Vitamin D has emerged as a potentially important molecule in ophthalmology. To date, all ophthalmic data pertaining to vitamin D has been restricted primarily to tear and serum analysis in human patients. Considering the isolated nature of the eye, we sought to determine the presence of intraocular vitamin D in ocular disease. METHODS 25-Hydroxyvitamin D3 (25(OH)D3) concentrations were measured in the eye and blood of 120 participants undergoing ophthalmic procedures. Ocular localization of the 1,25-dihydroxyvitamin D3-generating (CYP27B1) and deactivating (CYP24A1) hydroxylases was performed by immunohistochemistry. Gene expression of CYP27B1, CYP24A1 and VEGF-A was measured in eyes from patients with and without disease. RESULTS 25(OH)D3 was quantified in 112 ocular samples. In 40 cataract patient samples, the average 25(OH)D3 concentration was 0.057 ng/mL, compared to 72 retinal disease patient samples, average of 0.502 ng/mL (p < 0.001). Intraocular 25(OH)D3 did not correlate with serum levels of 25(OH)D3. There was no difference between the level of 25(OH)D3 measured in the aqueous and vitreous humour. The vitamin D-specific CYPs 27B1 and 24A1, strongly localized to complementary regions of the ciliary body, retinal pigment epithelium and neural retina. Gene expression analysis confirmed retinal CYP27B1 correlated strongly with VEGF-A in eyes from diabetic patients (r = 0.92, p < 0.001). CONCLUSIONS Our data confirms that vitamin D is present in the humours of the human eye and that local synthesis/degradation is possible via the ocular CYP27B1 and CYP24A1. This argues for a functional role for local vitamin D production and signaling in the eye and suggests that vitamin D may be an important intraocular mediator in disease pathogenesis.

中文翻译：

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眼内降钙素：在眼睛中发现维生素D的作用。

维生素D已成为眼科学中潜在的重要分子。迄今为止，关于维生素D的所有眼科数据主要限于人类患者的眼泪和血清分析。考虑到眼睛的孤立性，我们试图确定眼部疾病中眼内维生素D的存在。方法对120名接受眼科手术的参与者的眼睛和血液中的25-羟基维生素D3（25（OH）D3）浓度进行了测量。通过免疫组织化学进行了1,2,2-二羟基维生素D3生成（CYP27B1）和失活（CYP24A1）羟化酶的眼部定位。在患有和未患有疾病的患者的眼睛中测量CYP27B1，CYP24A1和VEGF-A的基因表达。结果在112个眼样本中定量了25（OH）D3。在40个白内障患者样本中，25（OH）D3的平均浓度为0.057 ng / mL，而72例视网膜疾病患者样品的平均浓度为0.502 ng / mL（p <0.001）。眼内25（OH）D3与血清25（OH）D3不相关。在水性和玻璃质幽默中测得的25（OH）D3含量之间没有差异。维生素D特异性CYP 27B1和24A1强烈定位于睫状体，视网膜色素上皮和神经视网膜的互补区域。基因表达分析证实了糖尿病患者眼睛中的视网膜CYP27B1与VEGF-A密切相关（r = 0.92，p <0.001）。结论我们的数据证实维生素D存在于人眼的幽默中，并且可能通过眼CYP27B1和CYP24A1进行局部合成/降解。