RU2801498C1 - Method of personalized correction of myopia using excimer laser ablation with a selective change of the wavefront - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method of personalized correction of myopia using excimer laser ablation includes diagnosing eye aberrations with a laser aberrometer, calculating eye refraction correction based on data from the aberrometer, and performing eye refraction correction on an excimer laser unit according to the calculation of eye refraction correction. Determination of aberrations of the entire optical system of the eye using a KR-1W aberrometer is carried out under conditions of a narrow pupil determining the values of the standard deviation of aberrations of the lower and higher orders, nm, within a pupil with a diameter of 6.0 mm. The data obtained are entered into the Platoscan refraction correction program, an ablation map is calculated with the use of objective values of the spherical and cylindrical refraction components, as well as the standard deviation of spherical aberration. The ablation depth is calculated as the sum of spherical refraction and spherical aberration. The optical ablation zone is selected from 6.0 to 7.0 mm and a scan file of the operation is formed, recorded on a removable media and transferred to the computer of the excimer laser unit. The myopia correction operation is performed on the Microscan Visum 1,100 Hz unit.

EFFECT: use of this invention will allow to maintain the balance of aberrations, improve the quality of life of the patient, increase visual acuity and improve the quality of vision under mesopic conditions.

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Description

The invention relates to medicine, namely to ophthalmology, and is intended for personalized excimer laser correction of myopia.

Currently, laser vision correction is one of the main methods of treating myopia. There is a constant optimization of certain methods of refractive surgery, various ablation profiles become available, which are aimed at increasing safety, reducing the risk of complications and, as a result, obtaining a high result. Personalized ablation forms have been developed to improve functional outcomes. (Ehlke GL, Krueger RR. Laser Vision Correction in Treating Myopia. Asia Ras J Ophthalmol (Phila). 2016 Nov/Dec;5(6):434-437. doi: 10.1097/APO.0000000000000237. PMID: 27898448)

Almost all types of laser correction induce an increase in spherical aberration, which leads to significant distortion and a decrease in visual functions after surgery. The main disadvantage of personalized operations that affect the entire wavefront and are calculated from the aberrometry data of the entire optical system of the eye is the focus on eliminating all aberrations at the time of the operation. While the wavefront of the entire eye changes over time due to age-related changes in the lens and vitreous body, it is not advisable to correct all aberrations at the same age. A violation of the aberrational balance is created in the future in such patients. Therefore, it is most effective to correct one aberration, the dynamic changes of which are easy to control in the future.

The closest analogue is the "Method of personalized excimer laser vision correction" RF patent for invention No. 2537069. According to this method, eye aberrations are diagnosed with a laser aberrometer capable of detecting lower and higher order aberrations of the eye. Calculate separately the correction for second-order aberrations and the correction for higher-order aberrations. The refraction correction operation is carried out in two stages, and at the first stage, second-order aberrations are corrected with an optical zone for correcting second-order aberrations, at the second stage, higher-order aberrations are corrected with an optical zone equal to the size of the pupil when diagnosing aberrations. The method allows for correction in patients with a narrow pupil, improve the quality of vision.

However, this method has a number of disadvantages.

Firstly, the method of personalized excimer laser vision correction proposed by the authors eliminates the possibility of a selective approach and includes data from all aberrations of the optical system of the eye.

Secondly, at present, surgeons are gradually refusing to act on aberrations of higher and lower orders, moving on to acting only on spherical aberrations, which practically do not change with the age of the patient.

The objective of the invention is to develop a method for personalized correction of myopia using excimer laser ablation with a selective change in the wavefront, which will make it possible to carry out ablations with an effect exclusively on spherical aberrations, which is most appropriate.

The technical result of the proposed method is to maintain the balance of aberrations, improve the patient's quality of life, increase visual acuity and improve the quality of vision in mesopic conditions.

The method is carried out as follows:

Measurement of aberrations of higher and lower orders of the entire optical system of the eye using a KR-1W aberrometer (Topcon, Japan) is carried out in a narrow pupil, the value of the standard deviation of higher and lower orders in nm is determined within a pupil with a diameter of 6.0 mm. The data obtained are entered into the Platoscan refraction correction program; objective values of the spherical and cylindrical refraction components, as well as the standard deviation of spherical aberration, are used to calculate the ablation map. The ablation depth is calculated (the sum of spherical-cylindrical refraction and spherical aberration), the optical ablation zone is selected from 6.0 to 7.0 mm, and a special scan file of the operation is generated, which is recorded on a removable media and transferred to the computer of the excimer laser unit. Operations for personalized correction of myopia using excimer laser ablation with selective change in the wavefront according to the proposed method were carried out on a high-frequency excimer laser scanning device Microscan Vizum 1100 Hz (Optosystems, Russia) Academician S.N. Fedorov" Ministry of Health of the Russian Federation.

The method is illustrated by the following examples.

Example 1

Patient A., aged 25. Diagnosis OU Mild myopia, myopic astigmatism. Vis OD = 0.05 sph -2.5 cyl -0.5 ax 10=1.0 and OS = 0.04 sph -2.0 cyl -0.75 ax 55=1.0. Pachymetry in the central part OD 560 µm OS 550 µm. A personalized correction of myopia was carried out using excimer laser ablation with a selective change in the wavefront according to the proposed method. The optical zone of ablation was 7.0 mm, the pupil diameter was 5.5 mm. The patient is subjectively satisfied with the obtained visual functions after the operation. The next day Vis OD = 1.2; Vis OS = 1.2. Before and after surgery, patients additionally measured spatial contrast sensitivity. After the treatment, patient A. observed the preservation of the balance of aberrations, an increase in visual acuity and an increase in the quality of vision in mesopic conditions.

Example 2

Patient B., 28 years old. Diagnosis OU Mild myopia, myopic astigmatism. Vis OD = 0.1 sph -5.75 cyl -1.0 ax 75=1.0 and OS = 0.03 sph -6.0 cyl -1.75 ax 5=1.0. Pachymetry in the central part OD 510 µm OS 515 µm. A personalized correction of myopia was carried out using excimer laser ablation with a selective change in the wavefront according to the proposed method. The optical zone of ablation was 6.0 mm, the pupil diameter was 4.5 mm. The patient is subjectively satisfied with the obtained visual functions after the operation. The next day Vis OD = 1.2; Vis OS = 1.0. Before and after surgery, patients additionally measured spatial contrast sensitivity. After the treatment, patient B. observed the preservation of the balance of aberrations, an increase in visual acuity and an increase in the quality of vision in mesopic conditions.

Claims (1)

A method for personalized correction of myopia using excimer laser ablation, including diagnosing eye aberrations with a laser aberrometer, calculating eye refraction correction based on data from the aberrometer, performing eye refraction correction on an excimer laser unit according to the calculation of eye refraction correction, characterized in that the determination of aberrations of the entire optical system of the eye with using a KR-1W aberrometer, it is carried out in a narrow pupil, determining the values of the standard deviation of aberrations of the lower and higher orders, nm, within a pupil with a diameter of 6.0 mm, the data obtained are entered into the Platoscan refraction correction program, an ablation map is calculated, for which they use objective values of the spherical and cylindrical components of refraction, as well as the standard deviation of spherical aberration; the ablation depth is calculated as the sum of spherical cylindrical refraction and spherical aberration, the optical ablation zone is selected from 6.0 to 7.0 mm and a scan file of the operation is generated, which is recorded on a removable medium and transferred to the computer of the excimer laser unit; Myopia correction surgery is performed on the Microscan Visum 1100 Hz unit.