Abstract
Abstract: :
Purpose: An analgesic effect has been postulated for NSAIDs, in addition to their well-known anti-inflammatory action. We studied the effect of NSAIDs on the sensations evoked by corneal stimulation. Methods: Corneal sensitivity was measured in ten subjects (mean age: 20.2±0.3 years) using a gas esthesiomether. Chemical (10-70% CO2 in air), mechanical (0-264 ml/min), and thermal (corneal temperature changes ranging from -5º to +3 ºC) stimuli were applied to the center of the cornea. The intensity and attributes of the evoked sensation were represented at the end of the pulse in a 10-cm, continuous visual analog scale (VAS). Threshold for the sensation was expressed as the first intensity that evoked a VAS value ≷0.5. Sensitivity was measured in both eyes of each subject in two separate days, one day without treatment and the other 30 min after topical application of 0.03% flurbiprofen (Ocuflur®, Allergan; 7 subjects) or 0.1% sodium diclofenac (Voltaren®, CIBAVision; 6 subjects). Results:Flurbiprofen produced a slight reduction of the response to mechanical and chemical stimulation that became significant only for the irritation evoked by the most intense chemical stimulus (70% CO2). Diclofenac flattened the stimulus-response curves for all the sensation parameters evoked by mechanical, chemical and thermal stimuli. Conclusion:Flurbiprofen has a very light analgesic effect on the acute sensation evoked by corneal irritation. Diclofenac reduced the corneal sensation evoked by all types of corneal stimuli suggesting that this drug additionally has a mild local anesthetic effect.
Keywords: 514 pharmacology • 442 innervation: sensation