RU2197210C2 - Method for correcting ametropia - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves fixing transplant when making epikeratoplastic repair operation using interrupted sutures. Refractometric and keratotopographic examination is carried out after performing operation. Sutures fixing the biological lens are removed. All sutures fixing the biological lens are removed in single operation based on data received in refractometric and keratotopographic examination within 1 month period to reduce refraction power of the cornea, 3 months later it is done for increasing refraction power of the cornea and in the period from 1 to 3 months for retaining the refraction power unchanged. EFFECT: enhanced effectiveness of treatment. 2 dwg

Description

 The invention relates to medicine, namely to ophthalmology, and can be used in the correction of high degree ametropia by the method of refractive epikeratoplasty.

 A known method for the correction of high degree ametropia is epikeratoplasty, first proposed by H. Kaufman in 1980. The essence of the method consists in stitching to the front surface of the cornea of the recipient a scattering or collecting biolens, turned from a donor cornea. Technique of operation: after marking on the cornea of the border of the bed, a circular keratotomy is performed to a depth of 200 - 250 microns with a diamond knife with a micrometric feed of the blade or with a trepan. A bed of the biolinz wing is formed with a phionic exfoliator by creating a peripheral "pocket" up to 0.5 mm wide in the stroma of the cornea of the outer edge of circular keratotomy. The epithelium is removed with a micro spatula within the boundaries of the biolins bed. A prefabricated negative, positive or neutral biolens is set to a central position and fixed by overlaying from 8 to 16 nodal joints. Joint removal is performed in the period from 3 weeks to 6 months according to different authors.

 One of the disadvantages of the method is the frequent hypo- or hyper-effect of the operation due to the mismatch between the calculated and the resulting refraction.

 The closest technical solution is the method of combined suture technique for fixation of the graft with selective removal of sutures depending on astigmatism, used for through keratoplasty. (Ophthalmology, 1989, Vol. 96 - p. 698 - 703. Musch D.C., Meyer R.F., Sugar A. Corneal astigmatism after penetrating keratoplasty). The essence of the method lies in the fact that the corneal transplant is fixed with 12 interrupted sutures, after which a continuous suture is applied. After the operation, central keratometry and photokeratoscopy are performed to determine the magnitude of astigmatism. If it is 3 diopters or more, then at least 1 month after the operation, on average 2 nodal joints in the strongly refracting meridian are removed, which leads to a decrease in refraction in this meridian and, consequently, to a decrease in astigmatism. Subsequently (at least 3 months after the operation), the remaining nodal joints and the continuous suture are removed.

 However, this method does not allow to regulate clinical refraction and is aimed at correcting astigmatism.

 We have set the task of postoperative regulation of clinical refraction in epikeratoplasty.

 To solve this problem, a method for correcting ametropias is proposed, which consists in fixing the graft during epikeratoplasty with nodal sutures, performing refractometry and keratotopography after surgery and subsequent removal of sutures that fix the biolines, characterized in that, based on the data of refractometry and keratotopography, all the fixation sutures that are fixed in the biological lens are performed simultaneously. up to 1 month to reduce the refractive power of the cornea; in terms later than 3 months. - to increase the refractive power of the cornea; in the period from 1 to 3 months. - when changes in postoperative refraction are not required.

 The advantage of this method compared to the prototype is the ability to change clinical refraction by a significant amount to correct errors of achieved refraction after epikeratoplasty.

 The method is as follows.

 When carrying out epikeratoplasty, nodal sutures are used to fix the biolens. After the epithelization of the biolens is completed and its optical properties are restored, refractometry and keratotopography are performed. Based on these data, the timing of removal of the sutures that fix the biolins is determined. If it is required to reduce the refraction of the cornea, then the sutures are removed in a period of up to 1 month. This option is used to eliminate hypocorrection after myopic epikeratoplasty and hypercorrection after hyperopic epikeratoplasty. If postoperative refraction is as expected, then the sutures are removed after 2.5-3 months, since the removal of sutures within these periods does not lead to noticeable changes in the achieved correction. If it is necessary to increase the refraction of the cornea, the sutures are removed no earlier than after 3 months, which is used to eliminate hypercorrection after myopic epikeratoplasty and hypocorrection after hyperopic epikeratoplasty.

The method is illustrated by the following examples:
Example 1
A series of keratograms (Fig. 1) of patient Sh., 8 years old, shows the results of keratometry when removing sutures that fix the biolins on day 25 after myopic epikeratoplasty.

 On the first keratogram, before surgery, the refraction of the cornea in the center (1 zone): K1 = 41.5 D; in the paracentral 2nd zone K2 = 44.1 D, the difference between 1 and 2 zones ΔK = 0.1; on the periphery (3 and 4 zones) K3 = 43.0 D, the difference between 2 and 3 zones ΔK = 1.1.

On the 24th day of surgery:
K1 = 41.9; K2 = 45.1; ΔK = 3.2; K3 = 49.0; ΔK = 3.9
On the first day after the stitches are removed:
K1 = 35.5; K2 = 36.5; ΔK = 1.5; K3 = 41.0; ΔK = 5.5.

On the second day:
K1 = 32.5; K2 = 36.0; ΔK = 3.5; K3 = 40.1; ΔK = 4.1
After 1 month:
K1 = 32.1; K2 = 39.4; ΔK = 7.3; K3 = 44.5; ΔK = 5.0
After 10 months:
K1 = 31.6; K2 = 38.8; ΔK = 7.1; ΔK = 5.1
Changes in the ratios of keratometry data in the central and paracentral zones of the biolens with early removal of sutures can eliminate hypocorrection after myopic epikeratoplasty.

Example 2
A series of keratograms (Fig. 2) of patient R., 10 years old, who underwent epikeratoplasty to correct aphakic refraction at + 13.5 D with corneal refraction, K = 41.5 D, was shown 6 weeks after surgery (K = 53.5 D) ), in connection with the weakening, the seams fixing the biolins are removed. On the second day, the refraction of the cornea increased, while the center became flatter (K = 44.5 D). On day 6, flattening of the center was even more pronounced (K = 42.6 D). 9 months after surgery and 7.5 months after suture removal, corneal refraction in the center (K = 45.5 D) was significantly lower than that achieved in the early postoperative period.

 With hypercorrection after hypermetropic epikeratoplasty, complete removal of sutures in the early stages allows to reduce errors of postoperative refraction.

 Thus, the clinical results allow us to conclude that the proposed method for the correction of ametropia allows to achieve the goal, namely, to correct the clinical refraction of the cornea after the performed epikeratoplasty and, thereby, correct the errors of postoperative refraction and come closer to emmetropia.

Claims (1)

 A method of correcting ametropia, which consists in fixing the graft during epikeratoplasty with interrupted sutures, performing refractometry and keratotopography after surgery and subsequent removal of sutures that fix biolines, characterized in that, based on refractometry and keratotopography data, all sutures fixating biolens are removed simultaneously up to 1 month decrease the refractive power of the cornea; after 3 months to increase the refractive power of the cornea and from 1 to 3 months to maintain the achieved postoperative refractive power of the cornea.

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