RU2458624C1 - Method of determining value of addition in selection of progressive glasses in case of myopia - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to ophthalmology, and is intended for determination of addition value during selection of progressive glasses in case of myopia. Value of objective accommodation response at distance 33 cm is determined. Accommodation response is restored to normal values by means of positive lenses with step 0.5 dioptres. Value of addition is determined as lens power, which makes it possible to obtain objective accommodation response with value - 2.5 dioptres.

EFFECT: method makes it possible to objectively evaluate addition power in selection of progressive eyeglasses in case of myopia.

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Description

The present invention relates to ophthalmology and is intended for an objective determination of the strength of the required addition for close by the value of the accommodation response.

Addition is a positive addition for near, which indicates the difference in diopters between the correction values for the distance and for the near. According to foreign authors (Gwiazda J., Hyman L., Hussein M. et al. A randomized clinical trial of progressive addition lenses versus single vision lenses on the progression of myopia in children. Invest Ophthalmol Vis Sci 2003; 44: 1492-500 ; Scheiman M. Clinical management of binocular vision: heterophoric, accommodative, and eye movement disorders. 2 ^nd ed., 2002; and others), positive accessory lenses are prescribed for accommodation insufficiency (short accommodation, inertia of accommodation, inequality of accommodation and paralysis of accommodation ) In a study of the effect of various corrections: progressive (PO) and ordinary single-focal (OO) glasses on the development of myopia (COMET), it was shown that within 3 years of observation, the decrease in the rate of progression in the PO group compared to OO was only 0.2 diopters. At the same time, when comparing children with an initially reduced accommodative response and esophoria for near, the advantage of correction with progressive glasses was 0.64 diopters for 3 years.

Existing methods for determining the magnitude of the required addition are subjective and more often calculated.

It is known that tables for determining visual acuity at close range are used to select addi- tion. There are no strict rules regarding the font size to be guided by.

A positive spherical lens is selected (an addition to the correction for distance), with which it is most comfortable to read a test text from a working distance (Rosenblum Yu.Z. Optometry. St. Petersburg: Hippocrates, 1996; p.175-176). This method has been preferred by many domestic ophthalmologists for many years. However, modern requirements for the selection of corrections for nears are increasingly forcing doctors to use this method as an approximate one, and to refine / control use additional tests (for the range of distances, with a fixed cross-cylinder, with a duochrome test for near, with a Helmholtz target, a banded figure Duanet et al.).

Known objective measurement of addivation, which is carried out using close retinoscopy (Harvey B., Franklin A. Objective and subjective refraction // Optician. 2005. V.230, N 8. P.30-33). To determine addiction, retinoscopy is performed from the required working distance. A test subject in conditions of complete correction for distance fixes a test for near, mounted directly on a retinoscope (usually just above the illuminator). If accommodation is not disturbed, neutralization of the shadow will be noted at the time of the study. If accommodation is weakened (for example, presbyopia), the shadow will move in the direction of the retinoscope movement. In this case, plus lenses of increasing magnitude are placed on the subject’s eye until the shadow is neutralized. The plus lens with which this is achieved is regarded as the amount of addition required. This method is taken as the closest analogue. However, this method using retinoscopy is not objective enough, since the results obtained depend on the qualifications of the doctor (optometrist), vary in different hands, that is, there is the so-called “subjectivity of the researcher” (S.E. Avetisov. Automated system for determining clinical refraction , its assessment and the possibility of its use in clinical practice. Author's abstract of thesis ... Candidate of Medical Sciences. M., 1977, 11 pp.).

The technical result of the proposed method is the ability to objectively determine the strength of the add in the selection of progressive glasses for myopia.

The technical result is achieved by determining the value of the accommodation response by 33 cm by adding positive glasses of increasing strength in increments of 0.5 diopters until dynamic refraction with the glass reaches -2.5 diopters.

All studies are carried out using an “open field” automatic binocular ref keratometer, such as the Grand Seiko WR-5100K. Conventional refractometers use a special system to prevent accommodation in the patient, but, despite this, during the measurement, the patient has errors associated with instrument accommodation or the so-called instrumental myopia. These errors are caused by the fact that the patient needs to look at the internal target of the device. Grand Seiko WR-5100K automatic ref keratometer eliminates the possibility of such errors, as it uses a transparent window instead of the target. Measurements can be carried out both without correction (for emmetropes), and with optical correction (for patients with ametropia) under conditions of simultaneous presentation of the fixation object in an open field at a distance of 5 m to 20 cm.

The method is as follows. First, the patient is determined by refraction when looking into the distance (the fixation target is located at a distance of 5 m). If refraction is impaired, based on the data obtained, spherical and cylindrical glasses are placed in the test frame, which completely correct the revealed refraction anomaly, and re-conduct refractometry. Dynamic refraction measurements are carried out with the same corrective glasses. Before the eyes at a distance of 33 cm (which corresponds to the accommodation task of 3.0 diopters), text No. 4 is placed from the table for near and autorefractometry is performed with binocular fixation. The obtained value of dynamic refraction corresponds to an objective accommodative response to a given distance. Normally, the value of the objective accommodative response (JSC) by 33 cm is -2.5-3.0 diopters (Kolotov MG, Objective accommodative response in myopia and the possibility of its optimization // Author. Thesis ... Candidate of Medical Sciences. - M .: - 1999. - 21 pp .; Filinova OB, Study of the effect of constant weakly myopic image defocusing on the dynamics of refraction, binocular functions and eye growth in children // Dis .... Candidate of Medical Sciences, M., 2009. 158 p.).

Lower values indicate a lag in the objective accommodative response (JSC). Depending on the magnitude of the backlog of OAO, the strength of the necessary addition for near is determined objectively by the value of the accommodation response (OAO). For this, positive glasses of increasing strength are added to the full correction and autorefractometry is performed under the same conditions until dynamic refraction with the glass reaches -2.5 diopters.

Example 1

Patient D., 11 years old. Diagnosis: myopia cf. Art., slowly progressing. First, the patient was determined by refraction when looking into the distance (the fixation target is located at a distance of 5 m). Refraction OD = -4.25 Dptr, OS = -4.25 Dptr. Spherical lenses were placed in the test frame, which completely corrected the refraction anomaly and re-performed autorefractometry. Before my eyes, at a distance of 33 cm (which corresponds to the accommodation task of 3.0 diopters), text No. 4 was placed from the table for near and autorefractometry was performed with binocular fixation. OJSC OD = -2.0 diopters, OS = -1.75 diopters. Then, positive glasses of increasing strength were added to the full correction in increments of 0.5 diopters and autorefractometry was performed under the same conditions until dynamic refraction with glass reached -2.5 diopters. This happened with glasses +2.0 diopters. So, the amount of add will be equal to 2.0 diopters.

Example 2

Patient I., 14 years old. Diagnosis: high myopia. Art., slowly progressing. First, the patient was determined by refraction when looking into the distance (the fixation target is located at a distance of 5 m). Refraction OD = -6.0 diopters, OS = -6.5 diopters. Spherical lenses were placed in the test frame, which completely corrected the refraction anomaly and re-performed autorefractometry. Before my eyes at a distance of 33 cm (which corresponds to the accommodation task of 3.0 diopters), they placed text No. 4 from the table for near and performed autorefractometry with binocular fixation. OJSC OD = -1.37 diopters, OS = -1.75 diopters. Then, positive glasses of increasing strength were added to the full correction and autorefractometry was performed under the same conditions until dynamic refraction with the glass reached -2.5 diopters. This happened with glasses +1.5 diopters. Therefore, the amount of addition will be equal to 1.5 diopters. As you can see, the necessary dynamic refraction of -2.5 diopters is not achieved by simple summation of the joint stock company and additional glass (1.75 + 1.5 ≠ 2.5), which confirms the need for an individual, objective, controlled selection of addition for near.

Thus, the proposed research method provides objective data in the calculation of addiction in patients with myopia and accommodation insufficiency.

Obtained using the proposed method, the data allows you to objectively determine the add-on necessary for the selection of progressive points.

Claims (1)

A method for determining the amount of add-on when selecting progressive glasses for myopia, characterized in that the objective accommodative response is determined at a distance of 33 cm, the accommodative response is restored using positive lenses with a step of 0.5 diopters to normal values, and the amount of add-on is determined as the strength of the lens, allowing get an objective accommodative response of -2.5 diopters.