Conjunctival sequestra causing eye pain and tearing in cats

Abstract

PURPOSE: Corneal sequestrum is a condition commonly observed in cats, though the pathogenesis is not fully understood. The occurrence of conjunctival sequestrum has not previously been documented. This report aims to describe a series of cases of conjunctival sequestra in cats. ANIMALS AND ANIMAL SAMPLES STUDIED: A 3-year-old male Persian cat presented after 2 months of blepharospasm and epiphora in the right eye, accompanied by mild conjunctival hyperemia. Histopathologic findings from four other cases are also included. METHODS: After presentation of Patient 1, the database (from 2007 to 2025) of the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) was searched for other cases of feline conjunctival sequestrum, four of which were identified. In all cases, an amorphous black plaque was observed in the conjunctival tissue during the ophthalmological examination. Three of the four cases also had corneal sequestra ipsilaterally. Histopathology of the corneal sequestra was available in two of the cases. RESULTS: Histopathology of all five conjunctival lesions revealed focally extensive compaction and brunescence of proprial collagen and absence of fibroblasts. Three of the cases had conjunctival ulceration overlying the sequestrum. The surrounding substantia propria was variably infiltrated by inflammatory cells and microorganisms. The appearance of conjunctival sequestra was remarkably similar to that of corneal sequestra. CONCLUSION AND CLINICAL RELEVANCE: This is the first reported case-series of feline conjunctival sequestrum. Variable presentation of concurrent ocular abnormalities and history led to no definitive conclusion to a common cause. Similar to corneal sequestra, chronic irritation and a possible contribution from FHV-1 infection are suspected.