Sulfur Hexafluoride 20% versus Lactated Ringer’s Solution for Prevention of Early Postoperative Vitreous Hemorrhage after Diabetic Vitrectomy

Purpose: To compare the hemostatic effect of sulfur hexafluoride 20% (SF6 20%) with lactated Ringer′s solution for prevention of early postoperative vitreous hemorrhage following diabetic vitrectomy. Methods: In a prospective randomized clinical trial, 50 eyes undergoing diabetic vitrectomy were divided into two groups. At the conclusion of surgery, in one group the vitreous cavity was filled with SF6 20% while in the other group lactated Ringer′s solution was retained in the vitreous cavity. The two groups were compared for the rate of early postoperative vitreous hemorrhage. Results: The incidence of vitreous hemorrhage was lower in the SF6 group than the Ringer′s group 4 days (20% vs 68%, P=0.001), 7 days (24% vs 60%, P=0.01) and 4 weeks (16% vs 40%, P=0.059) after vitrectomy. Conclusion: In comparison with lactated Ringer′s solution, SF6 20% had a significant hemostatic effect especially in the early postoperative period after diabetic vitrectomy and reduced the incidence of vitreous hemorrhage

A 10-year review of the visual outcomes of early versus late pars plana vitrectomy in eyes with dropped lens fragment or nucleus during phacoemulsification

Background: Pars plana vitrectomy (PPV) is a routine surgical option for the removal of dropped lens fragment or nucleus in the vitreous cavity due to complicated cataract surgery; however, its optimal timing is controversial. Therefore, we aimed to determine the visual outcomes of early versus late PPV in eyes with dropped lens fragment or nucleus due to complicated phacoemulsification cataract surgery. Methods: This descriptive-analytical retrospective study collected data of patients who underwent early (less than or equal to 1 week) versus late (> 1 week) PPV for the management of dropped lens fragment or nucleus resulting from complicated phacoemulsification cataract surgery over a 10-year period at Imam Khomeini Tertiary Referral Hospital, Ahvaz, Iran. Demographic characteristics, the interval between complicated phacoemulsification and PPV, pre- and postoperative intraocular pressures, best-corrected distance visual acuity (BCDVA), and postoperative complications were extracted from each patient’s record. Results: Fifty-one eyes of 51 patients with a mean (standard deviation [SD]) age of 64.66 (6.54) years and a male-to-female ratio of 33 (64.7%) to 18 (35.3%) were included over 10 years. The mean (SD) BCDVA before PPV was 1.87 (0.53) logarithm of the minimum angle of resolution (logMAR), which improved significantly to 0.54 (0.46) logMAR at the final postoperative visit (P < 0.001). The mean (SD) BCDVA was significantly better after early PPV than after late PPV (0.41 [0.30] versus 0.62 [0.52] logMAR; P < 0.05). There was no significant difference in the final BCDVAs among the three methods of lens fragment removal (P > 0.05). The rates of post-PPV complications were as follows: 29 (56.9%) eyes with corneal edema, 16 (31.4%) eyes with uveitis, 10 (19.6%) eyes with cystoid macular edema, 8 (15.7%) eyes with rhegmatogenous retinal detachment, and 8 (15.7%) eyes with other complications (optic nerve atrophy, choroidal neovascularization, vitreous hemorrhage, or epiretinal membrane formation). No significant differences were observed in the rates of complications according to the time interval between complicated phacoemulsification and PPV (all P > 0.05). The frequency of corneal edema was significantly higher when removing lens fragments using the trans-limbal method than using the other methods (P < 0.05), yet the rates of other complications were comparable among the three methods of lens fragment removal (all P > 0.05). Conclusions: Early PPV and removal of a dropped lens fragment or nucleus resulting from complicated phacoemulsification cataract surgery are recommended to achieve better visual outcomes. Future studies with longer follow-up, greater sample sizes, and analysis of other parameters of visual function, such as contrast sensitivity, visual field, color vision, and stereopsis, could provide more conclusive results and help verify our preliminary findings

Absorbable suture for band tightening of scleral buckling in pseudophakic rhegmatogenous retinal detachment: a modified surgical technique and a 6-month follow-up

Background: Rhegmatogenous retinal detachment (RRD) is a separation of the neurosensory retina from the retinal pigment epithelium as a result of liquid vitreous passing through a retinal break. Scleral buckling surgery (SB) is a conventional treatment for RRD. In SB, a silicon explant is used to indent the sclera, reduce vitreous traction, and close the retinal break, and an encircling band is used circumferentially, leading to myopia. This study aimed to evaluate the functional and biometric outcomes after SB with absorbable band-tightening sutures in patients with pseudophakic RRD. Methods: In this prospective interventional study, we included pseudophakic eyes with RRD treated surgically with SB and a temporary encircling band using a 6-0 absorbable Vicryl suture to tighten the band, instead of conventional permanent suture tightening. Anterior chamber depth (ACD), axial length (AL), intraocular pressure (IOP), spherical equivalent refractive error (SER), and best-corrected distance visual acuity (BCDVA) were measured preoperatively and at 1 day, 2 weeks, 3 months, and 6 months postoperatively. Results: We included 30 eyes of 30 patients with a mean (standard deviation [SD]) age of 66.1 (10.5) years who underwent SB with an absorbable band-tightening suture for pseudophakic RRD. Significant increases in AL and ACD were observed at 2 weeks after surgery, with a significant decline in values thereafter; however, at the 6-month follow-up, the values were significantly higher than those at baseline (all P < 0.05). Based on the Vicryl tension and its hydrolysis, mean (SD) SER at 2 weeks postoperatively was significantly more myopic than at baseline (-5.8 [1.6] D versus +1.3 [1.8] D). However, the mean (SD) SER decreased significantly throughout the 6-month follow-up (all P < 0.05), and it reached -1.8 (0.9) D, which was comparable with the mean baseline SER (P = 0.140). The participants experienced significant improvement in BCDVA throughout the follow-up period (all P < 0.05). Conclusions: Using an absorbable suture to tighten the encircling band in patients with pseudophakic RRD can reduce postoperative myopia without adversely affecting the anatomical or functional outcomes. Future comparative studies with larger sample sizes and longer postoperative follow-up are needed to verify these findings

Dosimetric Parameters Estimation for I-125 (model 6711) Brachytherapy Source

Determining dose distribution around the applied sources in brachytherapy, especially ones with low-energy is so crucial in treatment designing. In this study dosimetric parameters of a brachytherapy source I-125 (model6711) were calculated using Monte Carlo simulation method.A homogeneity water phantom with dimensions of 30´30´30 cm 3 were simulated with MCNPX(2.6.0) code. A brachytherapy source I-125 (model6711) considering its details (materials, dimensions and its emitted spectrum) was located in the center of phantom. Positioning the source inside the vacuum sphere its air kerma strength, S k , was calculated. Recommende

Topical Timolol Inhibits Corneal Neovascularization in Rabbits

Timolol is a non-selective beta-adrenergic antagonist that is similar to propranolol. The mechanism through which these drugs act on the regression of neovascularization is largely unknown. However, it is thought that the drugs may act through vascular endothelial growth factor signaling, vasoconstriction, and vascular endothelial cell apoptosis. The aim of this study was to determine the effect of timolol on corneal neovascularization in rabbits. Neovascularization was induced in the eyes of 20 rabbits. Next, the rabbits were divided into two groups: the timolol (experimental) group received eye drops containing timolol 0.5% twice per day; and the saline (control) group received saline drops twice per day for two weeks. After 7 days, the mean area of corneal neovascularization (presented as a percentage relative to baseline) was significantly lower in the timolol group than in the saline group (4.63 ± 4.61% versus 58.39 ± 6.31%, P < 0.001). After 2 weeks, the mean area of corneal neovascularization was 0.85 ± 1.33% in the timolol group and 1.73 ± 2.06% in the saline group (P = 0.315). After the first week of treatment, timolol significantly reduced the area of neovascularization compared to control. Timolol may increase the rate of recovery from corneal neovascularization.Â

Topical Timolol Inhibits Corneal Neovascularization in Rabbits

Timolol is a non-selective beta-adrenergic antagonist that is similar to propranolol. The mechanism through which these drugs act on the regression of neovascularization is largely unknown. However, it is thought that the drugs may act through vascular endothelial growth factor signaling, vasoconstriction, and vascular endothelial cell apoptosis. The aim of this study was to determine the effect of timolol on corneal neovascularization in rabbits. Neovascularization was induced in the eyes of 20 rabbits. Next, the rabbits were divided into two groups: the timolol (experimental) group received eye drops containing timolol 0.5% twice per day; and the saline (control) group received saline drops twice per day for two weeks. After 7 days, the mean area of corneal neovascularization (presented as a percentage relative to baseline) was significantly lower in the timolol group than in the saline group (4.63 ± 4.61% versus 58.39 ± 6.31%, P < 0.001). After 2 weeks, the mean area of corneal neovascularization was 0.85 ± 1.33% in the timolol group and 1.73 ± 2.06% in the saline group (P = 0.315). After the first week of treatment, timolol significantly reduced the area of neovascularization compared to control. Timolol may increase the rate of recovery from corneal neovascularization.

Prevention of Corneal Neovascularization; a Preliminary Experimental Study in Rabbits

The purpose of this study was to compare the effects of propranolol, timolol and bevacizumab with betamethasone to prevent corneal neovascularization (CNV) in rabbits. This study was performed on 28 male rabbits. CNV was induced by three 7-0 silk sutures 2 mm long and 1 mm distal to the limbus. Animals were randomly divided into 4 groups of propranolol + betamethasone, timolol + betamethasone and bevacizumab + betamethasone and betamethasone alone. Eye drops were started from the first day of study. On 7th, 14th, 21st, 28th, 35th and 42nd days, vascular progression, time of neovascularization and vascular area were evaluated and compared with the control group (betamethasone alone). There was a significant reduction in the area of ​​neovascularization in the timolol and bevacizumab groups compared to the control group (P-value = 0.05, P=0.047, respectively). Also, regarding vascular progression, there was a significant decrease in the timolol and bevacizumab groups (P-value = 0.014, P=0.002, respectively). Regarding delayed onset of neovascularization, there was a significant difference in the timolol and bevacizumab group in rabbits (P-value = 0.04, P=0.00, respectively). In conclusion, the use of timolol and bevacizumab drops besides betamethasone can delay neovascularization and decrease the length of corneal vascularization in rabbits

THE COMPARISON OF THE SEISMIC PERFORMANCE OF BRBF AND EBF BRACED STRUCTURES WITH IRREGULARITY IN HEIGHT

The Thirteenth East Asia-Pacific Conference on Structural Engineering and Construction (EASEC-13), September 11-13, 2013, Sapporo, Japan

Early Changes in Intraocular Pressure Following Phacoemulsification

Purpose: To evaluate early postoperative changes in intraocular pressure (IOP) following phacoemulsification and intraocular lens (IOL) implantation. Methods: This prospective study included 129 eyes with open angles and normal or high IOP undergoing phacoemulsification and IOL implantation for senile cataracts. The patients were divided into 3 groups (Gs) based on preoperative IOP: ≤15 mmHg (G1, n=76); from 16 to 20 mmHg (G2, n=43) and; from 21 to 30 mmHg (G3, n=10). IOP was measured by Goldmann applanation tonometry one day before surgery, and 1 and 6 weeks postoperatively. Results: IOP was decreased postoperatively in all study groups 1 and 6 weeks after surgery as follows: 2.8±1.5 and 1.8±1.7 mmHg respectively in G1 (P<0.001); 4.2±1.9 and 4.3±2.9 mmHg respectively in G2 (P<0.001), and 8.3±4.3 and 9.3±4.1 mmHg respectively in G3 (P<0.001). At the end of the sixth postoperative week, the percentage of IOP change for G1, G2 and G3 was 13.5%±12.7, 24.5%±11.7 and 38.3%±16.2, respectively. Conclusion: IOP significantly decreased after phacoemulsification and IOL implantation in normal subjects with open angles and those with ocular hypertension. IOP reduction was greater in eyes with higher preoperative IOP

Pars Plana Vitrectomy and Silicone Oil Injection in Phakic and Pseudophakic Eyes; Corneal Endothelial Changes

Purpose: To evaluate the effect of silicone oil (SO) on the corneal endothelium in SO filled phakic and pseudophakic vitrectomizied eyes. Methods: This prospective comparative consecutive case-control study evaluated the corneal endothelial characteristics of 64 SO filled vitrectomizied eyes (case group) as compared to 46 vitrectomizied eyes without SO injection (control group). Endothelial cell densities (ECD), coefficient of variation (CV), and percentage of hexagonal cells (hexagonality) at the corneal center were evaluated preoperatively, 1 month and 6 months after surgery using noncontact specular microscopy and were compared between the two groups. Exclusion criteria were previous vitreoretinal surgery, aphakia, any degree of anterior chamber inflammation, SO bubbles in the anterior chamber and increased intraocular pressure in the postoperative period. Results: Six months after SO injection, mean ECD was 2,438.2±327.6 cell/mm 2 in the case group and 2,462.6±361.7 cell/mm 2 in the control group (P = 0.714) and mean hexagonality was 49.6 ± 6.8 and 54.6 ± 8.9, in the case and control groups, respectively (P = 0.004). Six months after operation, CV in the case group was 39.3 ± 5.6 and that in the control group was 35.7 ± 6.4 (P = 0.003). Conclusion: Although the presence of SO in the vitreous cavity of phakic and pseudophakic eyes causes slight reduction in the number of endothelial cells, however it leads to significant changes in endothelial cell morphology. Thus, removal of SO after reaching the desired tamponade effect is recommended