Evaluation of partial tarsal plate excision using a transconjunctival approach for the treatment of distichiasis in dogs.

PURPOSE: To evaluate the clinical outcome, possible complications, and recurrence rate of distichiasis in dogs treated with partial tarsal plate excision (PTPE) technique using a transconjunctival approach. METHODS: Retrospective study including 17 client-owned canine patients affected with distichiasis and presenting with associated clinical signs (ie, blepharospasm, epiphora, chronic keratoconjunctivitis, or corneal ulceration) that underwent surgical removal of the aberrant lashes using a PTPE technique between January 2018 and February 2019. Data collected included breed, age, sex, affected eyelid(s), number of distichia, and tear film breakup time (TBUT). Resected cilia-bearing tarsoconjunctival strips were submitted for histopathological analysis. RESULTS: Thirty eyes (52 eyelids) from 17 dogs were included in the study. The median age was 688 days (range 118-4243 days). A successful outcome, defined as complete resolution of clinical signs attributable to the distichia, occurred in all eyes after a single procedure, with a mean follow-up time of 239 days (range 69-480 days). Appearance of new distichia occurred in 14/30 eyes (46.3%), and of these, three eyes needed a new PTPE procedure. Recurrence of the distichia only occurred in one eye (3.3%) which was asymptomatic. Following surgery, TBUT decreased below the normal value in 7/24 eyes (29.1%) although none developed clinical signs of qualitative tear film deficiency. Post-operative complications included trichiasis and cicatricial entropion, which developed in two eyes (6.6%), and these were successfully managed with corrective eyelid surgery. CONCLUSIONS: Partial tarsal plate excision, using a transconjunctival approach, had an excellent clinical outcome with a low incidence of complications.

Iris biopsy to investigate feline iris hyperpigmentation.

OBJECTIVE: To evaluate the benefit of iris biopsy in cats with iris hyperpigmentation to differentiate melanosis from early feline diffuse iris melanoma (FDIM). METHODS: The medical records of cats with unilateral iris hyperpigmentation that had undergone iris biopsy between February 2013 and September 2016 at Willows Veterinary Centre & Referral Service were reviewed. RESULTS: Seven cats with unilateral iris hyperpigmentation were included in this retrospective study. The biopsy procedure was performed under general anesthesia (n = 7) with neuromuscular blockade (n = 6) following pre-operative topical miotic therapy (n = 5). One to six biopsy samples per eye were harvested from areas of hyperpigmentation. The samples were partial thickness (n = 4 eyes) and full thickness (n = 3 eyes). Complications were minor: mild intra-operative hemorrhage (n = 4), fibrin clot (n = 2), corneal ulcer (n = 1), post-operative ocular hypertension (n = 1), dyscoria (n = 1), and pseudopolycoria (n = 2). The first biopsy was diagnostic in six cats; a repeat biopsy was necessary in one cat. Histopathology was consistent with melanosis in five cats and with early FDIM in two cats. Screening for signs of metastatic disease (thoracic computed tomography and abdominal ultrasonography) was negative in the two cats with a preliminary diagnosis of early FDIM. Subsequent enucleation and histopathology confirmed the initial diagnosis in both cases. CONCLUSIONS: Iris biopsy in cats with iris hyperpigmentation can be beneficial to differentiate melanosis from early FDIM and thereby help to justify the decision for early enucleation.