Peer-reviewed veterinary case report
How eye drops affect pupil size and pressure in healthy dogs
By Kahane, Nili et al.·Published in Veterinary ophthalmology·2016·Koret School of Veterinary Medicine·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: The effects of topical parasympatholytic drugs on pupil diameter and intraocular pressure in healthy dogs treated with 0.005% latanoprost.
- Species:
- dog
Plain-English summary
A group of ten healthy Labrador retrievers had their eye pressure and pupil size measured after being treated with a medication called latanoprost, which lowers eye pressure but can make pupils smaller. To see if other medications could help dilate the pupils for eye exams, the dogs were also given either tropicamide or atropine. The results showed that atropine was particularly effective at making the pupils larger without affecting the eye pressure-lowering effects of latanoprost. This means that atropine could be a good option for vets when they need to examine a dog's eyes after latanoprost treatment.
People also search for: dog eye pressure treatment · why are my dog's pupils small · atropine for dog eye exam
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.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/26607964/