Influence on tear film after instillation of timolol maleate ophthalmic gel-forming solution examination by a tear film stability analysis system
Kawasaki, S.; Mizoue, S.; Yamaguchi, M.; Ohashi, Y.
Nippon Ganka Gakkai Zasshi 112(6): 539-544
2008
ISSN/ISBN: 0029-0203 PMID: 18592978 Document Number: 615956
Purpose : Using a tear film stability analysis system (TSAS), we analyzed the tear film with regard to blurred vision after instillation of 0.5% timolol gel-forming solutions. Methods : Tear film stability was recorded before and after instillation of timolol gel-forming solutions in 9 healthy volunteers (age : 30 +/- 5.6 years; mean +/- SD). Thermosetting gel (Rysmon (R) TG), ion-activated gel (Timoptol (R) XE), or conventional timolol solutions (Timoptol (R) or TIMABAK (R) which does not contain an antiseptic) was applied to only one eye at a time. The subject was administered a single instillation. After instillation, the subject closed his eyelid for one minute. TSAS was carried out immediately after the subject opened his eye. TSAS was also carried out 3 minutes, 5 minutes and 10 minutes after the subject had opened his eye. The grade of blurred vision after each test was evaluated in 5 levels. Results : The tear film was remarkably unstable just after the opening of the eyelids following instillation of Rysmon (R) TG or Timoptol (R) XE. On the breakup map, the most unstable area of the cornea was the lower part after instillation of Rysmon (R) TG, and the center, after instillation of Timoptol (R) XE. In the breakup index (range 0-100), where the high portion showed stability, both gels were low (p < 0.05). Timoptol (R) XE was lower than Rysmon (R) TG (p < 0.05). For timolol gel forming solutions, the index 5 minutes after eye-opening was lower than before instillation. As compared with before instillation, blurred vision increase just after the opening of the evelids following instillation of Rysmon (R) TG or Timoptol (R) XE, and blurred vision increased at 3 minutes after opening of the eyelids following instillation of Timoptol (R) XE. Conclusion : It seems that the analysis by TSAS was useful to measure the effect on visual performance and the pharmacokinetics after the instillation of the gel-forming solutions.