Eye
Contact Lens. 2012 Jan;38(1):16-26.
Contact lens-induced
circumlimbal staining in silicone hydrogel contact lenses worn on a daily wear
basis.
Maïssa
C, Guillon
M, Garofalo
RJ.
Source
Department
of Optometric Technology Group Research & Consultancy, London, United
Kingdom. cmaissa@otg.co.uk
Abstract
OBJECTIVES:
The
principal objective of the study was to measure the conjunctival staining
produced in the circumlimbal region by silicone hydrogel contact lenses with
different edge designs. The secondary objective was to investigate the
association between circumlimbal staining and comfort.
METHODS:
Four
silicone hydrogel contact lenses: ACUVUE OASYS (knife edge design), AIR OPTIX,
Biofinity (chisel edge rounded edge combination), and PureVision (rounded edge
design), and 1 hydrogel contact lens, ACUVUE 2 (knife edge design), were
tested. The study was conducted on a cohort population of 27 established soft
contact lens wearers, who wore each contact lens type, in a random order, for a
period of 10 (±2) days. Circumlimbal staining was measured in a double-masked
fashion through image analysis of digital photographs of lissamine green taken
under controlled experimental conditions.
RESULTS:
The
results obtained showed that contact lens edge design was the primary factor
controlling circumlimbal staining for silicone hydrogel lenses: a rounded edge
away from the ocular surface produced the lowest staining (average, 0.19%) and
a knife edge in close apposition to the ocular surface produced the highest
staining (average, 1.34%). Contact lens material rigidity was also identified
to affect circumlimbal staining and an inverse association between circumlimbal
staining and contact lens comfort was demonstrated: the rounded edge design
produced the lowest comfort (72 of 100) and the knife edge design produced the
highest (87 out of 100).
CONCLUSION:
Soft
contact lens wear induces circumlimbal staining, the level of staining being
influenced by the contact lens edge design. However, high level of circumlimbal
staining is not associated with decreased comfort.
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