Bringing PROMs into the Intermediate Vision Equation

With a proliferation of trifocal and extended depth of focus (EDOF) lenses now available, there is a pressing need to accelerate the development of outcome-based quality registries and appropriate tools for patient-reported outcomes for intermediate vision, according to Anders Behndig MD, PhD.

“We do have some tools available to us, but there is still a lack of transparent and standardised outcome data when it comes to patient-reported outcome measures (PROMs) and intermediate vision,” Dr Behndig said. “We know, for instance, that distance visual acuity is poorly correlated with a patient’s total visual functioning.”

The patient’s quality of life and ability to function with daily tasks should be included in any feasible measure, he added.

“Ideally, a decision to perform cataract or clear lens extraction surgery should not be based on visual acuity alone but also consider the impact of the cataract and/or presbyopia on the patient’s quality of life and functioning,” he said. “Preferably, this should include new activities of daily life associated with social change, such as smartphones and laptops, all of which typically require good intermediate vision.”

PROMs provide a direct assessment of a patient’s subjective experience, encompassing aspects such as functional impairment, quality of vision, and overall satisfaction post-treatment, Dr Behndig explained.

In Sweden, for instance, validated questionnaires such as Catquest-9SF have been of considerable value in assessing the impact of cataracts on daily tasks since their introduction in 2007. Nevertheless, the questionnaire has not adapted to capturing the kind of data needed in an era of multifocal and EDOF lenses.

“It is a good gold standard, but one of the disadvantages of Catquest-9SF is its design for cataract with monofocal IOLs for distance vision and near vision corrected with glasses—so it does not really distinguish whether the patient has glasses,” Dr Behndig said. “Furthermore, there are no questions on spectacle independence as it wasn’t designed for that purpose. And while two questions do relate to intermediate vision, it is not possible to extract that data from Catquest-9SF.”

Another assessment tool, the Visual Function Index (VF-14), consists of 18 questions covering 14 aspects of visual function affected by cataracts, but again is not really geared to assessing intermediate vision.

“A lot of the questions include phrases such as ‘even with glasses,’ which rules out spectacle independence and intermediate vision,” he said.

The National Eye Institute Visual Function Questionnaire-9 (NEI VFQ-9) is more recent but does not fit Rasch analysis, which rules out any meaningful statistical analysis based on its data. Another tool, the Quality of Vision (QoV) questionnaire, includes 30 items and 10 symptoms and effectively measures subjective quality of vision.

“It is psychometrically robust but very demanding if you want to perform it on a large scale. The Visual Function Index has 18 items and is less demanding—but less psychometrically robust,” Dr Behndig said. “There is also the Near Activity Visual Questionnaire (NAVQ) designed for near-vision functioning in presbyopia—but it does not reflect more recent changes in technology as it was developed in 2008.”

Looking ahead, Dr Behndig said he envisions a future where PROMs are seamlessly integrated into clinical practice through electronic interfaces. Automated data transfer to registries could streamline data collection and analysis, enhancing the efficiency of outcome evaluation.

Dr Behndig presented this study at the 2024 ESCRS Winter Meeting in Frankfurt.

Anders Behndig MD, PhD is Professor of Ophthalmology, Umeå University Hospital, Umeå, Sweden. anders.behndig@ophthal.umu.se