VSPN AOW : Pharmacologic ciliary bod... |
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):125-130.1 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.
AbstractOBJECTIVE: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 NotesRetrospective 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:
Grants:
BluePearl Science
Archives Highlights:
|
VSPN AOW : Pharmacologic ciliary bod... |
800.700.4636 | help@vspn.org | 530.756.4881 | Fax: 530.756.6035
777 West Covell Blvd, Davis, CA 95616 Copyright 1991-2024, Veterinary Information Network, Inc. |
Contact Us |