Abstract
Purpose: :
To describe the distribution of near and distance visual function impairment (VFI) by type of refractive error (RE) and correction status, and to determine factors that significantly affect VFI.
Methods: :
Ophthalmic examination and the NEI-VFQ were administered to a random sample of 4509 Latino subjects over 40 years old from Tucson and Nogales, Arizona. Subjects were determined to have RE if they were wearing prescription glasses for distance vision and had a presenting visual acuity (PVA) of 20/25 or better, or had PVA worse than 20/25 and improved≥2 lines after subjective refraction. Uncorrected RE was defined as ≥2 line improvement in both eyes. Subjects with other eye disease, bilateral cataract surgery, no visual testing data, and bilateral BCVA worse than 20/200 were excluded. RE groups were defined by spherical error (SE) in the better eye; myopia was defined as SE≤-0.5, mild between -0.5 to 1.0, and hyperopia≥1.0. Three VFI score categories (under 75, 75-99, and 100) were created for near and distance VFI. An ordinal logistic regression was used to determine if the percentage of subjects in each score group was different for each RE group compared to the no RE group, adjusting for age, sex, diabetes, hypertension, income, education and acculturation.
Results: :
Of 4185 subjects, 945 were myopic (135 uncorrected), 535 mild RE (120 uncorrected), and 814 hyperopic (174 uncorrected). 55% of subjects were female, and the average age was 51. Of subjects with no RE, 71% reported no distance VFI (score 100), 23% "mild" distance VFI (score 75-99) and 6% "more" distance VFI (score<75). The respective percentages for near VFI in no RE subjects was 36%, 43%, and 21%. Subjects with myopia, mild RE, and hyperopia were significantly more likely to report more distance VFI than subjects without RE, whether or not they had correction (p<0.001). Corrected myopes reported less near VFI than subjects without RE (p=0.003), while uncorrected hyperopes reported more near VFI (p=0.001). Self reported distance and near VFI scores were sensitive to non-vision variables; namely, sex (p<0.001), diabetes (p=0.002), acculturation score (p<0.001), income (p<0.001), and education (p<0.001). Near vision score was also sensitive to age (p<0.001) and hypertension (p=0.046).
Conclusions: :
In subjects with any type of refractive error, visual correction is not sufficient to restore distance visual function to the level of subjects without refractive error. More research is necessary to determine the reasons for this shortcoming.
Keywords: quality of life • hyperopia • myopia