Use of the patient acceptable symptom state and the minimal clinically important difference to evaluate the outcomes of cataract extraction

Should We Perform Early Cataract Surgery? A Patient Reported Outcome Study

Purpose

Current guidance states that access to cataract surgery should not be restricted by visual acuity (VA); nevertheless, 6/12 is used as a cut-off criterion in some health institutions. This study aims to determine the benefits of performing cataract surgery in patients with VA of 6/9 or better in both eyes; determine whether these benefits change over time; and compare the benefit observed between early first eye and second eye surgery.

Patients and Methods

Fifty adults with VA at least 6/9 in the worst eye and no ocular comorbidity were recruited. The Visual Function Index (VF-14) and Impact of Visual Impairment (IVI) questionnaires were conducted pre-operatively, 4 months post-operatively, and 12 months post-operatively. The t-test or a non-parametric equivalent was used to compare averages between groups.

Results

The mean change in VF-14 from baseline to 4 months was 16.43 (95% CI 12.49–20.50, p < 0.001) and the median change in IVI was 6.5 (IQR 9.75, p < 0.001). There was no significant difference between 4-month and 12-month follow-up (p > 0.05). There was no significant difference in the change in visual function between the first and second eye surgery (p > 0.05).

Conclusion

This study provides evidence that visual function improves after cataract surgery in patients with pre-operative VA of 6/9 or better. The improvement observed was clinically significant and unchanged a year after surgery. Visual function improved after second eye as much as after first eye surgery. Assessing patient reported visual function may give a more realistic indication of the benefit of early cataract surgery than relying on VA alone.

Glaucoma and glare

PURPOSE

To determine whether a purpose-built glare tester, in combination with new glare-specific questions, can better assess glaucoma patients' experience of glare and visual disability than visual acuity (VA) or visual fields alone.

PATIENTS AND METHODS

Consecutive patients attending for visual fields in a single glaucoma clinic from 03/06/2019-01/11/2019 underwent VA assessment using a Brightness Acuity Tester as a glare source, examination for media opacities, and completed the VFQ-25 with four additional glare-related questions. One hundred and sixteen eyes (64 patients) were included for analysis. The amount of disability glare (VA reduction due to glare) was compared according to presence/absence of media opacity and glaucoma severity. Subjective glare symptoms were compared with objective disability glare measurement using a Bland-Altman plot.

RESULTS

Patients with advanced-severe glaucoma had significantly worse disability glare than those with mild-moderate glaucoma. VA reduction due to glare from mild-moderate to acute-severe glaucoma (mean -3.4 letters, P = 0.01, CI -0.8, -6.0) was of almost identical magnitude to that due to presence of any media opacity (mean -3.3 letters, P = 0.03, CI -0.4, -6.2). There was a trend towards greater disability glare in more symptomatic patients, with good agreement between subjective and objective glare measurements for those with few glare signs or symptoms, but progressively more variation either side of agreement as either measurement worsened.

CONCLUSIONS

Glaucoma is associated with objective and subjective acuity reduction in the presence of glare. We demonstrated an increase in disability glare in patients with more severe glaucoma. The worse the glare symptoms or signs, the more variable the agreement between objective and subjective assessments.