APHAKIC PHACOEMULSIFICATION AND AUTOMATED ANTERIOR VITRECTOMY, AND POSTRETURN MONITORING OF A REHABILITATED HARBOR SEAL (PHOCA VITULINA RICHARDSI) PUP

Congenital cataract and spherophakia leading to starvation in a free-ranging muskox neonate from the Northwest Territories, Canada

A muskox neonate (Ovibos moschatus) that died of starvation was diagnosed with congenital lenticular anomalies that included spherophakia and hypermature cataract associated with probable lens-induced lymphocytic uveitis and neutrophilic keratitis. Impaired sight as a result of cataract and associated inflammation likely contributed to abandonment and starvation, although maternal death cannot be excluded definitively. Ocular lesions, such as congenital cataracts and spherophakia in neonates, may be important factors affecting survival in free-ranging animals.

EVALUATION OF THE OPHTHALMIC DISEASE AND HISTOPATHOLOGIC EFFECTS DUE TO THE OCULAR TREMATODE PHILOPHTHALMUS ZALOPHI ON JUVENILE GALAPAGOS SEA LIONS ( ZALOPHUS WOLLEBAEKI)

The Galapagos sea lion ( Zalophus wollebaeki) is an otariid species endemic to the Galapagos archipelago and is currently listed as endangered. The ocular trematode Philophthalmus zalophi was recently reported to affect the survival of juvenile Galapagos sea lions on Santa Cruz Island, resulting in marked ophthalmic changes. This study evaluated the ophthalmic disease and histopathologic effects of P. zalophi on juvenile Galapagos sea lions in the largest rookery located on San Cristóbal Island. Twenty juvenile Galapagos sea lions (10 male and 10 female) were evaluated among five sites in the rookery El Malecón. Ophthalmic examination, including fluorescein staining and evaluation of the adnexa, cornea, and sclera, were performed on each eye. The presence, number, and location of ocular parasites were determined, and parasites were collected for identification. Conjunctival biopsy was performed on 11 animals: 2 that lacked parasites and gross lesions and 9 with both parasites and gross lesions. All parasites collected were confirmed as P. zalophi and identified in 80% (16/20) of the study animals and 70% (28/40) of the examined eyes. Philophthalmus zalophi was most frequently found attached to the nictitating membrane but also located on the palpebral conjunctiva or cornea. The most common clinical signs were varying degrees of conjunctival hyperemia (28/40 eyes), most frequently of the nictitating membrane and mucoid ocular discharge (12/40 eyes). The number of parasites was significantly associated with the degree of conjunctival hyperemia ( P < 0.001). Histopathology of conjunctival biopsies revealed organized lymphoid follicles and lymphoplasmacytic infiltrates. The histopathologic changes and gross lesions were likely due to the parasite's attachment to the conjunctiva. This study provides additional details of P. zalophi infection in juvenile Galapagos sea lions. Further research is warranted to detail the life cycle of this parasite, transmission to sea lions, and potential treatment protocols.

Bilateral Phacoemulsification in an African Elephant (Loxodonta africana)

A 37-year-old bull African elephant (Loxodonta africana) at the North Carolina Zoo (NCZ) was diagnosed with bilateral cataracts leading to behavioral changes and significant weight loss secondary to functional blindness. On initial examination, a weight loss of 234 kg, a mature cataract in the right eye, and a focal cataract in the left eye were diagnosed. Ultrasound and electroretinography (ERG) indicated normal retinal attachment and both eyes were viable candidates for surgery. After careful planning and behavioral training, the left cataract was surgically removed via phacoemulsification and irrigation/aspiration. The right eye subsequently developed a ventral lens subluxation, and phacoemulsification and irrigation/aspiration were performed six months after the first procedure. Four years after surgery, menace response, palpebral reflex, dazzle reflex, and pupillary light reflexes were present in both eyes. Body weight was 5,515 kg, 88kg more than at the time of the second surgery. This is the first published report of an African bull elephant undergoing bilateral cataract removal using phacoemulsification and irrigation/aspiration. The lack of significant postoperative inflammation and uneventful recovery of the elephant suggests that this surgical procedure along with proper preoperative planning and postoperative medical management can be a safe and effective treatment option for elephants with cataracts.