Clinical and Experimental Substantiation of the Possibility of Using a 25G Tip to a Permanent Magnet to Remove Intraocular Foreign Bodies

Purpose: to develop, experimentally study and evaluate in the clinic the effectiveness of using a 25G handpiece to a permanent operating magnet for IOFB removal.

Materials and methods. In the work, we analyzed the results of an experimental study and clinical application of 25 G handpieces. In the experimental part of it, a comparative analysis of magnetic properties was carried out: the force of attraction, strength and topography of the magnetic fields of a standard 25-mm handpiece by V.V. Volkov and 25G caliber handpieces (30, 35, 40, 45 mm long) for a permanent eye magnet. In the clinical part of the work, we analyzed the results of surgical treatment of 57 patients of the ophthalmology clinic with type C OGI (according to the ISOT classification) with localization in the posterior segment of the eye. The mechanism of injury, the area and depth of injury, intraoperative and postoperative complications were analyzed, and the advantages of IOFB removal by a combined method using a 25G tip to a permanent magnet were evaluated.

Results. According to the results of our experimental studies, it was revealed: the force of the 25G handpieces is sufficient to fix foreign bodies weighing up to 11 (for a 45 mm handpiece), and the minimum distance at which the magnetic field begins to act around the handpieces is at least 8 mm (data for the longest handpiece 45 mm). A pronounced decrease in the magnetic field strength at the tip surface at a distance of up to 2 mm was revealed. At the stage of using the 25G handpiece in the clinic, when assessing the OTG mechanism, the injuries were distributed as follows: household injury — 47 %, industrial injury — 27 %, road traffic accident — 13 %, combat injury — 13 %. Removal of IOFB was carried out in two versions: transvitreal and combined. IOFB was removed using a 25G permanent eye magnet tip and using a 25G vitreous forceps. During the operation, the following methods of removing IOFB were used: tweezers-tweezers, magnet-tweezers, magnet-magnet. Intraoperatively, in 7 % of cases, there was a slip and fall of IOFB to the fundus. In all cases, an increase in visual acuity was obtained, and in most cases, visual acuity at the time of discharge from the hospital was in the range from 0.05 to 0.1.

Conclusion. Removal of magnetic IOFB using a 25 G tip to a permanent magnet allows reliable fixation of IOFB, significantly reduces the risks of intraoperative complications and shortens the duration of surgery.

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