Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
Novaliq GmbH, Heidelberg, Germany.
Ocul Surf. 2019 Apr;17(2):241-249. doi: 10.1016/j.jtos.2019.02.010. Epub 2019 Mar 2.
Dry eye disease (DED) is one of the most prevalent ocular surface disorders that presents clinically. Recently, the semifluorinated alkane (SFA) perfluorohexyloctane (NovaTears; EvoTears) entered the market for the management of evaporative DED, while perfluorobutylpentane has been used as a vehicle to enhance ocular drug delivery. This study evaluated the mechanisms by which SFAs might improve therapeutic outcomes in DED.
Interactions of both SFAs with the corneal surface were evaluated ex vivo using high-speed photography. The in vivo influence of SFAs on tear fluid dynamics was evaluated in healthy rabbit eyes observing changes in lipid layer grade, tear evaporation rate, tear volume and tear osmolarity. Furthermore, ocular tolerability was confirmed by clinical scoring and sodium fluorescein staining.
Ex vivo studies demonstrated that both SFAs rapidly spread on the ocular surface with their contact angle on the cornea being virtually zero. A significant improvement in lipid layer grade was observed immediately after instillation of both SFAs in vivo, although the improvement was more sustained upon instillation of perfluorohexyloctane with a statistically significant difference compared to saline instillation evident from day five onwards. No significant changes in tear evaporation rate, volume or osmolarity, nor any signs of ocular irritation were observed after application of either SFA over the seven-day study period.
Both SFAs showed excellent spreading on the ocular surface. Perfluorohexyloctane improved the lipid layer grade significantly after topical application supporting its potential to stabilise the tear film lipid layer and thus provide symptomatic relief in evaporative DED.
干眼症（DED）是临床上最常见的眼表疾病之一。最近，半氟化烷（SFA）全氟己基辛烷（NovaTears；EvoTears）进入市场，用于治疗蒸发型 DED，而全氟丁基戊烷则被用作增强眼部药物递送的载体。本研究评估了 SFA 改善 DED 治疗效果的机制。
使用高速摄影术评估两种 SFA 与角膜表面的相互作用。在健康兔眼观察脂质层等级、泪液蒸发率、泪液体积和泪液渗透压的变化，评估 SFA 对泪液动力学的体内影响。此外，通过临床评分和荧光素钠染色确认眼部耐受性。
离体研究表明，两种 SFA 均可迅速在眼表面扩散，其在角膜上的接触角几乎为零。体内两种 SFA 均能立即显著改善脂质层等级，尽管在全氟己基辛烷滴眼后改善更为持久，与生理盐水滴眼相比，从第 5 天开始差异具有统计学意义。在为期 7 天的研究期间，应用任何一种 SFA 后，泪液蒸发率、体积或渗透压均无明显变化，也未观察到任何眼部刺激迹象。
两种 SFA 在眼表面均表现出良好的扩散性。全氟己基辛烷滴眼后显著改善了脂质层等级，支持其稳定泪膜脂质层的潜力，从而为蒸发型 DED 提供症状缓解。
