Epilepsy and coloured lenses.doc by fjwuxn

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									        TREATMENT OF PHOTOSENSITIVE EPILEPSY WITH
                    COLOURED LENSES

BACKGROUND

Photosensitive epilepsy is a quite rare form of epilepsy that can trigger a seizure on
exposure to certain types of flashing or flickering lights. Photosensitivity can
represent a problem in epilepsy patients because pharmacological treatment is often
ineffective.

THE TECHNOLOGY

Non-pharmacologic approaches to the management of photosensitive epilepsy have
included the use of sunglasses and coloured lenses of various types. Most studies
have used blue cross polarised lenses.

PATIENT GROUP

Patients with confirmed photosensitive epilepsy

RESEARCH EVIDENCE

See Table 1 for search terms and results

Table 1

       DATABASE                                 SEARCH TERM/S                     NUMBER OF HITS
OVID Medline 1966-2006                               Epilepsy                          98,176
      Cochrane DSR                                Photosensitive                       11,769
     ACP Journal Club                               Colo$red                           9,006
          DARE                                        Lens                             62,662
           CCTR                                     Spectacles                         3,710
        EMBASE                                       Glasses                           4,716
         CINAHL                                     Treatment                        3,343,794
           HMIC
           NICE                                       Epilepsy                           1
        Sumsearch                      Photosensitive epilepsy and treatment            106
          Google                      Photosensitive epilepsy and coloured lens        9,560
           TRIP                               Photosensitive epilepsy                    7
        UpToDate                              Photosensitive epilepsy                    2
National Electronic Library                           Epilepsy                          172
 for Health – Neurological
   conditions Specialist
          Library
         INAHTA                       Photosensitive epilepsy and coloured lens         0
           NICE
National Horizon Scanning
           Centre
National Research Register
 Current Controlled Trials




Dr M Webb, version 1, December 2007                                                            1
There were published observational studies1 2 3 with small number of patients on the
usefulness of coloured lens and glasses in photosensitivity control; randomised
controlled trial (RCT) data was however lacking. The largest study originates from
Italy and describes a multicentre study of a commercially available lens Z1 on 610
patients with confirmed photosensitive epilepsy.          With use of the lenses
photoparoxysmal response disappeared in 463 (75.9%) patients and was considerable
reduced in an additional 109 (17.9%).          No difference was found between
pharmacologically treated and untreated patients and age, sex or type of epilepsy did
not influence the results.4 One UK study of conventional polarised or cross polarised
glasses of 19 patients is relevant despite the small numbers, because the
neurophysiologist assessing the EEGs was unaware to which type of spectacle was
being used. In 17/19 patients polarising glasses were effective in reducing the photic
response and in 10 patients cross polarised spectacles were more effective than
conventional polarised spectacles. 5

COST EFFECTIVENESS

There was no relevant data on cost effectiveness

ONGOING RESEARCH

There were no current trials listed in the Register of Controlled Clinical Trials

CONCLUSIONS

There is limited evidence to indicate that coloured lenses may be useful in the
treatment of photosensitive epilepsies and there are no recommendations for their use
in the current national clinical guidelines for epilepsy. 6 7 There is a need for a well
designed RCT.

REFERENCES
1
  Wilkins Aj; Baker A; Amin D et al. Treatment of photosensitive epilepsy using coloured glasses.
Seizure 1999; 8: 444-449.
2
  Kopecs MR; Boro A; Haut S et al. A novel nonpharmacologic treatment for photosensitive epilepsy:
a report of three patients tested with blue cross-polarized glasses. Epilepsia 2004; 45:1158-1162
3
  Raciti L; Intilia F; Naso M et al. Effectiveness of lenses for photosensitivity control to the
management of photosensitive epilepsies. Bullettino Lega Italiana contro l’Epilessia 2005; 129: 115 –
Abstract read.
4
  Capovilla G; Gambardella A; Rubboli G et al. Suppressive efficacy by a commercially available blue
lens on PPR in 610 photosensitive epilepsy patients. Epilepsia 2006; 47: 529-533
5
  Jain S; Woodruff G; Bissessar EA. Cross polarized spectacles in photosensitive epilepsy. Journal of
Paediatric Ophthalmology and Strabismus 2001; 38: 331-334.
6
  National Institute for Health and Clinical Excellence. The epilepsies. The diagnosis and management
of the epilepsies in adults and children in primary and secondary care. NICE 2004; Clinical Guideline
20. Available at: http://www.nice.org.uk/nicemedia/pdf/CG020NICEguideline.pdf. Accessed 3rd
December 2007.
7
  Scottish Intercollegiate Network Guidelines. Diagnosis and management of epilepsy in adults. SIGN
2003. No. 70. Available at: http://www.sign.ac.uk/guidelines/fulltext/70/index.html. Accessed 3rd
December 2007.




Dr M Webb, version 1, December 2007                                                                2

								
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