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Comparative Study
. 2018 Nov 3;18(1):286.
doi: 10.1186/s12886-018-0956-2.

Thickness changes in the corneal epithelium and Bowman's layer after overnight wear of silicone hydrogel contact lenses

Fan Lu  1 , Aizhu Tao  2 , Weiwei Tao  3 , Xiran Zhuang  1 , Meixiao Shen  1
Affiliations
Comparative Study

Thickness changes in the corneal epithelium and Bowman's layer after overnight wear of silicone hydrogel contact lenses

Fan Lu et al. BMC Ophthalmol. .

Abstract

Background: To investigate thickness changes in the corneal epithelium and Bowman's layer after overnight silicone hydrogel contact lens (CL) wear by using ultra-high resolution optical coherence tomography (UHROCT).

Methods: Eleven subjects without CL wearing history were recruited for this study. An UHROCT was used to measure the thickness of the epithelium (ET), Bowman's layer (BT), stroma (ST), and total cornea (CCT) at the center of both eyes. A silicone hydrogel CL was inserted in the right eye of each subject, and the fellow non-CL wearing left eye served as the control. The lens was inserted at 9:30 pm and removed at 8:00 am the next morning. The subjects were evaluated at 9:00 pm (baseline), 9:30 pm (lens insertion), 10:00 pm (before sleep), 7:00 am (waking), 7:30 am, and 8:00 am (lens removal).

Results: Compared to the lens insertion level, the ET of the lens-wearing eye increased by 5.73% at eye opening (P = 0.001). The ET of the non-CL wearing eye and the BT in both eyes did not change after overnight CL wear. Compared to baseline, the CCT of the lens-wearing eye increased by 2.87% upon waking (P = 0.003) and recovered 30 min later (P = 0.555). In contrast, compared to baseline, the CCT of the non-CL wearing eye did not increase upon waking (P = 0.105).

Conclusions: By using UHROCT, we found that overnight CL wear induced different swelling responses in the various sublayers of the cornea.

Trial registration: Retrospectively registered. Registration number: ChiCTR1800015115 . Registered 07 March 2018.

Keywords: Bowman’s layer; Contact lens; Epithelium; Overnight; Thickness.

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Conflict of interest statement

Ethics approval and consent to participate

The study was approved by the human subjects review board at the Eye Hospital of Wenzhou Medical University. Each subject signed a consent form and was treated in accordance with the principles of the Declaration of Helsinki.

Consent for publication

Not Applicable.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Optical coherence tomography (OCT) image of one 29-year-old subject and longitudinal reflectivity profile. Left: OCT image of the cornea center at baseline. a: Epithelium; b: Bowman’s layer; c: Stroma. Right: Longitudinal reflectivity profile after removing the strong reflectivity at the center. The distance between peaks a and b was the thickness of the epithelium; the distance between peaks b and c was the thickness of Bowman’s layer; the distance between peaks c and d was the thickness of stroma; and the distance between peaks a and d was the total corneal thickness
Fig. 2
Fig. 2
A questionnaire was used to rate ocular comfort. Very poor comfort was defined as 0, and excellent comfort was defined as 50
Fig. 3
Fig. 3
Corneal epithelial thickness after overnight contact lens (CL) wear. Compared to the lens insertion level, the epithelial thickness of the lens-wearing eye increased at eye opening (P = 0.001). The epithelial thickness of the non-CL-wearing left eye did not change at waking (P > 0.05).*: P < 0.05, compared with the lens insertion level
Fig. 4
Fig. 4
Bowman’s layer thickness after overnight contact lens (CL) wear. The thickness of Bowman’s layer in both eyes did not change significantly after overnight CL wear (P > 0.05)
Fig. 5
Fig. 5
Total corneal thickness after overnight contact lens (CL) wear. Compared to baseline, the total corneal thickness of the lens-wearing right eye increased at waking the next day (P = 0.003) and recovered 30 min later (P = 0.555). In contrast, the total corneal thickness of the non-CL wearing left eye did not increase at waking (P = 0.105). *: P < 0.05, compared with baseline
Fig. 6
Fig. 6
Stromal thickness after overnight contact lens (CL) wear. Compared to baseline, the stromal thickness of the lens-wearing right eye increased at waking (P = 0.005) and recovered 30 min later (P = 0.383). In contrast, the stromal thickness of the non-CL-wearing left eye did not increase at waking (P = 0.467). *: P < 0.05, compared with baseline
Fig. 7
Fig. 7
Ocular comfort ratings after overnight contact lens (CL) wear. Ocular comfort decreased after lens insertion (P = 0.007) and remained low during CL wear. *: P < 0.05, compared with baseline
See this image and copyright information in PMC

References

    1. Mishima S. Clinical investigations on the corneal endothelium XXXVIII Edward Jackson memorial lecture. Am J Ophthalmol. 1992;93:1–29. doi: 10.1016/0002-9394(82)90693-6. - DOI - PubMed
    1. Steffen RB, Schnider CM. The impact of silicone hydrogel materials on overnight corneal swelling. Eye Contact Lens. 2007;33(3):115–120. doi: 10.1097/01.icl.0000242166.09513.aa. - DOI - PubMed
    1. Ladage PM, Jester JV, Petroll WM, Bergmanson JP, Cavanagh HD. Role of oxygen in corneal epithelial homeostasis during extended contact lens wear. Eye Contact Lens. 2003;29:S2–S6. doi: 10.1097/00140068-200301001-00002. - DOI - PubMed
    1. Wang J, Fonn D, Simpson TL, Jones L. The measurement of corneal epithelial thickness in response to hypoxia using optical coherence tomography. Am J Ophthalmol. 2002;133:315–319. doi: 10.1016/S0002-9394(01)01382-4. - DOI - PubMed
    1. Holden BA, Mertz GW. Critical oxygen levels to avoid corneal edema for daily and extended wear contact lenses. Invest Ophthalmol Vis Sci. 1984;25:1161–1167. - PubMed

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