Prophylactic efficacy of intravenous paracetamol administration to reduce the incidence of post-operative ocular hypertension in dogs undergoing phacoemulsification: A pilot study.

PURPOSE: To determine whether intravenous administration of paracetamol can prevent postoperative ocular hypertension (POH) in dogs following routine phacoemulsification. METHODS: Diabetic and non-diabetic patients (total 54 dogs) undergoing unilateral or bilateral phacoemulsification were recruited to this placebo-controlled, prospective study. The control group received 1 ml/kg saline via intravenous infusion while the treatment group received 10 mg/kg paracetamol via intravenous infusion. Infusions were administered 30 min prior to surgery and repeated 12 h following initial administration. All patients received topical latanoprost at the conclusion of surgery. Intraocular pressure (IOP) was measured before premedication (baseline), and at 1 h, 3 h, 5 h and 18 h following extubation. POH was defined as an IOP above 25 mmHg (POH25). In addition, the number of patients with an IOP exceeding 20 mmHg was analyzed (POH20). RESULTS: POH20 occurred in 33 of 54 animals (61.1%), including 19 of 25 animals (76.0%) in the control group and 14 of 29 animals (55.2%) in the treatment group. POH25 occurred in 23 of 44 animals (52.3%), including 13 of 25 animals (52.0%) in the control group and 10 of 29 animals (34.5%) in the treatment group. Paracetamol administration showed a significant positive effect on reducing the incidence of POH20 (p = .048), but not POH25 (p = .221). CONCLUSIONS: When comparing groups, treatment with paracetamol showed a statistically significant reduction in the incidence of POH20, although no differences were observed in the incidence of POH25 between groups. Further studies are warranted to explore whether alternative drug regimes or routes of administration can provide enhanced efficacy in the prevention of POH25.

Urrets-Zavalia syndrome following cataract surgery in dogs: A case series.

Background: In human medicine, Urrets-Zavalia syndrome (UZS) is a well-recognized but uncommon postoperative complication characterized by a fixed dilated pupil, accompanied by iris atrophy and glaucoma. Although it was originally reported in 1963 after penetrating keratoplasty surgery for keratoconus, it has been associated with various ophthalmic procedures such as cataract surgery. The condition has not been previously published in the veterinary literature. Case Description: Three client-owned diabetic dogs that developed UZS´s triad after cataract surgery are described. Despite uneventful phacoemulsification in the six eyes, five developed moderate-to-severe postoperative ocular hypertension. Although intraocular pressure (IOP) spikes were initially controlled, fixed dilated pupils accompanied by iris atrophy and chronic ocular hypertension were seen in the five affected eyes. Aggressive medical and surgical management maintained vision in three of those eyes. In one eye, uncontrolled IOP led to blindness. Conclusion: This is the first published description of UZS in dogs, occurring after phacoemulsification. Although no exact, demonstrable causative element could be determined, we believe that should be considered a triggering condition for this syndrome, as it directly affects the ocular blood flow autoregulation and intrinsic uveal tissue integrity. Until the contrary is proved, diabetes mellitus might be considered as a risk factor for developing this syndrome after cataract surgery in dogs.

Effect of Topically Applied 0.5% Apraclonidine Versus 0.5% Timolol Maleate on Intraocular Pressure of Healthy Horses.

This study aims to assess the effect of topical 0.5% apraclonidine on Intraocular pressure (IOP) in horses and compare the effects of timolol maleate 0.5% with 0.5% apraclonidine in the equine eye. Twenty healthy female thoroughbred horses were used. Horses were divided into two groups. Ten horses received single dose of 0.2 mL of 0.5% apraclonidine in one randomly selected eye and the contralateral eye received single dose of 0.2 mL of artificial tears. In the second group, 10 horses received single dose of 0.2 mL of 0.5% timolol maleate in one eye and the opposite eye received single dose of placebo (0.2 mL of artificial tears). Intraocular pressure was measured using rebound tonometer at the baseline and 30, 60, 120, 240, 360 minutes, and 24 hours after topical ophthalmic drops instillation. Any ocular side effects were recorded at each time point. Mean (SD) baseline IOPs of the treated and placebo eyes were 26.2(3.1) and 23.5(3.4) in apraclonidine group, and 25.7(2.6) and 23.2(3.3) in timolol group. In the apraclonidine group, significant reduction in the mean IOP started after 60 minutes (P= .005) and was still present after 24 hours (P < .001). In timolol group, IOP was reduced in the treated eyes, but this reduction was only significant in the treated eyes at T24h (P= .03). The highest reduction in IOP in timolol group was observed at T360 (21.0(2.2); 14.7%). Mean IOP was decreased prominently by apraclonidine compared to timolol in treated eyes. In conclusion, single dose of topical 0.5% apraclonidine reduced IOP significantly among normal horses in the present study. Further investigations are necessary for evaluating efficacy and safety of apraclonidine in horses.

Effects of 0.0015% preservative-free tafluprost on the equine eye.

OBJECTIVE: The purpose of this study was to determine the effects and potential side effects of topical preservative-free (PF) tafluprost 0.0015% in ophthalmologically normal horses. ANIMALS: Five adult grade horses. PROCEDURES: One of the eyes of each horse was randomly chosen as the "treatment" eye, and consequently, the contralateral eye served as the "control." A single dose of PF tafluprost 0.0015% (0.2 mL) was instilled in the treated eye of each horse. Intraocular pressure (IOP), Schirmer's tear test (STT) levels of each eye, and an ophthalmic examination were performed at T0 (baseline), T30, T120, T24 h, and T48 h. RESULTS: The mean IOP values of the treated eyes at baseline (T0), T30, T120, T24 h, and T48 h were 25.4 ± 4.8 mmHg, 21.2 ± 1.92 mmHg, 15.20 ± 2.48 mmHg, 18.40 ± 1.51 mmHg, and 24.60 ± 1.94 mmHg, respectively. Significant differences were observed between the mean baseline IOP level and the T120 and T24 h time points (p = .001 and p = .009). The mean STT levels at each time point showed insignificant fluctuations during the study (p = .140). Adverse effects such as chemosis and episcleral injection were observed 30 min after the instillation of tafluprost 0.0015% (T30). Blepharospasm and conjunctival hyperemia were observed 120 min (T120) after the administration of the medication. CONCLUSION AND CLINICAL RELEVANCE: Tafluprost 0.0015% showed potential in reducing IOP, but due to its local side effects, it is not a good candidate for management of glaucoma in horses. Tafluprost did not notably affect STT.

Safety and efficacy of topically administered netarsudil-latanoprost fixed dose combination (FDC; Rocklatan™) in normal and glaucomatous dogs with ADAMTS10-open-angle glaucoma (ADAMTS10-OAG).

OBJECTIVE: The aim of the study was to evaluate safety and efficacy of topically administered 0.02% netarsudil-0.005% latanoprost fixed-dose combination (FDC) (Rocklatan™; Aerie Pharmaceutical) in normal and glaucomatous dogs with ADAMTS10-open-angle glaucoma (ADAMTS10-OAG). ANIMALS STUDIED: Five normal and five glaucomatous beagle dogs with ADAMTS10-OAG were the study animals. PROCEDURES: In each dog, left (OS) or right eye (OD) was randomly selected for netarsudil-latanoprost FDC treatment. Contralateral eyes served as latanoprost-treated controls. The study was divided into four consecutive study periods: following a 4-day baseline period, two sequential 8-day study periods followed with once daily (q24h) and twice daily (q12h) treatments and ending with a washout period. Efficacy was measured by diurnal intraocular pressure (IOP) and pupil diameter. Safety was assessed by routine ophthalmic examination, gonioscopy, and pachymetry. Differences in least square means of quantitative outcome measures were compared between FDC and latanoprost treatments by using the linear Gaussian model. RESULTS: Baseline IOPs were 13.6 ± 0.7 mmHg (mean ± SEM) in normal and 28.3 ± 1.4 mmHg in OAG-affected dogs. There was a significant decrease in mean diurnal IOP following FDC administration in both normal (q24h: -2.1 mmHg; q12h: -4.1 mmHg) and glaucomatous dogs (q24h: -14.2 mmHg; q12h: -17.7 mmHg; p < .0001). There was no significant difference in the treatment effect when comparing FDC to latanoprost. Both FDC and latanoprost administration resulted in similarly significant pupil constriction (p < .0001). The FDC administration was well-tolerated but resulted in conjunctival hyperemia. CONCLUSIONS: Once or twice daily administration of netarsudil-latanoprost FDC (Rocklatan™) and latanoprost was equally effective in lowering IOP in normal and OAG-affected dogs. There was no netarsudil-related added treatment effect.

Gonioscopic iridocorneal angle morphology and incidence of postoperative ocular hypertension and glaucoma in dogs following cataract surgery.

PURPOSE: To investigate the relationship between gonioscopic iridocorneal angle (ICA) morphology and the incidence of postoperative ocular hypertension (POH) and postoperative glaucoma in dogs undergoing cataract surgery. ANIMALS STUDIED: Retrospective analysis of 138 eyes of 78 canine patients who underwent phacoemulsification at North Carolina State University from December 1, 2015 through April 30, 2017. METHODS: Medical records of all phacoemulsification patients with preoperative RetCam gonioscopic images were reviewed for preoperative, intraoperative, and postoperative variables. Gonioscopic angle indices were calculated using a novel (ZibWest) angle grading system, and these indices were analyzed for outcome-related significance. RESULTS: Increased surgeon experience was associated with increased probability of POH and vision loss. Higher average ZibWest Angle indices (ie, more open angles with less pectinate ligament dysplasia/ abnormality) were associated with a significantly decreased probability of medically unresponsive glaucoma. Increased patient age was significantly associated with an increased probability of both postoperative glaucoma and vision loss. Female dogs were significantly more likely to experience postoperative glaucoma compared to male dogs. Increased surgery time was significantly associated with increased probability of vision loss. CONCLUSIONS: The ZibWest angle index may predict increased risk for developing medically unresponsive glaucoma with cataract surgery. Female sex, and increased patient age, surgical time, and surgeon experience were associated with increased postoperative morbidity.

Effect of intracameral epinephrine on heart rate, post-operative ocular hypertension, and long-term outcome following canine phacoemulsification.

PURPOSE: To determine the effect of intrsacameral epinephrine on heart rate, blood pressure, post-operative ocular hypertension, and complications following canine phacoemulsification. PROCEDURES: A prospective, double-blinded, controlled trial was carried out using 30 client-owned dogs undergoing phacoemulsification. Eyes were randomly assigned to a treatment group receiving intracameral (IC) epinephrine (n = 31) or balanced salt solution (n = 25) at the beginning of surgery. Heart rate, post-operative intraocular pressures, and outcomes were compared between treatment groups. RESULTS: No adverse reactions to IC epinephrine or saline were observed. Post-operative ocular hypertension developed at the 2 and/or 4 hours pressure reading in 35% and 46% in the epinephrine and saline groups, respectively (P = .5072). There were 9.7% and 23.1% eyes that developed complications in the IC epinephrine and saline groups, respectively (P = .2373). CONCLUSIONS: Intracameral epinephrine is safe to use, and non-significant decreases in post-operative ocular hypertension and long-term complications were observed.

Treatment of canine postoperative ocular hypertension with combined latanoprost 0.005% and atropine 1% ophthalmic solutions.

OBJECTIVE: To compare the effects of topical 0.005% latanoprost (L) vs combined 0.005% latanoprost and 1% atropine (LA) on control of postoperative ocular hypertension (POH), development of posterior synechiae formation, pupil size, and blindness after phacoemulsification surgery in dogs. ANIMAL STUDIED: Dogs with postoperative ocular hypertension were included in the study: L-group, latanoprost (eight dogs, 14 eyes) and LA-group, latanoprost and atropine (nine dogs, 15 eyes). PROCEDURES: Complete ophthalmic examinations including tonometry were performed at 1, 7, and 21 days following phacoemulsification. RESULTS: No significant differences were found between the measured intraocular pressure (IOP) at days 1 and 7 postphacoemulsification surgery in the L-group and the LA-group (P = 0.26 [14.12 ± 1.76 mmHg vs 16.96 ± 1.68 mmHg] and P = 0.71 [15.45 ± 1.43 mmHg vs 16.20 ± 1.36 mmHg], respectively). No significant differences were found between pupil sizes at day 7 for the two groups (P = 0.25 [13.83% vs 24.77%]). No significant differences were found between odds of posterior synechiae formation at day 21 (P = 0.92) with a probability ± SE for L-group vs LA-group at 0.27 ± 0.14 vs 0.25 ± 0.13. No significant differences were found in odds of postoperative blindness between groups (P = 0.58) with a probability ± SE of 0.21 ± 0.11 vs 0.13 ± 0.09, respectively for L and LA. CONCLUSIONS: Combined topical latanoprost and atropine in dogs maintains normal postoperative IOPs but does not seem to cause increased mydriasis compared to latanoprost alone.

Effect of immediate postoperative intracameral tissue plasminogen activator (tPA) on anterior chamber fibrin formation in dogs undergoing phacoemulsification.

OBJECTIVE: To evaluate the postoperative effect of intracameral tPA (alteplase; Activase®, Genentech, San Francisco, CA), administered at immediate conclusion of phacoemulsification, on anterior chamber fibrin formation in dogs. PROCEDURES: Forty-one dogs (82 eyes) undergoing bilateral phacoemulsification received 25 µg/0.1 mL intracameral tPA in one eye and 0.1 mL unmedicated aqueous vehicle in the contralateral eye immediately after corneal incision closure. Intraocular pressure (IOP) was measured, and severity of anterior chamber fibrin formation, aqueous flare, pigment precipitates on the intraocular lens (IOL) implant, posterior capsular opacification (PCO), and corneal edema were graded at approximately 1 week, 2-3 weeks, 4-6 weeks, 8-12 weeks, and greater than 3 months postoperatively. RESULTS: Anterior chamber fibrin developed postoperatively in 68.3% of dogs (28/41) and 50% of eyes (41/82). In tPA-treated eyes, 53.7% (22/41) developed fibrin compared to 46.3% of control eyes (19/41). Some degree of postoperative ocular hypertension (POH) occurred in 53.7% of dogs (22/41) and 36.5% of eyes (30/82). In tPA-treated eyes, 34.1% (14/41) experienced POH compared to 39% of control eyes (16/41). Additional intracameral tPA injection was later required in 29.3% of both tPA-treated (12/41) and control eyes (12/41). CONCLUSIONS: Administration of intracameral tPA at immediate conclusion of canine phacoemulsification had no clinically observable effect on anterior chamber fibrin incidence at any time point. tPA-treated eyes showed no prophylaxis against POH or secondary glaucoma compared to control eyes and received late postoperative tPA injections at the same frequency as control eyes.

Effect of prophylactic topical hypotensive medications in reducing the incidence of postoperative ocular hypertension after phacoemulsification in dogs.

OBJECTIVE: To determine whether topical hypotensive medications prevent postoperative ocular hypertension (POH) after phacoemulsification. ANIMALS STUDIED: 52 client-owned dogs (88 eyes). PROCEDURES: Diabetic and nondiabetic dogs having undergone phacoemulsification were included in this retrospective study. The control group received no ocular hypotensive medications. The treatment groups received latanoprost, dorzolamide, or dorzolamide/timolol, beginning immediately after surgery, for 2-week duration. IOPs were obtained at initial examination followed by 4 h, 24 h, 7 days, and 14 days postoperatively. POH was defined as an IOP above 20 mmHg (POH20) or 25 mmHg (POH25). RESULTS: POH20 occurred in 33 of 87 eyes (37.93%), including 11 of 21 eyes (52.38%) in the control group, three of 23 eyes (13.04%) in the latanoprost group, eight of 15 eyes (53.33%) in the dorzolamide group, and 11 of 28 eyes (39.29%) in the dorzolamide/timolol group. Active treatment groups were compared to the control group, and the overall group effect was not significant (P = 0.11). POH25 occurred in 22 of 86 eyes (25.58%), including seven of 21 eyes (33.33%) in the control group, two of 23 eyes (8.70%) in the latanoprost group, five of 15 eyes (33.33%) in the dorzolamide group, and eight of 27 eyes (29.63%) in the dorzolamide/timolol group. Active treatment groups were compared to the control group, and the overall group effect was not significant (P = 0.31). Intraoperative use of intracameral tissue plasminogen activator significantly decreased the chances of POH25 (P = 0.0063). CONCLUSIONS AND CLINICAL RELEVANCE: The latanoprost group had a substantially lower percentage of POH 20 and POH25 compared to the control and other active treatment groups, although statistical significance was not achieved. Intraoperative intracameral tissue plasminogen activator decreased the incidence of POH25.

Design of an intraocular pressure curve protocol for use in dogs.

OBJECTIVES: To establish an intraocular pressure curve protocol that is safe for corneal health and detects harmful elevations of intraocular pressure outside normal clinic hours. To determine inter-user variability and if repeated measurements affect intraocular pressures. MATERIALS AND METHODS: Intraocular pressures were measured in dogs with glaucoma using three protocols: Protocol 1 used applanation tonometry every 2 hours over a 24-hour period; Protocols 2 and 3 used applanation or rebound tonometry, respectively, and measured intraocular pressures every 3 hours over a 30-hour period. A total of 60 additional intraocular pressure curves from dogs with glaucoma and 20 from healthy dogs were then analysed for inter-user variability. RESULTS: A total of 128 intraocular pressure curves were determined in 30 dogs. Protocol 1 resulted in one ulcer in five pressure curves, Protocol 2 in one ulcer in 62 pressure curves and Protocol 3 in no ulcers in 61 pressure curves. Elevated intraocular pressures were detected on 61 occasions, of which 26 developed outside normal clinic hours. A total of 61 additional intraocular pressure curves revealed that repeated measurements had no effect on intraocular pressure. CLINICAL SIGNIFICANCE: Protocol 3, using rebound tonometry every 3 hours for 30 hours is safe corneal health and identified elevated intraocular pressures outside normal clinic hours in 12 of 30 (40%) patients that single intraocular pressure measurement during consultation hours would not have identified. Intraocular pressure curves may be recommended for clinical practice and glaucoma studies.

Mathematical Discrepancies of the Tono-Pen Applanation Tonometer.

PURPOSE OF THE STUDY: The purpose of the study was to determine if Tono-Pen tonometers use simple average and coefficient of variation (CV) algorithms to calculate intraocular pressure (IOP). MATERIAL AND METHODS: IOPs were measured as part of routine ocular examination in 152 client-owned dogs. Using 11 Tono-Pen's, a total of 778 averaged readings were collected. Individual IOP readings, and average IOP and CV displayed by the instrument, were recorded. Average IOP and CV were then manually calculated from individual readings and compared with those displayed by the instrument. RESULTS: The mean absolute difference between the calculated and displayed average IOP was 1.37±2.01 mm Hg (P<0.001). In 6% of cases, the calculated average IOP was 5 to 15 mm Hg different from the displayed average IOP. The difference between the displayed and calculated average IOP was significantly higher in hypertensive eyes with displayed IOP≥25 mm Hg. Calculated CV was equal to, lower than, or greater than displayed CV in 28.6%, 1.5%, and 69.7% of cases, respectively. In 17.6% of cases, calculated CV was >20%, but displayed CV was <5%. Receiver operating characteristic analysis could not correlate number of individual IOP readings with magnitude of difference in average IOP. CONCLUSIONS: Calculated average IOP and CV differ significantly from values displayed by the instrument, especially at higher IOPs. A difference of ≥5 mm Hg between calculated and displayed average IOP seen in 6% of cases may impact clinical judgement. Displayed CV<5% does not correlate with accurate IOP measurement based on individual results.

Effects of perioperative topical dorzolamide hydrochloride-timolol maleate administration on incidence and severity of postoperative ocular hypertension in dogs undergoing cataract extraction by phacoemulsification.

OBJECTIVE To assess the effects of topically applied 2% dorzolamide hydrochloride-0.5% timolol maleate ophthalmic solution (DHTM) on incidence and severity of postoperative ocular hypertension (POH; ie, intraocular pressure [IOP] > 25 mm Hg) in dogs undergoing cataract extraction by phacoemulsification. DESIGN Randomized, masked, controlled study. ANIMALS 103 dogs (180 eyes). PROCEDURES Pertinent history, signalment, and ophthalmic examination findings were recorded. Dogs received 1 drop of DHTM or sham treatment solution (sterile, buffered, isotonic eye drops) in both eyes 14 hours and 2 hours before anesthetic induction and at the time of corneal incision closure (ie, end of surgery); IOPs were assessed by rebound tonometry 2, 4, 6, and 8 hours after surgery and between 7:30 and 8:00 am on the following day. Dogs with IOPs of 26 to 45 mm Hg received 1 drop of 0.005% latanoprost solution topically; the surgeon's treatment of choice was used for dogs with IOPs > 45 mm Hg. Incidence of POH and postoperative IOPs were compared between treatment groups. RESULTS DHTM treatment resulted in significantly lower incidence of POH than did sham treatment at the level of the dog (18/53 [34%] vs 31/50 [62%]) and the eye (24/94 [26%] vs 42/86 [48%]). Mean IOP did not differ between groups at the time of POH detection. The DHTM-treated eyes that developed POH were significantly more likely to have a 1-hour follow-up IOP < 25 mm Hg after latanoprost administration than were sham-treated eyes (19/25 [76%] vs 18/35 [51%]; OR, 3.87). CONCLUSIONS AND CLINICAL RELEVANCE Multidose perioperative administration of DHTM in dogs undergoing phacoemulsification reduced the incidence of POH and improved responsiveness of POH to latanoprost treatment.

Hypokalemia and suspected renal tubular acidosis associated with topical carbonic anhydrase inhibitor therapy in a cat.

OBJECTIVE: To describe the occurrence of hypokalemia, metabolic acidosis, and suspected renal tubular acidosis associated with the administration of topical ophthalmic carbonic anhydrase inhibitor (CAI) in a cat. CASE SUMMARY: A 2-year-old, 5.3 kg, male, castrated, domestic short-haired cat developed hyporexia 6 weeks after starting topical ophthalmic dorzolamide 2% therapy for treatment of ocular hypertension. Two weeks later, the cat was evaluated for severe weakness, cervical ventroflexion, and anorexia. Plasma electrolyte and acid-base measurement revealed hypokalemia (K+ = 2.9 mmol/L; reference interval 3.8-5.4 mmol/L) and metabolic acidosis (plasma HCO3- = 9.8 mmol/L; reference interval 15-23 mmol/L) in the presence of a urine pH of 7.5 (reference interval 6.5-7.5). The pH abnormalities were consistent with a renal tubular acidosis. Clinical and biochemical abnormalities resolved with short-term supportive care, potassium supplementation, and discontinuation of dorzolamide therapy. NEW OR UNIQUE INFORMATION PROVIDED: This is the first report of hypokalemia and metabolic acidosis associated with topical CAI therapy in a cat.

Medical management of acute ocular hypertension in a western screech owl (Megascops kennicottii).

A wild young adult western screech owl (Megascops kennicottii) of unknown sex was presented for evaluation of an abnormal left eye (OS). Ophthalmic examination OS revealed raised intraocular pressure (37 mm Hg; reference interval 7-16 mm Hg), mydriasis, conjunctival and episcleral hyperemia, shallow anterior chamber due to anterior displacement of the lens and iris, rubeosis iridis, and engorgement of the pecten. The intraocular pressure in the right eye (OD) was 11 mm Hg. Multifocal pale, variably translucent, curvilinear to vermiform opacities were observed in the medial and ventral peripheral regions of the retina OD, consistent with focal retinitis. Mannitol (0.46 g/kg IV) was administered over 10 minutes. Forty minutes later, the intraocular pressure was 27 mm Hg OS and 13 mm Hg OD. Dorzolamide (one drop OS q12h), diclofenac (one drop OU q8-12h), and meloxicam (0.5 mg/kg PO q24h) were administered for 3 days. The intraocular pressure OS was within normal limits 1 day (11 mm Hg), 7 days (13 mm Hg), and 4 weeks (14 mm Hg) after this treatment. Complications arising during hospitalization and rehabilitation included superficial corneal ulceration of both eyes presumed secondary to trauma on being caught and superficial damage to a talon. The owl was released after a period of rehabilitation. Characteristic presenting signs as well as response to therapy suggest aqueous misdirection was the cause of ocular hypertension in this owl. To our knowledge, this is the first report of suspected aqueous misdirection and its medical management in a raptor.

IOP change undergoing anesthesia in rhesus macaques (Macaca mulatta) with laser-induced ocular hypertension.

The objective of the study was to examine changes of intraocular pressure (IOP) undergoing anesthesia in Rhesus Macaques (Macaca mulatta) with Laser-induced Ocular Hypertension. Twenty male rhesus macaques (hypertensive glaucoma eye in OD; normal eye in OS) between 6 and 20 years of age were used for the study. The monkeys were anesthetized with ketamine hydrochloride (10 mg/kg intramuscularly) and 1% isoflurane, and then IOP in both eyes was measured by a single investigator using a calibrated Tonopen(TM) applanation tonometer (Mentor, Norwell, MA, U.S.A.). The mean IOP with ketamine anesthesia was 36.70 ± 12.04 (right eye: OD) and 15.88 ± 2.84 (left eye: OS). The mean IOP with isoflurane anesthesia was 19.98 ± 6.67 (right eye: OD) and 15.32 ± 2.15 (left eye: OS). Undergoing isoflurane anesthesia, the IOP of OD was significantly decreased. Conclusively, careful examination of IOP is required to prevent unexpected contraindication on glaucoma patient with isoflurane anesthesia.

Effects of one-week versus one-day preoperative treatment with topical 1% prednisolone acetate in dogs undergoing phacoemulsification.

OBJECTIVE: To compare the effects of 2 preoperative anti-inflammatory regimens on intraocular inflammation following phacoemulsification. DESIGN: Randomized controlled trial ANIMALS: 21 dogs with immature cataracts. PROCEDURES: All dogs had cataract surgery via phacoemulsification, and most received prosthetic intraocular lenses. Dogs were randomly divided into 2 groups. Group A dogs were treated topically with prednisolone acetate for 7 days prior to surgery, whereas prednisolone acetate treatment commenced the evening prior to surgery in group B dogs. Postoperative care was identical for both groups. Blood-aqueous barrier breakdown was quantified by use of anterior chamber fluorophotometry, with fluorescein entry into the anterior chamber measured 2 and 9 days after surgery compared with baseline scans obtained prior to surgery. Ophthalmic examinations were performed before surgery and 1 day, 9 days, 3 weeks, 7 weeks, 3 months, and 6 months after surgery. A subjective inflammation score was established at each examination. Intraocular pressures were measured 4 and 8 hours after surgery and at each follow-up examination. RESULTS: There was no difference in the extent of blood-aqueous barrier disruption between the groups at 2 or 9 days after surgery. Subjective inflammation scores were also similar at most time points. Dogs in group A developed postoperative ocular hypertension at a higher frequency (60%) than did those in group B (18%). CONCLUSIONS AND CLINICAL RELEVANCE: In dogs that underwent cataract surgery via phacoemulsification, a full week of topical prednisolone acetate treatment prior to surgery did not decrease postoperative inflammation, compared with commencement of topical prednisolone acetate treatment the evening prior to surgery, and was associated with a greater incidence of postoperative ocular hypertension.

Evaluation of four drugs for inhibition of paracentesis-induced blood-aqueous humor barrier breakdown in cats.

OBJECTIVE: To compare inhibitory effects of topically applied 1% prednisolone acetate suspension, 0.03% flurbiprofen solution, 0.1% dexamethasone suspension, and 0.1% diclofenac solution on paracentesis-induced blood-aqueous barrier breakdown in cats. ANIMALS: 9 healthy cats. PROCEDURES: Paracentesis of the anterior chamber was performed in both eyes of each cat. One eye of each cat was treated with a topically administered anti-inflammatory medication (1% prednisolone [n = 7 cats], 0.03% flurbiprofen [7], 0.1% dexamethasone [9], or 0.1% diclofenac [8]) immediately following paracentesis and at 6, 10, and 24 hours after paracentesis. The contralateral untreated eye served as the control eye. Each cat had a 6-day washout period between experimental drugs. Breakdown of the blood-aqueous barrier was quantified by use of laser flaremetry. RESULTS: Topical administration of 1% prednisolone significantly reduced aqueous humor flare at 4, 8, and 26 hours after paracentesis. Topical administration of 0.1% diclofenac significantly reduced aqueous humor flare at 8 and 26 hours after paracentesis. Topical administration of 0.1% dexamethasone and 0.03% flurbiprofen did not significantly decrease flare at any time point. There were significant differences in intraocular pressures between NSAID-treated eyes and untreated contralateral eyes. CONCLUSIONS AND CLINICAL RELEVANCE: Topical administration of 1% prednisolone and 0.1% diclofenac significantly reduced intraocular inflammation in cats with paracentesis-induced uveitis. Topical administration of 1% prednisolone or 0.1% diclofenac may be appropriate choices when treating cats with anterior uveitis. Topical administration of diclofenac and flurbiprofen should be used with caution in cats with a history of ocular hypertension.

Effect of three treatment protocols on acute ocular hypertension after phacoemulsification and aspiration of cataracts in dogs.

OBJECTIVE: To compare the effect of topical latanoprost, intracameral carbachol, or no adjunctive medical therapy on the development of acute postoperative hypertension (POH) and inflammation after routine phacoemulsification and aspiration (PA) of cataracts in dogs. DESIGN: Retrospective study. PROCEDURES: Dogs received either one drop of topical 0.005% latanoprost (21 dogs, 39 eyes), an intracameral injection of 0.3 mL of 0.01% carbachol (15 dogs, 30 eyes), or no adjunctive therapy (46 dogs, 90 eyes) immediately following PA of cataract(s). Intraocular pressure (IOP) was measured in all dogs 2 and 4 h after surgery. IOP was measured and aqueous flare assessed at 8 am the day after surgery. RESULTS: Carbachol-treated dogs had significantly higher mean IOP (33.2 +/- SD 20.8 mmHg) 2 h after surgery than dogs receiving no adjunctive therapy (22.0 +/- SD 14.1 mmHg) (P = 0.049). There were no significant differences in IOP among groups at any other time point. There were no significant differences in number of POH episodes between dogs treated with carbachol (47%), latanoprost (29%), or dogs that received no adjunctive therapy (33%). There were no significant differences in mean aqueous flare grade between eyes treated with latanoprost (1.7 +/- SD 0.4) or carbachol (1.4 +/- SD 0.6), and eyes that received no adjunctive therapy (1.7 +/- SD 0.4). CONCLUSIONS: Topical 0.005% latanoprost or intracameral injection of 0.3 mL of 0.01% carbachol after PA in dogs did not reduce POH or increase intraocular inflammation compared to dogs not receiving adjunctive therapy after PA of cataracts.

Presumed primary uveal melanoma with brain extension in a dog.

A 13-year-old, female, mixed, cocker spaniel was examined for a unilateral exophthalmia and protruding mass in episcleral region of the right eye. Mode B ocular ultrasonography revealed a mass extended intraocular from anterior chamber to posterior pole without evidence of extraocular extension. A presumptive diagnosis of melanocytic tumour was made. A complete blood count and chemistry and thoracic radiographs did not show any abnormal changes. The recommended treatment was enucleation, and melanocytic nature of the tumour was confirmed by immunohistochemistry. Three months after surgery, the animal showed a status epilepticus refractory to treatment. Computed tomographic examination of the brain revealed changes compatible with a tumour. Cerebrospinal fluid analysis was normal. Because of the poor clinical prognosis, the owners elected to have the dog euthanased.