Effect of intracameral carbachol on intraocular pressure following clear corneal phacoemulsification

Purpose To investigate the effect of 0.01% carbachol on early intraocular p ressure (IOP) after cataract extraction with phacoemulsification. Methods Fifty-one patients who underwent cataract extraction with phacoemul sification and intraocular lens implantation were prospectively randomly as signed to one of two groups. Twenty-seven patients were given 0.5 ml carbac hol intracamerally (carbachol group); the other 24 patients were given the same amount of balanced salt solution intracamerally (control group). IOPs were measured by Goldmann applanation tonometry on the day before surgery, and at 8 h, 24 h and 7 days post-operatively. Results There was no difference between the mean IOPs of the groups pre-ope ratively (p > 0.5). All the mean post-operative IOP values of the carbachol group were lower than those of the control group. At 8 and 24 h postoperat ively the mean IOP was 12.4 +/- 3.4 mmHg and 13.1 +/- 4,5 mmHg respectively in the carbachol group, 19.4 +/- 6.4 mmHg and 17.2 +/- 4.2 mmHg respective ly in the control group. The differences were significant (p < 0.04 and p < 0.05). There was no significant difference between the values at 7 days po st-operatively (p > 0.8). An IOP greater than 25 mmHg was recorded at 8 h a nd 24 h post-operatively in 8 (33%) and 4 (17%) of the control group and in 1 (4%) and 1 (4%) of the carbachol group. All the IOPs were 20 mmHg or low er in both groups at 7 days post-operatively. Conclusion Patients treated with intracameral carbachol following uncomplic ated clear corneal phacoemulsification and posterior chamber intraocular le ns implantation demonstrate lower early post-operative IOP.