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Comparative Analysis of Adverse Events From a Series of Proof-of-Principle Extended Wear Studies

Ozkan, Jerome, BOptom., Ph.D.; Lazon de la Jara, Percy, BOptm., Ph.D.; Willcox, Mark, B.Sc., Ph.D., D.Sc.

doi: 10.1097/ICL.0000000000000546

Aim: A series of proof-of-principle extended wear (EW) contact lens studies were conducted to assess what effect different interventions had on adverse events (AEs). Comparative analysis of AEs across studies was conducted to determine whether some interventions were more effective at reducing inflammatory AEs.

Method: Multiple logistic regression analysis of AEs from 30-day EW studies each with a different intervention including (1) nightly replacement (NR) of lenses, (2) morning replacement (MR) of lenses, (3) instillation of prophylactic antibiotic drops (AB) each morning/evening, (4) daily lens cleaning (LC) each morning. All studies conducted at the same site using same lens type (lotrafilcon A) and EW schedule.

Results: Comparison of the different interventions to the individual control groups showed no difference in significant corneal infiltrative event (CIE) or mechanical events. Replacing lenses nightly, during an EW schedule, had the highest incidence of significant CIEs (4.9% [NR] vs. 2.5% [MR] vs. 1.8% [AB] vs. 0% [LC]); however, adjusted logistic regression analysis of the combined control data compared with the individual interventions showed no difference in significant CIEs (P=0.086) or mechanical AEs (P=0.140).

Conclusions: Replacing lenses each night seemed to be inferior compared with the other interventions of replacing lenses each morning, daily lens cleaning, and daily antibiotic drop instillation during EW. The results of the collective studies and additional analysis suggest that overnight wear of contact lenses seems to create an adverse environment that remains, despite the various interventions intended to improve this adverse environment.

School of Optometry and Vision Science (J.O., P.L.d.l.J., M.W.), University of New South Wales, Sydney, New South Wales, Australia; Currently Director of Research Programs (P.L.d.l.J.), CooperVision, Pleasanton, CA.

Address correspondence to Jerome Ozkan, BOptom, Ph.D., Level 3, Rupert Myers Building, University of New South Wales, Kensington, Sydney, NSW 2052, Australia; e-mail:

The authors have no funding or conflicts of interest to disclose.

Accepted July 01, 2018

© 2019 Contact Lens Association of Ophthalmologists, Inc.