Eye emergencies

Severe pain, headache and vomiting with a red eye, a cloudy cornea, a fixed mid-dilated pupil and a hard globe, in an older, often hypermetropic patient, in the evening. Pressure-lowering drops and intravenous acetazolamide now; laser iridotomy in both eyes when the cornea clears.

Glaucoma: the angle

Painless loss of vision in one eye over seconds, to counting fingers or worse, with an afferent pupillary defect; a pale retina with a cherry red spot within hours. A stroke of the eye: the same-day work is the source (carotid, heart) and giant cell arteritis in anyone over fifty. There is no proven treatment for the eye once the first hours have gone.

New floaters and flashes, then a shadow or curtain spreading across the vision. A detached retina is grey and elevated; a tear is at its edge. Macula-on detachments are repaired within a day or so to keep central vision; every new flashes-and-floaters patient needs a dilated examination to find the tear before it becomes one.

Flashes and floaters pathway

Infection inside the eye, days after cataract surgery or an injection, after a penetrating injury, or from a glaucoma bleb: increasing pain, falling vision, a red eye, a hypopyon and a hazy view of the fundus. Hours count: a vitreous tap for culture and intravitreal antibiotics the same day. Blebitis is the same infection caught at the bleb before it reaches the vitreous.

A full-thickness wound of the cornea or sclera: after a hammer-on-metal injury, a fall onto something sharp, or a blunt blow hard enough to rupture the eye. A peaked pupil pointing at the wound, iris or uveal tissue at the wound, a shallow or deep chamber, a soft eye, a positive Seidel test (fluorescein washed away by leaking aqueous). Do not press on the eye, do not measure the pressure, shield it (no pad), keep the patient nil by mouth, give antiemetics, and get the CT for a foreign body and the ophthalmologist for the repair.

A contact lens wearer with a painful, photophobic, watering red eye and a white spot on the cornea has bacterial keratitis until the scrape says otherwise; Pseudomonas can melt a cornea in two days. Lens out, corneal scrape, intensive topical antibiotics, daily review. Acanthamoeba in a lens wearer who swims: pain out of proportion, a ring infiltrate, weeks of treatment.

Behind the septum: proptosis, painful and restricted eye movements, chemosis, fever, and, when it threatens the optic nerve, reduced vision, colour loss and an afferent pupillary defect. Usually from sinusitis, often in a child. Admission, intravenous antibiotics, CT of the orbits and sinuses, and ENT for the sinus. Preseptal cellulitis has none of the orbital signs.