Does the Swedish Interactive Threshold Algorithm (SITA) accurately map visual field loss attributed to vigabatrin?

Article English OPEN
Conway, Miriam L. ; Hosking, Sarah L. ; Zhu, Haogang ; Cubbidge, Robert P. (2014)
  • Publisher: Springer Nature
  • Journal: BMC Ophthalmology, volume 14 (eissn: 1471-2415)
  • Related identifiers: doi: 10.1186/1471-2415-14-166, pmc: PMC4391113
  • Subject: Research Article | RE | Vigabatrin | Visual field | Ophthalmology | Swedish interactive threshold algorithm
    mesheuropmc: eye diseases | genetic structures

Background Vigabatrin (VGB) is an anti-epileptic medication which has been linked to peripheral constriction of the visual field. Documenting the natural history associated with continued VGB exposure is important when making decisions about the risk and benefits associated with the treatment. Due to its speed the Swedish Interactive Threshold Algorithm (SITA) has become the algorithm of choice when carrying out Full Threshold automated static perimetry. SITA uses prior distributions of normal and glaucomatous visual field behaviour to estimate threshold sensitivity. As the abnormal model is based on glaucomatous behaviour this algorithm has not been validated for VGB recipients. We aim to assess the clinical utility of the SITA algorithm for accurately mapping VGB attributed field loss. Methods The sample comprised one randomly selected eye of 16 patients diagnosed with epilepsy, exposed to VGB therapy. A clinical diagnosis of VGB attributed visual field loss was documented in 44% of the group. The mean age was 39.3 years ± 14.5 years and the mean deviation was -4.76 dB ±4.34 dB. Each patient was examined with the Full Threshold, SITA Standard and SITA Fast algorithm. Results SITA Standard was on average approximately twice as fast (7.6 minutes) and SITA Fast approximately 3 times as fast (4.7 minutes) as examinations completed using the Full Threshold algorithm (15.8 minutes). In the clinical environment, the visual field outcome with both SITA algorithms was equivalent to visual field examination using the Full Threshold algorithm in terms of visual inspection of the grey scale plots , defect area and defect severity. Conclusions Our research shows that both SITA algorithms are able to accurately map visual field loss attributed to VGB. As patients diagnosed with epilepsy are often vulnerable to fatigue, the time saving offered by SITA Fast means that this algorithm has a significant advantage for use with VGB recipients. Electronic supplementary material The online version of this article (doi:10.1186/1471-2415-14-166) contains supplementary material, which is available to authorized users.
  • References (34)
    34 references, page 1 of 4

    1. Aicardi J, Mumford J, Dumas C, Wood S: Vigabatrin as initial therapy for infantile spasms: a european retrospective survey. Epilepsia 1996, 37:638-642.

    2. Tolman JA, Faulkner MA: Vigabatrin: a comprehensive review of drug properties including clinical updates following recent FDA approval. Expert Opin Pharmacother 2009, 10:3077-3089.

    3. Hardus P, Verduin W, Postma G, Stilma J, Berendschot T, Van Veelen C: Long term changes in the visual fields of patients with temporal lobe epilepsy using vigabatrin. Br J Ophthalmol 2000, 84:788-790.

    4. Midelfart A, Midelfart E, Brodtkorb E: Visual field defects in patients taking vigabatrin. Acta Ophthalmol Scand 2000, 78:580-584.

    5. Gaily E, Jonsson H, Lappi M: Visual fields at school-age in children treated with vigabatrin in infancy. Epilepsia 2009, 50(2):206-216.

    6. Wild JM, Chiron C, Ahn H, Baulac M, Bursztyn J, Gandolfo E, Goldberg I, Goñi FJ, Mercier F, Nordmann JP, Safran AB, Schiefer U, Perucca E: Visual field loss in patients with refractory partial epilepsy treated with vigabatrin: final results from an open-label, observational, multicentre study. CNS Drugs 2009, 23:965-982.

    7. Schmidt T, Rüther K, Jokiel B, Pfeiffer S, Tiel-Wilck K, Schmitz B: Is visual field constriction in epilepsy patients treated with vigabatrin reversible? J Neurol 2002, 249:1066-1071.

    8. Nousiainen I, Mäntyjärvi M, Kälviäinen R: No reversion in vigabatrin-associated visual field defects. Neurology 2001, 57:1916-1917.

    9. Manuchehri K, Goodman S, Siviter L, Nightingale S: A controlled study of vigabatrin and visual abnormalities. Br J Ophthalmol 2000, 84:499-505.

    10. Miller N, Johnson M, Paul S, Girkin CC, Perry JD, Endres M, Krauss GL: Visual dysfunction in patients receiving vigabatrin: clinical and electrophysiologic findings. Neurology 1999, 53:2082-2087.

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