Powerful new tool to test for all major eye diseases
Novel system measures ophthalmic quality of life with greater precision
A new testing system for quality of life (QoL) patient-reported outcome measures will give ophthalmologists a powerful new tool to test for all major eye diseases across all population groups, according to Konrad Pesudovs PhD.
“The Eye-tem Bank project is a large project that develops a third-generation approach to the measurement of ophthalmic QoL across 13 different disease groups. We have made tremendous progress in the last year or so and have now completed phase I for 10 disease groups,” he told delegates at the XXXIV Congress of the ESCRS in Copenhagen, Denmark.
Dr Pesudovs, Foundation Chair of Optometry and Vision Science at Flinders University in Adelaide, South Australia, said that Eye-tem will eventually be made available for wider use via an Internet-based ophthalmic QoL measurement system to provide online testing, real-time scoring and data storage across a range of digital formats.
Although a wide variety of patient-reported outcomes (PROs) already exist in ophthalmology, they are not all the same in terms of technology or content, said Dr Pesudovs.
Invalid scoring is the main issue with first-generation PROs which use summary scoring, where ordinal values are applied to response categories, he explained. “They are not really suitable for statistical analysis of correlation or change,” he said.
While Rasch analysis solves this problem in second-generation instruments, allowing them to be used for statistical analysis, these PROs also have limitations, said Dr Pesudovs. “The content of a questionnaire may not suit the population and may be too easy or too difficult. There is a trade-off of length versus applicability, they are not adaptable to change and they use a paper-based format, so are not very convenient or efficient to use,” he said.
The approach of the Eye-tem Bank system is to use item banking combined with advanced information technology to overcome the handicaps of first- and second-generation PROs.
“Item banking uses a very large collection of questions or items and these items are calibrated on a single measurement scale using Rasch analysis. The advantage of having many items is that you can suit all patients’ abilities and therefore all populations. It is dynamic, new questions can be added to keep the content current, and measurements can be made very quickly using computer adaptive testing (CAT),” he said.
Studies thus far show that new domains of QoL should perhaps also be considered, such as “coping” and “driving”, said Dr Pesudovs.
“We may also need to consider splitting groups further in vitreoretinal into hereditary and acquired diseases, and we have shown the clear importance of disease-specificity, with only 20% of items common across all groups,” he added.
Konrad Pesudovs: email@example.com