Case Description—A 9-year-old castrated male Bichon Frise was evaluated because of a 3-week history of a nonhealing corneal ulcer and corneal pigmentation of the left eye.
Clinical Findings—Ophthalmic examination of the left eye revealed conjunctival hyperemia, corneal neovascularization, corneal edema, corneal ulceration, and central corneal pigmentation. Intraocular structures of the left eye could not be visually examined because of the diffuse nature of the corneal lesions. The right eye had anterior cortical incipient cataracts, nuclear sclerosis, and an inactive chorioretinal scar.
Treatment and Outcome—Superficial lamellar keratectomy of the left eye was performed for both therapeutic and diagnostic purposes. Histologic evaluation of corneal biopsy specimens revealed dematiaceous fungal keratitis of the left eye, and topical administration of voriconazole was used to successfully resolve the keratitis. Seven months after diagnosis of dematiaceous fungal keratitis, the dog had no clinical signs or history of recurrence of the keratitis.
Clinical Relevance—Dematiaceous fungal keratitis should be considered as a possible cause of nonhealing corneal ulceration with heavy pigment deposition in dogs. Results suggested that lamellar keratectomy along with topical administration of voriconazole can be used successfully to treat dematiaceous fungal keratitis in dogs.
To compare the efficacy of 0.05% difluprednate ophthalmic emulsion and 1% prednisolone acetate ophthalmic suspension for controlling aqueocentesis-induced breakdown of the blood-aqueous barrier in healthy dogs.
34 healthy dogs.
Dogs were allocated to 5 groups (6 to 8 dogs/group) to receive 0.05% difluprednate, 1% prednisolone acetate, or saline (0.9% NaCl) solution (control treatment) in both eyes 2 or 4 times daily. Eye drops were administered topically for 5 consecutive days. Anterior chamber paracentesis (aqueocentesis) was performed in 1 eye on the third day. Automated fluorophotometry was performed immediately before and 20 minutes and 24 and 48 hours after aqueocentesis. Relative fluorescence (RF), defined as fluorescence of the eye that had undergone aqueocentesis divided by fluorescence of the contralateral eye, was calculated to help control for variation among dogs.
Mean RF was significantly lower at 24 hours after aqueocentesis in dogs treated twice daily with 0.05% difluprednate or 4 times daily with 1% prednisolone acetate than in dogs receiving the control treatment. At 48 hours after aqueocentesis, mean RF was significantly lower in dogs treated 4 times daily with 1% prednisolone acetate than in control dogs. Mean RF differed over time in dogs treated 4 times daily with 0.05% difluprednate but did not differ over time for any of the other treatments.
CONCLUSIONS AND CLINICAL RELEVANCE
All 4 treatments were effective for reducing aqueocentesis-induced anterior uveitis in healthy dogs regardless of the drug or frequency of administration. Topical ophthalmic administration of 0.05% difluprednate may be a viable treatment option for dogs with anterior uveitis and warrants further study.
Objective—To determine the effects of ocular administration of ophthalmic 2% dorzolamide hydrochloride solution on aqueous humor flow rate (AHFR) and intraocular pressure (IOP) in clinically normal cats.
Animals—20 clinically normal domestic shorthair cats.
Procedures—Following an acclimation period, IOP was measured in each eye of all cats 5 times daily for 3 days to determine baseline values. Fifteen cats received 1 drop of 2% dorzolamide solution and 5 cats received 1 drop of control solution in each eye every 8 hours for 5 days (treatment phase). The IOP of each eye was measured 5 times during each day of the treatment phase. Prior to and after the treatment phase, AHFR in both eyes of each cat was measured via fluorophotometry.
Results—Prior to treatment, AHFR or IOP did not differ between the treatment and control groups. In dorzolamide-treated cats, mean AHFR after the treatment phase (3.47 ± 1.5 μL/min) was significantly lower than the value prior to treatment (5.90 ± 2.2 μL/min) and mean IOP during the treatment phase (11.1 ± 1.0 mm Hg) was significantly lower than the baseline mean IOP (14.9 ± 1.0 mm Hg). In the control group, IOP values did not differ before or during the treatment phase and AHFRs did not differ before and after the treatment phase.
Conclusions and Clinical Relevance—Ocular administration of 2% dorzolamide solution significantly decreased AHFR and IOP in clinically normal cats. Application of 2% dorzolamide solution may be an effective treatment in cats with glaucoma.
Objective—To evaluate aqueous humor flow rate in the eyes of clinically normal cats by use of a noninvasive technique successfully used in other species.
Animals—20 domestic shorthair cats.
Procedures—1 drop of 10% fluorescein sodium was instilled into both eyes of 5 cats every 5 minutes until 3 drops had been administered. Fluorophotometry was performed at 2, 4, 5, 6, 7, 8, 9, and 10 hours after fluorescein application to monitor fluorescein removal and determine aqueous humor flow rate. The 3-drop protocol was used for the remaining 15 cats, and fluorophotometry was performed at 5, 6, 7, and 8 hours after fluorescein application. Aqueous humor flow rates were calculated manually by use of established equations with minor adjustments to constant values to reflect feline anatomic features. Correlation coefficients and slope ratios were calculated to assess the legitimacy of the flow rate data. Paired t tests were calculated to assess for differences between the right and left eyes.
Results—Mean ± SD calculated aqueous humor flow rate in the right, left, and both eyes of the 20 cats was 5.94 ± 2.30 μL/min, 5.05 ± 2.06 μL/min, and 5.51 ± 2.21 μL/min, respectively. Correlation coefficients and slope ratios revealed that the aqueous humor flow rates were accurate. No significant differences in values for the right and left eyes were detected.
Conclusions and Clinical Relevance—Accurate aqueous humor flow values for cats can be determined by use of the fluorophotometric technique evaluated in this study.
Objective—To measure ocular effects (blood-aqueous barrier breakdown and intraocular pressure [IOP]) following aqueocentesis performed with needles of various sizes in dogs.
Animals—28 healthy adult dogs.
Procedures—24 dogs underwent unilateral aqueocentesis (24 treated eyes and 24 contra-lateral untreated eyes); 25-, 27-, or 30-gauge needles were used in 3 treatment groups (n = 8/group). Four dogs were untreated controls. Aqueocentesis was performed during sedation and topical anesthesia. Anterior chamber fluorophotometry was performed before and after aqueocentesis on day 1. On days 2 through 5, sedation and fluorophotometry were repeated. Intraocular pressure was measured with a rebound tonometer at multiple time points.
Results—Aqueocentesis resulted in blood-aqueous barrier breakdown detected via fluorophotometry in all treated eyes, with barrier reestablishment by day 5. On day 2, the contralateral untreated eyes of all 3 groups also had significantly increased fluorescence. Use of a 25-gauge needle resulted in a significant increase in treated eyes' anterior chamber fluorescence on days 3 and 5 as well as a significant increase in IOP 20 minutes following aqueocentesis, compared with the other treatment groups.
Conclusions and Clinical Relevance—Aqueocentesis performed with a 25-gauge needle resulted in the greatest degree of blood-aqueous barrier breakdown and a brief state of intraocular hypertension. Use of a 27- or 30-gauge needle is recommended for aqueous paracentesis. A consensual ocular reaction appeared to occur in dogs following unilateral traumatic blood-aqueous barrier breakdown and may be of clinical importance.
Objective—To perform repeated anterior chamber fluorophotometry on both eyes of ophthalmologically normal dogs to measure fluorescein concentrations over a 5-day period and identify any change in the degree of anterior chamber fluorescence over time or difference between eyes.
Animals—9 healthy adult dogs (18 eyes).
Procedures—Each dog received an IV injection of 10% fluorescein solution, and anterior chamber fluorophotometry was performed 1 hour later on both eyes. This procedure was repeated at the same time each day for 5 consecutive days.
Results—A significant increase in fluorescein concentration was evident in the anterior chamber on day 5 in the right eye and days 2, 3, 4, and 5 in the left eye. There was no significant difference in concentration between the left and the right eyes on any day.
Conclusions and Clinical Relevance—The increase in ocular fluorescein concentration in the study dogs was unlikely to be of clinical importance and is only pertinent for subsequent research studies. This is a limitation that should be considered when reporting fluorophotometry data as fluorescein concentration or as change in fluorescein concentration from baseline.
Objective—To compare efficacy and duration of effect on corneal sensitivity of 0.5% proparacaine hydrochloride, 0.5% bupivacaine hydrochloride, 2% lidocaine hydrochloride, and 2% mepivacaine hydrochloride solutions following ocular administration in clinically normal horses.
Animals—68 clinically normal horses.
Procedures—60 horses were assigned to receive 1 anesthetic agent in 1 eye. For each of another 8 horses, 1 eye was treated with each of the anesthetic agents in random order with a 1-week washout period between treatments. Corneal sensitivity was assessed via corneal touch threshold (CTT) measurements obtained with a Cochet-Bonnet aesthesiometer before and at 1 minute, at 5-minute intervals from 5 to 60 minutes, and at 10-minute intervals from 60 to 90 minutes after application of 0.2 mL of anesthetic agent. General linear mixed models were fitted to the CTT data from each of the 2 experimental groups to assess the effects of the anesthetic agents over time, accounting for repeated observations within individual horses.
Results—Corneal sensitivity decreased immediately following topical application of each anesthetic agent; effects persisted for 35 minutes for proparacaine and mepivacaine treatments, 45 minutes for lidocaine treatment, and 60 minutes for bupivacaine treatment. Maximal CTT reduction was achieved following application of bupivacaine or proparacaine solution, whereas mepivacaine solution was least effective.
Conclusions and Clinical Relevance—Ocular application of each evaluated anesthetic agent reduced corneal sensitivity in horses; although 0.5% proparacaine or 2% lidocaine solution appeared to induce adequate short-duration corneal anesthesia, use of 0.5% bupivacaine solution may be more appropriate for procedures requiring longer periods of corneal anesthesia.
Objective—To assess inhibitory effects of orally administered anti-inflammatory medications on paracentesis-induced intraocular inflammation in clinically normal cats.
Animals—30 clinically normal domestic shorthair cats.
Procedures—Cats were randomly assigned to a control group and 4 treatment groups. Cats in the treatment groups received an anti-inflammatory medication orally once daily at 7 am (acetylsalicylic acid [40.5 mg/cat], meloxicam [0.1 mg/kg], prednisone [5 mg/cat], or prednisolone [5 mg/cat]) for 5 days beginning 2 days before paracentesis-induced breakdown of the blood-aqueous barrier (BAB) and continuing until 2 days after paracentesis. Paracentesis of the anterior chamber was performed in 1 randomly selected eye of each cat. Fluorophotometry was performed in both eyes of each cat immediately before (time 0) and 6, 24, and 48 hours after paracentesis.
Results—At 24 and 48 hours after paracentesis, fluorescein concentration in the eye subjected to paracentesis in the cats receiving prednisolone was decreased, compared with that in the control cats. At 48 hours, a decrease in the fluorescein concentration was also apparent in the eye subjected to paracentesis in the cats receiving meloxicam, compared with that in the control cats. There was no evidence of treatment effects for acetylsalicylic acid or prednisone. There was no evidence of treatment effects in eyes not subjected to paracentesis.
Conclusions and Clinical Relevance—Orally administered prednisolone and meloxicam significantly decreased intraocular inflammation in clinically normal cats with paracentesis-induced BAB breakdown. Oral administration of prednisolone or meloxicam may be an effective treatment for cats with uveitis.
A 9-month-old miniature Hereford heifer was evaluated for a mass on the right inferior eyelid that had progressed in size over 3 months.
Physical examination revealed a firm, ulcerated, pedunculated mass on the right inferior eyelid that extended from the medial quarter to beyond the lateral canthus of the eye. The base of the mass measured 7.4 × 6.7 cm, and the dorsal margin of the base of the mass was approximately 3 mm ventral to the inferior eyelid margin. Histologic evaluation of incisional biopsy specimens from the mass was consistent with fibrosarcoma.
TREATMENT AND OUTCOME
The mass was surgically resected with care taken to preserve the eyelid margin. The resulting 10 × 8.5-cm surgical wound was treated with adjunct CO2 laser therapy and closed by primary closure at its medial and central aspects and placement of a 4.6 × 2.6-cm lyophilized equine amnion multilayer graft and 2 sheets of 4-ply porcine small intestinal submucosa at its lateral aspect. The grafts were kept moist by alternating topical antimicrobial and artificial tear ointments for 3 weeks. The wound healed without complications, resulting in a functional and aesthetically pleasing outcome despite the development of moderate ectropion at the lateral aspect of the inferior eyelid.
Results suggested that a combination of extracellular matrix scaffolds may be an alternative to extensive skin flaps for management of large dermal wounds, particularly wounds resulting from blepharoplasty where preservation of an eyelid margin is desired.
Objective—To investigate long-term outcomes and owner-perceived quality of life associated with sudden acquired retinal degeneration syndrome (SARDS) in dogs.
Animals—100 dogs with SARDS examined at 5 academic veterinary institutions from 2005 to 2010.
Procedures—The diagnosis was based on documented acute vision loss, normal results of ophthalmic examinations, and evaluation of extinguished bright-flash electroretinograms. Primary owners of affected dogs completed a questionnaire addressing outcome measures including vision, systemic signs, and perceived quality of life for their dogs.
Results—Age at diagnosis was significantly correlated with positive outcome measures; dogs in which SARDS was diagnosed at a younger age were more likely to have alleged partial vision and higher owner-perceived quality of life. Polyphagia was the only associated systemic sign found to increase in severity over time. Medical treatment was attempted in 22% of dogs; visual improvement was not detected in any. Thirty-seven percent of respondents reported an improved relationship with their dog after diagnosis, and 95% indicated they would discourage euthanasia of dogs with SARDS.
Conclusions and Clinical Relevance—Blindness and concurrent systemic signs associated with SARDS appeared to persist indefinitely, but only polyphagia increased in severity over time. Most owners believed their pets had good quality of life and would discourage euthanasia of dogs with SARDS.