Impact of modulus of elasticity of silicone hydrogel contact lenses on meibomian glands morphology and function

ABSTRACT

Clinical relevance: It is important to investigate the effect of modulus of silicone hydrogel contact lens on meibomian glands. Evaluating meibomian gland health and function in follow-up appointments should be considered, with the option of changing lens modulus.

Background: To evaluate and compare the effect of modulus of elasticity of silicone hydrogel contact lenses on morphological and functional parameters of the meibomian glands.

Methods: A prospective study was conducted on soft silicone hydrogel contact lens wearers of different modulus of elasticity and age and gender-matched controls. Morphological and functional parameters were assessed along with standard patient evaluation of the eye dryness questionnaire.

Results: A statistically significant difference was noted in meibomian gland loss in the upper lid (percent) between the low modulus (18.23 ± 6.63) and high modulus group (27.40 ± 10.21) (p < 0.001) and between high modulus (27.40 ± 10.21) and non-contact lens wearers (19.57 ± 7.65) (p = 0.001). The current study reported significantly higher total meiboscore grading in the high modulus group 3 (2-3) compared to the low modulus 2(2-3) (p = 0.007) and non-contact lens wearing groups 2 (2-3) (p = 0.012). Meibum quality was significantly compromised in the high modulus group 1 (0-1) compared to the low modulus 0 (0-0.75) group (p = 0.01). Standard patient evaluation of the eye dryness questionnaire was found to be significantly higher (p = 0.01) in high modulus 4 (2-8) compared to low modulus wearers 2 (2-4). A significant difference was noted (p < 0.001) in corneal staining grading only between high modulus 0 (0-1) and non-contact lens wearers 0 (0-0) group. A positive correlation was noted in the low modulus group between total meiboscore and meibomian gland expressibility (Rs = +0.69, p < 0.001) and also noted between standard patient evaluation of the eye dryness questionnaire scoring and meibomian gland expressibility (Rs = +0.45, p = 0.012) in the high modulus group.

Conclusion: Higher modulus of elasticity of silicone hydrogel contact lens may influence meibomian gland morphology and function over a period of contact lens wear.

KEYWORDS:

• Contact lens
• meibomian gland
• silicone hydrogel
• standard patient evaluation of the eye dryness
• tear break-up time

Acknowledgements

The authors like to acknowledge the efforts of the Contact Lens Department of Medical Research Foundation in enrolling patients. Our sincere thanks to Dr Jaya Sowjanya Siddireddy for her contribution in formatting the manuscript. The authors thank the research and faculty team of Medical Research Foundation

Disclosure statement

No potential conflict of interest was reported by the authors.