Case Description—A 4-year-old Hanoverian gelding was evaluated because of a mobile worm-like structure in the right eye.
Clinical Findings—Ophthalmologic examination of the right eye revealed a white, thin, coiled, mobile parasite, which was presumed to be a nematode, located in the ventral portion of the anterior chamber of the eye; there also were vitreal strands located temporally and inferiorly near the margin of the pupil. Results of ophthalmologic examination of the left eye were unremarkable.
Treatment and Outcome—The horse was treated with a neomycin-polymyxin B-dexamethasone ophthalmic solution applied topically (1 drop, q 8 h) to the right eye and penicillin V potassium (22,000 U/kg [10,000 U/lb], IV, q 6 h). The horse was anesthetized. A stab incision was made in the cornea, and a viscoelastic agent was infused around the parasite. The parasite was extracted via the incision by use of an iris hook and tying forceps. The horse had an uncomplicated recovery from the procedure and retained vision in the right eye. Gross and microscopic examination was used to identify the parasite as an adult metastrongyloid nematode consistent with a fully developed male Parelaphostrongylus tenuis.
Clinical Relevance—To the authors' knowledge, this is the first report of intraocular parelaphostrongylosis in a horse. This report provided evidence that vision could be retained after treatment for intraocular P tenuis infection in a horse.
Objective—To compare ultrasonographic and histologic examination findings for eyes of animals with ocular diseases.
Design—Retrospective case series.
Animals—116 eyes of 113 animals examined at 2 facilities.
Procedures—Diseased eyes of animals were examined by means of ultrasonography, removed via enucleation or exenteration, then histologically examined. Ultrasonographic images and histopathologic slides were evaluated, and diseases of eyes were identified with each of those methods and allocated to various categories. For each disease category, agreement between results of ultrasonography and those of histologic examination was assessed via determination of κ statistic values.
Results—Tests had good agreement for identification of iris or ciliary body neoplasia. Overall, intraocular neoplasia was not detected via ultrasonography for only 2 of 31 eyes with histologically detected neoplasia. Hemorrhagic or inflammatory changes were misinterpreted as neoplasia for 8 of 37 (22%) eyes. Tests had moderate to acceptable agreement for identification of retinal detachment. Retinal detachment was not detected by means of ultrasonography for 14 of 38 (37%) eyes with that diagnosis determined via histologic examination at one of the facilities (primarily in eyes with intraocular hemorrhage); however, retinal detachment was not identified via histologic examination for 6 of 38 (16%) eyes with that diagnosis determined via ultrasonography at the other facility.
Conclusions and Clinical Relevance—Agreement between tests evaluated in this study was clinically satisfactory for identification of intraocular neoplasia. Typically, diseases were misdiagnosed via ultrasonography for eyes with poor image contrast. Because determination of ultrasonographic diagnoses of retinal detachment and intraocular neoplasm may be of prognostic importance, performance of additional ultrasonographic techniques may be indicated.