Factors associated with topographic changes of the optic nerve head induced by acute intraocular pressure reduction in glaucoma patients.

PURPOSE: To investigate factors associated with changes in optic nerve head (ONH) topography after acute intraocular pressure (IOP) reduction in patients with primary open-angle glaucoma (POAG). METHODS: Untreated POAG patients (IOP >21 mm Hg) were prospectively enrolled. Systemic and ocular information were collected, including central corneal thickness (CCT) and corneal hysteresis (CH). All patients underwent confocal scanning laser ophthalmoscopy and tonometry (Goldmann) before and 1 h after pharmacological IOP reduction. The mean of three measurements was considered for analysis. Changes in each ONH topographic parameter were assessed (one eye was randomly selected), and those that changed significantly were correlated with patient's systemic and ocular characteristics. RESULTS: A total of 42 patients were included (mean age, 66.7 ± 11.8 years). After a mean IOP reduction of 47.3 ± 11.9%, significant changes were observed in cup area and volume, and in rim area and volume (P < 0.01), but not in mean cup depth (P = 0.80). Multiple regression analysis (controlling for baseline IOP and magnitude of IOP reduction) showed that CH (r(2) = 0.17, P < 0.01) and diabetes diagnosis (r(2) ≥ 0.21, P < 0.01) were negatively correlated with the magnitude of changes in ONH parameters, whereas the cup-to-disc ratio was positively correlated (r(2) = 0.30, P < 0.01). Age, race, disc area, and CCT were not significant (P ≥ 0.12). Including all significant factors in a multivariable model, only the presence of diabetes remained significantly associated with all ONH parameters evaluated (P < 0.01). CONCLUSIONS: Different systemic and ocular factors, such as diabetes, CH, and the relative size of the cup, seem to be associated with the magnitude of changes in ONH topography after acute IOP reduction in POAG patients. These associations partially explain the ONH changes observed in these patients and suggest that other factors are possibly implicated in an individual susceptibility to IOP.

Effect of etidronate treatment on bone mass of male nephrolithiasis patients with idiopathic hypercalciuria and osteopenia.

Osteopenia is frequently found among calcium stone forming (CSF) patients with hypercalciuria. We investigated the effect of a 2-year therapeutic course of etidronate, a bone-sparing agent, in 7 young male CSF patients. The treatment consisted of a cyclic intermittent administration of phosphate followed by sodium etidronate and calcium supplementation every 74 days. Bone mineral density (BMD) measured at 12-month intervals and bone biopsies performed at baseline and after 2 years were the primary efficacy parameters. Mean lumbar spine BMD increased significantly after the 1st year by 2.6 +/- 1.0% (mean +/- SE, p < 0.05) and nonsignificantly after the 2nd year by 5.6 +/- 2.6%. Nonsignificant changes were observed for femoral neck mean BMD after either the 1st or the 2nd year (decrease of 2.0 +/- 1.0% and 2.0 +/- 3.0%, respectively). Mean histomorphometric parameters showed that bone volume, osteoid volume, and eroded surfaces did not differ from baseline (13.9 +/- 2.2 vs. 12.2 +/- 1.1%, 1.2 +/- 0.7 vs. 2.6 +/- 0.7%, and 20.7 +/- 6.2 vs. 13. 7 +/- 1.3%, respectively). Osteoid surface was significantly lower than baseline values (9.5 +/- 5.2 vs. 18.8 +/- 5.3%, p < 0.05). These data suggest that etidronate given to young male CSF patients presenting with hypercalciuria and osteopenia led to a significant amelioration of BMD, evident only in the lumbar spine after 1 year of treatment. There was no histological evidence of long-term improvement in bone remodeling.