Comparison of ocular tolerability between preserved and preservative-free diclofenac sodium drops

To compare the tolerability of preserved diclofenac sodium 0.1% (Voltaren Ophtha) and preservative-free diclofenac (Dicloftil).

Thirty healthy volunteers received a single drop of Voltaren Ophtha in 1 eye, and a single drop of Dicloftil in the other. Both drops were instilled at the same time, in a single-blind manner. Visual analog scale grading was used to measure ocular discomfort, itch, burn, and pain. Grading was obtained before drop instillation and after 15 s, 1 min, 5 min, 15 min, and 30 min.

Both preparations caused discomfort, itch, burn, and pain, with a peak effect on all 4 parameters at 15 min. However, preservative-free Dicloftil proved to be more tolerable than preserved Voltaren Ophtha. Data show significantly lower reported levels of discomfort and itch up to 15 min, lower levels of burn at the first minute, and less pain immediately after instillation.

This is the first study to compare subjective ocular tolerability of a single drop. Our results indicate that Dicloftil has better tolerability than Voltaren Ophtha. Ophthalmologists should be aware of this significant difference when prescribing diclofenac, especially in patients with low compliance or who require prolonged therapy.