Combination phacoemulsification and pars plana vitrectomy for retinal reattachment surgery in the Siberian Husky breed.

OBJECTIVE: To report the success rate and complications of combined phacoemulsification and pars plana vitrectomy (PPV) for treatment of cataracts and retinal detachment in the Siberian Husky breed. ANIMALS STUDIED: Client-owned Siberian Husky dogs that underwent combined phacoemulsification and PPV at two veterinary referral centers. PROCEDURE: Retrospective study of 16 Siberian Husky dogs that underwent combined phacoemulsification and PPV with a minimum 3-month postoperative follow-up. Signalment and preoperative ophthalmic examination findings, intraoperative findings, and postoperative visual status and complications were recorded. Functional success was defined as the maintenance or restoration of vision. RESULTS: Seventeen eyes of 16 dogs were evaluated. Immediate postoperative anatomic success was achieved in all 17 eyes (100%), with functional success through the last known follow-up examination achieved in 88.2% of operated eyes (15/17). The most common postoperative complication was silicone oil migration into the anterior chamber (AC-SiO migration), occurring in 47.1% of eyes (8/17), followed by corneal endothelial decompensation and glaucoma each occurring in 17.6% of eyes (3/17). CONCLUSIONS: Combined phacoemulsification and PPV is a viable option in Siberian Husky dogs with cataracts and preoperative retinal detachment. Visual success was achieved in 88.2% of eyes, with the most common postoperative complication being AC-SiO migration.

Intraoperative findings and postoperative results associated with cataract surgery performed after retinal reattachment surgery in dogs-36 cases (41 eyes).

OBJECTIVE: To report intraoperative findings and complications associated with cataract surgery performed after retinal reattachment surgery (RR) via pars plana vitrectomy (PPV) using perfluoro-n-octane (PFO), laser retinopexy, and silicone oil tamponade in dogs. ANIMALS STUDIED: Retrospective record review of dogs that underwent post-RR cataract surgery. Signalment, time between RR and cataract surgery, type of lens extraction, postoperative visual status, and intra- and postoperative complications were recorded. Cataract formation or progression after RR was categorized as early (≤12 months) or late (>12 months). RESULTS: A total of 36 dogs (41 eyes) were included. Average time between RR and cataract surgery was 665 days (median: 546). Early postoperative incidence of cataracts occurred in 19 eyes (46.3%). Types of lens extraction included phacoemulsification with intraocular lens (86.1%, 31/36 dogs), phacoemulsification alone (11.1%, 4/36 dogs), and intracapsular lens extraction (2.8%, 1/36 dogs). Visual improvement occurred in 95.1% of eyes (39/41) immediately postoperatively. Long term, 93.9% of eyes (31/33) maintained vision at 1 month, 85.2% of eyes (23/27) at 3 months, 77.3% of eyes (17/22) at 6 months, and 60% (12/20) at 12 months postoperatively. The most common postoperative complications were glaucoma (29.3%, 12/41 eyes), corneal ulceration (24.4%, 10/36 eyes), fibrin formation (21.9%, 9/41 eyes), and silicone oil migration into the anterior chamber (19.5%, 8/41 eyes). CONCLUSION: Post-RR cataract surgery should be considered in dogs with vision loss from cataracts after RR. In most eyes, vision was maintained up to 1 year postoperatively.

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.

The effects of topical aqueous sirolimus on tear production in normal dogs and dogs with refractory dry eye.

PURPOSE: To evaluate the effect of twice daily aqueous 0.02% sirolimus drops on tear production in normal dogs and dogs with refractory keratoconjunctivitis sicca (KCS). METHODS: Two groups of dogs were studied. Ten normal dogs with no signs of ocular disease were administered topical 0.02% sirolimus ophthalmic solution in right eye, and a vehicle control in the left eye twice daily for 4 weeks. Complete ophthalmic examinations, including Schirmer tear test were performed weekly. Eighteen dogs with refractory KCS were randomly assigned to receive 0.02% sirolumus ophthalmic solution or 0.02% tacrolimus ophthalmic solution twice daily. Complete ophthalmic examinations were was performed at 2 and 6 weeks following treatment. RESULTS: Tear production in the sirolimus-treated eyes of normal dogs was greater when compared to vehicle controls with a mean difference over all time points of 3.46 mm (95% CI 1.17, 5.75; P = 0.006). After 4 weeks of treatment, the mean difference was 5 mm (95% CI 1.95, 8.05; P = 0.002). In dogs with refractory dry eye, 37.5% of eyes treated with sirolimus exhibited increased tear production >4 mm/min after 6 weeks of treatment, compared to 20% of eyes receiving tacrolimus (P = 0.433). One normal dog experienced topical irritation to both sirolimus and vehicle-treatment. Side effects were not reported in any treated eyes with chronic KCS. CONCLUSION: Topical 0.02% sirolimus might be an alternative treatment for canine patients with keratoconjunctivits sicca. The drug appears safe when applied topically in an aqueous suspension for up to 6 weeks. While initial results are promising, further studies are warranted.

Comparison of topically applied flurbiprofen or bromfenac ophthalmic solution on post-operative ocular hypertension in canine patients following cataract surgery.

OBJECTIVE: To compare the prevalence and kinetics of ocular hypertension after routine cataract extraction when using a predominately COX-2 inhibitor (bromfenac) versus a predominately COX-1 inhibitor (flurbiprofen) in combination with a topical corticosteroid. PROCEDURES: Patients undergoing unilateral or bilateral cataract surgery were randomly assigned to receive flurbiprofen or bromfenac at the day of surgery and continued for 6 weeks postoperatively, along with topical neo poly dexamethasone. No systemic nonsteroidal anti-inflammatory medications were administered before or after surgery. Intraocular pressure was monitored pre and postoperatively. When an IOP of >25 mmHg was detected, therapeutic intervention was performed. RESULTS: Eyes in both treatment groups showed a similar IOP profile with the highest mean IOP occurring two hours postsurgery and slowly declining during the next 6 weeks. However, eyes receiving bromfenac had a higher mean IOP at 2 h post-op (22.1 mmHg) than eyes receiving flurbiprofen (18.8 mmHg) and a slower decrease in IOP in the weeks after surgery. Over the course of the study, a higher percentage of eyes receiving bromfenac had therapy discontinued over concerns of elevated IOP compared to eyes receiving flurbiprofen (bromfenac 23.1% and flurbiprofen 9.8%). On average, the risk of having elevated intraocular pressure with bromfenac is 1.04 times higher than with flurbiprofen. CONCLUSION: Elevated postoperative IOP was observed in both treatment groups; however, bromfenac-treated eyes were more likely to require intervention for elevated IOP.

Preoperative findings and visual outcome associated with retinal reattachment surgery in dogs: 217 cases (275 eyes).

OBJECTIVE: Report the correlation of pre-operative findings with visual outcome in dogs undergoing retinal reattachment surgery for giant retinal tears. PROCEDURES: Retrospective analysis of dogs that underwent pars plana vitrectomy (PPV) with silicone oil (SiO) tamponade and endolaser retinopexy at one institution. Recorded parameters included signalment, etiology, and duration of retinal detachment, observable retinal tissue architecture, visual reflexes, lens status, presurgical aqueous flare, visual status postoperatively, and complications. RESULTS: Two hundred and seventeen patients (275 eyes) were included. Common etiologies of detachment were primary vitreoretinal disease (50.5%), lens surgery (35.3%), and hypermature cataracts (6.2%). Immediate postoperative anatomic success was noted in 98% of operated eyes. Maintenance or return of vision was noted in 74.2% of patients (72% of eyes) through the last known follow-up, with return of vision on average 18.5 days postoperatively. In those eyes that regained vision, 71.7% had retained vision at the last known recheck examination, with an average follow-up time of 550 days. Pre-operative findings correlated with postoperative vision included presence of a dazzle reflex, presence of a menace response, and retinal tissue architecture. The most common complications included migration of SiO into the anterior chamber (49.4%), corneal ulceration (25.7%), glaucoma (25.7%), and cataract formation (24.5%). CONCLUSION: Giant retinal tears in dogs can be successfully managed via PPV with SiO tamponade and endolaser retinopexy. Vision was maintained in the majority of cases with long-term follow-up. Patient history and thorough ophthalmic examination with attention to retinal tissue architecture are important in assessing surgical candidacy.

Diode laser ablation of progressive pigmented iris lesions in 317 cats (356 eyes) appears overall safe and effective in decreasing progression of iris pigmentation.

OBJECTIVE: To describe a novel scoring system of feline pigmented iris lesions prior to utilization of diode laser ablation of progressive pigmented iris lesions and to retrospectively evaluate short- and long-term patient outcomes following transcorneal diode laser ablation. ANIMALS: 317 client-owned cats (356 eyes) were included. CLINICAL PRESENTATION: Records of cats undergoing diode laser ablation from January 2000 to December 2018 were retrospectively reviewed. A novel clinical grading system to describe severity of feline iris hyperpigmentation was developed. Recorded parameters included signalment, operated-upon eye, presurgical iris pigmentation score, intraocular pressure, visual status, postoperative complications, repeat laser surgery, patient status at last follow-up, time to death, and presumptive or known cause of death. RESULTS: Complications included corneal ulceration (25/356 [7%]), glaucoma (18/356 [5%]), uveitis (4/356 [1.1%]), and corneal edema (3/356 [0.8%]). Enucleation was performed in 12 eyes due to blindness and secondary glaucoma. Repeat laser due to continued progression of pigment was performed in 18.5% of eyes. Two study patients were euthanized due to presumptive metastatic disease. Of the 250 cats for whom confirmation was available via phone call or medical records, 240 (96%) were alive at 1 year. CLINICAL RELEVANCE: Diode laser ablation appears safe overall and may be effective in decreasing progression of feline iris pigmentation. Complication risks appear minimal.

Comparison of capsular opacification and refractive status after placement of three different intraocular lens implants following phacoemulsification and aspiration of cataracts in dogs.

OBJECTIVE: To evaluate the effect of lens design and biomaterial on formation of posterior capsular opacification (PCO) and refractive correction. Animals studied Sixty dogs undergoing bilateral phacoemulsification for mature or diabetic cataracts. PROCEDURES: One randomly selected eye received a rounded edge 41D polymethyl-methacrylate (PMMA) intraocular replacement lens (IOL) and the contralateral eye received either a squared edge 41D hydrophilic acrylic IOL (n = 35) or a squared edge 40D hydrophobic acrylic IOL (n = 25). At the (mean = 79 day) reexamination period, PCO was graded using direct slit-lamp observation and by masked observer evaluation of digital images of the IOLs. Streak retinoscopy and B-mode ultrasound were performed at this period. RESULTS: The PCO score via direct slit-lamp was significantly lower for the hydrophilic acrylic IOL when compared to the PMMA IOL. Masked observer evaluation of digital images revealed that the acrylic IOLs had lower but generally not statistically significant PCO scores than the PMMA IOLs. Streak retinoscopy showed that the PMMA IOL was significantly closer to emmetropia (+0.44 D) when compared to either the hydrophilic acrylic (+0.96 D) or the hydrophobic acrylic (+1.2 D) IOLs. B-mode ultrasonography revealed the center of the hydrophilic acrylic IOL is 0.31 mm closer to the retina and the center of the hydrophobic acrylic IOL is 0.63 mm further from the retina when compared to the center of the PMMA to retina distance. CONCLUSIONS: Square edged foldable acrylic IOLs show a predisposition towards generating slightly less PCO than round edged PMMA IOLs in the early postoperative period, however, both acrylic IOLs had greater persistent hyperopia than the PMMA IOLs.

Effect of topical 0.02% tacrolimus aqueous suspension on tear production in dogs with keratoconjunctivitis sicca.

OBJECTIVE: To investigate the effect of 0.02% tacrolimus in aqueous suspension on tear production in dogs with keratoconjunctivitis sicca (KCS). Animals studied One hundred five dogs diagnosed with KCS [Schirmer tear test (STT) < or = 10 mm/min and clinical signs of dry eye]. Eyes with marginally decreased STT (11 < or = 15 mm/min) and clinical signs of dry eye were also evaluated. PROCEDURE: The investigation was conducted in two parts: an initial efficacy study and a subsequent double blinded controlled study. In the efficacy study, the effect of topical tacrolimus (formerly FK-506) on tear production in dogs with primary KCS was evaluated. Dogs were divided into four categories: 1) 59 eyes (38 dogs) naïve to tear stimulation therapy with initial STT < or = 10 mm/min; 2) 28 eyes (21 dogs) naïve to tear stimulation therapy with initial STT 11 < or = 15 mm/min; 3) 30 eyes (15 dogs) maintained successfully on CsA therapy; 4) 47 eyes (24 dogs) unresponsive to CsA therapy. STT and clinical signs were evaluated prior to and after 6 to 8 weeks of twice daily tacrolimus administration. Tacrolimus was substituted for CsA therapy in categories 3 and 4. The controlled study compared the effect of topical tacrolimus in aqueous suspension to administration of the aqueous carrier alone on tear production in 20 dogs with primary KCS. RESULTS: In the efficacy study, STT increased by 5 mm/min in 84.7%, 25.0%, 26.7% and 51.1% of eyes in categories 1, 2, 3 and 4 respectively after tacrolimus administration. Eighty-three percent of eyes with extremely low initial STT (< or = 2 mm/min), increased 5 mm/min after tacrolimus. In the controlled study, STT increased by 5 mm/min in 7/10 dogs (14/20 eyes) that received tacrolimus and in none of the 10 dogs that received aqueous carrier alone. Dogs receiving just the aqueous carrier were subsequently treated with tacrolimus, and STT increased 5 mm/min in 9 dogs (18/20 eyes) after administration. CONCLUSIONS: Twice daily administration of 0.02% tacrolimus in aqueous suspension effectively increased tear production in dogs with KCS. Topical tacrolimus is a promising alternative to topical CsA for treatment of KCS and may be beneficial in patients with less than optimal response to topical CsA.