The effects of topical parasympatholytic drugs on pupil diameter and intraocular pressure in healthy dogs treated with 0.005% latanoprost

Nili Kahane, Hilli Raskansky, Tali Bdolah-Abram, Ron Ofri*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Purpose: Prostaglandin analogs induce miosis and lower intraocular pressure (IOP). As pupils of latanoprost-treated eyes may have to be dilated for ophthalmoscopy or intraocular surgery, we studied whether 0.5% tropicamide or 1% atropine alter the effects of 0.005% latanoprost on pupil diameter (PD) and IOP in healthy dogs. Methods: IOP and PD were measured hourly, 8 AM–4 PM, with the right and left eyes serving as control (CE) and treated (TE) eyes, respectively. Measurements were conducted in ten Labrador retrievers with one-week washout: (i) baseline values, (ii) latanoprost at 8 AM, (iii) tropicamide at 8 AM, (iv) latanoprost at 8 AM and tropicamide at 11 AM, and (v) latanoprost at 8 AM and atropine at 11 AM (n = 4). Results: At 4 PM, TE PD was 5.88 ± 0.59, 3.62 ± 0.66, 6.33 ± 1.00, 5.42 ± 0.57, and 8.12 ± 1.24 mm in sessions 1–5, respectively. TE PD was significantly different between treatment sessions 2, 4, and 5 (P = 0.018, Friedman), being most mydriatic in session 5. At 4 PM, TE IOP was 11.27 ± 2.07, 7.10 ± 1.07, 11.1 ± 2.21, 7.70 ± 1.85, and 8.87 ± 1.42 mm Hg in sessions 1–5, respectively, with no differences between treatment sessions 2, 4, and 5 (P = 0.105, Friedman). Conclusions: Tropicamide and atropine counteracted latanoprost's miotic effect, with atropine causing significantly larger mydriasis, sufficient for indirect ophthalmoscopy. Neither drug counteracted the hypotensive effect of latanoprost during this study period. Further studies are necessary to evaluate the potential risks in glaucomatous dogs.

Original languageAmerican English
Pages (from-to)464-472
Number of pages9
JournalVeterinary Ophthalmology
Volume19
Issue number6
DOIs
StatePublished - 1 Nov 2016

Bibliographical note

Publisher Copyright:
© 2015 American College of Veterinary Ophthalmologists

Keywords

  • atropine
  • glaucoma
  • lower intraocular pressure
  • miosis
  • mydriasis
  • tropicamide

Fingerprint

Dive into the research topics of 'The effects of topical parasympatholytic drugs on pupil diameter and intraocular pressure in healthy dogs treated with 0.005% latanoprost'. Together they form a unique fingerprint.

Cite this