RU2337658C1 - Method for vision correction after surgical procedures, performed on eye cornea - Google Patents

Abstract

FIELD: medicine, ophthalmology.

SUBSTANCE: method includes carrying out of laser stromal keratoablation after stabilisation of refractometry, kerato-topography, and aberrometry indices of the operated eye. Increase in surgical reliability due to processes stabilisation control in eye cornea after the graft formation, increase in vision performance after operations.

EFFECT: increase in visual acuity after diverse surgical operations and after various eye injuries.

3 ex

Description

The invention relates to ophthalmology and allows to increase visual acuity after various surgeries performed on the cornea of the eye, in particular through keratotransplantation, various types of anterior keratotomy, as well as after various eye injuries.

There is a method of correcting vision by performing a repeated operation of a sublapular photokeratectomy after a previously performed radial keratotomy, which consists in highlighting the edges of the lamellar flap of the cornea, separating it, conducting photo keratoablation and re-laying of the corneal flap, in which the search and separation of the edges of the lamellar flap are performed keratotomy scars, without affecting the latter, separation of the flap is also performed in each individual segment in alignment from the edge to the center, and the separation of the scar zone is carried out alternately in the direction from the center of the optical zone to the edge of the corneal flap, RU 2222299.

The disadvantage of this method is the unreliability of the result due to the impossibility of correctly predicting the final visual acuity, since the behavior of scars after surgery is not taken into account and the processes occurring in the eye are not monitored.

There is also a method of correcting vision after an earlier through keratotransplantation, in which laser keratoablation (LASIK) is performed (Arenas E., Maglione A. "Laser in situ keratomileusis for astigmatism and myopia after penetrating keratoplasty" J. Refract Surg. 1997, Jan-Feb , 13 (1) p. 27-32).

In the known method, the corneal flap is formed on the pedicle simultaneously with excimer laser keratoablation.

The known method has the following disadvantages:

- the terms after the end-to-end keratotransplantation operation have not been established at which laser keratoablation is optimal;

- there are cases of inducing astigmatism after LASIK surgery;

- there are difficulties in calculating the operation algorithm due to an error in the readings of devices with through keratoplasty. Very often occurring astigmatism is incorrectly determined. There are differences in the preoperative and postoperative directions of astigmatism.

More reliable is the method of vision correction after surgery performed on the cornea of the eye, including the formation of a flap on the leg and laser stromal keratoablation, in which vision correction is performed while maintaining stable transplant parameters after 24 months of end-to-end keratotransplantation, while keratoablation is performed after 3 -5 weeks after the formation of the flap on the stalk, RU 2159599 C1, since after 3-5 weeks stabilization of processes can occur in some cases, occurring them in the cornea after the formation of the flap.

Its disadvantage is the fact that in many cases the stabilization of the above processes in the cornea of the eye occurs within 1-2 weeks after the formation of the flap, in which case the patient loses time for postoperative rehabilitation and return to work and normal life; also in many cases, stabilization of processes in the cornea of the eye occurs more than 5 weeks (sometimes up to 10 weeks) after the formation of the flap; in this case, satisfactory vision correction is not achieved.

A known method of vision correction after surgery performed on the cornea of the eye, including the formation of a flap and laser stromal keratoablation after stabilization of refractometric and keratotopographic parameters, abstract of the article MULARONI A. et al Two-step LASIK with topography-guided ablation to correct astigmatism after penetrating keratoplasty. // J. Refract.Surgery, 2006, Jan-Feb, vol.22, # 1, p. 67-74 (PMID 16447939).

The method allows to take into account, to a greater extent than the analogs described above, the state of the optics of the anterior surface of the cornea and such a significant indicator as defocus, however, very important aberrometric indicators (horizontal coma, vertical coma, spherical aberration, treyfoyl (higher order aberration), etc.) characterizing the optics of the living eye as a whole, the state of its optical media and refractive surfaces in the prototype method are not taken into account, since the method is carried out regardless of these indicators. Since laser stromal keratoablation is carried out before stabilization (the quality of the optics of the eye after ablation, and therefore the quality of vision, as a rule, is significantly reduced), which leads to a decrease in the reliability of the operation.

This technical solution is taken as a prototype of the present invention.

The objective of the present invention is to increase the reliability of the operation by improving the quality of the optics of the eye and preventing or reducing the degree of decrease in the quality of vision after surgery.

According to the invention, in a method of correcting vision after surgical operations performed on the cornea of the eye, including the formation of a flap and laser stromal keratoablation after stabilization of refractometric, keratotopographic parameters, laser stromal keratoablation is carried out after stabilization of the aberrometric parameters of the operated eye.

The applicant has not identified sources containing information about technical solutions identical to the present invention, which allows us to conclude that it meets the criterion of "novelty."

A new property of the invention is the fact that stabilization of not only refractometric and keratotopographic indicators, but along with aberrometric indicators is taken into account, which ensures the preservation of the quality of the optics of the eye after surgery or its decrease to a small extent, which allows, practically, to maintain the quality of vision

The applicant has not identified sources of information that would contain information about the influence of the distinguishing features of the invention on the resulting new property. The specified new property of the object determines, according to the applicant, the compliance of the invention with the criterion of "inventive step".

The claimed method is illustrated by examples.

Example 1. Patient N., 42. A history of radial keratotomy from 1988 for myopia at 4.0 diopters. The first ten years after keratotomy, visual acuity without correction reached 1.0. When applying to the clinic of St. Petersburg branch of the Federal State Institution IRTC "Eye Microsurgery" 13 years after keratotomy - visual acuity without correction: 0.1, with correction minus 2.75 diopters visual acuity: 1.0. Prior to the first stage of flap cutting, according to keratotopography SAI = 1.18, SRI = 0.78, potential visual acuity PVA = 0.8-0.7. According to Sheck-Hartman aberrometry, the integral level of higher order aberrations (PV OPD НО) was 6.11 μm, and the square root of this value (RMS PV OPD НО) was 0.88 μm. After the flap cutting stage, stabilization of refractive, keratotopographic and aberrometric indicators occurred after 7.5 weeks. Visual acuity without correction increased from 0.1 to 0.3. The corrective sphere was minus 1.5 diopters. Keratopographic indices also improved (SAI = 1.09; SRI = 0.27, and the potential visual acuity of PVA increased to 1.3-0.8) and the topographic picture of the cornea became more uniform. According to Sheck-Hartman aberrometry, the integral level of higher order aberrations (PV OPD НО) became 5.79 μm, and the square root of this value (RMS PV OPD НО) was 0.78 μm. At the second stage, 7.5 weeks after the flap was cut out and the above parameters were stabilized, the flap was raised and residual myopia of minus 1.5 diopters was eliminated using the MEL-80 excimer laser using the standard ablation algorithm for the LASIK operation. Visual acuity without correction on the day after the second stage was 1.0 and remains stable over the past 3.5 years.

Example 2. Patient K., 49 l. A history of 1989 radial tangential keratotomy for myopia at 6.0 diopters and myopic astigmatism at 2.0 diopters. The first 12 years after keratotomy, visual acuity without correction reached 1.0. When contacting the clinic 14 years after keratotomy - visual acuity without correction: 0.2, with correction sphere minus 1.75 diopters visual acuity: 0.9. Prior to the first stage of flap cutting, according to keratotopography data SAI = 1.33, SRI = 0.95, potential visual acuity PVA = 0.6-0.4. According to Sheck-Hartman aberrometry, the integral level of higher order aberrations (PV OPD НО) was 7.86 μm, and the square root of this value (RMS PV OPD НО) was 0.92 μm. After the flap cutting stage, stabilization of refractive, keratotopographic and aberrometric indicators occurred after 6 weeks. Visual acuity without correction increased from 0.2 to 0.4. The corrective sphere was minus 0.75 diopters. Keratopographic parameters also improved (SAI = 1.02; SRI = 0.29, and the potential visual acuity of PVA increased to 1.0-0.8), the topographic picture of the cornea also became more uniform. According to Sheck-Hartman aberrometry, the integral level of higher order aberrations (PV OPD НО) became 5.45 μm, and the square root of this value (RMS PV OPD НО) was 0.74 μm. At the second stage, 6 weeks after cutting the flap and stabilizing the above parameters of the eye, the flap was raised and residual myopia of minus 0.75 diopters was eliminated using the MEL-80 excimer laser using the standard ablation algorithm for LASIK surgery. The visual acuity without correction the day after the second stage was 1.0 and remains stable over the past 2.5 years.

Example 3. Patient R., 39 l. A history of transverse keratoplasty (CEP) from 2000 regarding primary unstabilized keratoconus. 2.5 years after UPC, against the background of stabilization of refractometric, topographic and aberrometric indicators, the patient had myopia at 3.0 diopters and myopic astigmatism at 4.0 diopters during the last year. When contacting the clinic 14 years after keratotomy, visual acuity without correction: 0.04, with correction sphere minus 3.0 diopters and cylinder minus 4.0 diopters visual acuity: 0.6. Prior to the first stage of flap cutting, according to keratotopography SAI = 2.03, SRI = 1.55, potential visual acuity PVA = 0.4-0.2. According to Sheck-Hartman aberrometry, the integral level of higher order aberrations (PV OPD НО) was 12.15 μm, and the square root of this value (RMS PV OPD НО) was 1.82 μm. After the flap cutting stage, stabilization of refractive, keratotopographic and aberrometric indicators occurred after 15 weeks. Visual acuity without correction increased from 0.04 to 0.1. With correction, the sphere - 2.0 diopters and the cylinder - 3.0 diopters, visual acuity increased to 0.8. Keratonographic indicators also improved (SAI = 1.32; SRI = 0.69, and the potential visual acuity of PVA increased to 0.8-0.6), the topographic picture of the cornea also became more uniform. According to Sheck-Hartman aberrometry, the integral level of higher order aberrations (PV OPD НО) became 8.45 μm, and the square root of this value (RMS PV OPD НО) was 1.01 μm. At the second stage, 15 weeks after cutting the flap and stabilizing the above parameters of the eye, the flap was raised and the residual refraction anomaly (sphere and cylinder) was eliminated with the MEL-80 excimer laser using the standard ablation algorithm for LASIK operation. The visual acuity without correction the day after the second stage was 0.6 and remains stable over the past 1.5 years.

When implementing this method, the accuracy, reliability and safety of excimer laser correction of residual ametropia in the eyes with corneal scars after various types of keratotomy, end-to-end keratoplasty and injuries is significantly increased. This method allows for a much more economical laser ablation and preserves the native tissue of the cornea.

Claims (1)

A method for correcting vision after surgeries performed on the cornea of the eye, including the formation of a flap and laser stromal keratoablation after stabilization of refractometric and keratotopographic parameters, characterized in that they additionally determine aberrometric parameters and laser stromal ablation after stabilization along with refractometric and keratotopographic indicators .