Relationship between refractive correction, visual symptoms, and optical device selection for low-vision patients in Taiwan

Assessing low vision care and the utilisation of optical low vision aids among patients with visual impairment in Taiwan

PURPOSE

The aim of this study was to examine the quality of assessment and the utilisation of optical low vision aids (OLVAs) among people with visual impairment (VI) in Taiwan.

METHODS

The study included 577 participants between 4 and 100 years of age (314 males and 263 females). All participants had been certified by the Ministry of the Interior of Taiwan, indicating that they had undergone a thorough and comprehensive low vision assessment, including evaluation of visual acuity (VA), contrast sensitivity, colour vision, visual fields and glare disability. Furthermore, all participants who consented to refraction had received prescriptions for OLVAs.

RESULT

All participants were prescribed one or more OLVAs such as eyeglasses, tinted lenses, magnifiers, closed-circuit television magnifiers, telescopes, or screen magnifiers. Among the 577 individuals, 515 received correction for refractive errors, providing the best-corrected VA (BCVA). The improvement in VA was significant at both distance and near, improving from 1.29 ± 0.55 to 1.01 ± 0.52 logMAR (p < 0.001) and from 1.29 ± 0.56 to 1.01 ± 0.52 logMAR (p < 0.001), respectively. Eyeglasses were the primary OLVAs chosen by 333 participants (64.7%), while 53.3%-80.3% of participants combined eyeglasses with other OLVAs to enhance their visual performance.

CONCLUSIONS

The most commonly used and effective OLVA was eyeglasses. Skilfully utilising appropriate refractive and VA measurements is crucial for determining the most suitable and beneficial OLVA for individuals with VI.

Effect of Blue Light Filters on Tear and Contrast Sensitivity in Individuals Using Electronic Devices

OBJECTIVES

To investigate the effect of contact lenses with blue light filters on contrast sensitivity and any alteration in tear quantity and quality.

METHODS

This prospective longitudinal pilot study required three visits by each participant. Monocular visual acuity, contrast sensitivity, phenol red thread test, and tear breakup time were measured at each visit.

RESULTS

There were significant differences in logarithmic contrast sensitivity between the groups. The breakup time (BUT) was significantly lower after using video display terminals than before (P<0.05). No differences in BUT were found between groups video display terminals and contact lenses having the blue filter (P>0.05). However, higher mean values were observed in the group after video display terminal use with contact lenses having the blue filter than that with standard contact lenses (P>0.05 in both groups). Furthermore, the mean value of phenol red thread test on the group after video display terminal use with contact lenses having the blue filter was lower than the group before its use (P>0.05).

CONCLUSION

The results establish a possible relationship between tear stability, improved contrast sensitivity, and the use of a blue filter in contact lenses.