Order of the ophthalmic examination: what comes first
7-year-old crossbreed dog with a red left eye, mucopurulent discharge and mild blepharospasm for a week. You want to perform a Schirmer tear test, culture, fluorescein, tonometry and fundus examination.
Which sequence is correct?
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A. Topical anaesthetic, Schirmer, fluorescein, tonometry and mydriatic
Topical anaesthetic abolishes reflex tearing and gives a falsely low Schirmer reading (that would be a Schirmer II test). Its preservatives can also inhibit bacterial growth if you culture afterwards.
B. Mydriatic, fundus examination, tonometry, Schirmer and fluorescein
Dilating first prevents assessment of pupillary reflexes, may alter intraocular pressure, and tropicamide reduces tear production. The mydriatic always goes last, after tonometry.
C. Schirmer, culture sample, fluorescein, tonometry and mydriatic
Correct. Nothing should touch the eye before the Schirmer test; the culture is taken before any drops (preservatives, dilution); then fluorescein, anaesthetic and tonometry, and finally the mydriatic for the fundus.
D. Fluorescein, saline flush, Schirmer, tonometry and mydriatic
Fluorescein and flushing add fluid to the conjunctival sac and stimulate reflex tearing, so the subsequent Schirmer reading is falsely high and you may miss keratoconjunctivitis sicca.
lightbulb Key takeaway
Practical rule: first what is measured without touching (reflexes, menace response, Schirmer), then samples, then stains and anaesthetic, and finally dilation. In dogs, a Schirmer reading ≥ 15 mm/min is normal and < 10 mm/min indicates keratoconjunctivitis sicca.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.