RU2495652C1 - Method for determining optimal diameter of graduated opening of posterior capsule - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to ophthalmology and may be used to determine the optimal diameter of graduated opening of the posterior capsule. The posterior capsulorrhexis diameter is determined by formula: D primary posterior capsulorrhexis = D anterior capsulorrhexis x K with the coefficient K falling within the range of 1.2 to 1.5, while the anterior capsulorrhexis diameter shall fall within the range of 5.5 mm to 6.0 mm.

EFFECT: method enables reducing a risk of lens position destabilisation.

Description

A method for determining the optimal diameter of a metered opening of the posterior lens capsule is proposed.

Technical field

The invention relates to ophthalmology (class A61F 9/007) and can be used in lens surgery when replacing it with an artificial lens in case of violation of the transparency of the optics of the eye and with refractive purpose.

State of the art

There is a method of opening the posterior lens capsule during surgery to replace it with refractive or optical purpose according to patent application No. 2008102719 patent No. 2376959 “Method for opening the lens capsule during surgery to replace it with refractive or optical purpose. Author: Takhtaev Yu.V.

Currently, this manipulation is carried out according to the following technology: Surgical access was made in the upper part of the cornea by performing a corneal tunnel incision 2.2 mm long. The anterior chamber was filled with Viscoat and Provisk viscoelastics. The opening of the anterior lens capsule was carried out by forming the anterior capsulorexis with a diameter of 5.5-6.0 mm. After hydrodissection and subsequent aspiration of the lens, primary posterior capsulorexis was performed. The capsule bag was pre-filled with Provisk viscoelastic. Using a 30 gauge needle, a valve was formed in the center of the posterior capsule. Provisk was introduced under the posterior capsule, pushing the anterior hyaloid membrane, then posterior capsulorexis 4.0-4.5 mm in diameter was formed using capsular tweezers. The implantation of an intraocular lens was carried out in a capsular bag. After aspiration of viscoelastic from the capsule bag, from the front and back chambers, the edges of the wound were sealed by hydration of the cornea.

The disadvantage of this method is that when performing the primary posterior capsulorhexis, there are no exact calculations of the ratio of the diameter of the anterior capsulorhexis to the diameter of the posterior capsulorhexis and the implantable intraocular lens. As a result, the operation time is extended. In the postoperative period, the stability of the position of the intraocular lens may be impaired, which significantly reduces the quantitative and qualitative characteristics of vision.

Proposed invention

This disadvantage is eliminated by this application. The essence of the application is as follows. Based on experimental studies, performed operations in the amount of 800 and the statistical calculations performed, the following formula was obtained for determining the diameter of the posterior capsulorhexis:

DPC * = DPC ** × K,

the value of the coefficient K lies in the range from 1.2 to 1.5, and the diameter of the anterior capsulorhexis should be at least 5.5 mm and not more than 6.0 mm.

* PZK - primary posterior capsulorexis;

** pc - anterior capsulorexis.

The diameter of the anterior capsulorexis is selected in accordance with patent No. 2376959, “A method for opening the lens capsule during surgery to replace it with refractive or optical purpose. Author: Takhtaev Yu.V. This patent states that the diameter of the anterior capsulorexis should be 0.5 mm smaller than the diameter of the implantable intraocular lens, and the posterior capsulorexis based on the above statistics is determined by the specified formula:

DPC = DPC × K

The implementation of the invention

The use of this formula in St. Petersburg Federal State Institution IRTC “Eye Microsurgery” named after Acad. S.N. Fedorova Rosmedtehnologii ”, using 25 operations as an example, demonstrated its effectiveness and accelerated the operation process. Long-term results showed a high level of stability of the main visual functions.

To facilitate the use of the formula by surgeons, a table was developed "Determining the optimal diameter of a metered opening of the posterior lens capsule."

Thus, when using the formula for determining the optimal diameter of a metered opening of the posterior lens capsule, a stable position of the intraocular lens is achieved by reducing the voltage inside the capsular bag while reducing the arches. The method for determining the optimal diameter of the primary posterior capsulorhexis accelerates the restoration of the barrier function of the iridocrystal diaphragm and solves the problem of the development of secondary cataract in the late postoperative period.

Summary

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."

The applicant has not found any sources of information containing information about the influence of the identified distinctive features on the technical result achieved as a result of their implementation. This, according to the applicant, indicates that this technical solution meets the criterion of "inventive step".

Claims (1)

A method for determining the optimal diameter of a metered opening of the posterior lens capsule, characterized in that the choice of the diameter of the posterior capsulorhexis is determined by the formula:
D of the primary posterior capsulorexis = D of the anterior capsulorexis × K, while the coefficient K lies in the range from 1.2 to 1.5, and the diameter of the anterior capsulorexis should be at least 5.5 mm and not more than 6.0 mm.