An 18-year-old woman was referred from the emergency department by the Internal Medicine service for blurred vision in both eyes of 5 days' evolution. Her only history was hypothyroidism treated with levothyroxine 100 micrograms/day, and headaches for which treatment with nadolol 40 mg/night and topiramate 25 mg in the mornings had recently been prescribed. He provides a recent analytical study, prior to treatment, within the normal range.
His ophthalmological clinical history showed a previous visual acuity, 6 months earlier, of unity (10/10) in both eyes with a correction of +0.50 sphere -0.75 cylinder at 100° in the right eye and +0.75 sphere -0.75 cylinder at 75° in the left eye.
A new refractive study was performed which determined a myopic change in both eyes with -4.25 sphere -0.50 cylinder at 110o in the right eye and -3.75 sphere -1.00 cylinder at 60o in the left eye, a correction with which he achieved visual acuity equal to 0.6 (6/10) in the right eye and 0.7 (7/10) in the left eye.

The biomicroscopic study showed mild hyperemia and conjunctival congestion in both eyes, narrow anterior chambers with a positive eclipse sign and transparent corneas and crystalline lenses, with no signs of inflammation or seclusion. Pupils are isochoric and normoreactive. Normal ocular motility. Intraocular pressure measured with applanation tonometer was 32 mmHg in the right eye and 29 mmHg in the left eye. Papillae and posterior pole examination were normal.

On suspicion of acute angular closure, oral treatment was started with carbonic anhydrase inhibitors (acetazolamide 250 mg), ½ cp every 8 hours, and topical treatment with bimatoprost and timolol maleate in eye drops, with discontinuation of the recently introduced medications (nadolol and topiramate).
At 24 hours he showed blood pressure of 23 mmHg in both eyes, and 13 mmHg in the right eye and 12 mmHg in the left eye at 48 hours, with normalisation of anterior chamber depth, so acetazolamide treatment was progressively reduced at 48 hours, third and fourth day until total suppression and topical treatment was withdrawn after 7 days, maintaining normal blood pressure of 17-18 mmHg in both eyes at 3, 6 and 12 weeks, without treatment.

Vision was completely normalised at 72 hours, with visual acuity equal to unity in both eyes and refraction similar to that prior to the episode.
A final diagnosis of myopisation and ocular hypertension due to acute angular closure secondary to treatment with topiramate was made, which was communicated to the patient, family and Internal Medicine service as the prescriber of the drug.