The psychological outlook of patients has an enormous influence on their perception of quality of life after cataract surgery, even if the visual outcome is poor. This was one of the main outcomes of a study performed at the Department of Ophthalmology at the Medical University of Vienna in cooperation with the Department of Psychology at the University of Vienna, Austria.

The study assessed the improvement of self-reported quality of life in cataract patients. The 105 patients included completed a number of quality of life questionnaires before surgery and one month after surgery. Among the standardized questionnaires used were the Short-Form-36 (SF-36), Nottingham Health Profile (NHP) and National Eye Institute Visual Function Questionnaire (NEI-VFQ). Additionally, the patients gave a self-reported subjective rating of their visual acuity (VA) using an analogue scale (VAS), and were tested for actual VA using Snellen charts.

Table 1: Categorizing patients into four groups according to their measured VA and their self-reported visual function using a visual analogue scale (VAS).

In order to analyze the study, the patients were categorized into one of four groups, as described by the psychologists Fillip and Ferring (Table 1). The categories were: good VA and good VAS (G1 - the fortunate); good VA and poor VAS (G2 - dissatisfaction dilemma); poor VA and good VAS (G3 - satisfaction paradox); and poor VA and poor VAS (G4 - the unfortunate).

Dissatisfaction is avoidable

Postoperative assessment found that some patients who had a relatively poor VA after cataract surgery remained quite satisfied with their quality of vision and life. Conversely, some with better-measured VA were less satisfied. These findings have important implications for patient selection.

As expected, significant improvements of self-reported quality of life were detected in 18 of 26 dimensions of the test instruments in all groups. Deterioration was detected in the dimension 'physical role' limitations, probably because of late spectacle correction. This was because patients were not immediately supplied with optimized reading glasses and therefore felt physically compromised. This calls for immediate support of patients with reading aids to be provided with reading vision until a definite prescription of reading glasses.

The patients that fell into the "fortunate" and the "unfortunate" groups were as we had expected. Patients who had good VA and also showed good self-reported visual function were happy, whilst patients who had poor VA and also reported their visual function to be poor were naturally less satisfied.

Patients with good vision still not satisfied

More interesting was the "satisfaction paradox" group; patients whose vision was relatively poor, but were happy anyway. We all know such patients, and it is probably best to leave them happy. However, the "dissatisfaction dilemma" patients, essentially the opposite of the "satisfaction paradox" group, give cause for concern. These patients have a good VA but they are still not satisfied.

To a certain extent, mental health explains the differences. The 'happy but unfortunate' patients tended to be in good mental health; however, there was a tendency for the mental health of the 'fortunate but unhappy' patients not to be as good. Consequently, surgeons should be sensitive to patients' attitudes and adapt their approach to these patients accordingly.

Surgeons must consider the fact that "satisfaction paradox" patients might often not need surgery. Postoperatively, this group of patients showed the least increase in both quality of vision and quality of life with surgery out of all four groups. They were probably happy before surgery, and also afterwards. It is therefore possible that this group of patients did not show significant symptoms from their cataract and they simply had cataract surgery because they were advised to do so. Prior to surgery, patients must be asked whether they feel constrained in their daily life by their decreased vision. Quite often patients from this group will not complain of any significant visual problems. If the cataract is not too significant, delaying surgery may be the best decision for these patients.

With regards to the "dissatisfaction dilemma" group, there may be several causes for low satisfaction in these patients, including: poorer visual function in comparison to measured VA; unrealistically high expectations; feelings of 'depression'. There are several factors that would cause a disparity between visual function and measured VA, such as poor contrast sensitivity due to higher order aberrations, or worse near acuity than before surgery due to a loss in depth of field or hyperopic shift in refraction compared with before surgery. Such phenomena can cause a change in the daily functional vision and can be disturbing to the patient, especially if not corrected with glasses as needed.

As pointed out earlier, patient expectations may have been too high before surgery. In these cases there is a need for a particularly thorough informed consent process preceding surgery. Finally, referral to a psychologist for additional help may be appropriate for some patients in this group, especially if no other obvious reasons for the dissatisfaction can be identified.

How can we make every patient happy?

In summary, cataract surgery generally improves the self-reported quality of life in patients with age-related cataract as expected. Categorizing patients according to their own estimation of visual function and the measured VA seems to be a promising way of identifying the causes of unhappiness after surgery.

The decision of whether and when to perform cataract surgery in patients with little or no complaints should be tuned more to the needs of these patients, since they were the ones that profited the least from surgery, even though satisfied. But these patients would probably also have been satisfied without surgery. On the other hand, in some patients who are less satisfied after surgery, even though their VA is good and after ruling out other causes for poor functional vision, a referral to a clinical psychologist for further work-up may be helpful.

Lastly, future studies should help to preoperatively identify patients who fall into the category of "dissatisfaction dilemma" because of unrealistically high expectations, and informed consent should be modified accordingly for these patients.