Effect of Hypoxia on the Survival and Production of Nitric Oxide in Trabecular Meshwork Cells

PURPOSE: To investigate the effect of hypoxia on the survival and nitric oxide (NO) production of cultured trabecular meshwork (TM) cells. METHODS: After inducing chemical hypoxia with sodium cyanide, the survival and nitrite production of the primarily cultured porcine TM cells were assessed with MTT and Griess assays. The effect of NOS inhibitor, N(omega)-Nitro-L-arginine methyl ester (L-NAME), was also assessed. Flow cytometry using annexin/PI was done to evaluate apoptosis. RESULTS: Chemical hypoxia decreased TM cell survival significantly (p<0.05) with increased NO production. This hypoxia-induced antiproliferative effect was abolished by L-NAME (p<0.05). Flow cytometric analysis revealed that hypoxia induced apoptosis of TM cells, which was inhibited by L-NAME. CONCLUSIONS: Hypoxia decreases the survival of TM cells and induced apoptosis, accompanied by increased NO production. The hypoxia-induced decreased survival of TM cells may be mediated by NO.

Effect of Gelrite on the Proliferation of Cultured Human Tenon's Capsule Fibroblasts

PURPOSE: To investigate the effect of Gelrite (Gelrite gellan gum), a natural gelling agent, on the viability and proliferation of human Tenon's capsule fibroblasts in tissue culture. METHODS: We studied the effect of two common preservatives, Gelrite and pure benzalkonium chloride (BAK) on the proliferation of primarily cultured human Tenon's capsule fibroblasts. After treatment of Gelrite and BAK with various serial dilutions, proliferation was assessed by MTT assay and the morphologic changes were evaluated with by inverted phase contrast microscopic examination after 24 hours and 1 week respectively. RESULTS: Gelrite did not affect the proliferation of fibroblasts and revealed no apparent morphologic change or viability of the fibroblasts in tissue culture. Also BAK did not affect the proliferation but inhibited the proliferation of the fibroblasts with toxic effects on cell morphology. CONCLUSIONS: Gelrite showed no apparent effect on the proliferation and morphology of the primarily cultured human Tenon's capsule fibroblasts.

Simultaneous Phacoemulsification, Pars Plana Vitrectomy, Intraocular Foreign Body Extraction, and Intraocular Lens Implantation

PURPOSE: To evaluate the effectiveness of simultaneous phacoemulsification, pars plana vitrectomy, the removal of posterior intraocular foreign body(IOFB), and primary intraocular lens implantation(IOL). METHODS: Simultaneous phacoemulsification, pars plana vitrectomy, the removal of posterior IOFB, and primary IOL implantation were performed in 10 eyes of 10 patients with ocular perforation and traumatic cataract due to posterior IOFB. The results showed no retinal detachment and endophthalmitis based on retrospective analysis. RESULTS: The follow-up period ranged from 3 to 45months(mean 19.6 months). In 8 eyes(80%), the final visual acuity was better than 0.9 but in remaining 2 eyes, it was less than 0.5 due to postoperative retinal detachment. There were enlargement of posterior capsule rupture and vitreous prolapse into anterior chamber in 2 cases, and lens dislocation into the vitreous cavity in 1 case during phacoemulsification. IOL was implanted into the bag in 4 eyes and into the ciliary sulcus without scleral fixation in remaining 6 eyes. CONCLUSIONS: Simultaneous phacoemulsification, pars plana vitrectomy, the removal of IOFB, and primary IOL implantation is a relatively safe operation. It provides rapid rehabilitation of the visual acuity and helps to save time and money in selected patients without the large posterior capsule rupture, retinal detachment, endophthalmitis and injury of macula and center of cornea due to IOFB.

IOP Change after Cataract Surgery in Patients with Controlled Chronic Glaucoma

PURPOSE: To evaluate the effect on intraocular pressure(IOP) of cataract surgery in chronic glaucoma patients. METHODS: We reviewed the change of IOP retrospectively in patients with controlled chronic primary glaucoma who did not show change in the number of glaucoma medications pre- and postoperatively after sutureless phacoemulsification and intraocular lens implantation up to 5 years of follow-up periods. This study included 15 patients with chronic open angle glaucoma and 13 patients with chronic angle closure glaucoma. Mean duration of follow-up period was 39.6 months. RESULTS: The mean preoperative IOP was 15.32 mmHg and mean postoperative IOP was 14.82 mmHg at last follow-up. There was statistically significant difference between pre- and postoperative mean IOP until 1 year postoperatively(p0.05). There was no significant difference in mean IOP during the follow-up period between chronic open angle and chronic angle closure glaucoma. The degree of IOP reduction was statistically significant until 1 year postoperatively but did not thereafter. There was no statistically significant difference in mean IOP reduction between chronic open angle and angle closure glaucoma during the follow-up periods. CONCLUSIONS: These results suggest that intraocular pressure(IOP) after cataract surgery in controlled primary glaucoma patients might be slight reduced up to 1 year postoperatively, but the removal of cataract does not seem to significantly affect IOP level in the long run.