Monitoring glaucomatous progression using a novel Heidelberg Retina Tomograph event analysis.
OBJECTIVE
To describe an event analysis (EA) for monitoring Heidelberg Retina Tomograph (HRT) progression and to establish specificity, detection rate, and agreement with visual field progression by application to longitudinal data.


METHODS
Retrospective analysis of data from a randomized controlled trial.


METHODS
One hundred ninety-eight ocular hypertensive and 21 control subjects.


METHODS
Change criteria were derived from rim area (RA) repeatability coefficients for different levels of image quality. Event analysis 1 (EA1) through EA4 were applied to longitudinal series of HRT images acquired from the ocular hypertensive and the control cohorts: EA1 (change confirmed in 2 of 3 consecutive tests in 1 or more sector), EA2 (2 of 3 in 2 or more sectors), EA3 (3 of 3 in 1 or more sector), EA4 (3 of 3 in 2 or more sectors). Specificity (1 minus false positive results) was estimated by the proportions of progressing controls and significantly improving subjects. Progression rates were compared with Advanced Glaucoma Intervention Study (AGIS) visual field (VF) criteria, an HRT trend analysis, and a VF trend analysis, with specificity matched at 95%.


METHODS
Estimated specificity, progression rate, and agreement between progression techniques.


RESULTS
Specificity estimates were 76.2% to 88.1% (EA1), 94.1% to 95.2% (EA2), 92.2% to 95.2% (EA3), and 99.1% to 100% (EA4). Of ocular hypertensive (OHT) subjects, 45.4%, 28.3%, 26.3%, and 16.2% were identified as progressing by each strategy, respectively. With specificity at 95%, 12.1% of OHT subjects progressed by both EA2 and AGIS criteria, with a median time to progression of 3.2 and 3.6 years, respectively. By EA2 alone, 16.2% progressed, and 9.6% progressed by AGIS criteria alone. The RA trend analysis identified 12% of OHT subjects as progressing.


CONCLUSIONS
The HRT EA represents a simple technique, taking into account image quality. In this cohort, it had a higher detection rate of progression, at 95% specificity, than RA trend analysis and the VF progression criteria.
Glaucoma Research Unit, Moorfields Eye Hospital, London, United Kingdom.
Tessa
T
Fayers
Nicholas G
NG
Strouthidis
David F
DF
Garway-Heath
D000328:Adult; D000368:Aged; D003941:Diagnostic Techniques, Ophthalmological; D018450:Disease Progression; D005189:False Positive Reactions; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014054:Tomography; D014786:Vision Disorders / Q000175:diagnosis; D014794:Visual Fields