Khanal Santosh, Simmons Peter A, Pearce Edward I, Day Mhairi, Tomlinson Alan
Department of Vision Sciences, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow, United Kingdom.
Optom Vis Sci. 2008 Aug;85(8):732-9. doi: 10.1097/OPX.0b013e318181ae1c.
To determine the effect of two artificial tears of different viscosities in the relief of environmental dry eye induced with a novel tear stress test (TST).
A novel TST was developed and validated. The following four test conditions were evaluated in 12 healthy normal subjects in a cross-over and subject masked study; unprotected (no test solution used), relief (test solution instilled just after application of TST), immediate protection (test solution instilled just before application of TST), and chronic protection (1 week prophylactic use of the solution). The test solutions were Cellumed, with high viscosity, and Refresh Contacts, with low viscosity. Low contrast visual acuity, symptoms with analogue scales (symptom scoring), non-invasive tear break-up time, and tear evaporation were measured before (prestress) and 2 min after (poststress) application of TST. Two weeks of washout period was allowed after first test solution.
In unprotected test condition, there was no significant difference between pre- and poststress visual acuity (p = 0.102), tear evaporation (p = 0.530), and non-invasive tear break-up time (p = 0.878), however, poststress total symptom score was significantly higher than prestress (p = 0.002). No significant differences were seen between pre- and post-total symptom score at relief (p = 0.241 for Cellumed and 0.114 for Refresh Contacts) and immediate protection (p = 0.890 for Cellumed and 0.136 for Refresh Contacts) for both test solutions, whereas postsymptoms total score was significantly higher than prestress at chronic protection (p = 0.003 for both). No significant differences were seen in the effect of the two solutions in all test conditions.
There is an increase in dry eye symptomatology after ocular stress. The use of artificial tears just before or after ocular stress is helpful in relieving resultant symptoms in normals.
通过一种新型泪液应激试验（TST），确定两种不同粘度的人工泪液对缓解环境性干眼的效果。
开发并验证了一种新型TST。在一项交叉、受试者遮蔽研究中，对12名健康正常受试者评估了以下四种测试条件；无保护（未使用测试溶液）、缓解（TST应用后立即滴入测试溶液）、即时保护（TST应用前立即滴入测试溶液）和长期保护（溶液预防性使用1周）。测试溶液为高粘度的Cellumed和低粘度的Refresh Contacts。在TST应用前（应激前）和应用后2分钟（应激后）测量低对比度视力、模拟量表症状（症状评分）、非侵入性泪膜破裂时间和泪液蒸发。在第一种测试溶液后允许两周的洗脱期。
在无保护测试条件下，应激前后的视力（p = 0.102）、泪液蒸发（p = 0.530）和非侵入性泪膜破裂时间（p = 0.878）无显著差异，然而，应激后的总症状评分显著高于应激前（p = 0.002）。两种测试溶液在缓解（Cellumed为p = 0.241，Refresh Contacts为p = 0.114）和即时保护（Cellumed为p = 0.890，Refresh Contacts为p = 0.136）时，应激前后的总症状评分无显著差异，而在长期保护时，症状后总评分显著高于应激前（两种溶液均为p = 0.003）。在所有测试条件下，两种溶液的效果无显著差异。
眼应激后干眼症状会增加。在眼应激之前或之后使用人工泪液有助于缓解正常人由此产生的症状。
