Quality of salivary tears following autologous submandibular gland transplantation for severe dry eye

Background: This study aimed to characterise the composition of the pre-ocu lar fluid after transplantation of the autologous submandibular gland (SMG) for patients with severe dry eye. Methods: Stimulated and unstimulated pre -ocular fluid from 15 patients (17 eyes) with a viable SMG graft ("SMG-sali vary tears"), as well as normal tears and SMC saliva (20 normal subjects/20 eyes). was sampled. As global teas parameters, fern pattern analysis and S DS gel electrophoresis were performed. As specific quality parameters, tota l protein content, secretory immunoglobulin A (SIgA), lysozyme, amylase, so dium, potassium and osmolality were measured using routine laboratory metho ds. The flow rate of SMG-salivary tears was determined in 5 patients by mea ns of sequential scintillography. Results: The fern pattern of SMG-salivary tears was coarse and thus more similar to normal SMG saliva than tears. SD S gel electrophoresis of the SMC-salivary tears showed albumin and two unid entified proteins in addition to the normal tear pattern. Osmolality and to tal protein content of SMG-salivary tears were higher than in normal SMC sa liva, but still lower than in normal tears. High activities of normal tear antibacterial proteins (SIgA, lysozyme and amylase) were detected in the sa livary tears. Stimulation of the secretion did not alter the composition of SMG-salivary tears. The flow rate of SMC-salivary tears was closer to that of normal tears than normal SMG saliva. Conclusion: Salivary tears resulti ng from SMG-transplantation represent condensed SMC saliva. Thus their qual ity is intermediate between normal tears and normal SMG saliva. High levels of secretory proteins demonstrate that the gland maintains an active Funct ion. Surgical denervation and residual tear components from the ocular surf ace are the most likely factors to cause the complex differences between no rmal SMC saliva and SMG-salivary tears. The effects of this secretion on th e ocular surface are currently being evaluated in a clinical and laboratory study.