Front Page VSPN Message Boards Chat Library Continual Education Search MyVSPN - Coming Soon Help Frequently Asked Questions Send us Feedback! Go to VIN Industry Partners Go to VetQuest Go to Veterinary Partner Go to Y2Spay
 
Menu bar   Go to the VIN.com Portal
 

ABSTRACT OF THE WEEK

Veterinary ophthalmology
Volume 24 Suppl 1 | Issue 0 (March 2021)

Pharmacologic ciliary body ablation for chronic glaucoma in dogs: A retrospective review of 108 eyes from 2013 to 2018.

Vet Ophthalmol. March 2021;24 Suppl 1(0):125-130.
Martha E Julien1, Simone A Schechtmann2, Tammy M Michau3, Anja Welihozkiy4, Terri L Baldwin5, Jessica M Stine6
1 BluePearl Veterinary Partners, Tampa, FL, USA.; 2 BluePearl Veterinary Partners, Tampa, FL, USA.; 3 BluePearl Veterinary Partners, Tampa, FL, USA.; 4 BluePearl Veterinary Partners, Sarasota, FL, USA.; 5 BluePearl Veterinary Partners, Clearwater, FL, USA.; 6 BluePearl Veterinary Partners, Clearwater, FL, USA.
© 2020 American College of Veterinary Ophthalmologists.

Abstract

OBJECTIVE:To evaluate the long-term outcome and efficacy of intravitreal injection of gentamicin and dexamethasone sodium phosphate (IVGD) or triamcinolone in end-stage glaucoma patients and determine pre-procedure prognostic indicators of success and post-operative complications.
PROCEDURE:Medical records were reviewed for 108 dogs (108 eyes) treated with intravitreal gentamicin with or without dexamethasone sodium phosphate or triamcinolone for glaucoma between 2013 and 2018 with 3 months of minimum follow-up. Signalment and clinical findings, including type of glaucoma, pre-procedure intraocular pressure (IOP), chronicity, procedure protocol, and outcome were recorded. Success was defined as an intraocular pressure of ≤25 mm Hg at the time of last re-examination or no ocular hypotensive medications at 3 months or longer post-injection.
RESULTS:The overall success rate for pharmacologic ablation was 95%. The success rate for dogs receiving no ocular hypotensive medications was 86%. Seventy-six eyes (70.4%) had primary glaucoma, and 32 eyes (29.6%) had secondary glaucoma. Age at the time of injection had no effect on initial success but did in final success (P =-.03) for dogs requiring repeat injections. Cocker Spaniels required the most repeat 2nd and 3rd injections (3/12 dogs) and (2/4 dogs), respectively. No preoperative variable significantly affected the success rate. The most common complications were phthisis bulbi (59.2%), corneal edema (25.9%), and ulcerative keratitis (22.3%). Uncontrolled IOP resulted in enucleation in two dogs (1.8%).
CONCLUSIONS:Pharmacologic ablation has a high overall success rate in lowering IOP to ≤25 mm Hg short-term in blind, glaucomatous canine eyes. Type of glaucoma, pre-procedure IOP, chronicity, and protocol did not affect success.

Companion Notes

Retrospective report on pharmacologic ciliary body ablation for chronic glaucoma in 108 dogs

- intravitreal gentamicin and dexamethasone sodium phosphate or triamcinolone

   

Introduction on the treatment of chronic glaucoma

- primary glaucoma is typically genetic

(bilateral with predisposition for certain breeds)

- has 2 main forms based on gonioscopy of the drainage angle

- primary open angle glaucoma

- primary closed angle glaucoma

- secondary glaucoma is associated with ocular and systemic diseases

- painful and difficult to manage with medical and surgical intervention

- pharmacologic ablation of the ciliary body or ciliary body ablation (CBA)

- generally doesn’t require anesthesia

- owners may prefer it cosmetically compared to enucleation or evisceration

- procedure involves vitreocentesis

- followed by an injection of dexamethasone sodium phosphate

- in conjunction with a recommended dose of 15-30 mg gentamicin

- gentamicin is toxic to the ciliary body epithelium

- previously reported success rate in lowering IOP: 65%

- 86.4% reported more recently for ciliary body ablation with gentamicin

   

Study design

- study population: dogs seen at ophthalmology service of 4 referral hospitals

- inclusion criteria:

- end-stage glaucoma

- chronic glaucomatous, avisual eyes refractory to medical therapy

- diagnosis of chronic glaucoma was based on the following:

- IOP ≥ 25 mm Hg

- absent menace response and dazzle reflexes

- ocular changes, including the following:

- episcleral injection

- buphthalmos

- corneal edema

- secondary lens luxation or subluxation

- posterior segment changes noted included the following:

- optic nerve atrophy

- optic disk cupping

- retinal vascular attenuation

- intravitreal gentamicin

- with or without dexamethasone sodium phosphate or triamcinolone

- 3 month minimum followup

- exclusion criteria:

- previous glaucoma surgery

- previous diagnosis of intraocular neoplasia

- history and signalment

- mean age of the 108 dogs in study at time of the procedure:

- 9.5 ± 2.7 years with a range of 2-16 years

- breeds represented by 5 or more cases

- cocker spaniel, overrepresented with 24 cases

- shih tzu, 8

- Labrador retriever, 6

- Siberian husky, 5

- Bichon Frise, 5

- procedure: records between 2013 and 2018 retrospectively reviewed

- 1 eye from bilateral cases randomly selected for analysis

- success defined as intraocular pressure ≤ 25 mm Hg at last re-examination

- or no ocular hypotensive medications at 3 months or longer post-injection

- diagnosis of canine primary glaucoma based on the following:

- elevated intraocular pressure

- optic nerve changes

- lack of readily identifiable concurrent ocular or systemic diseases

(on routine ophthalmic examination)

- causes of secondary glaucoma included the following:

- hypermature cataracts

- lens luxation

- pigmentary uveitis

- cataract surgery

- retinal detachment

- chronic uveitis

- lipid uveitis

- trauma

- procedure (dogs had sedation or anesthesia for bilateral procedures)

- intended eye(s) aseptically prepared with 0.5% betadine solution

- topical proparacaine hydrochloride 0.5% applied

- followed by topical phenylephrine 2.5%

- for conjunctival and episcleral hemostasis

- vitreocentesis using 25 gauge, 1-inch hypodermic needle

- inserted 6-8 mm posterior to the limbus to reduce IOP

- 0.5-0.6 mL of vitreous aspirated

- followed by 30-50 mg of gentamicin (100 mg/mL)

(1 ophthalmologist based dose on dog’s weight and another used

a standard dose of 30 mg)

- combined with 1 of the following:

(for injection-related inflammation)

- 0.4 mg of dexamethasone sodium phosphate (4 mg/mL)

 or

- 1-2 mg of triamcinolone (2 mg/mL)

- immediate post-injection IOP recorded

- if IOP remained ≥ 25 mm Hg, aqueocentesis performed

- using 27-30 gauge, 1-inch hypodermic needle

   

Results

- overall success rate: 95%

- success rate for dogs receiving no ocular hypotensive medications: 86%

- type of glaucoma in the 108 eyes

- 76 eyes (70.4%) had primary glaucoma

- 32 (29.6%) had secondary glaucoma

- cataract surgery, 14 eyes

- hypermature cataracts, 6

- pigmentary uveitis, 4

- retinal detachment, 3

- anterior lens luxation, 2

- single eyes with either anterior uveitis, trauma, or lipid uveitis, 0.9%

- effect of age at the time of injection

- no effect on initial success

- did effect final success for dogs requiring repeat injections

- all cases that needed repeat injections were 6 years or older

- 12 dogs required a 2nd intravitreal injection

- at a mean of 208 ± 157.9 days after the first

- 3rd injection, 4 dogs

- cocker spaniels required the most repeat injections

(3 of 12 required a 2nd injection and 2 of 4 required a 3rd injection)

- no preoperative variable found to significantly affect the success rate

- including type of steroid used and the dose of both steroid and gentamicin

- complications

- phthisis bulbi, 59.2%

- corneal edema, 25.9%

- ulcerative keratitis, 22.3%

- subconjunctival hemorrhage, 9.2%

- hyphema, 8.3%

- cataracts, 6.4%

- endophthalmitis, 3%

- enucleation due to uncontrolled IOP, 2 dogs

   

“Primary versus secondary glaucoma cases did not show a difference in the success rate. Moreover, neither lens luxation as a cause of secondary glaucoma nor chronicity of disease affected the success rate.”

Keywords
canine; ciliary body ablation; gentamicin; glaucoma; intravitreal injection; pharmacologic ablation;

Article Tools:
   Medline
   Email to me

Grants:
BluePearl Science

Archives Highlights:
Use of surgical lasers in small animal dermatology
This article covers the basics of lasers, including discussion of both diode and CO2 lasers. It also discusses several skin diseases and/or conditions in which lasers are commonly used.
Key Takeaways for Veterinarians from the NAVTA Demographics Survey
Low salary is still viewed as the most challenging aspect of the job, with 39% of respondents ranking this both the top challenge currently and the top projected issue for the next 5 years. One in 3 credentialed veterinary technicians maintains a second job, often full time, suggesting that they need additional income to support themselves and/or their families.
Sternal Abnormalities on Thoracic Radiographs of Dogs and Cats.
Sternal abnormalities were observed in 189/777 (24%) dogs and 53/183 (29%) cats, mostly around the intersternebral cartilages, accounting for 32/80 (40%) dogs and 20/35 (57%) cats. This was followed by an abnormal number of sternal segments (8% dogs, range 3-9 sternebrae; 15% cats, range 7-9 sternebra). Pectus excavatum was observed in 6/777 (0.8%) dogs and 6/183 (3%) cats, and pectus carinatum in 18/777 (2%) dogs and 2/183 (1%) cats.
Attitudes and Beliefs of a Sample of Australian Dog and Cat Owners towards Pet Confinement.
Dog owners showed the strongest support for confining dogs to the owners' property whenever unsupervised (98% agreement) and less support for confining dogs inside the house at night (54% agreement), and only 23% believed dogs had a negative impact on wildlife. Cat owners showed the strongest support for confining cats inside the house at night (89% agreement). Cat owners' non-supportive attitudes toward cat confinement were partly because of higher concern for cat quality of life and lower concern about their cats' predation behaviours, compared to non-cat owners.
Treatment and outcome following substantial ketamine overdose in a dog.
This case report documents an iatrogenic 338 times intravenous ketamine overdose in a dog, which was successfully managed with supportive care. In addition, it highlights the importance of doctor-technician communication and the potential errors in using electronic treatment sheets.

Back Print Save Bookmark in my Browser Email this article to me. Top of Page. VSPN AOW : Pharmacologic ciliary bod...
Contact Us