Listen carefully to patients complaints after cataract surgery

“We need to listen carefully to what we are being told by our patients. History taking is important to discuss symptoms such as glare, halos, starburst and so forth to determine the nature of the problem and to come up with a strategy to deal with it,” he said.

Surgeon bias must also be taken into account, said Prof Pesudovs, Foundation Chair of Optometry and Vision Science at Flinders University in Adelaide, South Australia.

“We have to not only ask the right questions, but also to hear the answers - and not just what we want to hear. Surgeons have their own biases and will tend to upregulate operable complaints and downregulate inoperable ones. So we need to listen carefully and tease out how it is that these complaints are affecting their vision,” he said.

"The range of patient responses can run a broad spectrum from barely noticing dysphotopsia to being completely miserable because of it,” said Prof Pesudovs.

“We have seen this in refractive surgery with LASIK, where about 30 per cent of patients say they experience some positive dysphotopsia and they may experience it a lot of the time. Yet, only one or two per cent of these LASIK patients are actually dissatisfied, so they are not really bothered by their positive dysphotopsia,” he added.

“While questionnaires are the mainstay of patient-reported outcomes, it is important to bear in mind that they are not all equal and can be divided into three categories: first generation (the majority of dysphotopsia questionnaires), second generation (Quality of Vision Questionnaire* for positive dysphotopsia), and third generation (the recent Eye-tem Bank project which aims to develop and validate disease-specific quality of life item modules implemented via computer adaptive testing (CAT) for all eye diseases across all populations)," said Prof Pesudovs.

“The main issue with first-generation questionnaires is invalid scoring,” said Prof Pesudovs.

“They use summary scoring where ordinal values are applied to response categories. They assume the spacing between response categories are equidistant and that all questions have the same value. So they are not really suitable for statistical analysis of correlation or change,” he said.

“Rasch analysis solves this problem in second-generation instruments and can be used for statistical analysis. The Quality of Vision Questionnaire* is available for positive dysphotopsias. There is currently no instrument available for measuring negative dysphotopsia and clinicians need to rely on simple documentation,” he added.

* McAlinden C, Pesudovs K, Moore JE. The development of an instrument to measure quality of vision: the Quality of Vision (QoV) Questionnaire. Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5537-45

Konrad Pesudovs: konrad.pesudovs@flinders.edu.au