Vetnuus | October 2024 39 The ocular lesions in dogs most commonly present as small, incidental, discrete, exophytic pedunculated masses growing from the bulbar and palpebral conjunctiva, ventral fornix, conjunctiva and eyelid itself. More rarely, they may be seen as a cauliflower, wart-like lesion growing from the corneal surface. These masses can frequently result in ocular irritation while others may make contact with the corneal surface causing keratitis, irritation and secondary lacrimation. Blepharospasm may also be noted. Extremely large adnexal lesions could potentially obstruct vision or cause discomfort. Corneal papillomas may result from papillomavirus infection or chronic keratitis. In rare cases, they may transform into malignant squamous cell carcinomas. Surgical excision followed by cryosurgery decreases recurrence. Treatment options: A variety of treatment options have been considered in the past. 1. The most successful treatment seems to be surgical excision of the mass. Around the eye, this is a very effective treatment option as lesions on the conjunctival surface most frequently involve lifting the loose conjunctiva and removing the mass. If small, no wound closure may be necessary. Surgery should involve minimal handling of the papilloma, wide excision (if possible), and perhaps, cryotherapy at the base of the lesion. Most papillomas on the cornea respond well to excision by superficial keratectomy. Recurrence may be decreased by cryosurgery using a double freeze-thaw cycle after the mass has been removed by superficial keratectomy. 2. Cryosurgery can be performed using a Cryoprobe. The instrument used must produce a very fine, well-controlled application of the cryogen. Always be conscious of the cornea not being accidentally frozen as well as the location on the globe or adnexa. Excessive freezing of the bulbar conjunctiva would certainly be a problem. 3. Exophytic lesions could be removed and an autogenous vaccine made. This has variable results. 4. Laser application. Treating the lesion with laser energy is a new and exciting option. This will soon be available at the JAEH. 5. There is no vaccine to prevent canine PV. Ideally, if surgical excision is to be considered then it is strongly advisable that histology is performed to differentiate from other tumours such as squamous cell carcinoma. The histological examination under a light microscope of a papilloma lesion shows very characteristic features. These include epithelial hyperplasia with acanthosis and hyperkeratosis that overlie fibrovascular cores. Koilocytes are cells with enlarged nuclei, irregular nuclear contour, hyperchromasia, and a perinuclear amphophilic cytoplasm halo; which predominate in the region of the stratum granulosa and they remain the mainstay of the histologic diagnosis. Keratohyaline granules may or may not be present. Occasionally, a basophilic intranuclear inclusion body may be identified. Regulars I Ophthalmology Column Papilloma lesion on the bulbar surface of the third eyelid >>> 40
RkJQdWJsaXNoZXIy OTc5MDU=