Department of Ophthalmology, Hospital Cologne-Merheim, Cologne, Germany.
Br J Ophthalmol. 2010 Nov;94(11):1519-22. doi: 10.1136/bjo.2009.177386. Epub 2010 Jul 21.
The Ex Vivo Eye Irritation Test (EVEIT) is used to analyse the clinical observations of corneal calcification attributed to the presence of phosphate within applied eye-drops used in treating glaucoma, Still-Chauffard syndrome, ocular burns and dry eyes.
Live corneas from abattoir rabbit eyes were cultured in order to study epithelial healing following mechanical abrasion of the corneal surface combined with repeated exposure to various eye-drops.
Obvious corneal calcification of the wound area along with a complete epithelial healing covering the calcified area was observed following exposure to phosphate hyaluronate eye-drops. Epithelial healing without calcification was achieved using citrate hyaluronate eye-drops.
Clinical observations show that topical use of artificial tears containing phosphate on injured eyes may lead to sight-threatening corneal complications. Simulation of such treatment conditions by the EVEIT convincingly demonstrates that changes in the composition of the pharmaceutically used treatments can prevent this undesired side effect. Although considerable healing was achieved during the repeated application of eye-drops, using either a phosphate or citrate buffer, only the drops containing citrate did not develop corneal calcification on the eye. The authors therefore recommend discontinuing the use of phosphate-buffered eye-drops, or other topically applied solutions, to avoid further injury to the patient.
体外眼刺激试验（EVEIT）用于分析因治疗青光眼、斯蒂尔-沙夫氏综合征、眼部烧伤和干眼症而应用的滴眼剂中存在磷酸盐导致的角膜钙化的临床观察。
屠宰场兔子的眼角膜在体外培养，以研究角膜表面经机械擦伤后与各种滴眼剂重复接触时的上皮愈合情况。
在用玻璃酸钠磷酸盐滴眼剂处理后，可观察到伤口区域明显的角膜钙化，以及覆盖钙化区域的完整上皮愈合。而用透明质酸钠柠檬酸盐滴眼剂则可实现无钙化的上皮愈合。
临床观察表明，在受伤的眼睛上局部使用含磷酸盐的人工泪液可能导致威胁视力的角膜并发症。EVEIT 模拟这种治疗条件，有力地证明了药物治疗中成分的变化可以预防这种不良副作用。尽管在用磷酸盐或柠檬酸盐缓冲液重复滴眼时，眼部的愈合情况相当可观，但只有含有柠檬酸盐的滴眼剂不会在眼睛上形成角膜钙化。因此，作者建议停止使用磷酸盐缓冲滴眼剂或其他局部应用的溶液，以避免对患者造成进一步的伤害。
