Abstract
Purpose: :
Some biguanide–based contact lens care systems used with conventional hydrogel lenses have demonstrated increased corneal staining which may be associated with discomfort and reduced wear time. The ocular affects of newer biguanide–based preservatives with silicone hydrogel lenses have not been fully evaluated. This study compares the performance of Regimen 1 (OPTI–FREE® EXPRESS®, Alcon Laboratories) and Regimen 2 (ReNu MoistureLoc, Bausch & Lomb) with a silicone hydrogel lens.
Methods: :
102 successful silicone hydrogel wearers (Acuvue Advance, Johnson & Johnson) were enrolled in an investigator masked open–label controlled 28 day clinical study. Patients did not wear lenses for 72 hours prior to the study. Corneal staining (sodium fluorescein, NEI grid; sum of 5 areas; 0–4 scale/area), conjunctival staining (lissamine green, NEI grid; sum of 6 areas; 0–3 scale/area), hyperemia (0–3 scale), comfortable wearing time and symptom frequency were obtained at each visit. The Schein questionnaire was used to differentiate symptomatic and asymptomatic patients.
Results: :
When adjusted for baseline differences mean type (P=0.003) and area (P=0.009) of corneal staining for Regimen 1 was significantly less than Regimen 2. The frequency of conjunctival staining increased for both groups, but Regimen 2 showed significantly more staining (P=0.014) than Regimen 1. Asymptomatic patients using Regimen 1 demonstrated less corneal type (P=0.014), corneal area (P=0.024), conjunctival (P=0.075) and mean difference in corneal staining (P=0.009) than Regimen 2. At day 14 there was a significant increase (P=0.004) in patients with no hyperemia for Regimen 1. No significant difference was found for comfortable wearing time although patients using Regimen 1 reported significantly cleaner lenses (P=0.007) and agreed more strongly that they 'liked this lens care product' (P=0.042).
Conclusions: :
Contact lens care systems used with a silicone hydrogel lens caused significantly different corneal and conjunctival reactions. A system preserved with POLYQUAD® (Regimen 1, OPTI–FREE EXPRESS) produces less intense and smaller areas of corneal and conjunctival staining than Alexidine–preserved system (Regimen 2 ReNu MoistureLoc).
Keywords: contact lens • cornea: epithelium • conjunctiva