Saratov JOURNAL of Medical and Scientific Research

phacoemulsification

The thermal safety of system for ultrasonic aspiration of lens cortex

Year: 2018, volume 14 Issue: №4 Pages: 919-922
Heading: Ophtalmology Article type: Original article
Authors: Idrisova G.M.
Organization: Bashkir State Medical University of the Russian Health Care
Summary:

The purpose of work is an experimental evaluation of the thermal safety of system for aspiration of lens cortex with the possibility of additional dosed low power ultrasonic. Material and Methods. The system for aspiration of cortex with the possibility of additional dosed low power ultrasonic consists of a specially designed ultrasonic instrument with a 21G tip and irrigation instrument with a 21G tip. Remote infrared thermometry (thermal imager Testo 882, Germany) was performed. In experiments a pig eyes were used (n=10). The eye was fixed in a titanium eye-holder, the tip of the ultrasonic instrument was inserted up through a 1.1 mm paracentesis on the meridian for 9 hours, the irrigation tip on the meridian for 3 hours. The initial temperature was recorded after irrigation and aspiration activation. Then ultrasound was activated (power 30%, activation time 10 s) and the final temperature was recorded. The rise in temperature was estimated as the difference between the final and initial temperatures. The software Testo IRSoft version 4.3 was used to process the images. Results. The average temperature rise in all experiment was 5.1±1.4°C. The maximum recorded temperature in the experiments were 33.5°C. Conclusion. Critical level of temperature for corneal burns was not reached in all of experiments. Conducted thermometric studies allow to conclude that the developed system for aspiration of lens cortex with the possibility of additional dosed low power ultrasonic is thermally safe.

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Experimental analysis of destructive ability of vacuum pulsation in cataract phacoemulsification

Year: 2018, volume 14 Issue: №4 Pages: 817-820
Heading: Ophtalmology Article type: Original article
Authors: Aznabaev В.М., Dibaev T.l., Mukhametov R.G.
Organization: Bashkir State Medical University of the Russian Health Care, ZAO Optimedservis
Summary:

 The purpose of the work. To evaluate the destructive ability of vacuum pulsation in cataract phacoemulsification. Materials and Methods. The experiments were performed on 40 separate pig eyes, in which cataract was induced in 3 stages of density according to the WetLab method. In the study group (n=20), phacoemulsification was carried out using a vacuum pulsation generation unit, in the control group (n=20) by the method of traditional ultrasonic phacoemulsification. For comparison of the two methods in both groups, the time of complete destruction of the lens fragment in seconds was recorded. Results. The average time of destruction of a 5x5 mm fragment of the lens, using vacuum pulsation was 23.6±4.9 seconds, for traditional ultrasonic phacoemulsification 17.7±8.9 seconds (p<0.05). Vacuum pulsation has a destructive power, but at the same time requires further refinements to increase the efficiency of phacoemulsification. Conclusions. Phacoemulsification based on vacuum pulsation is promising for further study, since it has a destructive ability. This method does not imply the use of high-energy effects, due to which there are no prerequisites for heating the tunnel incision and negative effects on the corneal endothelium.

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Lens densitometry in ultrasonic cataract phacoemulsification

Year: 2018, volume 14 Issue: №4 Pages: 815-817
Heading: Ophtalmology Article type: Original article
Authors: Aznabaev В.М., Dibaev T.l., Munasypova V/V., Khamidov U.B., Mukhamadeeva O.R.
Organization: Bashkir State Medical University of the Russian Health Care
Summary:

Purpose: to evaluate the effectiveness of using Pentacam HR sheimpflug camera for objective determination of cataract density. Material and Methods. The subject of the study was the method of determining the density of the lens (densitometry) by the Pentacam HR sheimpflug-camera. The object of the study were patients with age-related cataracts (147 eyes). All patients underwent ultrasound phacoemulsification with implantation of various types of intraocular lenses (IOL). Before treatment, the density of the lens was determined by non-contact method using PNS (Pentacam Nucleus Staging). During the surgery, the density of the lens was determined by the surgeon on a set of factors: the color of the nucleus, the mechanical density, the emulsification easiness. The equivalent ultrasound time and the fact of compliance or discrepancy in the degree of density of the lens with two methods of its determination were recorded for each patient. Results. It was found that the density of the lens recorded by the Pentacam HR is in a direct strong correlation with the equivalent ultrasound time. It was shown that the discrepancy between the PNS method and the contact method performed by the surgeon significantly lengthens the surgery time. Conclusion. The Pentacam HR sheimpflug-camera is an accurate method of determining the density of the cataract before the surgery. The advantage of this method is that it is non-contact, quick and relatively easy-to-perform with the possibility of objective assessment.

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