PurposePhosphodiesterase (PDE) inhibitors increase matrix metalloproteinase (MMP) production by inhibiting re-uptake of adenosine and may potentiate nitric oxide (NO) activity. This study was performed to investigate the effects and mechanisms of PDE inhibitors on trabecular outflow in cultured human trabecular meshwork cells (HTMCs).MethodsPrimary HTMC cultures were exposed to 0, 20, and 50 µM dipyridamole (DPD) or theophylline (TPN). Permeability through the HTMC monolayer was assessed using carboxyfluorescein. The production of NO was assessed using the Griess assay and MMP-2 levels were measured via Western blotting.ResultsDPD significantly increased permeability accompanied with increased nitrite concentration and MMP-2 levels (all p < 0.05). TPN increased nitrite but did not affect permeability or MMP-2 levels significantly (p > 0.05). When treated with DPD and TPN together, both permeability and nitrite production were increased; however, MMP-2 levels showed no difference compared to DPD exposure alone (p > 0.05).ConclusionsDPD increased trabecular permeability accompanied with increased nitrite production and MMP-2 levels. PDE inhibitors may increase trabecular outflow by increasing MMP-2 levels and by potentiating NO activity through cyclic GMP in HTMC.

Background To evaluate the effectiveness of resected muscle adjustment compared with the recessed muscle adjustment in patients with intermittent exotropia. Methods This retrospective clinical investigation analyzed the data of patients who underwent strabismus surgery with adjustment. Patients who were followed-up for at least one and half year after adjustment were enrolled. They were divided into two groups; patients who underwent adjustment on recessed lateral rectus muscle (LR-Adj group) and adjustment on resected medial rectus muscle (MR-Adj group). Postoperative changes were compared. Surgical success was defined as horizontal deviation < 5 prism diopters (PD) esodeviation and < 10 PD exodeviation on distance measurement at 1.5 years postoperatively. Results Forty patients were included; LR-Adj group included 21 and MR-Adj group included 19 patients. The mean esodeviation at distance fixation immediately after adjustment was 8.1 ± 5.4 PD in the LR-Adj group and 8.4 ± 4.7 PD in the MR-Adj group (P = 0.843). Postoperative exodrift occurred in both groups, and amount of exodeviation after 1.5 year were not significantly different. For the comparison of the amount of exodrift at near measurement, the amount of exodrift within 1 month after surgery was smaller in the MR-Adj group than that in the LR-Adj group (P = 0.01). Surgical success rates were 81.0% in the LR-Adj group and 84.2% in the MR-Adj group (P = 0.559). Conclusions The smaller amount of exodrift in the MR-Adj group may mean that the positional stability of the resected muscle is favorable in the early post-adjustment period. However, there was no significant difference groups in the final exodeviation and surgical success rate between the groups. Resected muscle adjustment was as effective as the conventional recessed muscle adjustment.