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.
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.
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).
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.
From the Department of Optometric Technology Group Research & Consultancy (C.M., M.G.), London United Kingdom; Alcon Research Ltd (R.J.G.), Fort Worth, TX.
Dr. Maissa is an employee of Optometric Technology Group Ltd. Dr. Guillon is the director of Optometric Technology Group. Optometric Technology Group received financial support from Alcon Research Ltd., Fort Worth, Texas, USA to carry out the research on which this article is based and to write and review the manuscript. Drs. Maissa and Guillon act as consultants to Alcon Laboratories, Johnson & Johnson VisionCare and Allergan. Dr. Garofalo is an employee of Alcon Research and is Senior Internal Clinic Manager for VisionCare R&D, Fort Worth, Texas, USA. Dr. Garofalo acted as the Sponsor Study Coordinator for this protocol to Optometric Technology Group.
Address correspondence and reprint requests to Cécile Maïssa, Ph.D., Optometric Technology Group Research & Consultancy, 66 Buckingham Gate, London SW1E 6AU, United Kingdom; e-mail: firstname.lastname@example.org
Accepted October 5, 2011.