Visual acuity and vision-related quality of life outcomes following cataract surgery in Ebola virus disease survivors

Abstract

Objectives: The objectives of this study were to assess relationships between vision-related quality of life (QoL) and visual acuity (VA) in Ebola virus disease (EVD) survivors after cataract surgery in the Ebola Viral Persistence in Ocular Tissues and Fluids (EVICT) Study.

Materials and methods: EVD survivors with undetectable Ebola virus (EBOV) ribonucleic acid in their aqueous humour were eligible to receive manual small-incision cataract surgery (MSICS). Among those that received surgery, assessments of VA and vision-related QoL were assessed pre-and post-cataract surgery. VA was converted from units on a tumbling 'E' chart to the logarithm of the minimal angle of resolution VA (logMAR VA). Vision-related QoL was assessed using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). Linear regression was used to evaluate the associations between VA and vision-related QoL. P = 0.05 was considered statistically significant for all analyses.

Results: Thirty-four EVD survivors underwent cataract surgery in the EVICT study. Before MSICS, the mean logMAR VA was 2.24 (standard deviation [SD]: 0.98), and the mean NEI-VFQ-25 composite score was 54 (SD: 15); however, there was no significant association between the pre-surgery measurements (average difference in VA/10 unit increase in NEI-VFQ-25: -0.04, 95% confidence interval (CI): -0.33-0.26, P = 0.80). There was a significant improvement in logMAR VA after MSICS (mean: 1.6, P < 0.001), but there was no significant change in the NEI-VFQ-25 composite (-0.87, 95% (CI): -10.32-8.59, P = 0.85). None of the subscales showed significant improvements (P > 0.12 for all); however, the magnitude of the mean change for distance activities (6.65), near activities (6.76), general vision (-7.69), social functioning (-9.13) and colour vision (13.33) met the criteria for a clinically meaningful difference (4-6). In the subset with paired measurements (n = 16), there were no significant association changes in logMAR VA and NEI VFQ-25 composite scores (P > 0.12 for all).

Conclusion: Following cataract surgery, VA in EVD survivors improved, but these improvements were not reflected in NEI VFQ-25 composite scores or specific subscales; however, the small sample size limits generalizability absent more research. Differences in sociocultural context and activities that affect the QoL in resource-limited areas may contribute to the limitations seen with NEI VFQ-25. In addition, better eye dominance could contribute to any lack of association as NEI VFQ-25 evaluates vision as a whole. Further, assessment of factors contributing to improved QoL may help to define the impact of vision health in varied environments.

Keywords: Cataract surgery; Ebola virus disease (EVD); Uveitis; Vision-related quality of life; Visual function questionnaire.

Figure 1:

CONSORT diagram – Ebola Viral Persistence in Ocular Tissues and Fluids (EVICT) participants included in analysis of visual acuity and national eye institute visual function questionnaire 25 vision-related quality of life before and after cataract surgery. N: number of subjects, NEI-VFQ25: National Eye Institute Visual Functional Questionnaire 25.

Figure 2:

Comparison of visual acuity and national eye institute visual function questionnaire 25 vision-related quality of life before cataract surgery. Note: The blue dotted line indicates the general trend of the data. logMAR: log of minimum angle of resolution, VFQ-25: National Eye Institute Visual Function Questionnaire 25.

Figure 3:

Comparison of the changes in visual acuity and national eye institute visual function questionnaire vision-related quality of life after cataract surgery. Note: The blue dotted line indicates the general trend of the data. logMAR: log of minimum angle of resolution, VFQ-25: National Eye Institute Visual Function Questionnaire 25.