Ultrasonographic diagnosis of persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous in two dogs

Congenital cataract associated with persistent hyperplastic primary vitreous and persistent tunica vasculosa lentis in a sambar deer (Rusa unicolor) - clinical, ultrasonographic, and histological findings

Ultrasonography suggested the diagnosis of cataract associated with persistent fetal intraocular vasculature in a 26-day-old sambar deer. The deer was ill and died despite intense critical care. Globes were removed. Histological characteristics of persistent fetal vasculature and secondary cataract are reported expanding the knowledge of ophthalmic disorders in wild ungulates.

[Cataracts in dogs--overview and guideline for decision making in treatment]

Cataract is the leading cause of impaired vision and vision loss in dogs. Because of the considerable progress in cataract surgery in recent decades, lens opacities can now be operated on with very good short-term success (90-95%), taking into account that proper patient selection is essential to maximize the probability of a successful surgical outcome. Following a description of anatomical and physiological lens characteristics, the etiology and complications of untreated cataracts are discussed. Furthermore, specific criteria for patient selection are addressed while delineating essential steps of the examination. This article aims to aid decision making in cataract therapy on the basis of diagnostic guidance and to facilitate the selection of an appropriate point of time for surgery.

Bilateral ocular abnormalities in a wild stranded harp seal (Phoca groenlandica) suggestive of anterior segment dysgenesis and persistent hyperplastic primary vitreous

A male yearling harp seal (Phoca groenlandica) stranded and was brought to Mystic Aquarium & Institute for Exploration's Seal Rescue and Rehabilitation Center. The seal presented with a bilateral pendular vertical nystagmus, negative menace response, and a positive palpebral response. Ophthalmological examination by slit lamp biomicroscopy revealed perilimbal corneal edema, excessive iridal surface structures, pupils that appeared to be shaped improperly (dyscoria), and suspected cataracts. Attempts to dilate the pupils with both dark-lighted conditions and repeated dosages of 10% phenylephrine and 1% atropine ophthalmic solution in each eye (OU) were unsuccessful. Ocular ultrasonography findings suggested bilateral cataracts with flattened anterior-posterior (A-P) diameter and possible persistent hyperplastic primary vitreous. It is possible that these structural congenital abnormalities could produce further ocular complications for this seal including uveitis, secondary glaucoma, retinal detachment, and/or vitreal hemorrhage in the future. This case demonstrates the importance of a thorough ophthalmological examination in stranded wild animals, especially if their symptoms appear neurological.

Congenital cataracts and persistent hyaloid vasculature in a llama (Lama glama)

A 9-month-old llama was evaluated for apparent blindness. Bilateral cataracts were diagnosed and cataract surgery was performed on the right eye. At the time of surgery persistent hyperplastic primary vitreous, persistent hyperplastic tunica vasculosa lentis, and a persistent hyaloid artery were observed. Prior to surgery Power Doppler ultrasound revealed a patent tunica vasculosa lentis OS. Despite reports of a poor success rate for llama cataract surgery, through use of careful tissue handling, phacoemulsification, viscoelastic endothelial protectants, anti-inflammatories, and BSS-Plus irrigating solution, vision was successfully restored in both eyes of the llama.

Ocular complications of persistent hyperplastic primary vitreous in three dogs

Persistent hyperplastic primary vitreous (PHPV) syndrome associated with either severe ocular complications or multiple ocular lesions was diagnosed in three young dogs, a Samoyed, a Spanish Pachon, and a mixed breed dog. Due to opacification of the anterior ocular structures, B-mode and color-flow Doppler ultrasonography were performed to aid diagnosis. The Samoyed presented with unilateral hyphema; the Spanish Pachon presented with unilateral secondary glaucoma associated with uveitis and hyphema OD and leucocoria OU; and the mixed breed presented with bilateral leucocoria. B-mode ultrasonography of the Samoyed revealed a subcapsular cataract and a hyperechoic tubular structure attached from the optic disk to the posterior lens capsule. In the Spanish Pachon B-mode ultrasonography of the right eye indicated microphakia, cataract formation, and a retrolental mass with a thin hyperechoic strand stretching from the optic disk to the posterior lens; and for the right eye cataract formation, PHPV, retinal detachment, and vitreous hemorrhage. In the mixed breed dog, B-mode ultrasonography of both eyes indicated microphthalmia, retrolental mass, and hyperechoic lenses. By color-flow Doppler imaging, blood flow was present in the retrolental mass of the right eye suggesting a persistent hyaloid artery.

Cross-sectional imaging techniques in veterinary ophthalmology

Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) are useful, complementary cross-sectional imaging modalities of the eye and orbit. High-resolution US provides excellent morphological information of ocular structures but offers limited information on the periocular tissues. CT and MRI provide valuable morphologic and topographic images of both ocular and periocular structures, thereby giving a more complete picture of the pathological process. US can be performed on awake patients, whereas CT and MRI require general anesthesia. In addition, US equipment is readily available and less costly than CT or MRI units. Fine-needle aspirations and biopsies under US or CT guidance can also be performed. This article reviews the technique and normal findings of ocular and orbital structures as displayed in each of these imaging modalities. Representative clinical cases are presented to illustrate the interpretation principles as well as to provide an illustrative reference for common ocular and orbital changes.