Frequency of Visual Fields Needed to Detect Glaucoma Progression: A Computer Simulation Using Linear Mixed Effects Model : Journal of Glaucoma

Secondary Logo

Journal Logo

Novel Glaucoma Insights: Original Studies

Frequency of Visual Fields Needed to Detect Glaucoma Progression: A Computer Simulation Using Linear Mixed Effects Model

Sabouri, Samaneh MSc*; Haem, Elham PhD*; Masoumpour, Masoumeh MD; Vermeer, Koenraad A. PhD; Lemij, Hans G. MD, PhD; Yousefi, Siamak PhD§,∥; Pourahmad, Saeedeh PhD*

Author Information
Journal of Glaucoma 32(5):p 355-360, May 2023. | DOI: 10.1097/IJG.0000000000002155

Abstract

Précis: 

Irregular visual field test frequency at relatively short intervals initially and longer intervals later on in the disease provided acceptable results in detecting glaucoma progression.

Purpose: 

It is challenging to maintain a balance between the frequency of visual field testing and the long-term costs that may result from insufficient treatment of glaucoma patients. This study aims to simulate real-world circumstances of visual field data to determine the optimum follow-up scheme for the timely detection of glaucoma progression using a linear mixed effects model (LMM).

Materials and Methods: 

An LMM with random intercept and slope was used to simulate the series of mean deviation sensitivities over time. A cohort study including 277 glaucoma eyes that were followed for 9.0±1.2 years was used to derive residuals. Data were generated from patients with early-stage glaucoma having various regular and irregular follow-up scenarios and different rates of visual field loss. For each condition, 10,000 series of eyes were simulated, and one confirmatory test was conducted to identify progression.

Results: 

By doing one confirmatory test, the percentage of incorrect progression detection decreased considerably. The time to detect progression was shorter for eyes with an evenly spaced 4-monthly schedule, particularly in the first 2 years. From then onward, results from twice-a-year testing were similar to results from examinations scheduled 3 times per year.

Conclusions: 

Irregular visual field test frequency at relatively short intervals initially and longer intervals later on in the disease provided acceptable results in detecting glaucoma progression. This approach could be considered for improving glaucoma monitoring. Moreover, simulating data using LMM may provide a better estimate of the disease progression time.

Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.

You can read the full text of this article if you:

Access through Ovid