Kuppens E V, de Jong C A, Stolwijk T R, de Keizer R J, van Best J A
Department of Ophthalmology, Leiden University Hospital, The Netherlands.
Br J Ophthalmol. 1995 Apr;79(4):339-42. doi: 10.1136/bjo.79.4.339.
The purpose of this study was to assess whether the preservative benzalkonium chloride (BAC 0.01%) present in timolol induced a decrease in basal tear turnover and a deterioration of precorneal tear film in patients with glaucoma and ocular hypertension using topical timolol.
The basal tear turnover of 20 patients with open angle glaucoma or ocular hypertension was measured by computerised objective fluorophotometry when using topical timolol preserved with BAC and 2 weeks after changing to topical timolol containing no preservative. Evaluation of the precorneal tear film was done by measuring the break up time (BUT) before and 2 weeks after changing medication.
The tear turnover of the patients before the change was 32% lower than that of healthy controls (mean tear turnover values (SD) (%/min): 10.7 (3.0) and 15.6 (5.4), respectively, p < 0.0001). A mean increase of 28% (47%) in the individual tear turnover values was found after the change to the preservative-free timolol (p = 0.04). The BUT values before the change of medication did not differ significantly from those after the change (p = 0.5) but both values were significantly lower than the values of healthy controls (p = 0.009 and p = 0.003, respectively).
Preservative-free timolol solution has a favourable effect on the tear turnover of patients with glaucoma and ocular hypertension in comparison with timolol containing BAC. The integrity of the precorneal tear film persisted to be affected when using timolol without BAC. Timolol without preservative can be recommended in those patients who have keratoconjunctivitis sicca or a borderline tear production since BAC may exacerbate a dry eye state.
本研究旨在评估噻吗洛尔中含有的防腐剂苯扎氯铵（0.01%苯扎氯铵）是否会导致青光眼和高眼压症患者在使用局部噻吗洛尔时基础泪液更新率降低以及角膜前泪膜恶化。
通过计算机化客观荧光光度法测量20例开角型青光眼或高眼压症患者在使用含苯扎氯铵防腐剂的局部噻吗洛尔时以及改用不含防腐剂的局部噻吗洛尔2周后的基础泪液更新率。通过测量换药前和换药2周后的泪膜破裂时间（BUT）来评估角膜前泪膜。
换药前患者的泪液更新率比健康对照组低32%（平均泪液更新率值（标准差）（%/分钟）：分别为10.7（3.0）和15.6（5.4），p<0.0001）。改用不含防腐剂的噻吗洛尔后，个体泪液更新率值平均增加了28%（47%）（p = 0.04）。换药前的BUT值与换药后的BUT值无显著差异（p = 0.5），但这两个值均显著低于健康对照组的值（分别为p = 0.009和p = 0.003）。
与含苯扎氯铵的噻吗洛尔相比，不含防腐剂的噻吗洛尔溶液对青光眼和高眼压症患者的泪液更新有有利影响。使用不含苯扎氯铵的噻吗洛尔时，角膜前泪膜的完整性持续受到影响。对于患有干燥性角结膜炎或泪液分泌处于临界状态的患者，可推荐使用不含防腐剂的噻吗洛尔，因为苯扎氯铵可能会加重干眼状态。
