Abstract
Abstract: :
Purpose: To assess the effect of cold balanced salt solution (BSS) and naphazoline 0.025% on the ocular surface temperature (OST). Methods: We enrolled 30 consecutive patients with non–infectious conjunctivitis and normal tear production. Patients were randomized to receive either cold BSS (4ºC) or naphazoline 0.025% (20ºC). OST was measured over the temporal bulbar conjunctiva while having the patient look to the opposite side. The mean of three temperature measurements was recorded. Readings were taken before instilling the eyedrops, 10 minutes, 1 hour, 2 hours, and 3 hours after instilling the eyedrops. Results: . There were 13 males and 17 females. The average was 25 years with a range of 17 to 42 years. The mean OST in patients who received BSS was 34.89ºC, 34.78ºC, 34.70ºC, 34.56ºC, and 34.38ºC at baseline, 10 minutes, 1 hour, 2 hours, and 3 hours respectively. The mean OST in the naphazoline group was 34.82ºC, 34.88ºC, 34.61ºC, 34.75ºC, and 34.87ºC at baseline, 10 minutes, 1 hour, 2 hours, and 3 hours respectively. There was statistically significant decrease in the mean OST in the first hour compared to baseline in the BSS (p=0.0047) and the naphazoline groups (p=0.0028). The BSS group had significantly lower OST compared to baseline at 2 hours (p=0.0002), and at 3 hours (p=0.0001). On the other hand, in the naphazoline group, the decrease in temperature compared to baseline was not significnt at 2 hours (p=0.4811), and at 3 hours (p=0.5722). The difference in temperature reduction at each time point between BSS and naphazoline was not significant at 10 minutes (p=0.3792) and at 1 hour (p=0.1841), but was significant at 2 hours (p=0.0044), and at 3 hours (p<0.0001). Conclusions: The use of naphazoline caused initial decrease followed by a rebound increase in ocular surface temperature. Cold BSS showed statistically significant decrease in ocular surface temperature compared to baseline without rebound phenomenon. Furthermore, cold BSS had greater ocular surface temperature lowering effect than naphazoline.
Keywords: drug toxicity/drug effects • conjunctivitis