Ganglion cells apoptosis in diabetic rats as early prediction of glaucoma: a study of Brn3b gene expression and association with change of quantity of NO, Caspase-3, NF-κB, and TNF-α

AIM: To find a new concept to show whether or not apoptosis of retinal ganglion cells (RGCs) can be determined in the histology of acute hyperglycemia in the role of expressed Brn3b gene related to nitric oxide (NO), caspase-3, nuclear factor kappa-B (NF-κB), and tumor necrosis factor-α (TNF-α) as an early predictor of primary open angle glaucoma (POAG) eyes and their associations. METHODS: Experimental in vivo study was carried out using adult male, white Sprague-Dawley rats aged ≥2mo, weighing 150-200 g. The animals were divided into two groups, one group receiving intraperitoneal injection of STZ 50 mg/kg in 0.01 mol/L citric buffer and pH 4,5 and a comparison made with the control group. Retinal tissue was divided into two parts (both experimental and control groups respectively): a) right retina for IHC (caspase-3 and TNF-α); b) left retina was divided into two parts for the purpose of real-time PCR test (RNA extraction for Brn3b gene expression analysis) and ELISA test (NO and NF-κB). RESULTS: The experimental group showed a decrease in Brn3b gene expression compared to the control group (1,3-fold lower in 2nd month; 1,1-fold lower in 4th month and 2,5-fold lower in 6th month). However, there was a decrease of NO, caspase-3, and an increase of NF-κB and TNF-α quantity. CONCLUSION: The expression of mRNA Brn3b gene is inversely proportional to apoptosis in RGCs. The quantity of NO, caspase-3, NF-κB and TNF-α is influential in expression of Brn3b in RGCs caused by hyperglycemia in diabetic rats.

Effect of nepafenac 0.1% on retinal thickness after cataract surgery in patients without risk factors for cystoid macular edema

AIM: To evaluate the effect of topical preoperative nepafenac 0.1% treatment on postoperative macular edema using optical coherence tomography (OCT) after uncomplicated cataract surgery.METHODS: Ninety eyes of 90 patients without any risk factors were included in the study. The patients were assigned to three groups: group 1, treated with topical prednisolone acetate 1%; group 2, treated with topical nepafenac 0.1% in addition to prednisolone acetate (1%); and group 3, those who started receiving nepafenac 0.1% treatment 3d prior to surgery and continued the treatment postoperatively in addition to prednisolone acetate (1%). Central retinal thickness (CRT) and macular volume values were recorded using OCT at weeks 3 and 6.RESULTS: The increases in macular volume in the central 1 mm area after 3 and 6wk were significantly lower in patients who used prophylactic topical nepafenac preoperatively (group 3) compared with those in group 1 (P=0.028 and 0.008, respectively). No significant differences in the increase in macular volume and CRT were noted between groups 2 and 3 (P>0.05). In group 1, the increases in macular volume in the central 3 mm area at weeks 3 and 6 were significantly higher than that in group 2 and 3 (3rd week, P=0.004; 6th week, P=0.005).CONCLUSION: Nepafenac 0.1% treatment in addition to topical steroids after uncomplicated cataract surgery reduce the increase in macular volume in the early postoperative period.