Clinical features and management of keratoconjunctivitis associated with inadequate tear drainage.

OBJECTIVE: To describe clinical features and management of toxic keratoconjunctivitis associated with punctal and (or) canaliculus stenosis (toxic soup syndrome). DESIGN: Retrospective observational case series. METHODS: Electronic medical record database search for the keywords "toxic soup syndrome" and retrospective chart review were performed. Thirty-five eyes of 25 patients were seen at a tertiary cornea clinic between January 2017 and December 2021. Sex, age, distance-corrected visual acuity, topical medications, symptoms, clinical signs, and outcomes after medical and surgical interventions were analyzed. The main outcome measured was improvement in ocular surface signs and symptoms after interventions. RESULTS: Overall, 35 eyes of 25 patients with a mean age of 66.8 ± 12.8 years, of which 72% were female, were included. The primary complaint was hyperemia and epiphora in all patients. Rosacea or meibomian gland disease were present in all patients, 7 (28%) had glaucoma, and 7 (28%) developed limbal stem cell deficiency. Twenty-two patients (88%) were using topical medications on presentation. All eyes had either punctal plugs, cauterized puncta, or punctal and (or) canaliculus stenosis. Management of all patients consisted of suspension of all preserved topical medications and institution of some type of anti-inflammatory therapy. Nineteen patients (76%) improved after improvement of lacrimal drainage. One patient with severe resistance in the canaliculus required ongoing preservative-free topical steroids. CONCLUSIONS: Chronic drug-induced or pooled inflammatory mediators causing toxic conjunctivitis may be aggravated by punctal and (or) canaliculus stenosis, leading to toxic soup syndrome. Clearance of punctal obstruction leads to improvement in most patients.

Spectral-Domain OCT Lens Meridian Position as a Metric to Estimate Postoperative Anatomical Lens Position.

PURPOSE: To evaluate the prediction of postoperative anatomical lens position (ALP) using intraoperative spectral-domain optical coherence tomography (SD-OCT) lens anatomy metrics in patients who underwent femtosecond laser-assisted cataract surgery. METHODS: Intraoperative SD-OCT (Catalys; Johnson & Johnson Vision) and postoperative optical biometry (IOLMaster 700; Carl Zeiss Meditec AG) were used to assess anterior segment landmarks, including lens thickness, lens volume, anterior chamber depth, lens meridian position (LMP), and measured ALP. LMP was defined as the distance from the corneal epithelium to the lens equator, and ALP was defined as the distance from the corneal epithelium to the IOL surface. Eyes were divided into groups according to axial length (> 22.5 mm, 22.5 to 24.5 mm, and > 24.5 mm) and IOL type (Tecnis ZCB00 [Johnson & Johnson Vision]; AcrySof SN-60WF [Alcon Laboratories, Inc], or enVista MX60E [Bausch & Lomb]) to further analyze the correlation between LMP and ALP. Theoretical effective lens position was back-calculated using a specific formula. Primary outcome was correlation between postoperative measured ALP and LMP. RESULTS: A total of 97 eyes were included in this study. Linear regression analysis displayed a statistically significant correlation between intraoperative LMP and postoperative ALP (R2 = 0.522; P < .01). No statistically significant correlation was observed between LMP and lens thickness (R2 = 0.039; P = .06) or between ALP and lens thickness (R2 = 0.02; P = .992). The greatest predictor for ALP was LMP (ß = 0.766, P < .001; R2 = 0.523). CONCLUSIONS: Intraoperative SD-OCT-measured LMP correlated better than anterior chamber depth and axial length to postoperative ALP. Further studies are necessary to analyze the impact of preoperative or intraoperative LMP measurements on postoperative refractive outcomes. [J Refract Surg. 2023;39(3):165-170.].

Clinical Outcomes of Transscleral-Sutured Intraocular Lens Combined With Descemet Membrane Endothelial Keratoplasty.

PURPOSE: The aim of the study was to report clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) combined with transscleral-sutured intraocular lens (IOL) compared with DMEK combined with phacoemulsification and posterior chamber IOL (Phaco-DMEK). METHODS: A retrospective chart review of all patients who underwent DMEK combined with transscleral-sutured intraocular lens fixation or combined with phacoemulsification for Fuchs endothelial corneal dystrophy from 2016 to 2021 at the Toronto Western Hospital or the Kensington Eye Institute (Toronto, ON, Canada) and had at least 18 months of follow-up was performed. Main outcomes were postoperative distance-corrected visual acuity, rebubbling rate, graft survival rate, and complications. RESULTS: Twenty-one cases of DMEK combined with transscleral-sutured IOL (DMEK-TSS-IOL) and 44 cases of Phaco-DMEK were evaluated. Twelve eyes (57.15%) had a foldable acrylic 3-piece IOL (AR40E) and 9 (42.85%) had a single-piece polymethylmethacrylate (PMMA) IOL (CZ70BD). LogMAR distance-corrected visual acuity improved significantly from 1.48 ± 0.62 (SD) to 0.86 ± 0.82 ( P = 0.01) 12 months after DMEK-TSS-IOL and from 0.41 ± 0.29 logMAR to 0.11 ± 0.11 logMAR ( P < 0.0001) after Phaco-DMEK. No statistically significant differences were observed in donor ( P = 0.97) or 1-year postoperative endothelial cell density ( P = 0.11) between the groups. Rebubbling was necessary in 33.33% of eyes in DMEK-TSS-IOL compared with 25% of Phaco-DMEK eyes ( P = 0.55). Graft survival rate was 76.19% in the DMEK-TSS-IOL group compared with 90.90% in the Phaco-DMEK group ( P = 0.13). CONCLUSIONS: Transscleral-sutured IOL combined with DMEK is an option for the management of endothelial diseases in aphakic eyes or those which require IOL exchange for the experienced surgeon. However, when compared with routine Phaco-DMEK, there are higher complication and lower survival rates at 18 months.

Comparative evaluation of four Descemet membrane endothelial keratoplasty graft preparation techniques.

OBJECTIVE: To compare subjective and objective outcomes of 4 different Descemet membrane endothelial keratoplasty (DMEK) peeling techniques performed by novice surgeons at different stages in their surgical career. DESIGN: An ex vivo prospective study. METHODS: In the first round, 2 DMEK peeling techniques were pitched against each other: the peripheral scoring and Sinskey dissection technique with the peripheral scoring and microhoe dissection and the peripheral blunt microhoe dissection against the scleral spurectomy and microhoe dissection. Three surgeons with different operative experience performed the peeling. Outcome measures included graft peeling time, surgeon's peeling difficulty grading (on a scale of 1-10, 1 being the easiest and 10 the hardest), number of radial and circumferential tears before and after trephination, and tissue loss. The 2 techniques that performed the best from the first round proceeded to the final round to identify the best overall technique. RESULTS: In total, 90 tissues (45 pairs) were peeled by 3 surgeons. Following the first-round results, the peripheral scoring and Sinskey dissection and peripheral blunt microhoe dissection proceeded to the final round. There were no significant differences between the groups in terms of peeling times, subjective feeling of difficulty, post-trephination tears, and peeling success rates (P > 0.05 for all). However, the peripheral scoring and Sinskey dissection technique had significantly fewer pretrephination radial tears (1.3 ± 1.3 vs 6.1 ± 5.2, P = 0.007) and circumferential tears (0.6 ± 0.9 vs 1.8 ± 2.1, P = 0.02). CONCLUSIONS: This study demonstrates that the learning curve can be overcome quickly with appropriate DMEK peeling techniques. The peripheral scoring and Sinskey dissection peeling technique allows efficient peeling with fewer related tears.

Five-Year Safety and Efficacy of Femtosecond Laser-Assisted Descemet Membrane Endothelial Keratoplasty.

PURPOSE: The purpose of this study was to evaluate 5-year safety and efficacy outcomes of femtosecond-enabled Descemet membrane endothelial keratoplasty (F-DMEK) in patients with Fuchs' endothelial dystrophy (FED). METHODS: This was a retrospective study, including patients with FED and cataract who underwent either F-DMEK (16 eyes of 15 patients) or manual DMEK (M-DMEK) (42 eyes of 37 patients) combined with cataract extraction. Outcome measures included visual acuity, graft detachment, graft survival, and endothelial cell loss. RESULTS: The average follow-up in F-DMEK and M-DMEK was 57.1 ± 12.4 months and 58.5 ± 17.3 months, respectively ( P = 0.757). The rates of primary failure (0% vs. 9.5%, P = 0.567), secondary failure (0% for both), and graft rejection (0% vs. 7.1%, P = 0.533) did not differ significantly between the groups. Improvement in best spectacle-corrected visual acuity was similar in F-DMEK and M-DMEK (0.32 ± 0.27 logarithm of the minimum angle of resolution and 0.35 ± 0.44 logarithm of the minimum angle of resolution, respectively, P = 0.165) and persisted at 2, 3, 4, and 5 years and at the last follow-up. The rates of graft detachment and rebubbling were significantly lower with 6.25% in F-DMEK and 33.3% in M-DMEK ( P = 0.035). Cell-loss rates were lower in F-DMEK compared with M-DMEK throughout the follow-up, significantly so up to 2 years with a difference of 8.6% at 1 year ( P = 0.023), 11.8% at 2 years ( P = 0.021), 7.6% at 3 years ( P = 0.088), 5.8% at 4 years ( P = 0.256), 13.6% at 5 years ( P = 0.169), and 7.1% at the final follow-up ( P = 0.341). CONCLUSIONS: F-DMEK had an excellent safety and efficacy profile which was maintained over 5 years of follow-up. Lower endothelial cell-loss rates in F-DMEK compared with M-DMEK may help extend the duration of graft survival.

Long-Term Stability of Femtosecond Astigmatic Keratotomy After Treatment of High Postkeratoplasty Astigmatism.

PURPOSE: The purpose of this study was to assess long-term stability and outcomes of femtosecond astigmatic keratotomy (FSAK) after treatment of high postkeratoplasty astigmatism. METHODS: This retrospective study included patients who underwent FSAK for high astigmatism (≥4 D) after penetrating keratoplasty or deep anterior lamellar keratoplasty. Main outcome measures were corneal astigmatism, uncorrected visual acuity, and best-corrected visual acuity (BCVA) at 1 month and 1, 5, and 10 years. RESULTS: Overall, 61 eyes of 61 patients (mean age 56 ± 19 years, 54.1% male) were included in this study. Preoperative corneal astigmatism ranged from 4 to 25 D. One month after FSAK, mean corneal astigmatism was significantly reduced from 9.02 ± 3.97 D to 4.86 ± 3.10 D ( P < 0.001). Thereafter, corneal astigmatism remained stable at all visits up to 10 years ( P < 0.05 for all compared with baseline). After FSAK, there was a significant improvement in logMAR uncorrected visual acuity from 1.21 ± 0.48 to 0.87 ±0.54 ( P < 0.001) and logMAR BCVA from 1.03 ± 0.55 to 0.49 ± 0.45 ( P < 0.001) which remained stable up to 10 years. A mild reduction in BCVA improvement was seen between 1 month and 1 year. CONCLUSIONS: Femtosecond astigmatic keratotomy was effective and stable at reducing very high magnitudes of postkeratoplasty astigmatism over the long term. The procedure also had a stable effect on visual acuity, albeit some reduction in the degree of BCVA improvement was seen over the early postoperative period.

KAMRA presbyopic inlay refractive outcomes: a Canadian perspective.

OBJECTIVE: To retrospectively analyze the visual outcomes of KAMRA (AcuFocus Inc, Irvine, Calif.) inlay insertion in a cohort of patients reporting success of procedure, complications, patient satisfaction, and refractive outcomes. DESIGN: Retrospective trial at the TLC Laser Centre, Toronto. METHODS: A total of 5 surgeons at the practice inserted 35 KAMRA inlays in 35 patients between October 2012 and June 2014. Some patients had a sole KAMRA inlay insertion, whereas others had combined laser vision correction (LVC) and KAMRA inlay on either the same day or sequentially. There was a small cohort of patients who had previous unrelated LVC. Mean time of follow-up was 299 days. RESULTS: After KAMRA inlay insertion there was a significant improvement in uncorrected near visual acuity (p = 0.00009), uncorrected intermediate visual acuity (p = 0.00006), and uncorrected distance visual acuity (p = 0.02), but levels of patient dissatisfaction were 43%. The most common cause for dissatisfaction was requirements for readers (23%), followed by dysphotopsias (11%). The explantation rate was 11.42%, and 28.5% of patients required enhancements after inlay insertion. CONCLUSIONS: The KAMRA corneal inlay has significant improvements in uncorrected near visual acuity, uncorrected intermediate visual acuity, and uncorrected distance visual acuity when used in isolation or combined with LVC. Appropriate patient selection is crucial. This procedure should not be used as first-line presbyopia management because of low levels of patient satisfaction, biocompatibility concerns, and explantation rates.

Ray-tracing Analysis of Accommodation and Pseudoaccommodation in Phakic and Pseudophakic Eyes.

PURPOSE: To compare objective measurements of accommodation and pseudoaccommodation in phakic and pseudo-phakic eyes using ray-tracing aberrometry. METHODS: Patients with normal and hyperprolate corneas (post-hyperopic laser in situ keratomileusis) who underwent cataract surgery from March 2018 to October 2019 at the Medical University of South Carolina were examined and received either a diffractive intraocular lens (IOL) with an echelette design (Tecnis ZXR00 Symfony; Johnson & Johnson Vision), a monofocal IOL with negative spherical aberration (Tecnis ZCB00; Johnson & Johnson Vision), or an aberration-free IOL (MX60E; Bausch & Lomb). The control groups consisted of young and presbyopic phakic patients. Ray-tracing wavefront analysis was performed 1 to 3 months postoperatively. Objective ray-tracing metrics of accommodation and pseudoaccommodation included the effective range of focus, sphere shift accommodation, and depth of focus. RESULTS: Sixty-two eyes received a Tecnis ZCB00, 39 a MX60E, and 43 a Tecnic ZXR00 Symfony IOL; furthermore, 20 young phakic eyes and 19 presbyopic eyes were included in this study. The effective range of focus and sphere shift accommodation in the young control group were statistically larger than in the presbyopic group (P = .005 and P < .001, respectively). There was no difference in effective range of focus, sphere shift accommodation, and pseudoaccommodations between the different IOL groups. The young control group had the highest visual Strehl optical transfer function for near and distant targets (0.64 ± 0.24 and 0.56 ± 0.19, respectively), whereas the aberration-free IOL in the MX60E hyperprolate cornea group presented the lowest visual Strehl optical transfer function value for near (0.49 ± 0.19). CONCLUSIONS: Ray-tracing aberrometry can objectively assess accommodative amplitude in phakic eyes and pseudoaccommodation (depth of focus) in pseudophakic eyes. [J Refract Surg. 2022;38(10):661-667.].

Impact of interstitial elements on the stacking fault energy of an equiatomic CoCrNi medium entropy alloy: theory and experiments.

We investigated the effects of interstitial N and C on the stacking fault energy (SFE) of an equiatomic CoCrNi medium entropy alloy. Results of computer modeling were compared to tensile deformation and electron microscopy data. Both N and C in solid solution increase the SFE of the face-centered cubic (FCC) alloy matrix at room temperature, with the former having a more significant effect by 240% for 0.5 at % N. Total energy calculations based on density functional theory (DFT) as well as thermodynamic modeling of the Gibbs free energy with the CALPHAD (CALculation of PHAse Diagrams) method reveal a stabilizing effect of N and C interstitials on the FCC lattice with respect to the hexagonal close-packed (HCP) CoCrNi-X (X: N, C) lattice. Scanning transmission electron microscopy (STEM) measurements of the width of dissociated ½<110> dislocations suggest that the SFE of CoCrNi increases from 22 to 42-44 mJ·m-2 after doping the alloy with 0.5 at. % interstitial N. The higher SFE reduces the nucleation rates of twins, leading to an increase in the critical stress required to trigger deformation twinning, an effect which can be used to design load-dependent strain hardening response.

Surgical Management of Fuchs Endothelial Corneal Dystrophy: A Treatment Algorithm and Individual Patient Meta-Analysis of Descemet Stripping Only.

PURPOSE: This study aims to determine predictive factors for success of Descemet stripping only (DSO) in Fuchs corneal endothelial dystrophy and propose a DSO treatment algorithm. METHODS: Ovid MEDLINE, Embase, and Cochrane CENTRAL databases were searched to evaluate DSO case series, including combined phacoemulsification and DSO, and the use of Rho-kinase inhibitors (ROC-i). Our primary outcome was success of corneal clearance. Secondary outcomes included the time to corneal clearance, the postoperative endothelial cell count (ECC), and the impact of ROC-i. RESULTS: Sixty-eight cases were evaluated with a mean follow-up of 12.4 months. DSO corneal clearance was achieved in 85% (n = 58) with a mean time of 4.9 weeks for the ROC-i group compared with 10.1 weeks in the observation group (P < 0.0001). The mean central ECC postoperatively was higher in the ROC-i group compared with the observation group 1151 ± 245 versus 765 ± 169 cells/mm2, respectively (P < 0.018). The postoperative best-corrected visual acuity (BCVA) improved in 61 eyes (90%), with mean final BCVA of 0.17 (0.26) logMAR (P = 0.001), which was statistically significant compared with preoperative BCVA. Factors influencing success were 4-mm descemetorhexis size, a clear peripheral ECC with no clinical sequelae of decompensation or guttae, and a low central corneal thickness. No intraoperative complications were noted. The commonest postoperative complication was deep corneal stromal scars noted at the descemetorhexis edge (n = 9). CONCLUSIONS: DSO has a role in the treatment of a subset of patients with Fuchs corneal endothelial dystrophy and that adjuvant treatment with ROC-i may lead to faster corneal clearance.

"Smoldering" Rejection of Keratolimbal Allograft.

PURPOSE: The purpose of this study was to report a case of "smoldering" keratolimbal allograft (KLAL) rejection in a patient with subtherapeutic levels of systemic immunosuppression in temporal association with BNT162b2 messenger RNA vaccination for severe acute respiratory syndrome coronavirus 2. METHODS: This was a case report. OBSERVATIONS: A 72-year-old man presented with circumferential perilimbal engorgement, stagnation, and tortuosity of vessels with mild chemosis in his right eye KLAL segments 1 month after receiving the BNT162b2 messenger RNA vaccine while his tacrolimus trough blood levels were subtherapeutic measuring <2 ng/mL. He had undergone KLAL 6.5 years before for total limbal stem cell deficiency from a chemical injury and had been stable without any history of rejection. The donor was blood type O, and the patient had no systemic comorbidities. The patient was treated with hourly difluprednate 0.05% and increasing of his oral tacrolimus dose to 2 mg twice a day with improvement of rejection signs. CONCLUSIONS: There may be a temporal association between KLAL rejection after immunization against severe acute respiratory syndrome coronavirus 2 in patients with subtherapeutic levels of systemic immunosuppression. Patients should be on alert for any ocular signs or symptoms postimmunization and present for treatment immediately.

Outcomes of femtosecond laser-assisted cataract and refractive lens surgery in patients with prior radial keratotomy.

PURPOSE: To investigate outcomes of femtosecond laser (FL)-assisted cataract surgery (FLACS) and refractive lens exchange (RLE) in patients with prior radial keratotomy (RK). SETTING: Single clinical practice. DESIGN: Retrospective observational case series. METHODS: All patients with prior RK undergoing FLACS- or FL-assisted RLE surgeries over a 6-year period were reviewed. Inclusion criteria were diurnal stability and stable manifest refraction. Exclusion criteria were any other incisional corneal surgery, macular or glaucomatous pathology, or vision loss due to any other cause. Data collected included demographics, visual acuity, laser settings, and complications. Main outcome measures were intraoperative and postoperative complications and visual outcomes. Safety and efficacy indices were evaluated. RESULTS: 16 eyes of 9 patients were included. Mean age and follow-up time were 59.9 ± 9.9 years (range 44 to 75 years) and 3.3 ± 2.5 months, respectively. The mean number of RK cuts was 11.8 ± 5.3 (range 8 to 20). Mean preoperative uncorrected (UDVA) and corrected distance visual acuity (CDVA) were 0.9 ± 0.4 logMAR (Snellen 20/160) and 0.2 ± 0.3 logMAR (Snellen 20/30), respectively. 2 intraoperative anterior capsule tears were identified. 1 postoperative intraocular lens dislocation occurred. Postoperatively, the mean UDVA and CDVA were 0.2 ± 0.2 logMAR (20/30) and 0.1 ± 0.1 logMAR (20/25), respectively. The safety index was 1.6, and the efficacy index was 1.2. CONCLUSIONS: FLACS- or FL-assisted RLE surgery in RK patients has a high risk for anterior capsule tear and should be avoided. Thickened incisional scars are potential sources of incomplete laser penetrance. Toric lens implantation in RK eyes provide unpredictable astigmatic correction and should also be avoided.

Tape Splint Tarsorrhaphy for Persistent Corneal Epithelial Defects.

PURPOSE: To report outcomes of tape splint tarsorrhaphy (TST) for persistent corneal epithelial defects (PCED). DESIGN: Retrospective, interventional case series. METHODS: The study population was consecutive patients with a PCED (14 days or longer) treated at a tertiary cornea clinic with TST. Patients with a corneal epithelial defect that did not respond to treatment with a bandage contact lens were included. Patients with a follow-up time of less than 3 months were excluded. Time to PCED resolution was the main outcome measure. RESULTS: Thirty-four eyes of 33 patients (mean age 62.9 ± 17.8 years; range, 27-90 years) were included in this study. The main etiologies of the PCED were post keratoplasty (n = 15), herpes simplex virus (n = 4), superficial keratectomy (n = 3), neurotrophic cornea (n = 4), fungal keratitis (n = 2), exposure keratopathy (n = 2), failed graft (n = 1), peripheral ulcerative keratitis (n = 1), rosacea (n = 1), and stitch abscess (n = 1). Mean ± SD time from PCED presentation to TST was 58.9 ± 106.3 days (range, 14-390 days). The mean ± SD area of the PCED was 25.1 ± 15.7 mm2 (range, 0.50-42.0 mm2). After TST, resolution of the PCED was achieved in 29/34 eyes (85.3%) without the need for additional interventions within 22.5 ± 24.3 days (range, 2-105 days). The mean ± SD logMAR best-corrected visual acuity improved significantly from 1.11 ± 0.41 to 0.83 ± 0.70 (P = .02). There were no complications attributed to TST and 2 patients elected to discontinue due to discomfort. CONCLUSIONS: TST achieved resolution of PCEDs secondary to various etiologies in 85.3% of eyes, with significant improvement in vision demonstrated. This simple, inexpensive, noninvasive technique may be considered for patients with PCEDs.

Refractive Accuracy of Barrett True-K vs Intraoperative Aberrometry for IOL Power Calculation in Post-Corneal Refractive Surgery Eyes.

PURPOSE: To compare the refractive predictability of intraoperative aberrometry (IA, ORA, Alcon) and Barrett True-K/Universal II formulas for intraocular lens (IOL) power calculations in post-corneal refractive surgery and normal eyes. METHODS: Retrospective study of normal and post-corneal refractive surgery eyes that underwent cataract surgery with IA at tertiary academic center. Preoperatively, IOL power calculations were performed using Barrett Universal II (normal eyes) or Barrett True-K (post-corneal refractive surgery eyes) formulas. Intraoperatively, aphakic IA measurements were used for IOL power calculations. Mean absolute refractive prediction error (MAE) and the percentage of eyes with prediction error within ±0.50, ±0.75 and ±1.00 D were calculated. Refractive predictability was also evaluated in short, normal, and long eyes. RESULTS: Two hundred and seventy-three eyes were included in the analysis. No statistically significant differences were observed between the MAE of preoperative formulas and IA for post-hyperopic laser vision correction (LVC), post-myopic LVC, post-radial keratotomy (RK) and normal eyes. For prediction error within ±0.5 D in post-corneal refractive surgery eyes, range of agreement between Barrett True-K and IA ranged from 28% (7/25) of the time in post-RK eyes to 49% (40/81) of the time in post-hyperopic LVC; the corresponding value for Barrett Universal II/IA was 62% (64/103) in normal eyes. When there was disagreement, IA outperformed Barrett True-K in post-hyperopic LVC eyes and Barrett formula outperformed IA in post-myopic LVC, post-RK, and normal eyes. CONCLUSION: IA appears to be comparable to Barrett formulas for IOL power calculations in post-corneal refractive surgery and normal eyes. In post-hyperopic LVC, IA yields better results compared to Barrett True-K formula; in real-life scenarios, IA reveals statistical advantage over the Barrett True-K no history formula for eyes post-hyperopic LVC.

Tailoring a Refractory High Entropy Alloy by Powder Metallurgy Process Optimization.

This paper reports the microstructural evolution and mechanical properties of a low-density Al0.3NbTa0.8Ti1.5V0.2Zr refractory high-entropy alloy (RHEA) prepared by means of a combination of mechanical alloying and spark plasma sintering (SPS). Prior to sintering, the morphology, chemical homogeneity and crystal structures of the powders were thoroughly investigated by varying the milling times to find optimal conditions for densification. The sintered bulk RHEAs were produced with diverse feedstock powder conditions. The microstructural development of the materials was analyzed in terms of phase composition and constitution, chemical homogeneity, and crystallographic properties. Hardness and elastic constants also were measured. The calculation of phase diagrams (CALPHAD) was performed to predict the phase changes in the alloy, and the results were compared with the experiments. Milling time seems to play a significant role in the contamination level of the sintered materials. Even though a protective atmosphere was used in the entire manufacturing process, carbide formation was detected in the sintered bulks as early as after 3 h of powder milling. Oxides were observed after 30 h due to wear of the high-carbon steel milling media and SPS consolidation. Ten hours of milling seems sufficient for achieving an optimal equilibrium between microstructural homogeneity and refinement, high hardness and minimal contamination.

The "Two-Flaps" Technique for Descemet Stripping Only.

PURPOSE: The success of Descemet stripping only (DSO) is optimized by performing a well-centered, accurately sized diameter of descemetorhexis with a smooth curvilinear border. To achieve this success, we describe a repeatable and relatively straightforward technique to optimize this descemetorhexis for DSO. METHODS: The "two-flaps" technique uses the Gorovoy DSO forceps. The technique takes advantage of the flat and smooth surface of the forceps to create the desired 4-mm Descemet stripping with minimal stromal trauma along with a continuous curvilinear descemetorhexis, minimizing the risk of postoperative stromal scarring and extension of the rhexis beyond 4 mm. RESULTS: This technique has been used successfully in 11 cases performed by 1 surgeon or directly supervised by him. All cases achieved the desired 4-mm circumference without any residual tags or visually significant stromal scarring, with successful clearing of the central cornea and endothelial cells repopulating the central stripped area. CONCLUSIONS: This technique described provides a consistent, reproducible, and relatively trauma-free peeling of Descemet membrane and associated endothelial cells/guttae to optimize the success of DSO.

Neurotrophic keratitis after penetrating keratoplasty for lattice dystrophy.

PURPOSE: To report clinical outcomes of a patient with unilateral neurotrophic keratitis following penetrating keratoplasty for lattice dystrophy treated with topical recombinant human nerve growth factor. OBSERVATIONS: A 75-year-old male with lattice dystrophy and history of herpes simplex keratitis, presented with recurrent neurotrophic ulceration in the right eye two years following penetrating keratoplasty. The patient was successfully treated with topical recombinant human nerve growth factor. CONCLUSION: Neurotrophic keratitis is a rare chronic disorder that affects quality of life due to the risk of vision loss. Topical recombinant human nerve growth factor is a novel and effective treatment option that may help improve optical quality and patient's satisfaction as shown in this case of recurrent neurotrophic keratitis.