Dislocation force of scleral flange-fixated intraocular lens haptics.

PURPOSE: To measure the dislocation forces in relation to haptic material, flange size and needle used. SETTING: Hanusch Hospital, Vienna, Austria. DESIGN: Laboratory Investigation. METHODS, MAIN OUTCOME MEASURES: 30 G (gauge) thin wall and 27 G standard needles were used for a 2 mm tangential scleral tunnel in combination with different PVDF (polyvinylidene fluoride) and PMMA (polymethylmethacrylate haptics). Flanges were created by heating 1 mm of the haptic end, non-forceps assisted in PVDF and forceps assisted in PMMA haptics. The dislocation force was measured in non-preserved cadaver sclera using a tensiometer device. RESULTS: PVDF flanges achieved were of a mushroom-like shape and PMMA flanges were of a conic shape. For 30 G needle tunnels the dislocation forces for PVDF and PMMA haptic flanges were 1.58 ± 0.68 N (n = 10) and 0.70 ± 0.14 N (n = 9) (p = 0.003) respectively. For 27 G needle tunnels the dislocation forces for PVDF and PMMA haptic flanges were 0.31 ± 0.35 N (n = 3) and 0.0 N (n = 4), respectively. The flange size correlated with the occurring dislocation force in experiments with 30 G needle tunnels (r = 0.92), when flanges were bigger than 384 micrometres. CONCLUSIONS: The highest dislocation forces were found for PVDF haptic flanges and their characteristic mushroom-like shape for 30 G thin wall needle scleral tunnels. Forceps assisted flange creation in PMMA haptics did not compensate the disadvantage of PMMA haptics with their characteristic conic shape flange.

Size variability and fitting of 30-gauge thin-wall needles and 3-piece intraocular lens haptics for the flanged intrascleral fixation technique.

PURPOSE: To assess the diameter of different 30-gauge thin-wall needles and 3-piece intraocular lens (IOL) haptics readily used for the flanged-haptic intrascleral fixation technique. SETTING: Hanusch Hospital, Vienna, Austria. DESIGN: Laboratory investigation. METHODS: 5 30-gauge thin-wall needles and 5 3-piece IOLs were assessed. An upright light microscopy was used for measurements. The inner and outer diameters of the needles and the end thickness of the haptics were analyzed and compared for haptic fitting into the needle. RESULTS: Among the needles, the inner diameter of the T-lab needle was significantly wider compared with all the others (mean 209.3 ± 8.0 µm, P < .001), followed by TSK (194.8 ± 5.0 µm), MST (194.7 ± 5.8 µm), Sterimedix (187.5 ± 9.0 µm) and significantly narrower Meso-relle (mean 178.7 ± 7.0 µm, P < .05). The outer diameter of the T-lab needle was significantly larger of all (mean 316.0 ± 2.0 µm, P < .001). Concerning the IOLs, the AvanseePreset Kowa's haptic was significantly thinner (mean 127.2 ± 0.7 µm) than all the others, such as the TecnisZA900 Johnson & Johnson (143.5 ± 3.1 µm), the CTLucia202 Zeiss (143.8 ± 1.3 µm), and the AcrysofMA60AC Alcon (143.9 ± 1.4 µm). The only haptic that was thicker than all the others assessed was that of SensarAR40 Johnson & Johnson (170.7 ± 1.7 µm, P < .001). CONCLUSIONS: Most of the analyzed haptics would fit into most of the measured needles, with the exception of the Sensar AR40 in combination with the Meso-relle or Sterimedix needles. The combination of a larger needle lumen and a thinner haptic could result in more ease of insertion during surgery. If the dimensions of the needle and IOL haptics used are unknown, we recommend trying insertion before beginning surgery.

MicroRNA of Epithelial to Mesenchymal Transition in Fuchs' Endothelial Corneal Dystrophy.

AIM: a review of miRNA expression connected to epithelial mesenchymal transition studies in Fuchs' endothelial corneal dystrophy (FECD). METHODS: literature search strategy-PubMed central database, using "miRNA" or "microRNA" and "epithelial mesenchymal transition" or "EMT" and "Fuchs' endothelial corneal dystrophy" or "FECD" as keywords. Experimental or clinical studies on humans published in English regarding miRNA profiles of epithelial mesenchymal transition in Fuchs' endothelial corneal dystrophy published between 2009 and 2022 were included. CONCLUSION: The publications regarding the miRNA profiles of epithelial mesenchymal transition in Fuchs' endothelial corneal dystrophy are scarce but provide some valuable information about the potential biomarkers differentiating aging changes from early disease stages characterized by epithelial mesenchymal transition. In the corneal tissue of FECD patients, miRNA-184 seed-region mutation as well as unidirectional downregulation of total miRNA expression led by the miRNA-29 were demonstrated. For early diagnostics the miRNA of epithelial mesenchymal transition in aqueous humor should be analyzed and used as biomarkers.

Are miRNAs Dynamic Biomarkers in Keratoconus? A Review of the Literature.

AIM: A review of miRNA (microRNA) profiling studies in keratoconus. METHODS: Literature search strategy-PubMed central database, using miRNA or microRNA and keratoconus as keywords. RESULTS: Eleven experimental or clinical studies on humans regarding miRNA and keratoconus, published in English between 2009 and 2020 were retrieved. CONCLUSION: The publications regarding the role of miRNAs in keratoconus are scarce and diverse but provide some valuable information about potential new mechanisms of keratoconus development and progression. The cornea expresses almost 300 different miRNAs, 18 of which are specific, and miR-184 is by far the most abundant, with expression restricted to central basal and suprabasal epithelial cells. Mutations in the seed region of MIR184 were proved to be rare and nonspecific in patients with isolated keratoconus. Overall, in keratoconus, a total of 29 miRNAs were upregulated, and 11 were downregulated. It appeared that miR-143-3p, miR-182-5p, and miR-92a-3p were highly expressed, while the miRNAs connected to cell-cell junction, cell division, and motor activity were downregulated. In less advanced forms, altered expression of four miRNAs-miR-151a-3p, miR-194-5p, miR-195-5p, miR-185-5p-was proved in the cone epithelium; in contrast, in advanced keratoconus, the expression of miR-151a-3p and miR-194-5p remained altered, changes in the expression of miR-195 and miR-185 were not reported, and the expression of miR-138-5p, miR-146b-5p, miR-28-5p, and miR-181a-2-3p was also altered in the corneal epithelium. Keratoconus is a dynamic process of corneal stromal thinning that might result from a dynamic miRNA expression in the corneal epithelium exposed to environmental and behavioral factors causing repetitive traumas. Further experimental studies are needed to prove this hypothesis.

Successful treatment of Candida albicans anterior chamber infection after penetrating keratoplasty.

Purpose: To report the successful management of an anterior chamber (AC) infection after penetrating keratoplasty (PK) caused by Candida albicans. Observation: A 53-year-old female had a PK in her right eye. The donor rim tested positive for Candida albicans one week later. Despite initiation of prophylactic topical 1% voriconazole drops, the patient presented with a white mass in the anterior chamber one month later. Biopsy confirmed Candida. Antifungal therapy was intensified with the addition of intravenous fluconazole, and with repeated irrigations of the AC and intracameral administration of amphotericin B (off-label use). After two weeks of apparent lack of treatment response, the infection suddenly quiesced. The final outcome was visual acuity of 0.2 and a clear graft with an endothelial cell density of 2260 cells/mm. 2. Conclusions and Importance: Fungal intraocular infections after PK are usually devastating. Due to low intraocular penetration of topical antifungals, serial intracameral injections were used to maintain a therapeutic concentration of amphotericin B within the anterior chamber, and intravenous fluconazole was administered to protect against the spread of infection into the vitreous. A clinical response developed after two weeks. The reported case represents a favorable outcome using a multimodal approach.

Impact of laser pulse duration on the reduction of intraocular pressure during selective laser trabeculoplasty.

PURPOSE: To evaluate the efficacy of selective laser trabeculoplasty (SLT) to lower intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG), normal tension glaucoma (NTG) or ocular hypertension (OHT), when performed with laser pulse duration of 1 ns compared with standard 3-5 ns. METHODS: Bilateral SLT with a 532 nm Q-switched neodymium-doped yttrium aluminium garnet laser was conducted in 30 patients (60 eyes) with POAG (n = 5), NTG (n = 2) or OHT (n = 23). Pulse duration was 1 ns in the right eye (30 eyes; cases) and 3-5 ns in all left eyes (controls). Main outcome measures were IOP at 1 h, 1 day, 8 weeks and 6 months, and the rate of adverse ocular tissue reactions in all eyes. RESULTS: Mean 1 ns and 3-5 ns SLT IOPs were 24.1 and 24.3 mmHg, respectively, at baseline. No statistically significant difference in mean 1 ns and 3-5 ns SLT IOP was observed at 1 h (P = 0.761), 1 day (P = 0.758), 8 weeks (P = 0.352) and 6 months postoperatively (P = 0.879). No significant difference in postoperative anterior chamber inflammation was observed between the eyes (P = 0.529). Treatment with both laser pulse durations resulted in minor ultrastructural changes in the drainage angle. CONCLUSIONS: SLT performed with a 1 ns laser pulse duration does not appear to be inferior to SLT performed with the standard 3-5 ns duration at lowering IOP in treatment-naïve patients with POAG, NTG or OHT.

Visual Acuity, Retinal Sensitivity, and Macular Thickness Changes in Diabetic Patients without Diabetic Retinopathy after Cataract Surgery.

Aim. Functional and morphological macular study after cataract surgery in a group of diabetics without diabetic retinopathy compared to nondiabetics to evaluate the effect of surgical oxidative stress on diabetic retina. Methods. Prospective, comparative study. Preoperative eye exam, best corrected visual acuity (BCVA) measured by ETDRS letters, and optical coherence tomography (OCT) were followed by standard cataract surgery. The follow-up visits at 1, 3, and 6 months postoperatively included BCVA, OCT, and microperimetry, to analyze changes within and between the groups. Results. The BCVA improved significantly in diabetics and controls: 64.2 to 81.0 and 61.9 to 82.1 ETDRS at 6 months, respectively. The central macula at OCT significantly thickened in both groups, while the central 5 fields, corresponding to the microperimetry area, subclinically thickened from 284.20 to 291.18 µm at 6 months only in diabetics (p = 0.026). A matching slight decrease in the microperimetry sensitivity from 1 to 6 months was found also only in diabetics, with mean average difference -0.75 dB (p = 0.04). Conclusion. Underlying diabetes does not influence the surgical outcome in diabetics without diabetic retinopathy. However, slight thickening of wider macula and corresponding decrease in retinal sensitivity observed in diabetics 6 months postoperatively might influence visual function on long term.