Ophthalmic disease in exotic species.

This article highlights factors that must be kept in mind when dealing with species other than cats, dogs, and horses. Diseases of the eye are similar regardless of whether they occur in humans or domestic or exotic species. There are unique conditions in exotic species that reflect differences in anatomy, physiology, pharmacology, and pathophysiology compared with domestic species.     

Ophthalmic emergencies.

Ophthalmic emergencies are common presenting complaints in an emergency room. Most ophthalmic emergencies can be treated and stabilized until an ophthalmologist can be consulted. Most ocular emergencies involve loss of vision, compromised globe integrity, or severe ocular pain. Delay in treating true emergencies may result ina blind eye or loss of an eye. This article discusses the clinical signs,diagnosis, and treatment as well as the prognosis of some of the more common ophthalmic emergencies.     

Ophthalmic imaging.

The availability of advanced imaging modalities in veterinary medicine has greatly widened the diagnostic imaging capabilities possible.Ultrasonography provides a rapid noninvasive modality that provides detailed examination and resolution of the intraocular structures and soft tissues surrounding the orbit of opaque eyes.Ultrasonography is cost-effective and widely available to practitioners,referral centers, and academic institutions. In many areas,mobile specialist ultrasonographers are available to supplement the equipment and skills of the practitioner. The added strengths of CT and MRI lie in their cross-sectional capability and better image quality. Unfortunately, the cost of CT and MRI currently limits their availability to referral centers and academic institutions.Primarily because of financial considerations, CT is currently more widely available for evaluation of equine disorders than MRI. A thorough evaluation of the multiple images and an understanding of normal anatomy and abnormal tissue patterns are indicated to maximize the use of each modality. Unlike ultrasonography, which can be performed in awake horses, the costs and contraindications of general anesthesia in some critical patients should also be considered when using CT and MRI. Finally, imaging artifacts are frequently encountered with each of these modalities. Thus, a thorough understanding of the various types of artifacts that occur is important so as to avoid interpretation pitfalls.     

Ophthalmic emergencies

Ocular emergencies can be very intimidating for veterinarians. Most ocular emergencies can be stabilized by the veterinarian until an ophthalmologist can be consulted if necessary. Proptosis, or forward displacement of the globe, can occur secondary to any blunt trauma to the head. The two options for a proptosed eye are enucleation or replacement with tarsorrhaphy depending on the viability of the extraocular tissues and eye. Glaucoma, or increased intraocular pressure (above 35 mm Hg), is diagnosed by measuring the intraocular pressure using a Shiotz or electronic tonometer. Emergency treatment includes intravenous mannitol and topical pilocarpine. Uveitis, or inflammation of the iris, ciliary body and/or choroid, can have many underlying causes such as neoplasia, infection, lens induced, and trauma. The treatment consists of treating the underlying cause, and administering topical atropine to alleviate pain and topical corticosteroids to decrease inflammation. Corneal ulcers, or defects in the corneal epithelium, are classified according to the depth of the defect. The treatment consists of topical antibiotics and topical atropine. If the ulcer is deep, is melting, or is a descemetocele, then a third eyelid or conjunctival flap is usually necessary. The cornea should be sutured if it is perforated or lacerated. Hyphema, or blood in the anterior chamber, can occur secondary to trauma, neoplasia, infection, or a coagulapathy. The treatment consists of treating the underlying cause and topical corticosteroids with or without antibiotics.     

Lymphocystis disease in imported tropical fish

Lymphocystis disease, affecting snake-skin gouramis (Trichogaster peltoralis) and blue gouramis (T. tricopterus), was diagnosed histologically in 2 shipments of imported tropical fish. Typical virus particles were readily demonstrated by electron microscopy in negatively stained preparations and in sectioned tissues. Attempts at viral isolation in 2 fish cell lines (RTG-2 and FHM) were unsuccessful as were attempts to transmit the infection to pearl gouramis (T. leeri).     

Tropical fish medicine. Necropsy examination of fish

Necropsy examination of moribund or dead specimens is an essential step in diagnosing fish diseases. This article discusses basic anatomy and necropsy procedures. A large part of the article has been devoted to methods of procuring samples for laboratory analysis and histologic examination. To determine which findings are responsible for the mortalities, the entire case history and gross necropsy findings must be reviewed. Careful observations made during the necropsy examination provide valuable information immediately, as well as later on in the interpretation of laboratory data.     

Ophthalmic surgical instruments

With proper training and diligent practice, many orbital, extraocular, and corneo-conjunctival surgeries can be successfully performed by the general practitioner. Specialized surgical instrumentation is necessary to achieve optimal results. This article reviews the essential surgical instruments required for these routine ophthalmic surgeries and provides guidelines for suture selection. Recommendations for handling and care of ophthalmic surgical instruments, including cleaning, sterilization, and storage, are provided.     

Tropical fish medicine. Anesthesia in fish

1. Before using anesthesia in fish, check water quality parameters for tropical fish aquariums in the locality. 2. Monitor any changes in water quality that result from anesthetic administration, especially pH and alkalinity. Have adequate buffering agents available to counter these changes. 3. Use one or two preferred agents, and become familiar with the effects they produce. 4. Where possible, withhold food from fish for 24 hours prior to administration of the anesthetic agent. 5. Try to anesthetize a few fish in a group first as a test batch. Wait 12 to 24 hours for signs of delayed mortality before proceeding to anesthetize the rest of the fish. 6. Always provide adequate aeration in holding vessels. 7. Where practical, use water that the fish has come from in the anesthetic tank. 8. Always have a container of the same water for the fish to recover in.