Development of Multifunctional Hybrid Coatings (Mechanically Resistant and Hydrophobic) Using Methyltrimethoxysilane-Diethoxydimethylsilane-Tetraethoxysilane Mixed Systems

For many industrial applications, the simultaneous presence in a material of different functional properties is necessary. The main interest lies in making a single material more versatile and durable, less fragile and more efficient. In this study, two concomitant properties in the same material were mainly studied: resistance to cracking and the increase in its hydrophobic properties. The chosen process was the sol-gel route due to its versatility and the ease of formulating materials from various precursors in order to obtain (multi)functional materials. In this paper, sol-gel coatings were prepared with tetraethoxysilane, methyltrimethoxysilane and diethoxydimethylsilane as precursors. Tetraethoxysilane was mainly used to improve the material's mechanical properties, especially hardness, and silicon oil was added to improve its hydrophobic behavior. The integration of silicon oil was monitored via 29Si NMR. Microstructural characterizations were carried out to correlate the multi-scale properties with the microstructure of the derived films. Young's modulus and hardness were measured to highlight the effect of key formulation parameters on the mechanical strength of the coatings. The synergistic effect of these precursors is underlined as well as the beneficial effect of silicon oil (generated in situ or precondensed).

Micropulse Transscleral Cyclophotocoagulation Results in Secondary Glaucoma

The aim of this study was to analyze the long-term outcome of first session of micropulse transscleral cyclophotocoagulation (MP-CPC) for refractory glaucoma developed after vitreoretinal surgery combined with silicone oil implantation. The inclusion criteria of this consecutive case series were: patients with secondary glaucoma in the refractory stage who underwent MP-CPC between 2018 and 2021, vitreoretinal surgery combined with silicon oil implantation, and at least a 24-month follow-up period after MP-CPC. Success was defined as the baseline eye pressure reduced at least 20%, and it should be ranged between 10 to 20 mmHg without further MP-CPC at the end of the follow-up. For this retrospective study, 11 eyes of 11 patients were selected. The reduction in IOP was found to be significant (p = 0.004) at the end of the follow-up time, and the success rate was 72% according to our results. The change in the number of antiglaucoma agents in the administered eyedrops was not significant compared to the baseline values. At the end of the follow-up period the change in BCVA values was not significant (p = 0.655). Our results confirm significant IOP lowering effect of this subthreshold method preserving visual performance safely even in eyes with previous vitrectomy surgery with a silicone oil implantation.

When the savior becomes a demon: Silicon oil synechia-induced glaucoma

Background

Silicon oil is an important adjunct for achieving internal tamponade in the treatment of retinal detachment. Silicone oil tamponade often leads to narrowing of the angle and development of adhesions between the iris and anterior chamber angle structures, with consequential elevation of the intraocular pressure. The video showcases the management of these challenging scenarios.

Purpose

To highlight the management of early synechial closures due to silicon oil tamponade.

Synopsis

The video highlights the management of early synechial closure following silicon oil tamponade. Surgical pupilloplasty has been demonstrated to break the peripheral anterior synechias on intraoperative gonioscopy as well as on anterior segment optical coherence tomography (AS-OCT). Performing pupilloplasty in the early phase of development of peripheral anterior synechias (PAS) helps to break the existing synechias and prevent angle closure and sequential deterioration of vision.

Highlights

Surgical pupilloplasty helps to relieve the post silicon oil-induced secondary angle closure glaucoma by breaking the peripheral anterior synechias and significantly opening the anterior chamber angles.

Online Video Link

https://youtu.be/xe2NGlhPBF4.

Long-Term Macular Vascular Changes after Primary Rhegmatogenous Retinal Detachment Surgery Resolved with Different Tamponade or Different Surgical Techniques

Background: The aim of this study was to assess long-term macular vascular changes and their correlation with functional recovery in patients successfully treated for Macula-ON and Macula-OFF rhegmatogenous retinal detachment (RRD). Methods: This retrospective observational study included 82 eyes of 82 patients who received primary successful retinal detachment surgery, 33 Macula-ON and 49 Macula-OFF. Superficial and deep capillary plexuses (SCP and DCP) were evaluated by optical coherence tomography angiography (OCTA), and were correlated with visual acuity (VA), surgical technique and tamponade at 12 months after surgery. The fellow eyes were used as controls. Results: At 12-month follow-up, there was a significant decrease in the vessel density (VD) in the SCP in the operated eyes compared to control eyes (p < 0.05) in both the Macula-ON and Macula-OFF groups. Vessel length density (VLD) decrease in SCP was more extended in the Macula-OFF group. No difference in the DCP perfusion parameters was found, compared to controls. Subgroup analysis dependent on the type of surgery or tamponade showed no significant differences of VD and VLD. An inverse correlation was found between the SCP VD and the duration of silicone oil (SO) tamponade (p = 0.039). A significant correlation was observed between parafoveal SCP VD and final best corrected visual acuity (BCVA) (p = 0.028). The multivariate linear regression analysis showed that only the type of tamponade was significantly correlated with the final BCVA in the Macula-ON group (p = 0.004). Conclusions: Our study described long-term perfusion changes in RRD after surgery, with lower SCP VD and VLD in the operated eyes compared to the fellow ones, not influenced by type of surgery or tamponade. The choice of tamponade and SO removal timing may affect functional outcomes, especially in Macula-ON RRD. In conclusion, such functional and perfusion changes can be considered biomarkers that highlight the relevance of careful management of this sight-threatening disease.

Characterizing Oligomeric Hydroxyl Silicon Oils by MALDI-TOF MS With the Pyridine-Modified Matrix

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) is a powerful technique for analysis of various polymers, but it is still very difficult to characterize silicone oil due to its poor ionization efficiency. In this work, oligomeric hydroxyl silicone oils were successfully characterized by MALDI-TOF, by using pyridine-modified 2,5-dihydroxylbenzoic acid (DHB) as the matrix. Furthermore, the mixed crystal of DHB and hydroxyl silicone oil was analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS), and the analytical results verified that modification with pyridine could remarkably improve the solubility of hydroxyl silicone oil in DHB, leading to the enhancement of its ionization efficiency in MALDI. The analysis of the MS spectra of a series of hydroxyl silicone oils indicated that they tended to be ionized by the attachment with Na⁺, and the average molecular weight and the degree of polymerization were measured for several oligomeric hydroxyl silicon oils.

Solution Crystallization of Polycarbonate Surfaces for Hydrophobic State: Water Droplet Dynamics and Life Cycle Assessment towards Self-Cleaning Applications

Polycarbonate sheets are optically transparent and have the potential to be used as one of the cover materials for PV applications. Solution treatment of polycarbonate surfaces enables to create surface texture topology giving rise to a hydrophobic state, which is favorable for self-cleaning applications. In the present study, hydrophobization of polycarbonate surface is investigated via crystallization of surface by a one-step process. The influence of texture topology, which is created via crystallization, on water droplet mobility and optical transmittance is examined. Findings revealed that solution treatment, using acetone, results in crystallized polycarbonate surfaces with a hydrophobic state. Depending on the treatment duration, the texture characteristics of crystallized surface change while influencing the water contact angle hysteresis. This in turn affects the droplet mobility over the inclined crystallized surface and alters the UV visible transmittance. Moreover, the droplet mobility improves and dust mitigation rates from the treated surface increase as the solution treatment duration are reduced to 2 min. Oil impregnated samples result in improved UV visible transmittance; however, droplet motion changes from rolling to sliding over the surface. A sliding water droplet enables the removal of the dust particles from the oil-impregnated sample surface.

Comparison Between Pars Plana Vitrectomy with and without Encircling Band in the Treatment of Pediatric Traumatic Rhegmatogenous Retinal Detachment

Background and Objectives

To compare anatomical and visual results of pars plana vitrectomy (PPV) with or without additional encircling band in the management of pediatric traumatic rhegmatogenous retinal detachment (RD) in a tertiary referral center.

Methods

A retrospective review of children diagnosed with traumatic rhegmatogenous retinal detachment treated by pars plana vitrectomy with or without encircling band.

Results

One hundred thirty-nine eyes of 139 children diagnosed with traumatic rhegmatogenous retinal detachment. Surgeries were performed between May 2011 and November 2016. Patients were followed up for at least 18 months after last intervention. The included eyes were categorized into two groups. Group A (vitrectomy with additional encircling band) included 72 eyes of 72 children; 58 boys and 14 girls. Group B (vitrectomy without encircling band) included 67 eyes of 67 children; 58 boys and 9 girls. In group A, the mean age was 9.21±3.24. Attached retina was achieved in 61% (44 out of 72 eyes), of which 34 eyes remained attached after silicon oil removal, and 10 eyes remained attached under silicon oil tamponade. Recurrent RD under oil was present in 28 eyes (38.9%). In group B, the mean age was 11.06±3.64. Attached retina was present in 61.2% (41 out of 67 eyes), of which 30 eyes remained attached after oil removal, and 11 eyes remained attached under silicon oil tamponade. Recurrent RD was present in 26 eyes (38.8%). In group A, the final visual acuity (VA) ranged from NLP to 0.5; 58.7% of patients achieved VA more than counting fingers at 1 meter, and 34.6% of patients achieved VA of 0.05 or more. In group B, the final postoperative VA ranged from NLP to 0.9; 16% of patients achieved VA from counting fingers at 1 meter to 0.05, and 29.2% achieved VA of 0.05 or more.

Conclusion

Although no statistically significant difference between the two groups (combined vitrectomy and encircling band versus vitrectomy alone in pediatric traumatic retinal detachment), it is wise to consider adding encircling band in severe trauma cases.

Changes in the Density of Corneal Endothelial Cells in Elderly Diabetic Patients After Combined Phacovitrectomy and Ex-PRESS Glaucoma Implants

BACKGROUND & OBJECTIVE

Corneal endothelial cells (ECD) are characterized by limited regenerative potential, which is additionally impaired in patients with diabetes. This retrospective study included 27 patients aged 58.1±13.6, 16 female and 11 males, who underwent 23-gauge vitrectomy in combination with cataract surgery (phacovitrectomy) and further Ex-PRESS shunt implantation throughout 2013-2017 at St. Barbara Hospital in Sosnowiec, Poland.

METHODS

In our study, we distinguished 4 periods: initial period; post phacovitrectomy and removal of oil tamponade; and 3 and 12 months post implantation of the Ex-PRESS shunt. Statistical analysis was performed at the level of statistical significance of p<0.05. It included an analysis of variance (ANOVA) and Tukey's post-hoc test in order to determine the differences in the density of ECD cells/mm2 between the periods of observation. The paired-samples t-Student test was also performed to determine whether the differences in visual acuity values before and after PPV and before and after Ex-PRESS shunt were statistically significant.

RESULTS

The initial count of ECD cells was 2381.1±249, which decreased to 1872.8±350.7 cell/mm2 and finally to 1677.9±327 at the endpoint. Differences in the density of ECD cells/mm2 were observed to be statistically significant between the periods: after PPV vs. initial number of ECD (p = 0.000138); before 3 months after Ex-PRESS shunt vs. initial number of ECD (p = 0.000138); 12 months after Ex- PRESS shunt vs. initial number of ECD (p = 0000138). Analyzing the changes in visual acuity, we observed a deterioration both before and 3 months after Ex-PRESS shunt (p = 0.007944) and before and after PPV (p = 0.060334). In turn, correlation analysis indicated that there is a statistically significant, moderate, positive relationship. The relationship between visual acuity after Ex-PRESS shunt and ECD cells/mm2 density turned out to be statistically significant (r = +0.521381; p < 0.05).

CONCLUSION

Regardless of the period of observation and the choice of ophthalmic treatment of diabetic complications, we observed a decrease in the number of ECD cells and a deterioration in visual acuity. It is, therefore, reasonable to provide the patient with complete information about the proposed procedures and to consider the risk-benefit balance.

Surgical results of pars plana vitrectomy combined with pars plana lensectomy with anterior capsule preservation, endophotocoagulation, and silicon oil tamponade for neovascular glaucoma

Purpose

To report on pars plana vitrectomy (PPV) combined with pars plana lensectomy (PPL) with a preserved anterior capsule, panretinal endophotocoagulation (EPC) throughout the pars plana, and silicon oil (SO) tamponade (PPV + PPL + EPC + SO tamponade) for neovascular glaucoma (NVG).

Methods

Thirteen eyes with NVG were treated. Ten eyes also underwent SO removal and intraocular lens (IOL) implantation (SO removal + IOL). Intraocular pressure (IOP), number of medications, and visual acuity were evaluated at the first visit, immediately before and 3 months after the procedure, 3 months after SO removal + IOL, and 1 year after the procedure.

Results

At the first visit, immediately before and 3 months after the procedure, 3 months after SO removal + IOL, and 1 year after the procedure, the IOPs were 29 ± 19, 23 ± 12, 13 ± 5, 17 ± 10, and 17 ± 6 mmHg; numbers of medications, 0.7 ± 1.4, 2.1 ± 2.0, 0.6 ± 0.7, 1.2 ± 1.2, and 1.6 ± 1.6; and best-corrected visual acuities converted to logarithm of the minimum angle of resolution (BCVA logMAR), 0.96 ± 0.96, 1.27 ± 0.80, 1.67 ± 0.91, 1.37 ± 0.89, and 1.90 ± 1.44, respectively. No severe hypotony or phthisis bulbi developed within 1 year after the procedure. The success rates (IOP ≤ 21 mmHg and sustained light perception) were 92.3% after 3 months and 69.2% after 1 year.

Conclusion

PPV + PPL + EPC + SO tamponade might have prevented acute increases of vascular endothelial growth factor and inflammatory cytokine production postoperatively and resulted in good vision in patients with NVG.