Sir,

Isolated topiramate maculopathy is a rare phenomenon.1, 2 We believe this is the first reported case of a ‘topiramate maculopathy’ secondary to dose titration.

Case series

A 27-year-old male presented to eye casualty with a one week history of bilateral reduced vision. He was a known migraine sufferer and had seen his neurologist 10 days earlier. It later transpired the neurologist had increased his topiramate from 75 to 100 mg. The patient reported no vision symptoms on the lower dose of topiramate. He was on no other medication and his past medical and ophthalmic history were unremarkable.

On examination his best-corrected visual acuity (BCVA) was 6/36 right and 6/24 left, with no improvement with pin hole. His intraocular pressure (IOP) was 13 in both eyes. The colour pictures reveal bilateral macular striae (Figure 1) which were confirmed by Topcon OCT (Figure 2) and red free (Figure 3). The fluorescein angiogram was normal. He was reviewed two weeks later and admitted discontinuing his topiramate of his own volition after the onset of his visual symptoms. His BCVA was now 6/9 right and 6/5 left. The repeat images (Figures 4, 5, 6) confirm the resolution of his retinal striae.

Figure 1
figure 1

Fundi reveal bilateral macular striae on presentation.

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Figure 2
figure 2

Striae confirmed by Topcon OCT on presentation.

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Figure 3
figure 3

Red free images on presentation.

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Figure 4
figure 4

Normalisation after drug cessation.

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Figure 5
figure 5

Improvement of OCT after drug cessation.

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Figure 6
figure 6

Red free images after recovery.

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Comment

Topiramate is a sulphamate-substituted monosaccharide derived from d-fructose. It is becoming increasingly popular for the management of epilepsy, migraine, trigeminal neuralgia, and depression.3, 4 The anterior segment ocular side effects have been extensively reported but the documentation and mechanism of a pure topiramate maculopathy is less well understood. This is highlighted by the omission of any reference of a pure maculopathy in the RCOphth guidelines.5 However, the guidelines precede the initial case report and will hopefully be amended in the revision which were expected in October 2013.

We advise taking a detailed drug history including any recent change in dosage when faced with a similar clinical scenario. It is imperative the underlying diagnosis behind the use of topiramate is established and changes in dosage or discontinuation must be carried out in consultation with the patient's GP and/or neurologist. Topiramate maculopathy is not a life-threatening condition whereas status epilepticus is.