Cataracts in New World camelids (llamas, alpacas, vicuñas, and guanacos).

Cataracts are the most frequently seen lens diseases in New World camelids. The causes of cataracts are unknown in many animals, but cataracts secondary to intraocular inflammation seem to be common. Congenital or juvenile-onset cataracts, if another cause is not apparent, should be considered as possibly caused by heredity, and the affected animals should not be bred. Persistent hyaloid vascular anomalies may also have an important role in cataract formation and could be heritable or caused by an in utero disturbance. Pedigree analyses, test breedings, and possibly DNA studies of llamas with cataracts will be required to determine their potential heritability in these species. Cataract surgery can be done successfully in camelids. It is important to evaluate the posterior segment with B scan ultrasonography before surgery in animals in which the posterior segment previously has not been seen. This evaluation allows the surgeon to better prepare for the presence of hyaloid vascular anomalies. Use of phacoemulsification, gentle tissue handling, liberal use of anti-inflammatory medications and endothelial protectants (BSS + and viscoelastics) during surgery has increased the success rate of this surgery in camelids. Unlike cataract surgery in dogs and horses undergoing, cataract surgery, in camelids seems to be important to remove much of the posterior lens capsule. This removal prevents severe capsular fibrosis and subsequent vision loss. There is evidence that a posterior capsulectomy and anterior viterectomy can help prevent postoperative glaucoma. Research needs to be done to see whether these species have an increased risk for ciliary-block glaucoma.