Factors associated with keratopathy in captive pinnipeds.

OBJECTIVE To identify factors associated with keratopathy in captive pinnipeds and to provide guidance for preventive measures. ANIMALS 319 captive pinnipeds (229 otariids [sea lions and fur seals], 74 phocids [true seals], and 16 odobenids [walrus]) from 25 facilities. PROCEDURES Descriptive data collected from questionnaires completed by facilities and from medical records and physical examinations of pinnipeds were compiled and evaluated. Variables were assessed with χ2 tests of homogeneity to determine potential association with keratopathy, and variables with values of P ≤ 0.25 were inserted into the multivariable logistic regression model. RESULTS Results indicated that variables associated with significantly increased odds of keratopathy in captive pinnipeds included lighter or reflective pool color (OR, 2.11; 95% confidence interval [CI], 1.20 to 3.97), pool water salinity < 29 g/L (OR, 3.48; 95% CI, 1.89 to 6.56), and history of eye disease (OR, 3.30; 95% CI, 1.85 to 5.98), trauma (OR, 3.80; 95% CI, 1.72 to 8.89), and having been tested for leptospirosis (OR, 3.83; 95% CI, 1.54 to 10.26). However, odds of keratopathy decreased with UV index ≤ 6 (OR, 0.39; 95% CI, 0.2 to 0.72) and age < 20 years (OR, 0.32; 95% CI, 0.15 to 0.66). CONCLUSIONS AND CLINICAL RELEVANCE Findings indicated that odds of keratopathy in pinnipeds could be reduced by maintenance of pool water salinity ≥ 29 g/L and reduction of UV radiation exposure (eg, with adequate shade structures and use of darker, natural colors). Because UV radiation exposure is cumulative, even small attempts to reduce lifetime exposure to it could help control keratopathy in pinnipeds.

Clinical management of Candida albicans keratomycosis in a bottlenose dolphin (Tursiops truncatus).

OBJECTIVE: Corneal ulceration secondary to trauma commonly affects marine mammals, often with opportunistic secondary bacterial or fungal infections. This report characterizes the combined use of auriculopalpebral and ophthalmic nerve blocks, adipose-derived stem cells, and subconjunctival injections for successful treatment of corneal trauma and infection in dolphins. ANIMAL STUDIED: An 11-year-old, female bottlenose dolphin (Tursiops truncatus) presented with bilateral diffuse corneal opacities, which progressed to keratomycosis caused by Candida albicans. PROCEDURE: Aggressive medical management was employed, including the use of subconjunctival injections of adipose-derived stem cells, plasma, topical and oral antifungals and antibiotics, and anti-inflammatory and pain medications. Anesthetic block of the auriculopalpebral and ophthalmic nerves was employed to evaluate the corneas. CONCLUSION: Subconjunctival injections were employed over 52 days, followed by topical drops for 5 months. At last evaluation, there was no evidence of blepharospasm bilaterally. Only a faint superficial gray corneal opacity remained OS. A temporal paraxial corneal opacity was present OD, with receding inactive vascularization and a small amount of melanosis temporally.

Subconjunctival antimicrobial poloxamer gel for treatment of corneal ulceration in stranded California sea lions (Zalophus californianus).

OBJECTIVE: Corneal ulcers are commonly encountered in pinnipeds. Prolonged oral antibiotics and topical ophthalmic solutions may not be practical to administer, and novel treatment techniques are desired. Thermodynamic gels are a potential solution because they hold antimicrobials at the site of injection, slowly releasing drug. This study investigated the clinical efficacy of antibiotic-impregnated poloxamer gel in management of corneal ulceration. ANIMAL STUDIED: Twenty-six California sea lions undergoing rehabilitation at The Marine Mammal Center. PROCEDURES: A poloxamer gel mixed with 2% enrofloxacin was subconjunctivally injected in the treatment group. Control animals received oral doxycycline. Systemic anti-inflammatories and analgesics were administered as needed. Corneal examinations under general anesthesia were repeated weekly, and included sampling for bacterial culture and corneal cytology, collection of high-quality corneal images, and treatment administration until the ulcers were healed. RESULTS: There was no gross or histologic evidence of a localized tissue reaction to the gel administration in the conjunctiva, and no evidence of systemic reaction to therapy in animals that died due to unrelated causes during the study period (n = 17). In animals that experienced a superficial corneal ulcer involving only epithelium or superficial stroma (n = 12), all lesions resolved completely, in both treatment and control groups. Of those animals with deeper or more complex ulcers involving keratomalacia or descemetoceles (n = 15), four demonstrated complete lesion resolution (all four received gel treatment). CONCLUSIONS: This study demonstrates that subconjunctival antibiotic poloxamer gel administration is a safe and effective alternative therapeutic option to traditional treatments for superficial corneal ulceration in pinnipeds.

CHARACTERIZATION OF ANTERIOR SEGMENT OPHTHALMOLOGIC LESIONS IDENTIFIED IN FREE-RANGING DOLPHINS AND THOSE UNDER HUMAN CARE.

Cetaceans in the wild and under human care develop a variety of ocular lesions. Although they have echolocation, cetacean species have good sight, making ocular health an important part of overall health care. The cornea is the primary site of abnormalities in both populations. Typical lesions of cetaceans under human care are characterized in this retrospective review of cases. One hundred eighty animals (n = 360 eyes) were chosen from the author's ophthalmologic examination reports from different geographic areas; they included Atlantic bottlenose dolphins (Tursiops truncatus), Pacific bottle nose dolphins (Tursiopstruncatus gilli), Indopacific bottlenose dolphins (Steno bredanensis), Indopacific humpback dolphins (Sousa chinensis), and roughtooth dolphins (Steno bredanensis). These animals were examined at least once, although most were examined numerous times over many years; lesions were categorized and are described. Seventy-seven eyes from 47 animals were normal. Medial keratopathy was the most common lesion and identified in 180 eyes from 97 animals, with 83 affected bilaterally. Horizontal keratopathy was identified in 69 eyes from 41 animals, with 28 affected bilaterally. Axial keratopathy and nonspecific axial opacities were identified in 67 eyes from 44 animals, with 21 affected bilaterally. Seventy-eight eyes from 50 animals, with 28 affected bilaterally, had more than one type of corneal lesion. Cataracts were identified in 32 eyes from 19 animals, with 13 affected bilaterally. Traumatic injuries were also common and involved eyelids and cornea. Sixteen eyes from 11 animals were blind; five dolphins were blind bilaterally due to phthisis bulbi secondary to corneal perforation or severe trauma. None of the diseases had a sex predisposition; however, medial keratopathy was significantly more common as a bilateral presentation than as a unilateral presentation. Cetaceans under human care with impaired sight can use echolocation; however, ocular health should definitely be a priority in their overall health plan.

Lens-Related Emergencies: Not Always So Clear.

Emergencies involving the crystalline lens are not common; however, their clinical signs must be recognized quickly to begin treatment or referred immediately to improve the chances of retaining sight. The lens is a unique structure because of its immunologically privileged status and its imperative clarity for vision. Any insult to the lens capsule's integrity, its position within the globe, or to its clarity may result in undesirable sequelae.

Estradiol biosynthesis in canine lens epithelial cells.

PURPOSE: To confirm that lens epithelial cells (LEC) synthesize 17ß-estradiol, active estrogen, and to identify the pathway(s) by which normal and cataractous LEC synthesize 17ß-estradiol. METHODS: ELISA was used to measure estradiol in aqueous humor; immunohistochemical staining was used to localize estradiol, testosterone and sulfatase; tritiated water release assay was used to measure aromatase activity; and qRT-PCR was used to quantify expression of aromatase and sulfatase in normal and cataractous canine and human LEC. RESULTS: Canine eyes with and without cataracts had no differences in aqueous humor estradiol levels; however, cataractous LEC had more intense immunoreactivity for estradiol than normal LEC. There were little to no differences in canine sulfatase protein and mRNA expression when normal and cataractous LEC were compared. qRT-PCR demonstrated that canine cataractous LEC had significantly higher expression of aromatase; this was confirmed with the tritiated water release assay. Similar to dogs, human cataracts had both sulfatase and aromatase mRNA expression. CONCLUSIONS: Normal and cataractous LEC can synthesize estradiol by the sulfatase pathway; however, cataractous LEC appear to use the aromatase pathway as well. Because no differences in aqueous humor estradiol levels were detected, we suspect that estradiol synthesized by the sulfatase pathway is secreted into the aqueous humor; whereas, estradiol synthesized by the aromatase pathway is used for, as yet unknown, intracrine purposes.

Safety study of capsular tension ring use in canine phacoemulsification and IOL implantation.

OBJECTIVE: To evaluate and compare surgical outcome and complications in canine eyes with stable, cataractous lenses undergoing routine phacoemulsification and intraocular lens (IOL) implantation with or without implantation of a capsular tension ring device (CTR). PROCEDURES: Dogs undergoing routine bilateral phacoemulsification and IOL implantation had one eye randomly chosen to have a CTR (47 eyes) inserted while the contralateral eye served as a control (47 eyes). The CTR was placed in the capsular bag following phacoemulsification and immediately prior to IOL implantation. All eyes received acrylic foldable IOLs. Patients were evaluated intra- and postoperatively, and complications were compared between eyes with and without a CTR. RESULTS: There were no intra-operative complications associated with implantation of the CTR. Postoperatively, the overall incidences of glaucoma (6%), intraocular hemorrhage (4%), and retinal detachment (2%) were equal between control and CTR eyes at the time of last follow-up. There was no significant difference in overall incidence of immediate postoperative uveitis (35% vs. 38%) or fibrin (19% vs. 15%) between control and CTR eyes. Follow-up time ranged from 2 weeks to 21 months. CONCLUSION: In canine eyes with stable cataractous lenses undergoing routine phacoemulsification and IOL implantation placement of a CTR does not increase the risk of intra- or postoperative complications.

Supplements for exotic pets.

The use of supplements has become commonplace in an effort to complement traditional therapy and as part of long-term preventive health plans. This article discusses historical and present uses of antioxidants, vitamins, and herbs. By complementing traditional medicine with holistic and alternative nutrition and supplements, the overall health and wellness of exotic pets can be enhanced and balanced. Further research is needed for understanding the strengths and uses of supplements in exotic species. Going back to the animals' origin and roots bring clinicians closer to nature and its healing powers.

Bilateral ocular anomalies in a South African fur seal (Arctocephalus pusillus pusillus).

A female South African fur seal (Arctocephalus pusillus pusillus) began having obvious clinical ophthalmologic problems by 8 weeks of age. The initial clinical sign was diffuse corneal edema, which progressed to bullae formation and ulcers; the underlying cause of corneal edema and bullous keratopathy was not identified antemortem.An ophthalmological evaluation was performed when the fur seal was approximately 6 months of age, but due to the diffuse corneal edema, intraocular structures could not be easily evaluated. An underlying infectious etiology was suspected; therefore,appropriate diagnostics were pursued, but did not identify a cause. Initial improvement was noted, but the fur seal then became blind and eventually became very painful.Due to decreased quality of life and aggressive behavior, the fur seal was euthanized.Histopathological diagnoses were persistent tunica vasculosa lentis and persistent hyperplastic primary vitreous with bilateral hypermature resorbed cataracts and retinal detachments with rosette formation.

A retrospective survey of the ocular histopathology of the pinniped eye with emphasis on corneal disease.

OBJECTIVE: A retrospective review of globes from 70 pinnipeds submitted to the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) describing the type and frequency of ocular disease. ANIMALS STUDIED: The study included 50 California sea lions, four animals listed only as 'sea lion', nine Northern elephant seals, five harbor seals, 1 Northern fur seal, and 1 Hooded seal. PROCEDURES: Globes were classified by microscopic findings. Categories were not mutually exclusive. RESULTS: The largest category was corneal disease (63 globes from 40 pinnipeds). The second largest was cataractous changes (35 globes from 23 pinnipeds). Additional ocular diseases included traumatic ocular injuries (nine globes from eight animals), phthisis bulbi (nine globes from eight pinnipeds), neoplasia (nine globes from six adult California sea lions), amyloid deposition in the corneal stroma, ciliary body, or both locations (five globes from four pinnipeds), and fungal disease (three globes from two pinnipeds). Pinnipeds with corneal disease were further categorized: stromal pathology (39 globes from 27 pinnipeds); epithelial pathology (37 globes from 27 pinnipeds); Descemet's pathology (11 globes from eight pinnipeds); endothelial attenuation or absence (33 globes from 22 pinnipeds); presence of retrocorneal membranes (15 globes from 10 pinnipeds); anterior synechia (eight globes from six animals), and keratitis (seven globes from five pinnipeds). CONCLUSIONS: This is the first report of ocular amyloid in pinniped eyes. All cases of neoplasia were in a pattern suggesting metastatic disease. In this study, there was a higher prevalence of ocular disease in captive pinnipeds, particularly in the posterior cornea.

Characterization of ocular gland morphology and tear composition of pinnipeds.

OBJECTIVE: The importance of tear film integrity to ocular health in terrestrial mammals is well established, however, in marine mammals, the role of the tear film in protection of the ocular surface is not known. In an effort to better understand the function of tears in maintaining health of the marine mammal eye surface, we examined ocular glands of the California sea lion and began to characterize the biochemical nature of the tear film of pinnipeds. PROCEDURES: Glands dissected from California sea lion eyelids and adnexa were examined for gross morphology, sectioned for microscopic analysis, and stained with hematoxylin and eosin. The tear film was examined using interferometry. Tears were collected from humans and pinnipeds for the analysis of protein and carbohydrate content. RESULTS: The sea lion has sebaceous glands in the lid, but these glands are different in size and orientation compared with typical meibomian glands of terrestrial mammals. Two other accessory ocular glands located dorsotemporally and medially appeared to be identical in morphology, with tubulo-acinar morphology. An outer lipid layer on the ocular surface of the sea lion was not detected using interferometry, consistent with the absence of typical meibomian glands. Similar to human tears, the tears of pinnipeds contain several proteins but the ratio of carbohydrate to protein was greater than that in human tears. CONCLUSIONS: Our findings indicate that the ocular gland architecture and biochemical nature of the tear film of pinnipeds have evolved to adapt to the challenges of an aquatic environment.

Absorption and ocular deposition of dietary lutein in marine mammals.

Cataracts and ocular disease are common lesions of marine mammals in zoological collections. Lutein, an oxygenated carotenoid, may have therapeutic or prophylactic effects on ocular disorder. Therefore, this study examined the ability of marine mammals to absorb dietary lutein. Two preliminary trials examined lutein in two forms (beadlet or ester) in a small sample size of marine mammals representing pinnipeds and cetaceans. Lutein was fed daily in tablets providing 0.89-3.6 mg lutein/kg body weight(0.75) per day for 15 days to 2 years. A third study was conducted using lutein beadlet fed at 3.6 mg lutein/kg body weight(0.75) per day for 15-21 days. Blood was analyzed for lutein pre- and postsupplementation. In the preliminary trials, lutein beadlet was observed to result in greater blood lutein levels than lutein esters, and cetaceans had more noticeable responses than pinnipeds. In Study 3, serum lutein and zeaxanthin increased postsupplementation in beluga whales (P < 0.05), and serum lutein tended to increase postsupplementation in dolphins (P < 0.10), but little change was seen in serum lutein in pinnipeds or manatee. Opportunistic retinal samples demonstrated some detectable lutein in the retina of a dolphin and several harp seals. The lutein levels in dolphins after supplementation are similar to those reported in free-ranging animals. Ocular lutein in harp seals demonstrates that ocular deposition occurs despite low circulating lutein levels.

Sustained-release celecoxib from incubated acrylic intraocular lenses suppresses lens epithelial cell growth in an ex vivo model of posterior capsule opacity.

PURPOSE: To determine whether celecoxib (CXB) can be released from incubated intraocular lenses (IOLs) sufficiently to inhibit lens epithelial cell (LEC) growth in an ex vivo model of posterior capsule opacification (PCO). MATERIALS: LEC growth was evaluated for 14 days in canine lens capsules (LCs) that had been exposed to media containing 20 µM CXB for 1-5 days. After the incubation of hydrophilic and hydrophobic IOLs in CXB solution, the determination of the in vitro release of CXB from the IOLs was performed for up to 28 days. The incubated and nonincubated IOLs were evaluated in the ex vivo model of PCO, and the rate of LEC growth was evaluated over 28 days. RESULTS: The treatment of LCs with 20 µM CXB for 4 and 5 days completely inhibited LEC growth. LEC repopulation did not occur after the removal of CXB. IOLs incubated in CXB for 24 h resulted in a sustained release of CXB in vitro at levels theoretically sufficient to inhibit PCO. LCs in the ex vivo model of PCO treated with acrylic IOLs incubated in CXB had significantly suppressed LEC ingrowth compared with untreated and IOL-only LCs. CONCLUSIONS: A 4-day treatment of LCs with a concentration of 20 µM CXB may effectively prevent PCO. IOLs incubated in CXB for 24 h resulted in a sustained release of CXB in vitro at levels sufficient to inhibit LEC growth in the ex vivo model of PCO. Further studies are needed to determine whether CXB-incubated IOLs can effectively prevent the development of PCO in vivo.

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.

The effect of phosphorylated Akt inhibition on posterior capsule opacification in an ex vivo canine model.

PURPOSE: To evaluate whether inhibition of phosphorylated Akt (pAkt) would reduce or prevent posterior capsule opacification (PCO) in an ex vivo canine lens capsule model. METHODS: Normal and cataractous lenses (n=6) were evaluated for pAkt via immunohistochemistry and immunoblotting. Primary cultures of lens epithelial cells (LEC) were exposed to ultraviolet light (UV) to induce pAkt. Cultures were then incubated in 0, 2.5, 5, or 10 µM (n=6) of a novel Akt inhibitor (AR-12) for either 8 or 24 h. Cultures were harvested and pAkt expression and telomerase activity examined by immunoblotting and telomeric repeat amplification protocol (TRAP)-enzyme linked immunosorbent assay (ELISA), respectively. Lens capsules were harvested post-sham cataract surgery and exposed to 0, 2.5, 5, 7.5, or 10 µM (n=8) of AR-12 for a total of 14 days treatment. Additional lens capsules (n=6) were exposed to 10 µM of AR-12 for 1 week followed by media alone for 1 week; or exposed to media alone for 1 week followed by 10 µM of AR-12 for 1 week. Histopathology and immunohistochemical staining were performed to evaluate PCO formation. Analysis of telomerase activity on the lens capsules was performed by TRAP-ELISA. RESULTS: pAkt protein expression was increased in clinical samples of canine cataracts compared to normal lenses. Following exposure to UV, cultures of LEC significantly (p<0.05) increased expression of pAkt and telomerase activity. Treatment with AR-12 for both 8 and 24 h following UV irradiation significantly (p<0.01) decreased pAkt expression. When UV-exposed LEC were allowed to recover in the presence of either 5.0 or 10.0 µM AR-12, there was a significant (p<0.05) decrease in telomerase activity. In the ex vivo model of PCO, within the region of the capsulorhexis, PCO inhibition was maximally achieved with 10 µM of AR-12. A significant decrease in LEC was noted on the posterior capsules containing 5.0, 7.5, and 10 µM AR-12 compared to the control capsules (p<0.01). Telomerase activity decreased in a dose-dependent manner. One week of treatment with 10 µM AR-12, immediately following capsule excision, was sufficient to inhibit PCO formation, while a delay in exposure to AR-12 after 1 week of media incubation alone did not prevent PCO formation. CONCLUSIONS: pAkt is known to have roles in cell survival, proliferation, and migration, and this study suggests its inhibition immediately following cataract surgery may be a useful approach to prevent PCO.

Characterization of progressive keratitis in otariids.

OBJECTIVE: To characterize a form of progressive keratitis that occurs commonly in otariids. MATERIALS AND METHODS: One hundred and thirteen captive otariids were evaluated by ophthalmologic examination and digital photography. RESULTS: Forty-six females and 67 males were in the reference population, average age of 14 years. California sea lions predominated (n = 100); there were also six Steller sea lions, five brown fur seals, one Guadalupe fur seal and one northern fur seal. Three stages of progressive keratitis are described. Overall, 64.6% animals and 142 eyes from 113 animals (62.8%) were affected with one of three stages. The mildest form, Stage 1 keratitis, occurred in 78 of 226 eyes (34.5%); the intermediate Stage 2 keratitis occurred in 30 of 226 eyes (13.3%); and the most severe, Stage 3 keratitis, occurred in 34 of 226 eyes (15%). All but six animals had bilateral disease. Animals with Stage 1 keratitis were significantly younger than those in more advanced stages. DISCUSSION: 'Otariid Keratitis' occurs in all populations of eared seals evaluated. A large-scale epidemiological study is ongoing to identify the risk factors that contribute to this disease. Exposure to chronic sunlight appears to be an important risk factor as shade diminishes clinical signs; animals kept out of sunlight the majority of the time have less severe clinical signs. Age may be important since exposure accumulates with aging. Progression of the disease is also associated with secondary opportunistic bacterial and fungal infections. The surface immune system may be imbalanced contributing to these infections and progression.

Anatomy of the California sea lion globe.

OBJECTIVE: This study analyzed the morphology of the California sea lion globe to determine what features may contribute to their characteristic visual abilities. PROCEDURE: Globes from the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) collection were examined from gross photographs and microscopic sections stained with hematoxylin and eosin, trichrome, smooth muscle actin, and alcian blue periodic acid-Schiff (PAS). Transmission electron microscopy of the cornea and iris was also performed. CLINICAL RESULTS: There was a round, flattened area ventromedial to the axial cornea. The pupil was tear-drop shaped. Pectinate ligaments were visible without magnification. The retina was holangiotic, containing numerous spoke-like venules and arterioles. The tapetum was green encompassing the entire fundus. The optic nerve was unmyelinated. HISTOLOGICAL RESULTS: The sclera was thinnest equatorially and thickest at the limbus and posterior pole. Bowman's layer was difficult to see by light microscopy but clear with transmission electron microscopy. The cornea had a thick epithelium, thin endothelium and Descemet's membrane, and the stroma thinned axially. The dilator muscle was absent near the pupil, but enlarged and mingled with the sphincter muscle near the iris base. A large, wide ciliary cleft with prominent trabeculae and a single continuous pectinate ligament was present. The corneoscleral trabecular meshwork was discontinuous. A round lens attached to the ciliary body via direct attachment to ciliary processes and delicate zonular ligaments. There was a circumferential muscle at the base of the ciliary processes. A thick tapetum covered the entire fundus except peripherally. The retina was characterized by sparse, large ganglion cells.