photonic modulation of ocular pain: case series in the role of light in the regulation of...
TRANSCRIPT
Photonic Modulation of Ocular Pain: Case Series in the Role of Light in the Regulation of ‘Corneal’ Sensation U AGRAVAL, K RAMAESH
TENNENT INSTITUTE OF OPHTHALMOLOGY, GLASGOW
THE AUTHORS HAVE NO FINANCIAL INTEREST TO DISCLOSE
Purpose
The eye senses light and somatic sensation from ocular structures including the cornea
The trigeminal nerve is responsible for the physiological pain sensation of the eye
Both light and pain efferent impulses converge in the thalamus
We believe photic input may modulate and accentuate the somatic efferent worsening corneal pain
Methods
Three patients, completed a visual analogue score (VAS) questionnaire to assess symptom severity in different conditions: Room light, darkness, dark glasses and dark contact lens/occlusion
Patient 1:• 58 year old male• Loss of sensation to left side of face secondary to penetrating head injury damaging trigeminal
nerve• Excruciating left eye pain and photophobia
Patient 2:• 68 year old male• Quiescent ocular cicatrical pemphigoid• Complaining of pain, photophobia and foreign body sensation
Patient 3:• 69 year old male• Unexplained left ocular pain • Alleviated by wearing bandage contact lens
Results
In Light After 10 minutes in Darkness
After 10 minutes with Dark Glassess
After 10 minutes with Dark Contact Lens/
Occlusion*
0
20
40
60
80
100100
0
70
0
70
0 0 00 0 0 0
VAS: PhotophobiaPatient 1
Patient 2
Patient 3
Patient 1:100% reduction in darkness and occlusion, 30% with dark glassesPatient 2:100% reduction in darkness, dark glasses and occlusionPatient 3: No photophobia
Results
In Light After 10 minutes in Darkness
After 10 minutes with Dark Glassess
After 10 minutes with Dark Contact Lens/
Occlusion*
0
20
40
60
80
100
70
50
60
30
100
70
60
0
4550 50
25
VAS: Ocular PainPatient 1
Patient 2
Patient 3 Patient 1: 28.5% reduction in darkness, 14.2% with dark glasses and 57.1% with occlusionPatient 2: 30% reduction in darkness, 40% with dark glasses and 80% with occlusion,Patient 3: no reduction in darkness or dark glasses, 44.4 % with occlusion.
Results
In Light After 10 minutes in Darkness
After 10 minutes with Dark Glassess
After 10 minutes with Dark Contact Lens/
Occlusion*
0
20
40
60
80
100
70 70
50
25
80
70
40
00 0 0 0
VAS: Burning/Stinging SensationPatient 1
Patient 2
Patient 3 Patient 1: No reduction in darkness, 28.5% reduction with dark glasses and reduced by 64.2% with occlusionPatient 2: 12.5% reduction in darkness, 50% with dark glasses, 100% with occlusionPatient 3: No symptoms
Results
In Light After 10 minutes in Darkness
After 10 minutes with Dark Glassess
After 10 minutes with Dark Contact Lens/
Occlusion*
0
20
40
60
80
100
0 0 0 0
79
60
40
0
50 50 50
25
VAS: Foreign Body SensationPatient 1
Patient 2
Patient 3 Patient 1: No symptomsPatient 2: 14.2% reduction in darkness, 42.8% with dark glasses, 100% with occlusionPatient 3: No reduction in darkness or dark glasses and reduced by 50% with occlusion
Conclusions
Outcomes: Patient 1: Occluding contact lens improves symptoms
Patient 2: Symptoms improved with dark glasses
Patient 3: Unable to manage occluding eye due to balance problems but trialling tinted contact lens
In our case series, total occlusion gave significant relief of symptoms
Supporting our hypothesis, that pain sensation and light perception impulses converge and modulate each other in the thalamus
Further research is needed to manage these complex patients
References
D. Gould et al. Visual Analogue Scale (VAS). Journal of Clinical Nursing 2001; 10:697-706
McPhee SJ, Papadakis MA: Current Medical Diagnosis and Treaatment 2011, 50th Edition: http://www.accessmedicine.com
Burton H. Somatic sensation from the eye. In: Hart WM, editor. Adler’s Physiology of the Eye. St. Louis: Mosby Year Book; 1992. pp. 71–100