Influence of Sodium Hyaluronate Concentration on Corneal Aberrations in Soft Contact Lens Wearers

Abstract

Purpose: This study aimed to evaluate the influence of varying concentrations of sodium hyaluronate (SH) eye drops on corneal aberrations in normal individuals wearing silicone hydrogel contact lenses.

Methods: Normal individuals wearing silicone hydrogel contact lenses were enrolled in this study. Subjects were classified into two groups depending on the concentration of the preservative-free SH used (group 1, 0.1% SH; group 2, 0.3% SH). All subjects were asked to blink five times after instillation of the SH eye drop and before the Galilei measurements. Corneal aberrations were measured over the contact lenses before and after SH eye drop instillation. Visual acuity (VA) over the contact lenses was also measured both before instillation of the SH eye drop and after the subjects completed the five blinks.

Results: There was no change in VA after SH instillation in group 1; however, group 2's VA significantly deteriorated after SH instillation. Changes in VA after SH instillation compared to baseline were significantly higher in group 2 than in group 1. Similarly, the increase in corneal aberrations after SH instillation was significant in group 2 but not significant in group 1. Among the significantly increased corneal aberration parameters, defocus was the main type in group 2. Changes in corneal aberrations after SH instillation compared to baseline were significantly higher in group 2 than in group 1.

Conclusions: A 0.3%-concentration of SH increases corneal aberration and decreases VA in soft contact lens wearers. Defocus is the main type of aberration that increased in the 0.3% SH instillation group.

Keywords: Contact lenses; Hyaluronic acid; Visual acuity; Wavefront aberration.

Fig. 1. Flow chart of the current study. Subjects wearing silicone hydrogel contact lenses were classified into two groups based on the concentration of preservative-free sodium hyaluronate (SH) used (group 1, 0.1% SH; group 2, 0.3% SH). Corneal aberrations were measured over the contact lenses before and after each SH eye drop instillation. BCVA = best-corrected visual acuity.

Fig. 2. Comparison of corneal aberrations before and after sodium hyaluronate (SH) instillation in contact lens wearers. (A) 0.1% SH and (B) 0.3% SH. HOA = high-order aberration; SA = spherical aberration. ^*Wilcoxon signed-rank test.

Fig. 3. Corneal aberration changes after 0.3% sodium hyaluronate (SH) instillation. (A) Before 0.3% SH instillation and (B) after 0.3% SH instillation. HOA = high-order aberration.

Fig. 4. Changes in corneal aberrations (Δ) after sodium hyaluronate (SH) instillation compared to baseline in contact lens wearers. HOA = high-order aberration; SA = spherical aberration. ^*Mann-Whitney U-test.