Functional and hemodynamic parameters in glaucoma patients after trabeculectomy

Abstract

Abstract Purpose To study a correlation of hemodynamic and electroretinography (ERG) parameters in patients with primary open angle glaucoma (POAG) before and after trabeculectomy. Methods 29 patients (32 eyes) with early, advanced and late stages of POAG were tested prior to surgery and at 2 months after trabeculectomy. Standard ERG methods and chromatic macular ERG were used. Ocular hemodynamics were evaluated by colour Doppler sonography. Peak systolic velocities (PSV), end‐diastolic velocities (EDV), and resistive indices (RI) of the ophthalmic artery, central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were obtained. Results After surgery reduction of IOP (62.7%, p≤0.001) revealed a significant increase of amplitude values of OPs and macular ERG (p≤0.05). In early and late stages of POAG there were no significant differences in ocular blood flow parameters before and after trabeculectomy. In advanced stage the PSV and EDV in CRA were increased (p≤0.05). We found a correlation between macular ERG to red stimuli, OPs and blood flow parameters in CRA and SPCA before trabeculectomy. After surgery statistics revealed a correlation only between OPs and PSV in CRA. Conclusion The functional changes of macular area and inner retina are more common in patients with simultaneous decrease of PSV and EDV in CRA and SPCA. Retinal bioelectric activity in early and advanced stages of POAG is IOP‐dependent, and can be partially restored after IOP reduction. In contrast to ERG, the retinal blood parameters are relatively constant before and after short period of trabeculectomy.