meters, corresponds to the accommodative response and the difference with the inverse of the initial observation distance

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(usually 40 cm) is the accommodative delay objectively explored, but subjectively calculated by the observer.

The monocular estimation method (MEM) consists in the estimation of the accommodative monocular response under binocular conditions by neutralizing the reflex observed while the subject reads a test of letters or drawings coupled to the retinoscope. For neutralization, spherical lenses are placed before the eye. The power of the positive or negative lens that neutralizes respectively the direct or reverse movement of the reflection, will be the value of the accommodative delay.

With both techniques a normal value is obtained (when there are no accommodative problems) of an average of +0.75 ± 0.50D.

However, despite the existing techniques, there is a lack of equipment less dependent on the human eye of the observer who sometimes does not have a test in the image of observation in functional vision problems, as is the case of excess and / or accommodative spasm

EXPLANATION OF THE INVENTION

The present invention describes an integral device capable of recording video images of the accommodation or ability of the eye to focus on objects at close distances (less than 1 m) for the evaluation of accommodative delay and, therefore, of the existence of a problem. accommodative

It is a device equivalent to the handheld retinoscope with batteries that eliminates the eyepiece by replacing it with a touch screen with the possibility of taking images in different formats and file sizes as well as videos of lower or higher quality. In order not to eliminate the intervention of the human being, it incorporates a wheel that allows changes of powers in negative and positive values of 0.25 D, with the lens disc, which includes a lens-free gap for the power of zero diopters. This wheel of changes, as well as the lens disc, has the option of initially changing with a button for the use of left-handed and right-handed people. The lens wheel is coupled to a rod that allows you to regulate the distance between the digital camera and the eye to be evaluated.

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More specifically, the device for objective technique of estimating accommodative delay comprises a head (1) that incorporates an optical system that allows measuring the refractive power of the eye by interpreting the light reflected in its retina when it is illuminated (2) and a digital device (6) with the capacity to visualize, record and store the images or films of the observed pupil To one side of the digital device (6) the gear wheel (10) or mechanical system that allows, through the plastic rod is coupled (11), manipulate the lens disc (12) to change the power of the lenses (13) placed in front of the eye to be observed.

The optical system (2) is equivalent to a retinoscope and has a bulb (3), a converging lens (4) and a semi-mirrored sheet (5) and a digital device (6). The head is coupled with a rigid rod (7) to the handle (8) that includes batteries for lighting the bulb (3). For the internal manipulation of the head (1) in the base there is a screw cap (9) for simple manipulation of the bulb (3) and even opening it in case of failure.

Thanks to the automation of the device of the invention, it is possible to generate recordings in a short lens range to store the information and obtain the objective delay value more accurately. Therefore, the image of shadows and lights can be assessed after being recorded

Usually, the distance from the retinoscope to the eye being evaluated is about 40 cm because it is the usual working distance; for this reason, in the device of the invention with a rod (11) it has a length of 40 cm and allows the retinoscope to be synchronized with the type of shadow observed until it is eliminated without the intervention of the observer who can analyze the Image and keep it by removing it from the device digital Therefore, the rod in addition to maintaining the standard measurement distance interposes the necessary lenses so that the device detects when the desired point or neutral point (without shadows) arrives.

In addition, in the specific case of children and adolescents, these normally present excesses of accommodation so that the eye cannot relax sufficiently or stay over time to focus a short distance comfortably. However, there are currently many young people and children who approach the mobile alarmingly so that the reading distance is shortened and the system conditions

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accommodative are becoming more frequent. The device allows the accommodative delay to be measured at shorter distances by decreasing the length of the rod.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, for illustrative and non-limiting purposes, the main features of the invention are shown.

Figure 1.- Device for the objective technique of estimating accommodative delay. The head (1) is observed with the handle (8) and the mechanical system that allows, through the plastic rod (11), to manipulate the lens disc (12) coupled to the device

Figure 2.- Head (1) incorporating the optical system (2) with bulb (3), a converging lens (4), a semi-mirrored sheet (5) and a digital device (6).

Figure 3.- Handle (8) with batteries.

Figure 4.- Lens disc (12) with representation of lens power (13). PREFERRED EMBODIMENT OF THE INVENTION

The present invention is further illustrated by the following example, which is not intended to limit its scope.

In this example, the head (1) of the device is made of rigid hollow black plastic with a bulb (3) with a tungsten filament or circular LED to produce a spot-shaped light with a diameter of 400 mm of 5 cm for cover the entire pupil and of a high but fixed power to make the test in conditions of dimmed light or full light. The converging lens (4) has a short focal length of 60 mm (to allow a head height of no more than 150 mm and to project the light, with Infinite focal thanks to the semi-mirrored sheet (5), towards the CCD camera of the digital device (6) and towards the eye simultaneously), and a diameter of 30 mm. The semi-mirrored sheet (5) has the mirrored lower face but allows light to diffuse through it and reflecting on this face. It has a size of 60x30x10 mm and is embedded in the inner hollow on the four sides that support it, by way of inclined grooves to allow a sufficient angle for reflection without hindering the image that comes from the pupil of the

Eye illuminated by the device. The digital device (6) with dimensions of 145x70x7 mm is made of rigid plastic with a resolution of 1920x1080 pixels with a RAM of 4 GB DDR and memory of 32 GB plus a micro SD up to 256 GB. The head (1) is coupled with a rigid metal rod (7) to the metal handle (8) which includes batteries for the ignition of the bulb (3). To one side of the digital device (6) the gear wheel (10) or mechanical system constituted with a light rigid plastic material that allows through a plastic rod (11) with metallic interior to manipulate the lens disk is coupled made of rigid plastic (13) with a diameter of 100 mm that allows changing the power of the lenses (13). The lenses, both positive and negative plus 10 of the neutral (or hollow without a lens), are formed by translucent plastic, have dimensions of 21 mm in diameter and are placed in front of the eye to be observed.

Claims (5)

1. Device comprising a head (1) that incorporates an optical system that allows to measure the refractive power of the eye by interpreting the light reflected in its retina 5 when illuminated (2) and a digital device (6) with display capability, recording and storage of images to which a gear wheel (10) or mechanical system is attached that allows manipulating a lens disc (12) to change the power of the lenses placed in front of the eye to be observed through a rod (11) of variable length. 10 2. Device according to claim 1, wherein the optical system comprises a bulb (3), a converging lens (4) and a semi-mirrored sheet (5). fifteen 3. Device according to claim 2, wherein the head (1) is coupled with a rigid rod (7) to a handle (8) 4. Device according to claim 3, wherein the handle (8) can carry rechargeable batteries or a transformer for connection to the network. twenty 5. Use of the claimed device to estimate accommodative delay.