Posters

Learning curve of automated perimetry in glaucoma patients

Poster Details

First Author: J.Lam SINGAPORE

Co Author(s):    S. Loon              

Abstract Details

Purpose:

To determine the minimum number of visual field tests needed for accuracy in glaucoma patients, using the Humphrey® automated perimetry for visual field testing (HVF).

Setting:

A general glaucoma clinic in the Ophthalmology department, National University Health System, Singapore.

Methods:

A retrospective case note review of 31 patients in a glaucoma clinic was carried out. Three criteria were selected as the basis for deciding whether a field was of sufficient accuracy, using the manufacturer's standard for a reliable field: fixation loss rate must be under 20%, false negative response rate and false positive rate must both be under 33%. If a printout fails to meet this criteria, the results of that field test was deemed unreliable. Visual field test for the right eye of each patient was included and the number of HVF was counted from the first HVF done by the patient. Demographic data was collected and the number of visual field testing needed to attain accuracy was determined for each patient.

Results:

Of the 31 patients, 67.7% were male and the majority were of Chinese ethnicity (83.4%). The median age was 65 years and the median number of HVF needed to achieve the reliability indices stated was 1. Primary open angle glaucoma was diagnosed in 11 out of 31 patients (35.5%) and 22.6% of patients suffered from primary angle closure glaucoma.

Conclusions:

Contrary to popular belief that two or more visual field tests are needed to attain a reliable HVF for diagnosis of glaucoma, based on the manufacturer's standard for a reliable field, the majority of our patients obtained reliable HVF on their first test. This important finding could result in fewer visual field tests for our glaucoma patients and reduce the economic burden that glaucoma has on our patients. FINANCIAL INTEREST: NONE