Cataract surgery: Why patient reported outcome measures matter
With implantation of presbyopia-correcting IOLs becoming more commonplace, Melbourne ophthalmologist DR LANA DEL PORTO says patient reported outcome measures in cataract surgery can improve results and patient satisfaction.
Incorporating patient reported outcome measures (PROMs) into my cataract assessment has led to better outcomes and increased patient satisfaction. Here, I will outline my reasoning for changing my practise and some of my clinical pearls.
Times are changing
The paternalistic days of medicine are behind us and it is no longer acceptable for IOL selection to be based on the “doctor knows best” philosophy. The days of leaving every patient presbyopic after cataract surgery are over too; they have wised up about their IOL choices and wish to make autonomous decisions. Our role as cataract surgeons is to guide them in the right direction. With recent technological advances, there are many more options available for presbyopia correction at the time of cataract surgery, including monofocal, multifocal and extended depth of focus (EDOF) IOLs.
We are constantly being told to “choose our patients carefully” when it comes to presbyopia-correcting IOL selection. But what does this really mean and how do we do it? I have developed a simple line of questioning, based on statistically validated cataract questionaries, that can help with this process.
“The paternalistic days of medicine are behind us and it is no longer acceptable for IOL selection to be based on the ‘Doctor knows best’ philosophy.”
What are PROMs?
The ‘patient’s view’ is increasingly recognised as a key measure in health service delivery. PROMs are tools that ask questions about people’s health. They gather information from patients about symptoms, condition and overall quality-of-life.
Some PROMs can be used for any condition, while other PROMs can be condition specific. There are hundreds of PROMs that have been developed for ophthalmic conditions from glaucoma through to cataract.
PROMs in cataract surgery
Visual acuity provides a poor indication of visual difficulty in a complex visual world. Patients’ self-reported visual difficulty related to cataract can be reliably measured using questionnaire instruments such as Cat-PROM5 (UK) and Catquest-9SF (Swedish). These questionnaires are used before and after cataract surgery.
Cat-PROM5 measures the self-reported impact of cataracts on vision and quality-of-life. It comprises five items:
1. Whether vision overall has been affected by the “bad” eye
2. The extent to which eyesight has interfered with life in general
3. A rating of vision overall
4. The frequency with which vision prevented usual activities
5. Difficulties in reading normal print in books or newspapers.
When asking patients these questions, the recall period for each is “the last month”.
The Cat-quest-9SF has nine questions. Two general questions about whether their sight causes difficulty with their everyday life and whether they are satisfied or dissatisfied with their vision overall.
There’s then seven questions about specific visual scenarios including reading newspapers, recognising faces, seeing prices when shopping, seeing to walk on uneven surfaces, seeing to do handicrafts, seeing subtitles on the TV and seeing to engage in hobbies. I have adapted this particular questionnaire for my cataract patients and updated it to the modern era.
So which of these PROMs should we be using?
Luckily there was a study that answered this question. It was entitled: ‘A head-to-head comparison of the Cat-PROM5 and Catquest-9SF self-report questionnaires’ and was published in 2018 in Eye, the peer-reviewed official journal of the Royal College of Ophthalmologists.
This study used a Rasch-based performance to assess 822 typical NHS cataract surgery patients across four centres in England. Rasch modelling is a tool used by the social sciences to quantify unobservable human conditions. Both questionnaires demonstrated excellent performance for all metrics assessed including; Reliability Indices of 0.90 (Cat-PROM5) and 0.88 (Catquest-9SF) and responsiveness to surgery (1.5 SD improvement from baseline for both).
The two tests were highly correlated with each other (R = 0.85). Both questionnaires were acceptable to patients, but they preferred the shorter CatPROM5, which allowed them to map their own issues to the questions as opposed to the more specific scenarios of Catquest-9SF.
How do I use PROMs to guide IOL selection?
I start with open ended question like: “What are your hobbies?”. Then ask specific questions including:
• Do you drive? Do you intend to drive at night?
• Do you play golf/tennis?
• Do you watch much TV? With subtitles?
• Do you use a desk-top computer?
• Do you have/use a smart phone?
• Do you read newspapers/books?
• Do you knit/sew?
Next, I ask how much time they spend doing each activity. Finally, I ask how important it is for them to be spectacle independent for each of these activities.
For patients who want it all, I distil it down to this simple yet valuable question: “Please prioritise what is more important to you, driving at night or reading a book without glasses.”
Once I have asked the patient these questions it generally becomes obvious whether they would be best suited to a monofocal, EDOF or multifocal IOL.
Of course, not every patient is suited to an EDOF or multifocal IOL from an ocular pathology standpoint. I steer away from these lenses in patients with amblyopia, macular pathology, corneal pathology, including dystrophies and those with optic neuropathy. These eyes need all the contrast they can get and I don’t want to degrade that contrast by giving them one of these presbyopia correcting lenses. I still describe all three lens types to patients with ocular pathology with an explanation of why certain lenses will not suit them. Most patients know someone who is now glasses independent following cataract surgery and will want to know why they have been left with reading glasses.
How to use PROMs to judge patient satisfaction
PROMs can also be used to judge patient satisfaction. Post-operatively, I ask my patients whether they can perform the following tasks without glasses (listed from least to most near vision requirement):
• Drive?
• Watch TV including subtitles?
• Use a desk-top computer?
• Cook/eat a meal?
• Read a restaurant menu?
• Read a book/newspaper?
• Read food labels?
• Thread a needle?
Answering these questions makes them realise how far they have come and what a good job you, the surgeon, have done.
A patient centred approach to cataract surgery outcomes is needed in our modern world. PROMs are likely to become a measure of cataract surgery success in the near future. This is especially important in the setting of rapidly progressing IOL technology such as presbyopia-correcting IOLs. Surgeons may wish to develop their own style of questioning preoperatively in order to help guide IOL selection and post-operatively to gauge patient satisfaction.