Abstract
Purpose: :
To investigate the effect of contact lens (CL) replacement schedule and material on symptoms and signs experienced by reusable CL wearers.
Methods: :
Part I: Data from 364 reusable CL wearers were used to estimate the prevalence of key symptoms and signs: frequent or constant dryness or irritation, uncomfortable wear (≥2 hours), ≥ grade2 of bulbar or limbal hyperaemia (0-4 scale), or ≥ grade 3 corneal staining (0-15). These patients had no evidence of ocular abnormality or disease that would contraindicate CL wear. Part II: Two-hundred and thirty-five (235)‘problem’ patients were fitted with either etafilcon A (etA) (107) or nelfilcon A (nelA) (128) daily disposable (DD) CL and reassessed 1-2 weeks later. The ‘problem’ population included 154 patients identified as such in Part I and 81 patients with objective signs of dry eye that were recruited in separate trials.
Results: :
Part I: Forty-two percent (154 of 364) of the reusable CL wearers had at least one of the qualifying criteria and were classified as ‘problem’ patients. Reduced comfortable wearing time (WT) was reported by 75% (of the 154) patients, dryness by 43.5% and irritation by 10.7%. Problematic conjunctival injection or corneal staining was observed in approximately 10% of patients. Part II: Refitting with DD CLs reduced the prevalence of dryness and uncomfortable WT by 18.7% (P=0.001) and 35.3% (P=0.041), respectively, while it had no significant effect on irritation, conjunctival injection or corneal staining. No significant differences were noted in the prevalence of symptoms and signs between patients fitted with etA or nelA CLs prior to fitting with these lenses. The proportion of patients reporting dryness following refitting nelA and etA CLs, however, was 44.5% and 31.7%, respectively. The prevalence of irritation was twofold higher in nelA-fitted (21.9%) in comparison to etafA-fitted patients (11.7%, P=.05). The equivalent numbers for reduced comfortable WT were 55.4% and 37.3% (P=0.04), respectively. Approximately 11% of the nelA-fitted patients were classified with ‘problematic’ injection compared to 1.8% in the etA-fitted group (P=0.003). No significant differences were reported in the prevalence of ‘problematic’ corneal staining between the two groups.
Conclusions: :
Daily disposable CLs could alleviate symptoms experienced with reusable CLs, and lens performance is affected further by material.
Keywords: contact lens • clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials