Impact of light conditions on reading ability following multifocal pseudophakic corrections

Abstract

Purpose

To examine the impact of light intensity and temperature on reading performance following bilateral pseudophakic multifocal presbyopic correction.

Patients and methods

This is a prospective clinic-based trial conducted at the Department of Ophthalmology in the University Hospital of Alexandroupolis, Greece. Three groups of patients were formed (G1: patients with bilateral bifocal implantation, G2: patients with bilateral trifocal implantation, and control group: patients with bilateral pseudophakic monofocal implantation). Reading ability was quantified with the Greek version of MNREAD chart with minimal reading speed at 80 words/min for the following light intensities (25, 50, and 75 Foot-Candles [FC]) and temperatures (3,000, 4,000, and 6,000 K). Preferred light conditions for reading were assessed, as well. ClinicalTrials.gov Identifier: NCT03226561.

Results

Control group demonstrated significantly lower reading ability at all light combinations with maximal ability at 75 FC and 6,000 K (0.58±0.18 logMAR). Bifocal group presented a light-dependent reading ability that ranged from 0.45±0.08 logMAR (25 FC and 3,000 K) to 0.40±0.11 logMAR (75 FC and 4,000 or 6,000 K). Trifocal participants presented the best reading ability that was light intensity-independent; however, their performance was reduced at 6,000 K. G1 and G2 preferred primarily intermediate light temperature, while control participants preferred cold light temperature.

Conclusion

Multifocal pseudophakic corrections improve reading ability; however, they present variable efficacy according to the light conditions.

Keywords:

• presbyopia
• light intensity
• Kelvin
• Foot-Candles
• trifocal
• bifocal

Author contributions

GL conceived and designed the study, performed the operations, wrote the main manuscript, and supervised the study. PN involved in data collection/data analysis/interpretation of data. EKP involved in data collection and drafting the manuscript. AK and MG involved in data acquisition. DD and IP involved in data analysis/interpretation of data. HS contributed to the conception and the design of the work, involved in data analysis/interpretation of data/statistical analysis and supervised the paper. All authors contributed to data analysis, drafting or revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.