Epidemiology of Field of Vision Disorders (eFOVID) study, Western Australia, 1988-2022. Report 1: Data collection and aggregation protocol.

Background: Computerised static visual field testing using dedicated machines such as the Humphrey Field Analyzer (HFA) can assess and track changes in visual field sensitivity. The use of retrospective visual field databases is a novel undertaking, with no studies published utilising large scale population-level data. This study phase developed a method to extract HFA data into a large standardised population-based database including point sensitivity data with additional derived variables.

Methods: Retrospective, longitudinal, population study of visual field data from people who attended an ophthalmology service and had a HFA field test, in Western Australia, between 1988 and 2022. Raw test data included patient demographic fields, sensitivity readings and test parameters. Calculated fields included reliability scores, and a novel combined reliability score.

Results: There were 606 230 tests for 92 215 study individuals, from 22 ophthalmology practices in metropolitan Perth and three public hospital eye clinics, representing around 85% of the field tests performed by ophthalmologists each year. Raw sensitivity values were available for all tests, and additional descriptors were available for most tests (97.5%-100% of tests) with the exception of data variables retired by the manufacturer.

Conclusions: Visual field data from 606 230 tests were collated into a single dataset, which is highly representative over a long period of time, for a defined population. This dataset has been linked to other administrative datasets to allow for epidemiological investigation of field of vision disorders.