Periocular Mass Due to Persistent Secretion Within a Transplanted Parotid Duct.

A male patient underwent microvascular transplantation of an autologous submandibular gland and its associated (Wharton's) duct for management of very severe right keratoconjunctivitis sicca due to Stevens-Johnson syndrome; due to hypersecretion, the gland was later removed in toto. Twenty-two years later, he presented with a nontender, sausage-like mass lying subcutaneously in the right temple. Intraoperatively a fluctuant tubular mass passing from the temporalis fossa to the superotemporal conjunctiva was identified and excised intact. Histology showed a slightly proteinaceous fluid within a duct lined with cuboidal epithelium, this being compatible with Wharton's duct. This case highlights that iatrogenic causes should be considered with any history of periocular injury or surgery.

Changes in tear production in a dog with keratoconjunctivitis sicca for a year after inevitable nictitating membrane gland resection due to suspicion of a malignant tumour.

Since the removal of the NM causes KCS in dogs, it was contraindicated to remove the NM unless unavoidable such as in a malignant tumour. However, to the best of author's knowledge, there are no reports of conjunctivitis and keratitis owing to decreased tear production following removal of the NM gland. This case study demonstrates the tear production changes in a dog for a year after removal of the nictitating membrane (NM) due to suspicion of a malignant tumour. A 13-year-old spayed female English Cocker Spaniel who had suffered from severe ocular discharge, discomfort, keratoconjunctivitis sicca (KCS), and NM enlargement in the right eye was brought to our hospital. The dog could not tolerate treatment with topical 0.2% cyclosporine or corticosteroids. The dog's right eye had NM gland prolapse, severe follicular conjunctivitis and a very low Schirmer tear test-1 (STT-1) value of 3 mm/min. Furthermore, the result of fine needle aspiration of the enlarged NM gland suggested a risk of malignancy. Despite the risk of KCS, complete NM resection was performed to diagnose the tumour. Fortunately, the final histopathological evaluation revealed chronic inflammation without any evidence of malignancy. Contrary to concerns that the STT-1 value would further decrease after the removal of the NM gland, the STT-1 value remained elevated compared to that before surgery, and the clinical symptoms improved for a year. It is generally known that NM gland resection is not recommended due to the risk of developing iatrogenic KCS unless a malignant tumour is suspected. In this case, surgical removal of the inflammatory NM gland that was not responsive to medications had a positive effect on KCS. Since the inflammatory and structural disease of the NM was strengthening KCS, the outcome was thought to be different from that when the normal third eyelid was removed.

Factors influencing the long-term results of autologous microvascular submandibular gland transplantation for severe dry eye disease.

We assessed long-term outcomes of autologous microvascular submandibular gland (SMG) transplantation for severe dry eye disease and investigated factors influencing long-term results. From August 1999 to January 2015, 185 patients (200 eyes) with severe dry eye received SMG transplantation. Subjective assessments and ophthalmologic evaluations were performed before and after transplantation. Follow-up results showed successful transplantation in 180 of 200 eyes (success rate: 90%), resulting in marked symptomatic relief of xerophthalmia. Surgery failed due to vascular thrombosis (15 glands) and duct obstruction (5 glands). Follow-up data were available for 163 eyes. Epiphora occurred in 98 (60.1%) eyes and was effectively managed by surgical reduction of graft, topical atropine gel and botulinum toxin injection. Wharton's duct obstruction occurred in 16 (10.6%) eyes and was treated by duct reconstruction. Subjective satisfaction was achieved in 143 (87.7%) eyes. Mean score of fluorescent staining reduced from 11.25±1.42 to 7.25±3.37. Postoperative best-corrected visual acuity improved in 85 (56.3%) eyes. Our clinical experience proved that SMG transplantation is effective and grants long-term improvement in severe dry eye. Secretory function of transplanted SMGs remains active and stable. Blood vessel thrombosis, Wharton's duct obstruction, and epiphora are primary factors influencing results.

Microvascular Submandibular Gland Transplantation for Severe Keratoconjunctivitis Sicca: A Single-Institution Experience of 61 Grafts.

PURPOSE: Keratoconjunctivitis sicca (KCS) is a relatively common disease that results in discomfort, tear film instability, visual impairment, and ocular surface damage. Artificial tear substitutes may be suitable for the treatment of mild KCS, but no effective treatment currently exists for severe KCS. Therefore, this study evaluated the effectiveness of autologous microvascular submandibular gland transplantation in the treatment of severe KCS. PATIENTS AND METHODS: A total of 61 eyes (56 patients) with severe KCS were treated with autologous submandibular gland transplantation from June 2002 to June 2017. The cephalic vein or the great saphenous vein was applied to solve the problem of unmatched veins. RESULTS: In 53 cases (53 of 56, 94.6%), 58 glands (58 of 61, 95.1%) were transplanted successfully. The mean Schirmer I test value improved from 0.78 ± 0.84 mm preoperatively to 18.83 ± 5.72 mm in the stable period after transplantation. Epiphora (14 of 58, 24.14%) was the most common complication of this procedure. Other postoperative complications included venous thrombosis (6 of 61, 9.84%), local infection (2 of 58, 3.45%), xerostomia (2 of 53, 3.77%), duct fistula (1 of 58, 1.72%), sialolithiasis (1 of 58, 1.72%), and ranula (1 of 58, 1.72%). CONCLUSIONS: Autologous microvascular submandibular gland transplantation is a credible and effective solution for severe KCS.

Canine oral mucosa evaluation as a potential autograft tissue for the treatment of unresponsive keratoconjunctivitis sicca.

PURPOSE: Labial mucosa transplantation for the treatment of canine keratoconjunctivitis sicca (KCS) has been reported recently. Postoperative alleviation of clinical signs was noted and assumed to be the result of labial salivary glands providing lubrication to the ocular tissue. The aim of this study was to evaluate the presence of minor salivary glands (MSG) in the canine oral mucosa. METHODS: Oral mucosal biopsies were collected from six dogs that died (n = 1) or were euthanized (n = 5) for reasons unrelated to this study. The breeds included were two Doberman Pinschers, one Labrador Retriever, one Portuguese Water Dog, one German Shepherd Dog, and one mixed canine. Three were spayed females, and three were castrated males with the median age of 9 years (range, 6-13 years). Samples were obtained by an 8-mm punch biopsy at the following locations of the canine oral cavity: upper rostral labial mucosa at midline, lower rostral labial mucosa at midline, upper labial mucosa near the commissure, lower labial mucosa near the commissure, and buccal mucosa approximately 1 cm caudal to the commissure. Samples were routinely processed with hematoxylin and eosin, and periodic acid-Schiff stains. Samples were evaluated by light microscopy. RESULTS: At the selected locations, no MSG or other secreting cells were detected. CONCLUSIONS: Minor salivary glands are not associated with alleviation of canine KCS symptoms following labial mucosa transplantation. Further studies are needed to determine the mechanism leading to the transient improvement of KCS symptoms in canine patients following labial mucosa transplantation.

The Use of Conjunctival Pedicle Flaps to Prevent Corneal Perforation in Graft-Versus-Host Disease.

PURPOSE: We report the clinical outcomes of two chronic graft-versus-host disease (cGVHD) corneal thinning cases that were successfully treated with conjunctival pedicle flaps in an effort to prevent impending corneal perforation. METHODS: The patients were treated with topical and systemic corticosteroids, therapeutic contact lenses, lubricants, and punctual plugs. Conjunctival pedicle flaps were used because conventional treatments had failed, and corneal perforation was imminent. RESULTS: Both patients were successfully treated with conjunctival pedicle flaps. Following conjunctival flap removal, one patient had corneal clarity restored following penetrating keratoplasty. CONCLUSIONS: Conjunctival pedicle flaps provided a strong barrier for the corneal surface and stabilized anterior chamber in cGVHD patients with impending corneal perforation following allogeneic hematopoietic stem cell transplant.

Carbachol improves the secretion of transplanted submandibular glands during the latent period after microvascular autologous transplantation for severe keratoconjunctivitis sicca.

Poor secretion of transplanted submandibular glands (SMGs) during the latent period may cause duct obstruction and affects the surgical outcome. The objective of this study was to investigate the efficacy and systemic side effects of carbachol on transplanted SMG secretion. Twenty-seven patients who underwent SMG transplantation for severe keratoconjunctivitis sicca were treated with subcutaneous injections of 0.2mg/2ml carbachol at 10 days, 1 month, and/or 3 months after surgery. The effect on secretion was evaluated by Schirmer test and technetium 99m ((99m)Tc) scintigraphy. Systemic side effects were evaluated subjectively using a questionnaire. The results showed that the time to onset varied from 4 to 9min and the duration of action from 50 to 110min after carbachol administration. The secretion at each time point after drug administration was significantly higher than the pre-administration value (all P<0.01). (99m)Tc scintigraphy showed a decline in the dynamic time-activity curve in 26 patients, demonstrating a stimulatory effect on the secretion of carbachol. No serious systemic side effects were experienced. In conclusion, the intermittent administration of carbachol could be an effective and safe strategy to promote secretion from transplanted SMGs in the latent period to prevent duct obstruction.

Effects of Capsaicin and Carbachol on Secretion From Transplanted Submandibular Glands and Prevention of Duct Obstruction.

PURPOSE: To investigate whether capsaicin and carbachol promote secretion from and prevent duct obstruction in transplanted submandibular glands (SMGs). METHODS: This retrospective cohort study included consecutive patients with severe keratoconjunctivitis sicca and successful SMG transplantation. Patients were divided into 2 groups: an exposed group receiving both capsaicin and carbachol after surgery and an unexposed group receiving neither. Secretion changes in response to capsaicin and carbachol administration were recorded in the exposed group. The main outcome measures were the secretory flow rate and duct obstruction rate in the transplanted SMGs. RESULTS: Forty-four patients (44 eyes) in the unexposed group and 115 patients (128 eyes) in the exposed group were followed up for more than 3 months postoperatively. The baseline characteristics were similar between the groups. The secretory flow rate before and 5, 25, 55 minutes after administration was 1 mm (0-2 mm) (median with interquartile range), 3 mm (1-5 mm), 4 mm (2-5 mm), 1 mm (0-2.5 mm), respectively, for capsaicin and 1 mm (0-3 mm), 1050 mm (450-1500 mm), 375 mm (150-600 mm), 0 mm (0-150 mm), respectively, for carbachol (P < 0.001 for both). In the exposed group, 6.2% of eyes had duct obstruction, whereas 18.2% of eyes in the unexposed group had duct obstruction (P = 0.031) (odds ratio = 0.3, 95% confidence interval, 0.105-0.856). CONCLUSIONS: This study provides evidence that capsaicin and carbachol effectively promote secretion from and prevent duct obstruction in transplanted SMGs during at least 3 months after transplantation.

The timing of acid-induced increase in saliva secretion in transplanted submandibular glands.

The purpose of this study was to determine the timing of acid-induced increase in saliva secretion and to investigate the possibility of parasympathetic reinnervation of transplanted submandibular glands (SMGs). Citric acid stimulation-induced changes in secretion of transplanted SMGs were evaluated in 27 patients who underwent SMG transplantation for keratoconjunctivitis sicca (KCS); (99m)Tc scintigraphy and Schirmer tests were done at 1, 3, 6, and 9 months after transplantation. Acetylcholinesterase staining was conducted to confirm the presence of parasympathetic reinnervation in three SMGs at 6 and 9 months after transplantation. Schirmer tests showed significantly increased secretion of the transplanted SMGs after acid stimulation at 6 and 9 months, but not at 1 and 3 months. On (99m)Tc scintigraphy, no decline was detected on the dynamic time-activity curve after acid stimulation at 1 and 3 months, but a decline was detected in nine glands at 6 months and in 19 glands at 9 months. No decline was observed in the remaining eight glands at 9 months after transplantation. The histology findings were consistent with scintigraphy results. In conclusion, acid-induced increase in saliva secretion occurs at ≥6 months after SMG transplantation, and parasympathetic reinnervation of the transplanted SMG might occur.

Dry Eye Disease Incidence Associated with Chronic Graft-Host Disease: Nonconcurrent Cohort Study (An American Ophthalmological Society Thesis).

PURPOSE: To determine if chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT) is associated with stable or progressive dry eye disease and to determine the true incidence in patients with no prior history of dry eye disease. METHODS: A nonconcurrent cohort study at a single institution with 136 patients who had no previous history of dry eye disease before HSCT. Survival analysis was used to estimate dry eye disease incidence. The incidence rate was calculated using life tables as the number of observed dry eye disease cases divided by the person-time at risk accumulated by the cohort. Transition probabilities were calculated from time of transplant to time of diagnosis, and then to last recorded visit. RESULTS: Incidence rate was 0.8 cases of dry eye disease per person-year, and half of the population at risk developed dry eye disease during the first 10 months post transplant. Time to develop dry eye disease was 2.5 months for mild dry eye disease, 9.6 months for moderate dry eye disease, and 13.2 months for severe dry eye disease. In terms of cumulative incidence, 73% of subjects developed dry eye disease (50% mild, 16% moderate, and 7% severe) at the time of diagnosis. CONCLUSIONS: Our findings suggest that dry eye disease associated with cGVHD is an extremely frequent event and shows a wide spectrum of severity, with a mild form presenting early and a moderate to severe form presenting later after HSCT. These findings need to be studied further to elucidate if these are two different pathophysiological entities or just different expressions of the same pathology.

Sialography of the transplanted submandibular gland.

Autologous transplantation of submandibular gland (SMG) is effective for severe keratoconjunctivitis sicca (KCS). Sialography is a method for morphological evaluation of the transplanted gland.We recruited 15 patients (15 eyes) with severe KCS who had successfully undergone SMG transplantation. Thirteen patients had normal transplanted SMGs, while two patients were suspected to have obstructive sialadenitis of the transplanted SMG. Sialography was performed in each patient with meglumine diatrizoate. Projections were applied immediately and 5, 7, and 10 min after contrast injection. The median dose of the contrast medium was 0.9 ml (range, 0.7-1.1 ml) for the full-size transplanted SMGs and 0.5 ml for the glands after reduction surgery. The acini and the ducts were clearly visible on sialograms. The contrast medium was completely excreted in 10 min in normal transplanted SMGs. The main duct had a regular shape in normal transplanted SMGs, while irregular dilation and stricture of the duct with delayed excretion of the contrast medium were found in the glands with obstructive sialadenitis. In conclusion, sialography is clinically feasible and valuable for the morphological evaluation of the transplanted SMG.

Corneal sequestrum in a dog with chronic unilateral keratoconjunctivitis sicca.

CASE DESCRIPTION: A 14-year-old 8.2-kg (18.04-lb) castrated male Cairn Terrier with chronic keratoconjunctivitis sicca in the left eye was evaluated because of severe blepharospasm and a black plaque of 3 weeks' duration. CLINICAL FINDINGS: Abnormalities of the left eye included a decreased Schirmer tear test value and the presence of a brownish-black plaque in the center of the cornea. The plaque was surrounded by fibrovascular tissue except at the medial aspect where there was mild malacia of the adjacent corneal stroma. TREATMENT AND OUTCOME: The plaque was removed by superficial keratectomy, and a conjunctival graft was performed. Histologic evaluation of the plaque and surrounding cornea revealed ulceration, stromal necrosis, and chronic suppurative keratitis with fibrosis and neovascularization. Evaluation of plaque sections that were stained with Gram and Von-Kossa stains yielded negative results for bacteria and mineralization, respectively; examination of sections stained with periodic acid-Schiff stain revealed multiple intracytoplasmic inclusions in macrophages. Virus isolation and a PCR assay for canine herpesvirus yielded negative results. Transmission electron microscopy revealed collagen disruption with interspersed macrophages and apoptotic keratocytes; no viral particles or evidence of other infectious agents was observed. The graft healed without complication and was trimmed 2 weeks after surgery. Four months after surgery, the Schirmer tear test value remained decreased from reference limits despite topical tacrolimus treatment, and pigmentary keratopathy was present surrounding the graft. CLINICAL RELEVANCE: Corneal sequestra are rare in species other than cats. In this dog, it was possible that chronic keratoconjunctivitis sicca might have contributed to the development of the corneal sequestrum.

Microvascular autologous transplantation of partial submandibular gland for severe keratoconjunctivitis sicca.

OBJECTIVE: To evaluate the feasibility of microvascular autologous transplantation of partial submandibular gland (SMG) to prevent or reduce epiphora in severe keratoconjunctivitis sicca (KCS). METHODS: A total of 39 patients with KCS, covering 42 eyes, were randomised to undergo transplantation of partial or total SMG from January 2006 to December 2009. Clinical data of survival rate of transplanted SMG, ophthalmologic features of best-corrected visual acuity, Schirmer test results, break-up time (BUT) of tear film, fluorescence staining, incidence of postoperative epiphora and frequency of subsequent surgery were compared between two groups. RESULTS: Total SMG transplantation was performed in 22 eyes, and partial SMG transplantation was performed in the other 20 eyes. All transplanted SMGs survived. Microvascular crisis occurred in one case of partial SMG transplantation, but the gland survived after exploration to remove the venous thrombus. Obstruction of the ductal orifice in one case of partial SMG transplantation was resolved by reconstruction of the ductal orifice. Symptoms of dry eyes disappeared, and patients were able to discontinue use of artificial tears. Severe epiphora occurred in 6 eyes undergoing partial SMG transplantation and in 19 eyes undergoing total SMG transplantation (p<0.01). Surgical reduction was performed in 6 eyes undergoing partial SMG transplantation and 18 eyes undergoing total SMG transplantation (p<0.01). CONCLUSIONS: Microvascular transplantation of partial SMG is feasible and effective for severe KCS and does not decrease the survival rate of transplanted SMG. For ample SMGs with normal function, transplantation of partial SMG alleviates the symptoms of dry eye and significantly reduces the incidence of severe postoperative epiphora.

Bilateral parotid duct transposition for keratoconjunctivitis sicca in a Connemara stallion.

A 7-year-old Connemara stallion was presented with a 4 month history of blepharospasm, recurrent corneal ulcerations, mucopurulent ocular discharge, and keratoconjunctivitis sicca (KCS) in both eyes unresponsive to medical therapy. Ophthalmic examination revealed lackluster corneas, axial corneal scarring and pigmentation with associated neovascularization, and absolute KCS in both eyes. Computed tomography scan and endoscopic evaluation of the upper airway and guttural pouches revealed no structural abnormalities to indicate neurogenic KCS. The stallion was diagnosed with immune-mediated dacryoadenitis as all other causes of KCS were excluded. Parotid duct transposition (PDT) was performed in the right eye followed by PDT in the left eye 4 weeks later. The right PDT was functional 2 years post-operatively with significant improvement in ocular comfort and reduced corneal fibrosis and neovascularization. The left PDT developed a salivary-cutaneous fistula over the left masseter muscle post-operatively due to avascular necrosis of the distal parotid duct (PD). Surgical reconstruction of the PDT using an expanded-polytetrafluoroethylene (e-PTFE) tube graft, an e-PTFE tube graft to autogenous caudal auricular vein graft, and an autogenous saphenous vein graft were all unsuccessful. Tear production in the left eye improved at 1 year post-surgery as a result of long term lacrostimulant therapy, and a permanent PD-cutaneous fistula was performed on the left PD at the level of the ventral mandible. Bilateral PDT in the horse is effective in resolving clinical signs associated with KCS; however, morbidity associated with avascular necrosis of the transposed PD may be significant and can result in surgical failure.

Corneal ulceration in a LASIK patient due to vitamin a deficiency after bariatric surgery.

PURPOSE: To review the case of a 41-year-old woman who underwent bariatric surgery in 2000. She subsequently underwent laser in situ keratomileusis (LASIK) surgery in 2008 and complained of dry eye since the LASIK surgery. In November 2010, she was diagnosed with a corneal melt and was treated with aggressive lubrication, followed by eventual amniotic membrane placement and a tarsorrhaphy. She then presented for consultation at the Bascom Palmer Eye Institute when she developed a corneal infiltrate. She was diagnosed with fungal keratitis with corneal xerosis. At that time, vitamin A levels were measured and were less than 2 µ/dL. The patient admitted noncompliance with nutritional supplements. METHODS: Case report. RESULTS: The patient was treated with aggressive lubrication and natamycin. Vitamin supplements were restarted, and the patient experienced dramatic improvement in symptoms with resolution of the infection. A central corneal scar with corneal thinning remains. The patient underwent a penetrating keratoplasty for visual rehabilitation. CONCLUSIONS: Patient education with emphasis on compliance with nutritional supplements is essential after bariatric surgery. Consider vitamin A deficiency in the differential diagnosis of dry eye after LASIK surgery.

Partial ligation of the transposed parotid duct at the level of the parotid gland for excessive salivary secretions.

OBJECTIVE: To determine the outcome and effect of a partial ligation of the transposed parotid duct at the level of the parotid gland in four dogs with excessive salivation and ocular irritation. METHODS: Four dogs were previously diagnosed with absolute keratoconjunctivitis sicca. After a parotid duct transposition (PDT) surgery, these dogs experienced excessive saliva production and abundant salivary precipitates, which resulted in epiphora, moist dermatitis, blepharospasm, and keratitis. In an effort to decrease saliva production, a partial ligation of the transposed duct at the level of the parotid gland was performed. Two or three accessory branches to the primary parotid duct were ligated at the level of the salivary gland. RESULTS: The four cases were three Yorkshire terriers and a Chihuahua. The average age of the four patients was 2.5 years. Partial ligation of accessory branches of the parotid duct at the level of the parotid gland after a PDT in this study demonstrated improved ocular comfort, decreased salivary precipitates, and adequate Schirmer tear test results without marked epiphora in three of the four animals. The male Yorkshire had epiphora after the initial partial ligations of two accessory branches were placed at the level of the parotid gland. To correct the excessive salivary flow, two additional ligatures were placed at a later date, which resolved the epiphora. CONCLUSION: Partial ligation of the parotid duct at the level of the parotid gland proved to be an effective technique in moderating the salivation in these four patients with excessive salivary secretions after PDT.

Parotid duct transposition in dogs: a retrospective review of 92 eyes from 1999 to 2009.

OBJECTIVE: The aim of this study was to perform a retrospective review of parotid duct transposition (PDT) in the dog to determine the rate and nature of complications, the success and failure rates and to evaluate owner satisfaction. METHODS: Medical records of 56 dogs (92 eyes) that underwent PDT and subsequent follow-up by a veterinary ophthalmologist were reviewed. Forty owners (40 dogs/66 eyes) were contacted by telephone and 37 owners (37 dogs/60 eyes) also completed a visual analog scale questionnaire. Statistical evaluation included Wilcoxon Signed Rank tests, one-way analysis of variance and Kaplan-Meier survival analysis with Wilcoxon and Log-rank tests. RESULTS: The mean follow-up was 38.7 months (range 1-109 months). The surgical success rate was 92% (85/92 eyes). Total failures (8%, 7/92 eyes) were because of severe saliva intolerance (n = 5 eyes) and PDT failure (n = 2 eyes). The complication rate was 50% (46/92 eyes) of which 61% (28/46 eyes) were managed medically and 39% (18/46 eyes) required further surgery. Ninety percent (36/40) of owners indicated that they would proceed with surgery again. Statistically significant improvements in owner perception of ocular comfort, number of daily topical treatments, ocular wetness, and postoperative vision were identified. CONCLUSIONS: This study shows that PDT is a successful procedure based on clinical findings and in terms of owner perception. It has also demonstrated that PDT improves ocular comfort and vision in medically refractive cases of keratoconjunctivitis sicca, and that a low level of on-going management is required in 33% of cases.

An experimental study of the management of severe keratoconjunctivitis sicca with autologous reduced-sized submandibular gland transplantation.

We have evaluated transplantation of reduced submandibular glands for the treatment of severe keratoconjunctivitis sicca. Thirty-four rabbits were allocated into three groups: dry eye (controls, n=10), transplantation of whole submandibular glands (n=12), and transplantation of reduced submandibular glands (n=12). Outcome measures included the results of Schirmer's test and the Rose Bengal test, and histological examination of the cornea and the transplanted gland. Volume of tears significantly increased after transplantation of the whole gland, but did not change after transplantation of the reduced gland compared with dry eyes induced preoperatively. Neither transplantion group had keratoconjunctivitis sicca postoperatively. There were no histological abnormalities in the transplanted tissues. The results that the surgical technique of using reduced submandibular glands for transplantation was feasible, and that the secretion from the reduced gland was similar to that from a normal lacrimal gland. In conclusion, transplantation of a reduced submandibular glands is feasible in the treatment of keratoconjunctivitis sicca.

Treatment of severe keratoconjunctivitis sicca by parotid duct transposition after tympanic neurectomy in rabbits.

PURPOSE: To investigate the feasibility of parotid duct transposition after tympanic neurectomy to treat severe keratoconjunctivitis sicca (KCS) in rabbits. METHODS: Thirty rabbits were divided into three groups in experiment 1. One eye was operated on, and the contralateral eye served as the control. In the KCS group, the lacrimal gland, harderian gland, and nictitating membrane were removed. In the group with parotid duct transposition (DT), the parotid duct was transposed into the lower conjunctival fornix. In the group with parotid duct transposition after tympanic neurectomy (DTTN), the tympanic nerve was resected in addition to parotid duct transposition. Schirmer test was performed and density of corneal staining was determined monthly after surgery, and goblet cell density was measured at postoperative month 3. In experiment 2, the tympanic nerve was resected on one side in 12 rabbits. Both sides of the parotid gland were resected for histopathology at intervals of 2 months to 1 year after surgery. RESULTS: Tear secretion from operated eyes at rest increased significantly after surgery in the treatment groups compared with the KCS group. Tear secretion from operated eyes after chewing was significantly lower in the DTTN than in the DT group. The corneal staining scores were higher in the operated than in the control eyes of the three groups, without significant difference among the operated eyes. Parotid gland atrophy on the operated side occurred at postoperative month 4 and recovered to normal 1 year after surgery. CONCLUSIONS: Parotid duct transposition after tympanic neurectomy could effectively reduce gustatory epiphora but may be insufficient to promote ocular surface health.