Purpose: Dry eye is often characterized by increased tear evaporation due to poor tear film quality, especially of the lipid component of the tear film. Using an environmental chamber to induce environmental stress, this study compared the effect of three lubricant eye drops on various aspects of tear physiology in a crossover design (evaporation was the principal outcome measure). Methods: Three eye drop formulas were tested: 0.5% carmellose sodium (Drop C), 0.5% carmellose sodium with added lipid (Drop C-L) and 1.0% glycerine with added lipid (Drop G-L). Nineteen control and 18 dry eye subjects used each product for 2 weeks, three times per day, in a random order, with a minimum 1-week washout between treatment periods. Tear evaporation, break up time, osmolarity, tear structure (by interferometry) and patient symptoms were assessed with the subjects adapted for 10 min in an environmental chamber controlled at 20% relative humidity and 22 °C. The treatment effects were analyzed using general linear model repeated measures analyses of variance. Results: In dry eye subjects, evaporation, break up time, osmolarity and symptoms improved for all formulas (p < 0.05). Normal subjects showed some improvements: evaporation with C-L, osmolarity with C and symptoms with C-L and G-L. Change in evaporation was greater for both C-L and G-L versus C (p < 0.05), and there was a trend for C-L to reduce evaporation more than G-L (p < 0.11). There were no significant treatment effects on tear film structure. Conclusion: Overall, the eye drop formula containing both carmellose sodium and lipid (C-L) produced a greater treatment effect on tear evaporation than the other formulations containing only one of these ingredients. This study also demonstrates the utility of a controlled environmental chamber in showing the difference in performance between dry eye treatments.

Pilot study-TER measurements required at least 10 minutes in the chamber to obtain a steady-state TER with no significant change to NITBUT. Study 1-TER has a reverse correlation with environmental humidity in the range of 5% to 70%, with TER reduced to zero at 70% RH. Dry eye subjects had a higher TER at all RH levels below 70%, and NITBUT is significantly different between DE and normal subjects at all humidities. Study 2-Emulsion-based drops reduced TER in DE patients by an amount equivalent to that obtained by raising environmental humidity by 30%. Noninvasive tear breakup time was improved in both normal and DE subjects at lower RH levels.

Aim To assess the safety of buccal infiltration local anaesthetic (LA) without additional factor replacement in patients with haemophilia (PWH) and association with clinical experience of the operator. Methods A consecutive sample of participants with mild, moderate and severe haemophilia scheduled to have dental treatment were recruited from a comprehensive care centre in Ireland. Infiltration LA was administered using a standard technique. Safety was defined as any adverse event at time of administration, immediate postoperative, or postoperative period. Clinical experience was dichotomized into fewer or greater than three years clinical experience. Results N = 135 buccal infiltration LAs without additional factor replacement were provided to N = 71 participants with mild (n = 20; 28%) and moderate to severe haemophilia (n = 51; 72%). Successful local anaesthesia was achieved in n = 133 cases (99%). No (0%) adverse bleeding events were recorded for any participants at time of administration of LA or during follow‐up. Three out of 135 (2.2%) LAs recorded superficial bleeding 30 seconds after administration of LA, all of which resolved within 2 minutes with application of pressure; 4 out of 135 (3%) LAs produced a superficial haematoma at the site of injection no greater than 2 mm all of which resolved at 4 minutes. There were no differences in bleeding rates between clinicians by level of experience (P = 0.435) or by severity of bleeding disorder (P = 1.0). Conclusion Local anaesthetic is safe to administer via buccal infiltration for people with mild, moderate and severe haemophilia without additional factor cover. This finding holds true regardless of operator experience.