Intraocular pressure lowering effect of dorzolamide/timolol fixed combination in patients with glaucoma who were unresponsive to prostaglandin analogs/prostamides.
OBJECTIVE
To evaluate the intraocular pressure lowering effect of the dorzolamide/timolol fixed combination (DTFC) in non-responder glaucoma patients to prostaglandin analogs/prostamides (prostas).


METHODS
All glaucoma patients treated with DTFC, between June 2003 and December 2005, who were unresponsive to prostaglandin analogs/prostamides, were identified through a retrospective medical records review. A non-responder was defined as an intraocular pressure (IOP) lowering effect less than 15% compared with baseline measurement. Two 12-hour IOP diurnal curves, measured between 8:00 a.m. and 8:00 p.m. (8:00 a.m., 10:00 a.m., 12:00 noon, 2:00 p.m., 4:00 p.m., 6:00 p.m. and 8:00 p.m.), were obtained retrospectively from the records of 31 patients, the first while on prostaglandin analogs/prostamides (baseline IOP) and the second while receiving DTFC (DTFC IOP). The study outcomes were the change in mean diurnal IOP and the reduction in IOP fluctuation as a result of receiving DTFC in patients unresponsive to prostas. The IOP was evaluated by intragroup comparisons with a two-tailed paired Student's t-test. A chi-square test was adopted for analysis of categorical variables.


RESULTS
31 patients were included in this retrospective study. DTFC significantly reduced IOP in the patients overall, from 25.4 (3.5) to 20.2 (1.0) mmHg, p < 0.0001. The majority of patients were diagnosed with pseudoexfoliative glaucoma (PEX) (58%; 18/31). DTFC reduced the mean IOP fluctuations over 12 hours (highest minus lowest IOP reading within the 12-hours pressure curve) from 8.6 (3.2) to 4.3 (1.4) mmHg, p < 0.0001. The most common adverse events were ocular burning (16%) and taste perversion (13%). There were no serious treatment-related adverse events.


CONCLUSIONS
DTFC significantly reduced the IOP in patients with glaucoma who did not respond to prostaglandin analogs/prostamides. Further research is needed to confirm these results.
Martínez
Antonio
A
Instituto Gallego de Oftalmologia, La Coruña, Spain. tontxu_1999@yahoo.com
Sánchez
Manuel
M
D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000175:diagnosis / Q000188:drug therapy*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D009883:Ophthalmic Solutions / Q000008:administration & dosage; D011336:Probability; D011465:Prostaglandins, Synthetic / Q000009:adverse effects / Q000627:therapeutic use; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013449:Sulfonamides / Q000008:administration & dosage*; D013876:Thiophenes / Q000008:administration & dosage*; D013999:Timolol / Q000008:administration & dosage*; D014065:Tonometry, Ocular; D017211:Treatment Failure; D016896:Treatment Outcome
D004338:Drug Combinations; D009883:Ophthalmic Solutions; D011465:Prostaglandins, Synthetic; D013449:Sulfonamides; D013876:Thiophenes; C479140:dorzolamide-timolol combination; D013999:Timolol