Aims: To study the safety and effectiveness of a combination of both intravenous injection of lidocaine and intraocular pressure-lowering medications, in the intraocular pressure control and relief of symptoms of refractory acute primary angle-closure glaucoma (PACG).
Methods: Five consecutive patients with their first attack of acute PACG, with intraocular pressure > or = 45 mmHg and a failure to release from the attack under antiglaucomatous medications for 4 hours, were recruited into the study. On presentation, each patient received topical pilocarpine and timolol, and systemic acetazolamide and mannitol as primary treatment. Then the patients accepted 2% lidocaine by intravenous injection at dose of 0.8 mg/kg in concert with antiglaucomatous medications. The intraocular pressures after intravenous injection at 30 minutes, and then at 1, 2, 4, 12, and 24 hours, were documented by applanation tonometry. Symptoms, visual acuity, intraocular pressure, corneal edema, angle status on gonioscopy, pupillary size, and reaction were also measured.
Results: Six eyes of five patients seen with acute PACG were recruited. The mean intraocular pressure was reduced from 50.83 +/- 5.34 mmHg to 39.5 +/- 3.45 mmHg at 30 minutes after intravenous injection, and then to 33.3 +/- 3.56 mmHg at 1 hour, and 24.55 +/- 5.09 mmHg at 2 hours after intravenous injection. The mean intraocular pressure was less than 21 mmHg at 4 hours and beyond. There was instant symptomatic relief for all patients. No complications were encountered.
Conclusions: From this preliminary study, intravenous injection of lidocaine seems to be safe and effective in controlling intraocular pressure and eliminating symptoms in acute PACG. But the exact efficacy and safety need further investigation in large case studies.