Attaining the optimal flange technique for transscleral capsular bag stabilization using iris hooks.

PURPOSE: To investigate the flange properties of different iris hooks. SETTING: Vienna Institute for Research in Ocular Surgery (VIROS), Hanusch Hospital, Vienna, Austria. DESIGN: Laboratory study. METHODS: The flanging properties of 4 different iris hooks made from polypropylene (PP), elastic polymer (EP), and nylon were investigated with different heating distances and both with and without forceps gripping. The maximum diameter of the flanges was measured, and the shape of the flanges was evaluated. RESULTS: Although both nylon and EP iris hooks had too small flange diameters for intrascleral fixation, PP iris hooks had a sufficient flange diameter (>330 µm) and mushroom-like shape. Furthermore, in PP hooks, heating distance was directly proportional to flange diameter. CONCLUSIONS: The findings of this study suggest that only PP iris hooks are suitable for flanged intrascleral fixation, which is off-label, to secure adequate fixation.

Occurrence of Corneal Staining after Cataract Surgery with and without Chitosan-N-Acetylcysteine Eye Drops.

INTRODUCTION: The objective of this study was to evaluate the prevalence of ocular surface damage assessed by corneal staining scores right after cataract surgery and whether it can be prevented using chitosan-N-acetylcysteine (C-NAC) eye drops. METHODS: We included patients scheduled for routine cataract surgery. Each patient was randomly assigned to one of three groups. Patients in group 1 underwent routine cataract surgery with no additional eye drops. In group 2, patients received C-NAC eye drops after cataract surgery, and in group 3, C-NAC was applied both before and after surgery. Both groups continued the treatment once daily for 4 days. Ocular surface alteration was assessed using the National Eye Institute (NEI) score, and the visual analog scale (VAS) was used to evaluate subjective complaints. RESULTS: Thirty-six patients were included in the final analyses. One hour after cataract surgery, a statistically significant increase in corneal fluorescein staining was observed in all groups, which decreased again after 1 week. There was no significant difference between the groups 1 h after cataract surgery, though a tendency toward lower NEI scores was observed during this time point in group 3. DISCUSSION: Cataract surgery induced ocular surface staining and subjective complaints after 1 h. However, the increase in VAS score was small and probably not clinically relevant. The application of perioperative C-NAC eye drops did reduce the rate of corneal staining after cataract surgery in a clinically relevant manner.

Effects of glaucoma surgery on visual field progression in open-angle glaucoma considering the floor effect.

PURPOSE: The aim of this retrospective analysis was to investigate whether trabeculectomy (TRAB) and XEN® Gel Stent implantation (XEN) - both filtrating surgery techniques - can slow down the deterioration of visual field (VF) parameters considering the floor effect, which could lead to a misestimation of pre- and postoperative VF rate of progression (ROP). METHODS: Included in this study were patients with open-angle glaucoma, who underwent either TRAB or XEN® gel stent implantation and who had at least three VF tests before and after surgery, over an observation period of 13 years. The annual ROP of the mean defect (MD) and the square root of loss variance (sLV) were calculated with two different censoring thresholds: by censored regression and by ordinary least squares regression (OLSR). In addition, the diagnostic range of sLV was calculated. RESULTS: 48 eyes of 39 glaucoma patients were included in the study. The annual rate of MD progression was significantly reduced by filtering surgery when calculating the yearly ROP using OLSR (p = 0.006) and by censoring values exceeding a precalculated cut-off of 14.20 dB (p = 0.041) and a cut-off from the literature of 15.00 dB (p = 0.028). On average, the MD was impacted by a significant floor effect of 14.20 dB (95% CI: 12.83-15.56), corresponding to 17.7/59 absolute defects or 29.9% of the whole VF. When applying both OLSR and censored regression, the annual rate of sLV progression did not show a significant difference. The sLV showed a diagnostic boundary at a MD of 15.78 dB. CONCLUSION: This study shows that filtering surgery can reduce the progression of VF in patients with open-angle glaucoma, especially those whose disease develops aggressively. This is valid even if the floor effect in advanced cases is compensated by censored regression. On average, the ROP of MD is affected by a significant floor effect at about 29.9% absolute loss of the whole VF.

Comparison of methods to experimentally induce opacification and elasticity change in ex vivo porcine lenses.

At the moment, cataract, which is the opacification of the eye's lens, can only be treated by surgery. In order to develop and test new pharmacological treatment strategies for the disease, there is a need for an appropriate in vitro model using ex vivo animal lenses. In this study, porcine lenses were incubated in either culture medium, glucose, triamcinolone acetonide, sodium chloride, hydrogen peroxide, sodium selenite, neutral buffered formalin, or were exposed to microwave heating to experimentally induce lens opacification. Changes in the lens morphology, weight, size, and elasticity were monitored 7 days after treatment. The fastest induction of dense opacification was seen in lenses exposed to sodium chloride, neutral buffered formalin, and microwave heating. No change in the size and weight of the lenses were detected, whereas loss in elasticity could be detected in lenses treated with formalin solution or microwave heating. Thus, neutral buffered formalin- and microwave-treated ex vivo porcine lenses seem to be a suitable model for mature cataracts, whereas hypertonic sodium chloride may be useful for studies on osmolarity-induced lens opacification.