Novel Combined Approach for Vision‐Preserving Iridociliary Tumour Excision in a Small‐Breed Dog: Contralateral Iris Excision With En‐Bloc Scleral Resection

This case report presents the first application of a novel combined surgical approach incorporating contralateral iris excision with en-bloc scleral resection for managing a recurrent iridociliary epithelial tumour in a small-breed dog. A 7-year-old castrated male Chihuahua (3.2 kg) presented with a recurrent iridociliary tumour following initial biopsy. Vision-preserving surgery was performed using an innovative combined contralateral and postero-anterior approach with bipolar cautery for haemostasis. The technique involved initial precise excision of tumour-bearing iris tissue through corneal paracentesis positioned opposite to the tumour location using miotic agents for accurate tumour margin assessment, followed by en-bloc excision of the tumour with adjacent scleral tissue via a stepped scleral flap approach. En-bloc tumour excision with intended 2-3 mm margins, including adjacent scleral tissue, was performed, though histopathology revealed incomplete excision at some borders. The tumour was confirmed as a highly pigmented iridociliary epithelial tumour with minimal scleral invasion. Postoperative complications included transient anterior uveitis and mild hyphema, both resolving within 4 weeks. At 3-month follow-up, the patient maintained functional vision despite developing incipient cataract and suspected partial retinal detachment. This novel combined contralateral approach with en-bloc scleral resection represents the first successful vision-sparing procedure specifically designed and reported in a small-breed dog, offering a promising alternative to conventional approaches and addressing the surgical space limitations encountered in small-breed patients.