Is the RAPDx Pupillograph Able to Distinguish Between Glaucoma Subjects and Healthy Subjects?

Wills Eye104 enrolled

Overview

The Konan RAPDx (Konan Medical USA, Irvine, CA) is a newly patented pupillography device.The aims of this study are to assess the ability of the RAPDx to distinguish between healthy subjects and patients with confirmed glaucoma using standard testing sequences developed for use at the Wills Eye Hospital Glaucoma Research Center and to determine the combination of demographic, clinical, and RAPDx testing parameters which allow for maximum sensitivity and specificity.

The RAPDx utilizes noninvasive digital, high-definition, infrared machine-vision with eye-tracking and automated blink detection technology to analyze and quantify the pupillary response to light. During the scheduled appointment, all patients will receive an undilated fundus examination by the attending ophthalmologist. The following data will be collected; Demographic information, Visual acuity, Intraocular pressure (IOP) measured by Goldmann applanation tonometry, Disc damage likelihood scale (DDLS), Vertical cup/disc ratio, Gonioscopy (if not documented in the chart within the past 2 years) and Humphrey visual field examination. Each participant will undergo RAPDx testing with two different testing sequences. They are separated by a 10-second resting period during which the patient is instructed to close his or her eyes. The exam may be paused at any time and re-alignment may be performed during any pause. The two testing sequences are: 1. Standard Factory Setting: 0.1-second stimuli with 2-second inter-stimuli pauses; 2. Custom Setting: 3-second stimuli with 1-second inter-stimuli pauses

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

104

Conditions

Glaucoma

Interventions

PupillometerDIAGNOSTIC_TEST

The Konan RAPDx (relative afferent pupillary defect) (Konan Medical USA, Irvine, CA) pupillometer utilizes digital, high-definition, infrared machine-vision with eye-tracking and automated blink detection technology to analyze and quantify pupillary response to light.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: Glaucoma patients: * optic nerve damage (neuroretinal rim notch, asymmetric inter-eye cup to disc (c/d\_ ratio \>0.2 or disc damage likelihood scale (DDLS) \>2, or absence of neuroretinal rim not due to other cause) * glaucomatous visual field (VF) deficits (cluster of 3 or more points on pattern deviation plot depressed below 5% level, at least 1 depressed below 1% level; OR corrected pattern standard deviation/pattern standard deviation significant at P \<0.05; or glaucoma hemifield test "outside normal limits") with good reliability indices (fixation losses, false-positive rate, false-negative rate each \< 33%). Healthy subjects: * normal optic nerve exam * normal reliable VF (Humphrey mean deviation (MD) \>-2 or Octopus MD ≤0.8; fixation losses, false-positive rate, and false-negative rate each \< 33%) * open angles gonioscopy. Exclusion Criteria: * Abnormal ocular motility preventing binocular fixation (e.g. strabismus, nystagmus). * Any condition preventing adequate visualization and examination of pupil or optic nerve (e.g. dense corneal opacities or lens opacities). * Active infection of anterior or posterior segments of the eye. * Any intraocular surgical or laser procedure within previous 4 weeks. * Any non-glaucomatous condition causing RAPD, anisocoria or corectopia (ex. optic neuropathy, Horner's syndrome, previous iris injury due to trauma or surgery, etc.). * Subjects under age 18 or subjects presently housed in correctional facility.

Outcomes

Primary Outcomes

Amplitude Asymmetry of Pupil Constriction

Pupil size changes when light shines into the eyes making the diameter of the pupil smaller (constriction). The size of the pupil's reaction to light, measured in millimeters, is the amplitude or change in diameter. Amplitude of maximum pupil constriction (pupil size) when light is shone is compared between the right and left eyes. Asymmetry is the difference between maximum pupil size of the two eyes.

Time frame: 1 examination, one hour

Latency Asymmetry of Pupil Constriction

Pupil size changes at different speeds when light shines into the eyes making the diameter of the pupil smaller (constriction). The speed of the pupil's reaction to light is the latency or amount of time. Latency of maximum pupil constriction when light is shone is compared between the right and left eyes. Asymmetry is the difference in time it takes for maximum pupil constriction between the two eyes.

Time frame: 1 examination, one hour

Maximum Constriction Asymmetry Duration

Log difference between duration of maximum pupil constriction when light is shone into the right versus the left eye. The duration of maximum constriction is calculated as time in milliseconds between point of maximum constriction and time when pupil amplitude has reached 50% of peak amplitude of dilation.

Time frame: 1 examination, one hour

Data from ClinicalTrials.gov

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