A new screening program for flicker perimetry

A NEW SCREENING PROGRAM FOR FLICKER PERIMETRY

CHOTA MATSUMOTO, SACHIKO OKUYAMA, SONOKO TAKADA, EIKO ARIMURA, SHIGEKI HASHIMOTO and YOSHIKAZU SHIMOMURA

Department of Ophthalmology, Kinki University School of Medicine, Osaka-Sayama, Osaka, Japan

Introduction

We have developed a new screening program for automated flicker perimetry in order to shorten the test duration and to reduce the patient’s task. In this study, we evaluated the clinical usefulness of the new screening program in normal subjects and glaucoma patients.

Methods

Fifty-seven eyes of 57 normal subjects and 63 eyes of 63 glaucoma patients were examined by light-sense perimetry, frequency-doubling technology (FDT) perimeter, and flicker perimetry. Flicker perimetry was performed using the Octopus 1-2-3 and its remote software package with a new screening program No. 38S. The screening program used a four-category, three-level, suprathreshold strategy, which we called a four-zone ‘probability’ strategy. The screening levels were set at 5%, 1% of probability of normality, and 5 Hz. FDT was performed using screening program C-20-1. Lightsense perimetry was performed using HFA-II full threshold program 24-2. Humphrey visual field testing was used as the gold standard, and the number of defect points observed with flicker perimetry and FDT were used for generating the receiver operating characteristics (ROC) curves.

Results

The average test duration with the screening program No. 38S was about 3 minutes in normal eyes and about 5.5 minutes in glaucoma patients. During the early stage of

Address for correspondence: Chota Matsumoto, MD, DSc, Department of Ophthalmology, Kinki University School of Medicine, Ohno-Higashi, Osaka-Sayama City, Osaka 589-8511, Japan. Email: chota@med.kindai.ac.jp

Perimetry Update 2002/2003, pp. 397–398

Proceedings of the XVth International Perimetric Society Meeting, Stratford-upon-Avon, England, June 26–29, 2002

edited by David B. Henson and Michael Wall

© 2004 Kugler Publications, The Hague, The Netherlands

glaucoma (MD < -6), the areas under the ROC curves were 0.93 with both flicker and FDT. During the moderate (MD < -12) and advanced (MD ≥ -12) stages of glaucoma, the areas under the ROC curves were 1.0 for both tests. In glaucoma suspects (normal visual field on light-sense perimetry with clear nerve fiber layer defect (NFLD) or glaucomatous optic discs, the areas under the ROC curves were 0.77 with flicker perimetry and 0.60 with FDT. In the normal hemifields of glaucoma subjects, the areas under the ROC curves were 0.83 with flicker perimetry and 0.65 with FDT (p < 0.02). This means that abnormal critical flicker fusion frequency values were detected in the normal hemifields of glaucoma subjects.

Conclusion

The four-zone ‘probability’ strategy is a time-saving and practical method for screening flicker field defects.

SCREENING FOR GLAUCOMA IN A GENERAL POPULATION WITH A NON-MYDRIATIC FUNDUS CAMERA AND A FREQUENCY-DOUBLING PERIMETER

THIERRY ZEYEN,1 MICHÈLE DETRY-MOREL,2 PHILIPPE KESTELYN,3 JACQUELINE COLLIGNON,4 MARC GOETHALS1 and

THE BELGIAN GLAUCOMA SOCIETY

1Department of Ophthalmology, St. Rafael University Hospital, KUL, Leuven; 2St. Luc University Hospital, Université Catholique de Louvain, Brussels; 3University Hospital, RUG, Gent; 4University Hospital, ULG, Liège, Belgium

Abstract

Purpose

To evaluate the validity of a non-mydriatic fundus camera (NMFu camera) and a frequency-doubling perimeter (FDP) for detecting glaucoma in a general population.

Methods

The population of three Belgian cities was invited by advertisement in the newspaper and on TV to take part in a glaucoma screening program. Intraocular pressure (IOP) was measured with a non-contact pneumo-tonometer (NCT) followed by applanation tonometry (AT) if the NCT-IOP was ≥ 17 mmHg. The visual field was screened with the FDP (C-20-5), and digitalized optic disc photographs (ODPs) were taken with the NMFu-camera. FDP was considered abnormal if at least one defective point was found. ODPs were graded as normal or glaucomatous by consensus of three glaucoma specialists. Patients undergoing treatment were excluded from the analysis.

Results

Sixteen hundred and eighty-five subjects were included in the study. Their mean age was 63.2 ± 10.7 years; 8.2% had AT-IOP > 21 mmHg; 98.1% of the ODPs could be interpreted. Glaucomatous optic discs were detected in 3.5% of the subjects. In this group, only 24% had AT-IOP ≥ 22 mmHg. FDP was abnormal in 32% of the subjects. The sensitivity and specificity of FDP for identifying patients with an optic disc graded as glaucomatous was 58.6% and 64.3%, respectively.

Conclusions

The NMFu camera is a useful method for screening glaucoma. IOP ≥ 22 mmHg was detected in 8% of the participants taking part in this mass glaucoma screening, but only in 24% of those with a glaucomatous optic disc. FDP in a screening strategy is not sensitive enough when the cut-off value is set at one defective test location.

Address for correspondence: Professor T. Zeyen, Department of Ophthalmology, UZ Leuven, Kapucijnenvoer 33, B-3000 Leuven, Belgium

Perimetry Update 2002/2003, p. 399

Proceedings of the XVth International Perimetric Society Meeting, Stratford-upon-Avon, England, June 26–29, 2002

edited by David B. Henson and Michael Wall

© 2004 Kugler Publications, The Hague, The Netherlands