Abstract
Purpose: :
This manometric study aims to quantify and compare ocular rigidity (R) and outflow facility (C) coefficients in medically treated open angle glaucoma (OAG) patients and controls.
Methods: :
Seventeen OAG patients and 17 controls undergoing cataract surgery were enrolled. The study was approved by the Institutional Review Board. A thorough ophthalmic examination was performed in all patients prior to surgery to rule out concomitant ocular disease, apart from cataract. Patients with early or moderate primary or pseudoexfoliative OAG were included in the OAG group. A computer-controlled system, consisting of a pressure transducer and a microstepping device was employed intraperatively. After cannulation of the anterior chamber, intraocular pressure (IOP) was increased by infusing the eye with microvolumes of saline solution. IOP was recorded after each infusion step. At an IOP of 40mmHg, an IOP decay curve was recorded for four minutes. R and C were estimated from IOP and volume recordings.
Results: :
Mean age was 75.4 (sd 9) years in the OAG and 70 (sd 6) years in the control group (independent samples t-test, p=0.06). R was 0.0214 (sd 0.005) in the OAG and 0.0236 (sd 0.005) ul-1 in the control group (p=0.29). C was 0.126 (sd 0.052) and 0.258 (sd 0.081) ul/min respectively (p<0.01).
Conclusions: :
OAG patients exhibit a lower outflow facility coefficient, in accordance with previous studies. However, manometric data did not reveal a difference in ocular rigidity coefficient between medically treated OAG patients and controls. These results may provide additional information towards the implication of biomechanics in the pathophysiology of glaucoma.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01315340
Keywords: intraocular pressure • sclera • aqueous