Letter to the Editor
2
Letter to the Editor Robert Arnold Pediatric Ophthalmology and Strabismus, Ophthalmic Associates, 542 West Second Avenue, Anchorage, Alaska 99501, USA. E-mail address: [email protected] Mimura, T., Amano, S., Funatsu, H., Araie, M., Kagaya, F., Kaji, Y., Oshika, T., Yamagami, S., and Okada, E. (2003) Oculocardiac reflex caused by contact lenses. Ophthal. Physiol. Opt. 23, 263–264. I read with interest this recent article. The syncope initiated by contact lens insertion was likely not oculo- cardiac reflex, but rather vasovagal syncope (Fenton et al., 2000; Suzuki et al., 2003) as ocular manipulation is not always associated with such events (Khurana, 2002). The pure ‘oculocardiac reflex’ is a trigemino- vagal reflex usually associated with stretching extraoc- ular muscles (Arnold, 2000). Eye doctors should take care to avoid iatrogenic skeletal trauma from unpro- tected falls after syncope prompted by vasovagal or oculocardiac reflex hypoperfusion. References Arnold, R. W. (2000) The human heart rate response profiles to five vagal maneuvers. Yale J. Biol. Med. 72, 237–244. Fenton, A. M., Hammill, S. C., Rea, R. F., Low, P. A. and Shen, W. K. (2000) Vasovagal syncope. Ann. Intern. Med. 133, 714–725. Khurana, R. K. (2002) Eye examination-induced syncope Role of trigeminal afferents. Clin. Auton. Res. 12, 399–403. Suzuki, M., Hori, S., Nakamura, I., Nagata, S., Tomita, Y. and Aikawa, N. (2003) Role of vagal control in vasovagal syncope. Pacing Clin. Electrophysiol. 26 (2 Pt 1), 571–578. Author’s reply Tatsuya Mimura Department of Ophthalmology, University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan (on behalf of all authors). E-mail address: [email protected] We appreciate the comments expressed by Robert Arnold, MD regarding our article. The most common syncope caused by contact lens insertion may be vasovagal syncope (Fenton et al., 2000; Arnold et al., 2002), as you suggested. However, the physical expressions of vasovagal syncope do not match with those exhibited by our patients. As we described in our article, the trigger of the vasovagal syncope is a reduction in venous return to the heart because of excessive venous pooling in the legs evoked by phobias, anxiety, physical injury and/or being in a standing position for a long time. The clinical symptoms of vasovagal syncope are dizziness, myoclonus, ocular hyperdeviation, presyncope and syncope but without nausea and vomiting, and bradycardia. Our patients did not evidence these symptoms (diz- ziness, myoclonus, ocular hyperdeviation) but their bradycardia, nausea and vomiting settled subsequently after unconsciousness. In contrast, oculocardiac reflex results in a decrease of intracerebral blood flow due to bradycardia. Bradycar- dia is the most common cardiac response to these stimuli. Stimulation of the vagus nerve causes vaso- dilation and pooling of blood in the capillary beds, which leads to a fall in blood pressure. Our patients’ blood pressure was decreased while unconscious. It is reasonable that the patients’ eyes were compressed by the optometrists and that their extraocular muscles were stretched (Arnold, 2000), and consequently they fell unconscious by oculocardiac reflex. Unconsciousness arising from insertion of contact lenses results mainly from vasovagal syncope, but can also be caused by oculocardiac reflex as in our patients. We should be aware that there are patients who may lose consciousness resulting from either vasovagal syn- cope or the oculocardiac reflex when trying to insert contact lenses. Ophthal. Physiol. Opt. 2003 23: 571–572 ª 2003 The College of Optometrists 571
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Transcript of Letter to the Editor
Letter to the Editor
Robert Arnold
Pediatric Ophthalmology and Strabismus, Ophthalmic Associates, 542 West Second Avenue,
Anchorage, Alaska 99501, USA. E-mail address: [email protected]
Mimura, T., Amano, S., Funatsu, H., Araie, M.,
Kagaya, F., Kaji, Y., Oshika, T., Yamagami, S.,
and Okada, E. (2003) Oculocardiac reflex caused by
contact lenses. Ophthal. Physiol. Opt. 23, 263–264.
I read with interest this recent article. The syncopeinitiated by contact lens insertion was likely not oculo-cardiac reflex, but rather vasovagal syncope (Fentonet al., 2000; Suzuki et al., 2003) as ocular manipulationis not always associated with such events (Khurana,2002). The pure ‘oculocardiac reflex’ is a trigemino-vagal reflex usually associated with stretching extraoc-ular muscles (Arnold, 2000). Eye doctors should takecare to avoid iatrogenic skeletal trauma from unpro-tected falls after syncope prompted by vasovagal oroculocardiac reflex hypoperfusion.
References
Arnold, R. W. (2000) The human heart rate response
profiles to five vagal maneuvers. Yale J. Biol. Med. 72,237–244.
Fenton, A. M., Hammill, S. C., Rea, R. F., Low, P. A. and
Shen, W. K. (2000) Vasovagal syncope. Ann. Intern. Med.133, 714–725.
Khurana, R. K. (2002) Eye examination-induced syncope Role
of trigeminal afferents. Clin. Auton. Res. 12, 399–403.Suzuki, M., Hori, S., Nakamura, I., Nagata, S., Tomita, Y.
and Aikawa, N. (2003) Role of vagal control in vasovagalsyncope. Pacing Clin. Electrophysiol. 26 (2 Pt 1), 571–578.
Author’s reply
Tatsuya Mimura
Department of Ophthalmology, University of Tokyo Graduate School of Medicine, 7-3-1 Hongo,
Bunkyo-ku, Tokyo 113-8655, Japan (on behalf of all authors). E-mail address:
We appreciate the comments expressed by RobertArnold, MD regarding our article.
The most common syncope caused by contact lensinsertion may be vasovagal syncope (Fenton et al., 2000;Arnold et al., 2002), as you suggested. However, thephysical expressions of vasovagal syncope do not matchwith those exhibited by our patients. As we described inour article, the trigger of the vasovagal syncope is areduction in venous return to the heart because ofexcessive venous pooling in the legs evoked by phobias,anxiety, physical injury and/or being in a standingposition for a long time. The clinical symptoms ofvasovagal syncope are dizziness, myoclonus, ocularhyperdeviation, presyncope and syncope but withoutnausea and vomiting, and bradycardia.
Our patients did not evidence these symptoms (diz-ziness, myoclonus, ocular hyperdeviation) but theirbradycardia, nausea and vomiting settled subsequentlyafter unconsciousness.
In contrast, oculocardiac reflex results in a decrease ofintracerebral blood flow due to bradycardia. Bradycar-dia is the most common cardiac response to thesestimuli. Stimulation of the vagus nerve causes vaso-dilation and pooling of blood in the capillary beds,which leads to a fall in blood pressure. Our patients’blood pressure was decreased while unconscious. It isreasonable that the patients’ eyes were compressed bythe optometrists and that their extraocular muscles werestretched (Arnold, 2000), and consequently they fellunconscious by oculocardiac reflex.
Unconsciousness arising from insertion of contactlenses results mainly from vasovagal syncope, but canalso be caused by oculocardiac reflex as in our patients.We should be aware that there are patients who maylose consciousness resulting from either vasovagal syn-cope or the oculocardiac reflex when trying to insertcontact lenses.
Ophthal. Physiol. Opt. 2003 23: 571–572
ª 2003 The College of Optometrists 571
References
Arnold, R. W. (2000) The human heart rate response profilesto five vagal maneuvers. Yale J. Biol. Med. 72, 237–244.
Arnold, R. W., Farah, R. F. and Monroe, G. (2002) The
attenuating effect of intraglossal atreopine on the oculocar-diac reflex. Binocul. Vis. Strabismus Q 17, 313–318.
Fenton, A. M., Hammill, S. C., Rea, R. F., Low, P. A. and
Shen, W. K. (2000) Vasovagal syncope. Ann. Intern. Med.133, 714–725.
Mimura, T., Amano, S., Funatsu, H., Araie, M., Kagaya, F.,
Kaji, Y., Oshika, T., Yamagami, Y. and Okada, E. (2003)Oculocardiac reflex caused by contact lenses. Ophthal.Physiol. Opt. 23, 263–264.
572 Ophthal. Physiol. Opt. 2003 23: No. 6
ª 2003 The College of Optometrists
