The Effect of Temperature on Soft Contact Lens Diameter

Young, Graeme P.; Potts, Matthew B.; Sulley, Anna

doi:10.1097/icl.0000000000000202

Cited by 11 publications

(6 citation statements)

References 9 publications

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“…The shrinkage factors were calculated from measurements of lens diameter at room and eye temperatures using an established method. 3,11 This represents the amount of change in BC and diameter when lenses are placed on the eye and raised to ocular surface temperature.…”

Section: Study Lensesmentioning

confidence: 99%

Theoretical fitting characteristics of typical soft contact lens designs

Sulley

Lorenz

Wolffsohn

et al. 2017

Contact Lens and Anterior Eye

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Section: Study Lensesmentioning

confidence: 99%

Theoretical fitting characteristics of typical soft contact lens designs

Sulley

Lorenz

Wolffsohn

et al. 2017

Contact Lens and Anterior Eye

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“…Because contact lens polymer properties in solution are functions of solution osmolarity and temperature, dimensional changes may occur from the time that a lens is removed from its blister pack or lens case at room temperature and inserted onto the eye, to the time that the lens water content and temperature equilibrate on eye. In most soft lenses, base curve, diameter, and sagittal depth decrease with increasing solution osmolality (Lum, Perera, & Ho, ), while diameter and modulus (of most silicone hydrogel and some conventional hydrogel lenses) decrease with increasing temperature (Young, Garofalo, Peters, & Harmer, ; Young, Potts, & Sulley, ). Changes beyond the ISO tolerances when the temperature is increased from room temperature to that of the ocular surface have been reported, but without effecting contact lens‐induced conjunctival staining (CLICS, one of the study endpoints) (Ozkan et al, ).…”

Section: Discussionmentioning

confidence: 99%

Effect of multipurpose care solutions upon physical dimensions of silicone hydrogel contact lenses

et al. 2019

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Interactions between contact lens multipurpose solution (MPS) components and the contact lenses with which they are used are both lens and solution dependent. As such, lens dimensional changes may arise after cleaning and immersion cycling in different lens care solutions over different time courses. In this study, the dimensional stability of five planned-replacement silicone hydrogel lenses (lotrafilcon B, comfilcon A, senofilcon A, senofilcon C, and samfilcon A) over 30 cycles in three different MPSs (Biotrue, OPTI-FREE Express, and OPTI-FREE Puremoist) was evaluated. Measurements of diameter, sagittal depth, power, roundness, and center thickness were obtained prior to, during, and after 30 cycles of cleaning and storage. Diameters of all lenses increased when soaked in Express or Biotrue but held the International Standards Organization (ISO) tolerance over the full course of 30 disinfection cycles; however, the diameters of comfilcon A, senofilcon A, senofilcon C, and samfilcon A lenses soaked in Puremoist exceeded ISO tolerance after between 4 and 9 immersion cycles. In contrast, the diameter of lotrafilcon B held tolerance. Similarly, all lenses cycled in Express or Biotrue held tolerance for sagittal depth, while in Puremoist only lotrafilcon B held tolerance. All lenses became less round in all MPSs but held tolerance for both power and central thickness. Given the lack of reported clinical issues with Puremoist when used with lenses other than lotrafilcon B, we propose that it may be appropriate to revisit the ISO test methods and tolerances to determine if they are still applicable for silicone hydrogel lenses. K E Y W O R D S ISO, lens care, lens-solution compatibility, multipurpose solution (MPS)

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“…The model assumed no shrinkage but, with actual lenses, the optimum design (8.60/14.2 mm) would need to be larger and flatter to compensate for on-eye shrinkage. 14,15 With the most temperature sensitive materials, such as high water non-ionic Group 2 materials, this would equate to approximately 9.00/15.0 mm (BC/diameter).…”

Section: Discussionmentioning

confidence: 99%