Evaluation of the intraocular pressure changes during micturition in patients with benign prostatic hyperplasia.

OBJECTIVE: To evaluate the effect of the Valsalva maneuver (VM) during micturition on intraocular pressure (IOP) in patients with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: IOP were measured before and during micturition in uroflowmetry testing by Tonopen-Avia (Reichert Inc., NY, USA) in 35 eyes of 35 patients with BPH. International Prostate Symptoms Score (IPSS) questionnaire was used for quantification of BPH symptoms. The subjects were divided into two groups according to IPSS questionnaire: patients with low IPSS scores and patients with high IPSS scores. RESULTS: The mean IOP before and during micturition in patients with BPH were 15.26 ± 4.39 mmHg and 16.23 ± 4.43 mmHg, respectively (p = 0.047). When patients with BPH were assigned to two distinct groups according to the IPSS scores, IOP did not differ in patients with low IPSS scores (p = 0.590), whereas mean IOP was significantly higher in patients with high IPSS scores (p = 0.007). CONCLUSIONS: The Valsalva maneuver, performed during micturition, can lead to significant IOP increase in patients with BPH, particularly in advanced disease.

Bioactive self-assembled peptide nanofibers for corneal stroma regeneration.

Defects in the corneal stroma caused by trauma or diseases such as macular corneal dystrophy and keratoconus can be detrimental for vision. Development of therapeutic methods to enhance corneal regeneration is essential for treatment of these defects. This paper describes a bioactive peptide nanofiber scaffold system for corneal tissue regeneration. These nanofibers are formed by self-assembling peptide amphiphile molecules containing laminin and fibronectin inspired sequences. Human corneal keratocyte cells cultured on laminin-mimetic peptide nanofibers retained their characteristic morphology, and their proliferation was enhanced compared with cells cultured on fibronectin-mimetic nanofibers. When these nanofibers were used for damaged rabbit corneas, laminin-mimetic peptide nanofibers increased keratocyte migration and supported stroma regeneration. These results suggest that laminin-mimetic peptide nanofibers provide a promising injectable, synthetic scaffold system for cornea stroma regeneration.

A short duration transient ischemia induces apoptosis in retinal layers: an experimental study in rabbits.

PURPOSE: To investigate retinal cell apoptosis in an experimental transient, short duration ocular ischemia model. METHODS: An experimental ischemia model, which simulates creating temporary high intraocular pressure to control intraocular bleeding during pars plana vitrectomy, was set up. Rabbits were randomly divided into three groups. Group 1 was the control group. In Group 2, intraocular pressure was increased to 97 mmHg for 5 minutes. In Group 3, intraocular pressure was increased to 97 mmHg for 10 minutes. After 24 hours, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling assay was used to detect retinal apoptosis in rabbit eyes. Only nuclear staining in retinal cells was counted. RESULTS: Groups with 5 minutes and 10 minutes of ischemia showed significantly higher amount of ganglion cell layer apoptosis when compared with the control group (p<0.05). Light microscopy and standard hematoxylin-eosin did not show any significant damage in the retina cells. CONCLUSIONS: Apoptotic cell death in the retinal cell layers occurs in temporary ischemia-reperfusion as early as 5 and 10 minutes duration.