The Effects of Gender, Age, and Refractive Error on Corneal and Conjunctival Epithelial and Overall Thicknesses

Abstract

Objective: To evaluate the corneal, conjunctival epithelial and overall thicknesses measured by anterior segment optical coherence tomography (OCT) in healthy population. Methods: This retrospective study included 134 eyes of 134 healthy individuals who were undergone a Cirrus HD-OCT examination using the Anterior Segment 5 Line Raster protocol. Corneal, conjunctival epithelial and overall thicknesses were measured on OCT images. The average values of four OCT parameters were compared between sexes and among the six subgroups with respect to age. Results: The average corneal epithelial and overall thicknesses were 51.30±4.60 µm and 532.47±37.30 µm, respectively. The average conjunctival epithelial and overall thicknesses were 47.20±8.03 µm and 237.07±40.62 µm, respectively. All of the measurements were thicker in males compared to females, however the significant difference was found for only corneal epithelium (p=0.043). Using the Spearman correlation coefficient, central corneal and conjunctival epithelial thicknesses showed significant negative correlations with age (p=0.006, p=0.005, respectively) and refraction (p=0.040, p=0.033, respectively). Conclusion: Ocular surface parameters measured by anterior segment OCT were gender, age, and refraction-related. Thus, further studies conducted to evaluate the corneal and conjunctival thicknesses should involve gender, age, and refraction-matched control groups. J Clin Exp Invest 2016; 7 (1): 78-82

Keywords

• Anterior segment optical coherence tomography,epithelial thickness

Kaynakça

1. 1. Egbert PR, Lauber S, Maurice DM. A simple conjunctival biopsy. Am J Ophthalmol 1977;84:798-801.
2. 2. Eckard A, Stave J, Guthoff RF. In vivo investigations of the corneal epithelium with the confocal Rostock Laser Scanning Microscope (RLSM). Cornea 2006;25:127-131.
3. 3. Francoz M, Karamoko I, Baudouin C, Labbé A. Ocular surface epithelial thickness evaluation with spectral-domain optical coherence tomography. Invest Ophthalmol Vis Sci 2011;52:9116-9123.
4. 4. Lim SH. Clinical Applications of Anterior Segment Optical Coherence Tomography. J Ophthalmol 2015;2015:1-12.
5. 5. Kunert KS, Bhartiya P, Tandon R, et al. Central corneal thickness in Indian patients undergoing LASIK for myopia. J Refract Surg 2003;19:378-379.
6. 6. Wang X, Dong J, Wu Q. Corneal thickness, epithelial thickness and axial length differences in normal and high myopia. BMC Ophthalmol 2015;15:1-5.
7. 7. Srivannaboon S. Relationship between corneal thickness and level of myopia. J Med Assoc Thai 2002;85:162-166.
8. 8. Ortiz S, Mena L, Rio-San Cristobal A, Martin R. Relationships between central and peripheral corneal thickness in different degrees of myopia. J Optom 2014;7:44-50.

9. 9. Feng Y, Simpson TL. Comparison of human central cornea and limbus in vivo using optical coherence tomography. Optom Vis Sci 2005;82:416-419.
10. 10. Reinstein DZ, Silverman RH, Rondeau MJ, Coleman DJ. Epithelial and corneal thickness measurements by high-frequency ultrasound digital signal processing. Ophthalmology 1994;101:140-146.
11. 11. Efron N, Al-Dossari M, Pritchard N. Confocal Microscopy of the Bulbar Conjunctiva in Contact Lens Wear. Cornea 2010;29:43-52.
12. 12. Feng Y, Simpson TL. Corneal, Limbal, and Conjunctival Epithelial Thickness from Optical Coherence Tomography. Optom Vis Sci 2008;85:880-883.
13. 13. Haque S, Jones L, Simpson T. Thickness mapping of the cornea and epithelium using optical coherence tomography. Optom Vis Sci 2008;85:E963-E976.
14. 14. Tao A, Wang J, Chen Q, et al. Topographic thickness of Bowman’s layer determined by ultra-high resolution spectral domain-optical coherence tomography. Invest Ophthalmol Vis Sci 2011;52:3901-3907.
15. 15. Reinstein DZ, Archer TJ, Gobbe M, et al. Epithelial thickness in the normal cornea: three-dimensional display with very high frequency ultrasound. J Refract Surg 2008;24:571-581.
16. 16. Wong AC, Wong CC, Yuen NS, Hui SP. Correlational study of central corneal thickness measurements on Hong Kong Chinese using optical coherence tomography, Orbscan and ultrasound pachymetry. Eye (Lond) 2002;16:715-721.
17. 17. Jalbert I, Sweeney DF, Stapleton F. The effect of long-term wear of soft lenses of low and high oxygen transmissibility on the corneal epithelium. Eye (Lond). 2009;23:1282-1287.
18. 18. Pérez JG, Méijome JMG, Jalbert I, et al. Corneal epithelial thinning profile induced by long-term wear of hydrogel lenses. Cornea 2003;22:304-307.
19. 19. Lei Y, Zheng X, Hou J, et al. Effects of long-term soft contact lens wear on the corneal thickness and corneal epithelial thickness of myopic subjects. Mol Med Rep 2015:11;2020-2026.
20. 20. Zhang X, Li Q, Xiang M, et al. Bulbar conjunctival thickness measurements with optical coherence tomography in healthy Chinese subjects. Invest Ophthalmol Vis Sci 2013;54:4705-4709.