Impact of temperature on ophthalmic viscosurgical devices and clinical implications: a pilot study.

Autor:	Henry C; From the Tennent Institute of Ophthalmology, Gartnavel General Hospital, Glasgow, United Kingdom (Henry, Lockington); James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow, United Kingdom (Castro, Rycroft, Syntouka, Oliveira); Advanced Materials Research Laboratory, University of Strathclyde, Glasgow, United Kingdom (Belkessa, Sillars); Edinburgh Complex Fluids Partnership (ECFP), SUPA and School of Physics & Astronomy, The University of Edinburgh, Edinburgh, United Kingdom (Silva)., Castro AT, Belkessa M, Rycroft E, Syntouka IM, Silva AF, Sillars F, Oliveira MSN, Lockington D
Jazyk:	angličtina
Zdroj:	Journal of cataract and refractive surgery [J Cataract Refract Surg] 2024 Nov 01; Vol. 50 (11), pp. 1173-1179.
DOI:	10.1097/j.jcrs.0000000000001513
Abstrakt:	Purpose: To evaluate how temperature affects the rheology of common ophthalmic viscosurgical devices (OVDs) and clinical implications. Setting: Tennent Institute of Ophthalmology, Glasgow, with Department of Mechanical and Aerospace Engineering, and Advanced Materials Research Laboratory, University of Strathclyde, Glasgow, United Kingdom. Design: Laboratory pilot study. Methods: The viscous and elastic responses of 3 OVDs (Eyefill-SC/Eyefill-C/Eyefill-HD) were measured using rotational and extensional rheometers at clinically relevant temperatures (5°C, 25°C, 37°C). Thermal properties were evaluated using differential scanning calorimetry and laser-flash analysis. Results: The OVDs tested exhibited viscoelastic properties and shear-thinning behavior. Apparent viscosities and relaxation time were higher at lower temperatures. The Eyefill-C and Eyefill-SC exhibited predominantly viscous character at low frequencies with a transition to predominantly elastic behavior at high frequencies. An increase in temperature led to a decrease in relaxation time under shear and extension. At low frequencies, Eyefill-C and Eyefill-SC moduli increase with decreasing temperatures. Eyefill-HD at 25°C and 37°C displays 2 crossover points, with the storage modulus dominating at low and high frequencies indicating a predominantly elastic behavior. Thermal property analysis revealed Eyefill-C had the lowest thermal conductivity. Conclusions: This pilot study confirms our clinical experience that OVD properties are affected by low temperatures, with increased viscosities at low shear rates and higher relaxation times. Cold OVD can cause greater resistance to initiation of intraocular lens (IOL) injection system forces (compared with warmer OVD). Excessively forced injection using cold OVD could contribute to inadvertent cannula detachment if incorrectly assembled, or uncontrolled IOL release leading to avoidable injury. (Copyright © 2024 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)
Databáze:	MEDLINE
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