[Influence on tear film after instillation of timolol maleate ophthalmic gel-forming solution examination by a tear film stability analysis system].
OBJECTIVE
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 TG), ion-activated gel (Timoptol XE), or conventional timolol solutions (Timoptol or TIMABAK 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 TG or Timoptol XE. On the breakup map, the most unstable area of the cornea was the lower part after instillation of Rysmon TG, and the center, after instillation of Timoptol XE. In the breakup index (range 0-100), where the high portion showed stability, both gels were low (p < 0.05). Timoptol XE was lower than Rysmon 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 eyelids following instillation of Rysmon TG or Timoptol XE, and blurred vision increased at 3 minutes after opening of the eyelids following instillation of Timoptol XE.


CONCLUSIONS
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.
Kawasaki
Shiro
S
Department of Ophthalmology, Ehime University School of Medicine. Shitsukawa, Tohon-shi, Ehime-ken 791-0295, Japan. skawasak@m.ehime-u.ac.jp
Mizoue
Shiro
S
Yamaguchi
Masahiko
M
Ohashi
Yuichi
Y
D000328:Adult; D005260:Female; D005782:Gels; D006801:Humans; D007322:Instillation, Drug; D008297:Male; D009883:Ophthalmic Solutions; D013666:Tears / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D013999:Timolol / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D014785:Vision, Ocular / Q000187:drug effects / Q000502:physiology
D005782:Gels; D009883:Ophthalmic Solutions; D013999:Timolol