Abstract
Purpose:
To quantify the self-reported degree of vision difficulty perceived by patients presenting with reduced visual acuity.
Methods:
The study population consisted of adult patients (age ≥ 25years) from the Ophthalmology Clinic of UNIFESP University Hospital with a wide range of ophthalmological diagnosis stratified by presenting binocular distance visual acuity (VA) measured with an ETDRS retro-illuminated chart, age, gender, and education level. Patients were first asked to assess the degree of difficulty seeing (none, mild, moderate, severe or extreme/cannot do) for five vision vignettes representing the visual acuity spectrum from normal vision to no light perception. Patients then ranked these five vignettes, along with their own vision, from the most desirable to the least desirable. Rank ordering was followed by a 0 to 100 analog scale rating of each of the six vision states, where a valuation of 0 (corresponding to a disability weight [DW] = 100) was to be considered as undesirable as death and a valuation of 100 (DW=0) as perfect vision. The correlation between the patient’s VA and the DW valuation of their own vision was assessed by Spearman coefficients. The association of DW valuations with VA, age, gender, and education level was assessed by multivariate regression.
Results:
A total of 606 patients (54.45% females) were included in the study. Mean valuations ranged from 90.55±12.7 for the normal vision vignette to 5.47±10.2 for the no light perception vignette. Overall, the mean valuation for the patient’s own vision state was 48.46 ±28.0. Mean valuations were 73.9 ±18.6 for those with VA≥20/32, 57.7 ±21.8 for those with VA 20/40 to 20/63, 47.8 ±20.1 for those with VA 20/80 to 20/160, 34.6 ±18.6 for those with VA 20/200 to 20/400, and 19.0 ±18.8 for those with VA ≤20/500. DW valuations were closely correlated with VA, with a Spearman correlation coefficient of .728, P<0.001. In multivariate regression, lower valuations were associated with decreased VA (P<0.001), younger age (P<0.001), and increased education level (P<0.05). Gender was not significant.
Conclusions:
The increasing impact on DW valuations was consistent with severity of visual acuity impairment, and also associated with age and education level. DW valuations provide a promising tool to quantify the patient-perceived burden of visual impairment due to ocular abnormalities.
Keywords: 465 clinical (human) or epidemiologic studies: systems/equipment/techniques •
584 low vision •
754 visual acuity