New treatment of dry eye: The effect of calcium ointment through eyelid skin delivery

Aim - To demonstrate the efficacy of a petrolatum based calcium ointment applied to the lower lid skin in the management of dry eye. Methods - In a controlled double masked study, the effects of water free petrolatum ointment containing calcium carbonate (10% w/w) on tear functional factors and ocular surface vital staining in dry eye patients were observed. Petrolatum without calcium carbonate served as control. Patients were instructed to place ointment to the lower lid skin twice a day. Evaluation of subjective complaints, fluorescein and rose bengal staining patterns, blink rate, tear evaporation and tear break up time (BUT) were performed before and 3 months after treatment. In order to demonstrate the movement of petrolatum from the skin to the tear film, petrolatum containing 1% sodium fluorescein was placed on the lower lid of four healthy volunteers, and the concentration of fluorescein in the tear film was followed up to 6 hours using an anterior fluorometer. Results - Subjective symptoms significantly improved both the calcium group (p = 0.001) control (p = 0.012), while only the calcium group demonstrated a significant improvement in fluorescein (p = 0.043), rose bengal (p = 0.021) scores, and blink rate (p = 0.004). Tear evaporation also significantly decreased in both the calcium group (p = 0.0004) and control (0.043). BUT did not improve in either group. Conclusion - Petrolatum based calcium ointment significantly improved symptoms, tear dynamics, and ocular surface staining in dry eye patients. However, some of the therapeutic effects may be due to lipids in the petrolatum vehicle. Petrolatum applied to the lower lid skin is an effective drug delivery system for slowly releasing drugs to the ocular surface.