Corneal staining and subjective symptoms with multipurpose solutions as a function of time

Short-term changes in corneal staining and ocular symptoms were assessed at defined intervals to evaluate combinations of three soft lenses and four multipurpose solutions.

A series of pilot studies were conducted over 11 months using a double-masked, randomized, crossover design. Asymptomatic, adapted, daily-wear soft lens users wore group II or IV soft hydrophilic or silicone hydrogel lenses for a maximum period each day. Before wear, new lenses were soaked overnight in one of four multipurpose solutions: Alcon OPTI-FREE Express MPDS, Bausch & Lomb ReNu MultiPlus Multipurpose Solution, CIBA Vision SOLO-Care PLUS Multipurpose Solution, or AMO Complete MoisturePLUS. Subjects rated comfort and ocular symptoms. Corneal staining type and area were evaluated at baseline and after lens removal.

Significantly increased extent of corneal staining, defined as the proportion of corneal zones showing staining of grade 1 or more severe, was observed at 1 and 2 hours when subjects wore group II lenses soaked in the polyhexamethylene biguanide-based systems. Significantly increased extent of staining was observed at 2 hours when subjects used silicone hydrogel lenses soaked in regimen 4. When subjects used regimen 1 and wore group II lenses, only a minimal staining response was observed at 1 and 2 hours of wear. Significant symptoms were not correlated with extent of staining.

This study design is a promising tool that can discriminate between the performance of different soft lens and multipurpose solution combinations rapidly using small patient samples. With some lens-care product combinations, corneal appearance may vary according to the time of day the patient is examined.