Failed Ahmed glaucoma valves: trabeculectomy versus repeat shunt surgery.

INTRODUCTION: To investigate the outcomes of trabeculectomy (TRAB) versus repeat Ahmed glaucoma valve (re-AGV) implantation in eyes with Ahmed glaucoma valve (AGV) failure. METHODS: This quasi-experimental study includes patients with failed AGV implants requiring additional surgical intervention between 2018 and 2022. Patients in the TRAB group underwent a fornix-based procedure with mitomycin C 0.01% injection (0.1 mL). Eyes in the re-AGV group underwent repeat shunt surgery. The choice of the procedure was based on conjunctival condition. The primary outcome measure was surgical success rate based on various intraocular pressure (IOP) targets and percentages of IOP reduction from baseline: IOP ≤ 21 mmHg and 20% reduction (conventional criteria), IOP ≤ 18 and > 20% reduction (criterion A), IOP ≤ 15 and > 25% reduction (criterion B), and IOP ≤ 12 and > 30% reduction (criterion C). RESULTS: Forty-eight eyes of 48 patients were operated and reported herein, consisting of 22 eyes of 22 patients undergoing TRAB and 26 eyes of 26 subjects undergoing re-AGV. No significant difference was observed between the study groups in terms of initial diagnoses, baseline IOP or the number of prior surgeries. The cumulative probability of survival at one year was significantly higher in the trabeculectomy group using the three stricter success definitions. In both study groups, IOP was significantly reduced from baseline at all postoperative visits, and was significantly lower in the TRAB group at all time points beyond one month. At 12 months, 5% of TRAB versus 48% of re-AGV eyes required glaucoma medications (P < 0.001). The rate of complications was comparable between the study groups (P = 0.76) but there was a trend toward a greater need for repeat surgery in the re-AGV group (4 eyes versus nil, P = 0.07). CONCLUSIONS: Trabeculectomy can be considered a safe and effective surgical option in eyes with failed AGV leading to significantly lower IOP levels and more favorable success rates than re-AGV in selected patients.

Femtosecond thin-flap laser assisted in situ keratomileusis for correction of post-penetrating keratoplasty ametropia: long-term outcome.

PURPOSE: To evaluate the long-term clinical outcomes of femtosecond thin-flap LASIK (femto-LASIK) for correction of refractive error after penetrating keratoplasty in keratoconus-affected eyes. SETTING: a private ophthalmology clinic. DESIGN: Prospective interventional case series. METHODS: This prospective interventional case series enrolled 22 eyes of 22 patients who underwent femto-LASIK for the management of post-penetrating keratoplasty ametropia. The refractive error, uncorrected (UDVA), and corrected (CDVA) distance visual acuities and vector analysis were reported in short-term and long-term period after surgery. RESULTS: The mean age was 32.7 ± 7.5 years (range, 23 to 47 years) at the surgery time. The average time between PK and femto-LASIK was 42.5 ± 31.7 months. The average follow-up duration after femto-LASIK was 81.2 ± 18.6 months. The mean preoperative UDVA significantly improved from 0.47 ± 0.15 logMAR to 0.35 ± 0.14 logMAR at 12 months (P = 0.048) and 0.4 ± 0.17 at final follow-up exam (P = 0.007). CDVA was 0.22 ± 0.1 at baseline which improved to 0.18 ± 0.15 and 0.15 ± 0.1 logMAR at 12 and 81 months, respectively. (Ps = 0.027, 0.014). The mean cylinder before surgery was - 5.04 ± 1.4D which significantly decreased to -1.5 ± 0.8 D at 12 months postoperatively. (P < 0.001). There was a significant increase in refractive astigmatism from 12 months to 81 months postoperatively (-3.1 ± 2.0, P = 0.002). At the final visit, the efficacy index was 0.83, and the safety index was 1.16. CONCLUSIONS: Despite the short-term outcome indicated that femo-LASIK was effective for correction of post-keratoplasty ametropia during short-term period, a notable regression in its effect was observed in the long-term follow-up. Therefore, the predictability of this technique might decrease in the long-term.

Performance, rumen fermentation, blood minerals, leukocyte and antioxidant capacity of young Holstein calves receiving high-surface ZnO instead of common ZnO.

This study was conducted to assess the effect of feeding high-surface ZnO instead of common ZnO on the performance, rumen fermentation, blood minerals, leukocytes and antioxidant capacity of pre- and post-weaning calves. Thirty male suckling Holstein calves were allotted to one of three experimental groups (10 replicates) in a completely randomised design. Calves received: (1) a low Zn diet without Zn supplementation (control diet), (2) a high Zn diet containing 50 mg supplementary Zn/kg dry matter (DM) as common ZnO or (3) a high Zn diet containing 50 mg supplementary Zn/kg DM as high-surface ZnO (nano-ZnO). The control diet contained a native Zn content of 35.5, 34.7 or 33.7 mg/kg DM for the age periods of 7 to 30, 31 to 70 and 71 to 100 d, respectively. Supplementation of the diet with Zn did not change the dry matter intake (DMI) of calves during d 7 to 30 but increased the ADG in this period (p < 0.05). During age periods of 31 to 70 and 71 to 100 d, DMI and ADG of the Zn supplemented calves were higher (p < 0.05) than the control animals. The nutrient digestibility and the concentration of rumen volatile fatty acids were positively affected (p < 0.05) and the rumen ammonia-N concentration decreased (p < 0.05) by dietary Zn supplementation. Furthermore, the incidence of diarrhoea and pneumonia was lower in calves receiving the Zn supplemented diets. Irrespective of ZnO source, the blood total antioxidant capacity, leukocyte and haematocrit levels significantly increased (p < 0.05) with the ZnO supplemented diets. The post-weaning DMI, nutrient  digestibility and blood haematocrit levels were higher in calves receiving high-surface ZnO, compared to those supplemented with common ZnO. With inclusion of the Zn sources in pre- and post-weaning diets, the blood Zn concentration increased (p < 0.05), but the blood Cu, Fe, Ca, P and Mg levels remained unchanged. Regardless of source, dietary supplementation of young calves with ZnO improved the performance and decreased rumen ammonia-N and the incidence of diseases. Moreover, high-surface ZnO had advantages over common ZnO in increasing the post-weaning feed intake, digestibility and blood Zn concentration.

Femtosecond laser implantation of a 340-degree intrastromal corneal ring segment in keratoconus: Short-term outcomes.

PURPOSE: To evaluate the short-term outcomes of femtosecond laser-assisted implantation of a 340-degree intracorneal ring (ICR) (Keraring) in patients with keratoconus. SETTING: Four centers in Iran. DESIGN: Prospective case series. METHODS: All cases had implantation of the 340-degree ICR after tunnel creation with a femtosecond laser. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, sphere, cylinder, manifest refraction spherical equivalent (MRSE), mean keratometry (K), steep K, and flat K were evaluated preoperatively and 1, 3, and 6 months postoperatively. RESULTS: Eighteen eyes of 17 patients were included. The mean follow-up was 4.33 months (range 1 to 6 months). The mean UDVA improved from 0.95 logarithm of the minimum angle of resolution (logMAR) ± 0.33 (SD) to 0.53 ± 0.35 logMAR (P = .001) and the mean CDVA from 0.39 ± 0.22 logMAR to 0.26 ± 0.21 logMAR (P = .09). The mean sphere decreased from -5.08 ± 3.74 diopters (D) to -1.67 ± 2.59 D, the mean cylinder from -5.83 ± 2.02 D to -2.72 ± 1.81 D, and the mean MRSE from -8.03 ± 3.88 D to -3.01 ± 2.82 D (P < .001). The mean K decreased from 51.43 ± 3.59 D to 47.42 ± 3.59 D (P < .001). All patients with a preoperative mean K greater than 55.0 D had worse CDVA. CONCLUSIONS: Implantation of a 340-degree ICR using femtosecond laser improved the visual, refractive, and topographic parameters in keratoconic patients. The findings indicate that patients with severe keratoconus (mean K >55.0 D) are not good candidates for this type of ICR.

Clinical Evidence of Decreased Iris Resistance in Patients With Keratoconus.

PURPOSE: To compare the total energy required for producing patent neodymium:yttrium-aluminum-garnet laser peripheral iridotomy in patients with or without keratoconus (KC). METHODS: In this case-control study, 36 eyes from 36 patients with KC and 24 eyes from 24 patients with myopia with or without astigmatism (as control group) who were scheduled for phakic intraocular lens implantation underwent neodymium:yttrium-aluminum-garnet laser peripheral iridotomy 1 week before surgery. The total laser energy was recorded and compared between the 2 groups. RESULTS: Mean total laser energy was significantly lower in patients with KC compared with the control group (114.7 ± 41.0 mJ and 263.9 ± 79.6 mJ, respectively, P < 0.01). Total laser energy was not correlated with patients' age, sex, race, refraction, maximum keratometry, or corneal thickness. CONCLUSIONS: Lower tissue resistance may be present in other ocular structures, such as iris, in patients with KC. Our findings supported a generalized abnormality in patients with KC rather than a localized corneal disease, at least in some cases.

Selection of Single Chain Antibody Fragments for Targeting Prostate Specific Membrane Antigen: A Comparison Between Cell-based and Antigen-based Approach.

Prostate cancer (PCa) is the most frequently diagnosed cancer and the second most common cause of cancer related mortality in United States male population. ScFv fragments have different usefulness. For example they have small size, high perfusion rate, high yield of production and are non-immunogenic, thus they can be used for therapeutic purposes. In this project we used a synthetic human ScFv library for isolation of ScFv monoclonal antibodies against prostate specific membrane antigen. For this purpose, after five rounds of cell-panning, and also five rounds of antigen-panning with rPSMA specific anti- PSMA ScFv-phage particles were isolated. Phages with high affinity toward PSMA were selected and used for further analysis. Specificity and affinity of both ScFv to PSMA and LnCaP cell line examined by ELISA. Recombinant ScFv antibody isolated from cell-panning had higher specificity and affinity for both the antigen and LNCaP cell line. Our result demonstrated that ScFv antibody obtained by cell-panning can target PSMA antigen and cell lines.

Measurement of Central Corneal Thickness Using Ultrasound Pachymetry and Orbscan II in Normal Eyes.

PURPOSE: To compare ultrasound pachymetry and Orbscan II for measurement of central corneal thickness (CCT) in normal eyes. METHODS: The current study was performed at Labbafinejad Medical Center (LMC), Tehran, Iran. Three hundred eyes from 150 healthy individuals referred for keratorefractive surgery were assessed first by Orbscan II and then by ultrasound pachymetry, and CCT values were recorded and compared. RESULTS: Overall, Orbscan II overestimated CCT as compared to ultrasound pachymetry by about 2.4% (mean values 547.6 ± 34.7 versus 534.8 ± 34.7, respectively, P < 0.001). The difference was more significant when CCT was less than 500 microns (mean values 493.2 ± 16.9 versus 479.9 ± 15.6, mean overestimation: 2.6%, P < 0.001). There was good linear correlation between the two methods (Pearson's correlation r = 0.968, P < 0.0001). CONCLUSION: Orbscan II has good correlation with ultrasound pachymetry for measurement of CCT in normal eyes; however Orbscan II should not be used to evaluate corneal thickness before keratorefractive surgeries, as it tends to overestimate corneal thickness and may result in undesirable, low residual stromal thickness.