Feasibility of Parotid Duct Transposition for the Treatment of Dry Eye: A Cadaveric Study.

Total dry eye is encountered less frequently, but it may lead to blindness. Transposition of parotid duct to the conjunctival cul-de-sac is a method of treatment for advanced cases of xerophthalmia to prevent blindness. Tears and parotid secretions have similar composition; therefore saliva provides an excellent replacement for tears. Limitation of this procedure is that the length of the parotid duct may not be adequate to reach the conjunctival cul-de-sac. This study was conducted in 30 fresh cadavers to assess the length of parotid duct and technical feasibility of parotid duct transposition for the treatment of dry eye. The parotid duct was dissected and resting length of parotid duct was measured on both sides without stretching. The distance between ear lobule to lateral canthus was also measured on both sides in each cadaver. The length of parotid duct ranges from 4.5 to 7 cm with average length was 5.8 cm. The majority of the cadavers had parotid duct length of 6 cm. Length of the right and left parotid duct was found to be equal in all cadavers. Parotid duct reached comfortably in 24 cadavers (80%) while it was short in 6 cadavers (20%) by 1-1.50 cm in length. Parotid duct can be transposed easily to the lower conjunctival cul-de-sac in majority of the cases. If the parotid duct is falling short than a cuff of the buccal mucosa can be taken in order to gain length.