Introduction Traditional visual field is done at doctors office - - PowerPoint PPT Presentation

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Ying Han, MD, Ph.D Associate Professor of Ophthamology University of California, San Francisco

Introduction

Traditional visual field is done at doctor’s office

High cost Labor intensive Time consuming

Would it be possible to test visual field at home?

Low or no cost Convenient to patients Possible screening tool

Introduction

Peristat, a free novel web-based perimetry

It can be done on any computer with a standard 17 inch

• r larger screen via internet connection at

www.keepyoursight.org1

It systematically maps out 24 degrees of visual field

function.

It takes ~5 mins to finish the test

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Testing condition

In a dark room The brightness and contrast sensitivity of the

monitor should be adjusted to 50% of maximal value

• f brightness and contrast sensitivity

One eye is covered Test distance is ~ 18-inches

Parameters

The target size is 3 mm in diameter and presents within 6-degree apart. Each target is presented for 0.2 seconds, and the patient is allowed an additional grace period of 1.8 seconds to respond. Points were tested at three stimulus brightness with a range of 1odB It ensures reliability through measurements of fixation losses, false positives, and false negatives.

Example – control subject

HVF Peristat

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Example

Left eye Right eye Left eye Right eye

Example – moderate glaucoma

HVF Peristat

Example – severe glaucoma

HVF Peristat

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A Clinic study on Peristat

To study the correlation between Peristat and

Humphrey visual field (HVF).

To evaluate sensitivity and specificity of Peristat for

detecting glaucoma.

Methods

Inclusion criteria:

Diagnosis of glaucoma with glaucomatous optic nerve

change and abnormal HVF.

Corrected visual acuity in tested eye better than 20/60. Without other ocular or neurological causes of visual

field defects.

Can reliably perform HVF.

Methods

All subjects performed 24-2 SITA-standard HVF and

Peristat in the office.

A reliable field for both tests was defined as fixation

loss, false positive and false negative ≤ 33%.

Mild, moderate and severe glaucoma were defined by

Hodapp-Anderson-Parrish criterion.

Results: Demographic Comparison

Glaucoma Patients (63) Control (12) P value Age (years) 64.8 ± 14.6 61.1 ± 10.7 0.2 Gender Female: 32 (51%) Male: 31 (49%) Female: 7 (58%) Male: 5 (42%) 0.36 Visual Acuity (logMAR) 0.24± 1.6 0.17± 1.4 0.54

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Methods

• Total number of abnormal points on HVF pattern

deviation and total number of abnormal Peristat points were counted. Spearman’s Rank correlation was analyzed.

• ROC analysis to evaluate the Peristat for detecting

mild, moderate and severe glaucoma.

Results: Correlation between HVF and Peristat

Abnormal Peristat points Abnormal HVF points 10 20 30 40 50 60 10 20 30 40 50

Correlation Coefficient (r) = 0.70 (p<0.0001)

Results: ROC for patients with mild glaucoma

Area under curve Total Points Mild glaucoma Light Grey 0.85 Dark Grey 0.77 Black 0.74 P-value comparing 3 curves P=0.004

Results: ROC for patients with moderate glaucoma

Area under curve Total Points Moderate glaucoma Light Grey 0.87 Dark Grey 0.88 Black 0.86 P-value comparing 3 curves P=0.57

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Results: ROC for patients with severe glaucoma

Area under curve Total Points Severe glaucoma Light Grey 0.90 Dark Grey 0.91 Black 0.88 P-value comparing 3 curves P=0.24

Results: ROC for patients with moderate and

severe glaucoma

Area under curve is 0.87-0.88

Sensitivity = 80% Specificity = 91%

Conclusion

Online visual field (Peristat) can be performed

reliably at doctor’s office.

Peristat has strong correlation with HVF. Peristat has moderate-high sensitivity and specificity

to identify eyes with moderate to severe glaucoma.

Peristat could be a good screening tool.

Limitation and Future Studies

Test whether Peristat can be performed reliably

• utside of doctor’s office by HVF-naïve patients.

Refining Peristat test to improve its usability. Longitudinal study to exam whether Peristat can be

used to detect progression with moderate-severe glaucoma.

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Thank you

Keepyoursight

Foundation:

Sean Ianchulev, MD

Stanford University

Robert Chang, MD Sean Wong

University of California,

San Francisco

Jing Hou, MD, PhD Shan Lin, MD Robert Stamper, MD Jeremy Keenan, MD Travis Porco, PhD Gene Lowry, MD Brian Chon, MD

Results

Consecutive seventy-seven glaucoma patients with 129

eyes and 12 controls with 14 eyes were enrolled.

Sixty-three (82%) glaucoma patients with 84 eyes and 12

controls (100%) with 14 eyes obtained reliable Peristat tests.

The number of eyes with mild glaucoma was 51 (60.7%). The number of eyes with moderate glaucoma was 18

(21.4%).

The number of eyes with severe glaucoma was 15 (17.9%).

Results: example

Peristat Light grey: -3 dB

Results: example

Peristat Dark grey: -6dB

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Results: example

Peristat Black: -10 dB