Current Neuro-Ophthalmology Research Projects

The Photo-Blink Reflex

We are studying the dynamics of the photic blink reflex to objectively measure:

1. Afferent light sensitivity in the  retina and trigeminal network

2. Efferent eyelid dysfunction in different disorders.

Protects the eye after a bright flash1-4

Quantitation of Facial Responses to Light

Facial Responses to Light Are Exaggerated in Light Sensitive Patients

Facial Responses to Light Are Exaggerated in Light Sensitive Patients
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Electrical Responses of Facial Muscles to Light
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Video responses of facial muscles to light in a migraine patient
Video responses of facial muscles to light in a migraine patient

 

Responses of four facial muscles quantified from video

 

Real-Time 3D Facial Tracking

Automated pupil, eyelid and facial feature responses to light from an accessorized iPad.

 

 

Average fissure size vs. pupil diameter

Corneal Blink Reflex – C02
Corneal Blink Reflex – C02
Illustrations of time- displacement pro les of upper lid movement during and after a stimulated blink. (A) Baseline blink re ex time-displacement pro le. (B) Blink re ex time-displacement pro le after active play. Latency is increased. Differential latency is decreased. Log of number of oscillations is less. (C) Blink re ex time- displacement pro le after a head impact causing a concussive event. Latency is decreased. Differential latency is increased. Log of number of oscillations is increased.

 

 

Laser Speckle Flowgraphy

Introduction to Laser Speckle Flowgraphy (LSFG)

Blood Flow Quantified Simultaneously in the Retina, Optic Nerve and Choroid

This motion picture demonstrates the blood flow change in retinal vessels, tissue of optic nerve head and the choroid of human eye. You note the blood flow changes periodically being synchronized with the heart beats.  From this time-varying map you may realize the LSFG’s potential to become a useful tool, not only for diagnoses of various eye diseases, but also for studying the functions of cardiovascular system. 

 

Blood flow
LSFG

Use of Ocular Blood Flow to Test New Treatments

Use of ocular blood flow to test new treatments

Laser speckle flowgraphy can be used to discover new treatments for improving blood flow to the eye and brain.

 

Measurement of ocular circulation with LSFG-NAVI while IOP acutely lowered using vacuum goggles

Measurement of ocular circulation with LSFG-NAVI while IOP acutely lowered using vacuum goggles

 

Autoregulation

Light Flicker Evoked Increases in Ocular Blood Flow

Light Flicker Evoked Increases in Ocular Blood Flow

 

Blood Flow Changes in Response to Light Flicker

 

Optic Nerve Head Blood Flow Increases in Response to 10 Hz Light Flicker

Perfusion Pressure/ Flow = Resistance

Perfusion Pressure/ Flow = Resistance

Perfusion Pressure = MAP-IOP

Ocular Perfusion Pressure =2/3 MAP-IOP

Laser Speckle Measurement in response to Light Flicker

Smartphone Test of Visual Function 

Smartphone test of visual function