Golebiowski Blanka, Chao Cecilia, Stapleton Fiona, Jalbert Isabelle
*BOptom, PhD †BOptom, PhD, FAAO ‡MCOptom, PhD, FAAO §OD, PhD, FAAO School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia (all authors).
Optom Vis Sci. 2017 Apr;94(4):534-542. doi: 10.1097/OPX.0000000000001063.
To determine tear neuropeptide levels in contact lens wearers and non-wearers, and to examine relationships with indices of corneal innervation, tear function, and ocular discomfort.
A cross-sectional, single-visit, investigator-masked pilot study. Assessments included Ocular Comfort Index (OCI), central and mid-peripheral corneal nerve density and morphology (HRT-Rostock), corneal sensitivity (Cochet-Bonnet aesthesiometer), tear Substance P and calcitonin gene-related peptide (CGRP) concentration (ELISA), in situ tear osmolarity (TearLab), tear secretion (Phenol Red Thread), and noninvasive tear break-up time (NITBUT; Keeler Tearscope). Groups were compared using independent t-test or Mann-Whitney U test, and regional differences assessed using paired t-tests. Associations were analyzed using Pearson or Spearman correlation. Significance was determined at P < .05.
Twenty contact lens wearers (7M:13F, 32 ± 5 years) and 20 non-wearers (7M:13F, 31 ± 5 years) completed the study. OCI score was numerically higher in lens wearers (32.27 ± 5.33) than non-wearers (27.66 ± 9.94). Tear osmolarity was higher [298.0 (IQR 291.0-309.8) vs. 288.5 (282.3-298.3) mOsmol/L; P = .01] whereas NITBUT was lower (9.8 ± 3.4 vs. 13.8 ± 5.6 s; P = .01) in lens wearers compared with non-wearers. Tear neuropeptide concentrations were not different between groups [Substance P 4.29 ng/ml (IQR 1.57-6.05), CGRP 14.89 ng/ml (5.08-59.26)], and there were no differences in nerve morphology or ocular surface sensitivity. Higher nerve density, interconnections, and tortuosity were observed in the central cornea than mid-peripherally (P < .05). OCI score was moderately associated with nerve tortuosity (r = 0.42, P = .01). CGRP was associated with central nerve density (ρ = 0.38, P = .02), as was tear secretion (r = -0.37, P = .02). Nerve interconnections were strongly associated with corneal sensitivity (ρ = 0.64, P < .001).
Relationships were demonstrated between nerve density, tear CGRP, and corneal sensitivity. Markers of corneal neurobiology and sensory function do not appear to be altered in contact lens wear despite worse tear function (osmolarity and stability) in lens wearers. This suggests that mechanisms other than overt changes in corneal innervation regulate tear function during lens wear. The relationship between nerve tortuosity and ocular discomfort requires elucidation.
测定隐形眼镜佩戴者和非佩戴者泪液神经肽水平，并研究其与角膜神经支配、泪液功能及眼部不适指标之间的关系。
一项横断面、单次就诊、研究者设盲的试点研究。评估内容包括眼部舒适度指数（OCI）、中央和中周边角膜神经密度及形态（HRT-罗斯托克）、角膜敏感性（科谢-博内眼压计）、泪液P物质和降钙素基因相关肽（CGRP）浓度（酶联免疫吸附测定）、原位泪液渗透压（泪液实验室）、泪液分泌（酚红棉线）及非侵入性泪膜破裂时间（NITBUT；基勒泪液镜）。采用独立t检验或曼-惠特尼U检验比较组间差异，采用配对t检验评估区域差异。使用Pearson或Spearman相关性分析关联性。P <.05为差异有统计学意义。
20名隐形眼镜佩戴者（7名男性：13名女性，32±5岁）和20名非佩戴者（7名男性：13名女性，31±5岁）完成了研究。佩戴者的OCI评分在数值上高于非佩戴者（32.27±5.33）（27.66±9.94）。与非佩戴者相比，佩戴者的泪液渗透压更高[298.0（四分位间距291.0 - 309.8）对288.5（282.3 - 298.3）mOsmol/L；P =.01]，而NITBUT更低（9.8±3.4对13.8±5.6秒；P =.01）。两组间泪液神经肽浓度无差异[P物质4.29 ng/ml（四分位间距1.57 - 6.05），CGRP 14.89 ng/ml（5.08 - 59.26）]，神经形态或眼表敏感性也无差异。中央角膜的神经密度、相互连接和迂曲度高于中周边角膜（P <.05）。OCI评分与神经迂曲度中度相关（r = 0.42，P =.01）。CGRP与中央神经密度相关（ρ = 0.38，P =.02），泪液分泌也与之相关（r = -0.37，P =.02）。神经相互连接与角膜敏感性密切相关（ρ = 0.64，P <.001）。
证实了神经密度、泪液CGRP与角膜敏感性之间的关系。尽管佩戴者的泪液功能（渗透压和稳定性）较差，但角膜神经生物学和感觉功能指标在隐形眼镜佩戴者中似乎未发生改变。这表明在佩戴隐形眼镜期间，除了角膜神经支配的明显变化外，还有其他机制调节泪液功能。神经迂曲度与眼部不适之间的关系有待阐明。
