The combined use of surgical debulking and diode laser photocoagulation for limbal melanoma treatment: a retrospective study of 21 dogs

Abstract

Objective To evaluate effectiveness and safety of debulking and diode laser photocoagulation (DPC) for the treatment of limbal melanoma (LM). Procedure Retrospective multi-institutional case series. Medical records of animals diagnosed with LM at the Centro Veterinario Specialistico (CVS) and at the Long Island Veterinary Specialists from 1994 to 2014 were retrieved. Signalment, location, extent of tumors, recurrence rate, and early and late complications were reported. Patient follow-up information was obtained from veterinary ophthalmologists, primary care veterinarians, and where appropriate, owners.Results Twenty-one eyes of 21 dogs (13 females and 8 males) were included in this study. The dogs' average age was 6 years (range: 7 months-11 years). The follow-up period ranged from 1-108 months (median 48 months) after the last DPC procedure. Long-term follow-up was obtained by telephone interviews in 6 of 20 cases and by clinical re-evaluations in 14 of 20 cases. The most common early complications were a moderate anterior uveitis and peripheral corneal edema (21/21 eyes). Late complications included corneal fibrosis and/or pigmentation (20/21). In one case, a severe bullous keratopathy associated with extensive corneal fibrosis was observed (1/21). One case was blind due to concurrent Sudden Acquired Retinal Degeneration (SARD). However, after surgery 2 of 20 eyes lost vision and one of these was enucleated.Conclusions Debulking, in addition to diode laser photocoagulation, was technically straightforward to perform, minimally invasive, well tolerated, and highly successful in this case series.

Deep lamellar keratectomy and penetrating scleroplasty using CO2laser photoablation and bimodal grafting for the treatment of a limbal melanoma in a dog

“…The type of surgical resection should be based on patient selection, equipment availability, and surgeon experience. En bloc resection of limbal melanomas is generally regarded as the ideal surgical technique to most reliably prevent tumor regrowth; however, this approach requires concurrent grafting procedures and can be associated with more severe complications including marked uveitis, dyscoria, extensive intraocular hemorrhage, and cataract formation . Partial‐thickness resection of limbal masses is commonly combined with adjunctive procedures used to cause necrosis of remaining neoplastic cells such as cryotherapy, photocoagulation, and plesiotherapy …”

“…Cryotherapy and photocoagulation are well‐established treatment modalities in veterinary ophthalmology. Cryotherapy induces crystallization of the cellular cytoplasm leading to tissue destruction and cellular necrosis . Due to a high water content, melanocytes are particularly sensitive to cryonecrosis leading to the recent investigation of this therapeutic in the treatment of limbal melanomas .…”

“…The most common long‐term complication was persistent or recurrent corneal lipidosis in 3 of 14 eyes . Another recent report described the combined use of surgical debulking of limbal melanomas and diode laser photocoagulation with 18 of 21 eyes (86%) visual 72 months after surgery and 19 of 21 eyes (90%) showing no signs of discomfort . This procedure resulted in 2 of 21 eyes being affected by persistent corneal lipidosis after surgery.…”

“…Over the last several decades, numerous surgical approaches have been described for the resection of limbal melanomas, including full-or partial-thickness resection and various grafting procedures with or without adjunctive treatments including cryotherapy, plesiotherapy, and diode or Nd:YAG laser photocoagulation. 4,[6][7][8][9][10][11][12][13] To the authors' knowledge, this is the first clinical report to describe the surgical resection of a limbal melanoma by way of penetrating scleroplasty using exclusively CO 2 laser photoablation. The deep lamellar keratectomy and conjunctival advancement were routinely performed as described in the literature.…”

“…1,2,5 A number of surgical techniques have been described in the veterinary literature which include lamellar or penetrating sclerokeratoplasty with various replacement grafting procedures, and partial resection modalities combined with cryotherapy, strontium-90β plesiotherapy, and diode laser photocoagulation. 4,[6][7][8][9][10][11][12][13] This report describes the surgical treatment of a limbal melanoma in a dog by a deep lamellar keratectomy and penetrating scleroplasty using sharp lamellar dissection and CO 2 laser photoablation, followed by reconstruction of the corneoscleral defect using both a double-layered biosynthetic graft and conjunctival advancement flap.…”