Impact of Visual Impairment and Blindness on Self-Reported Visual Function and Related Quality of Life in Patients From a University Hospital in Brazil

Abstract

 

Purpose:

 

To assess the negative impact of visual impairment and blindness by self-reported visual function and related quality of life in patients presenting several degrees of reduced visual acuity.

 

Methods:

 

The study population consisted of adult patients (age ≥ 25years) from the Ophthalmology Outpatient Clinic of Federal University of São Paulo (UNIFESP) University Hospital (Hospital São Paulo) with a wide range of ophthalmological diagnosis stratified by presenting binocular distance visual acuity (PBVA) measured with an ETDRS retro-illuminated chart (≥20/32; 20/40-20/63; 20/80-20/200; 20/200-20/400; ≤20/500), age (25-39, 40-49, 50-59, 60-69 and 70+yrs.), gender and socio-economic status. The WHO 20-item International Visual Functioning Questionnaire (VFQ) was translated to the Portuguese language and then re-translated to the English language by an expert official translator. Piloting of the instrument was conducted to identify issues that could be misunderstood and to perform cross-cultural adaptations before administration of the instrument in individual interviews. Validation of the instrument was provided by examining internal consistency of responses to subscale questions as measured by Cronbach’s alpha statistic. The association of VFQ scores with PBVA and socio-demographic variables was assessed by multivariate regression.

 

Results:

 

A total of 606 patients (54.45% females) was included in the study. Subscales for visual functioning (distant vision, near/intermediate vision, sensory adaptation) and quality of life (pain, social/work activities, mental status) had internal consistency of responses of .943 and .785, respectively. VF and QOL subscale scores were closely correlated with PBVA (Spearman correlation coefficients of .766 and .461, respectively). Older age was associated with higher VF and QOL scores (P<0.001 and P<0.001) as was better overall health status (P=0.007 and P<0.001, respectively); more education was associated with higher VF scores (P=0.004). Gender was not significant.

 

Conclusions:

 

An increasing impact on vision-related quality of life was consistent with severity of visual impairment. This VFQ instrument might be a useful tool to assess the burden of visual impairment and blindness in developing countries. Prevention of visual impairment and blindness is important in mitigating the quality of life impact of these conditions.

 

Keywords: quality of life • low vision • clinical research methodology