Minimum Angle Research Articles

A Novel Artificial Endothelial Replacement Membrane for the Treatment of Chronic Corneal Edema.

The purpose of this study was to report the safety and efficacy results of an artificial lamellar implant for the treatment of chronic corneal edema. The EndoArt (EyeYon Medical, Ness Ziona, Israel), an artificial endothelial replacement membrane designed to treat corneal edema, was implanted in 24 eyes of 24 patients with low-to-normal visual potential. We present the safety and efficacy results from a prospective, open-label, single-arm, multicenter study conducted over a 12-month period. Twenty-four patients were enrolled, with no device-related serious adverse events reported. Seventeen patients completed 12-month follow-up, showing a reduction in average central corneal thickness from 759 ± 116 μm to 613 ± 135 μm. Best-corrected distance visual acuity improved from 1.88 ± 0.79 logarithmic minimum angle of resolution (logMAR) to 1.34 ± 0.57 logMAR. Sixty percent gained at least 3 early treatment diabetic retinopathy study (ETDRS) lines. The EndoArt was removed in 5 cases due to incomplete attachment and replaced by corneal transplants; 1 patient was lost to follow-up, and 1 had a procedure failure. No device-related long-term complications, infections, or inflammations were reported. The implants remained transparent throughout the study. The first-in-human results of EndoArt implantation demonstrated the device's potential to treat patients suffering from corneal edema with a favorable safety profile and effective edema reduction in most subjects, with no device-related serious adverse event. The EndoArt may offer a viable solution in regions facing a shortage of donor corneas, as well as for patients who have poor prognosis with human tissue.

Safety and efficacy of the Yamane technique for intraocular three-piece lens implantation in Egyptian patients diagnosed with Marfan syndrome: a retrospective study

BackgroundThis study aimed to investigate the safety and efficacy of the Yamane technique (flanged intrascleral haptic fixation with double-needle technique /FIHFT) for three-piece intraocular lens (IOL) implantation in Egyptian patients diagnosed with Marfan syndrome (MFS) presented with subluxated lenses (ectopia lentis, EL).MethodsThis was a retrospective evaluation of thirty-three patients who were diagnosed with MFS and had subluxated lenses in a total of forty eyes. Seven of these patients had bilateral subluxation. Lensectomy or phacoemulsification was performed with limited anterior vitrectomy, followed by IOL implantation using the FIHFT method. Data was collected from medical records, including preoperative and postoperative corrected distant visual acuity (CDVA) using logarithm of the minimal angle of resolution (log MAR), preoperative and postoperative refractions, intraoperative and postoperative complications, and follow-up periods.ResultsThe mean age of patients in the study was 30.79 years, with a mean follow-up of 23.9 months. Post-surgery, the refractive sphere decreased significantly from -9.1 ± 1.4 diopter (D) to -1.4 ± 0.7 D, and cylinder measurements dropped from -4.5 ± 0.8 D to -1.4 ± 0.6 D. The spherical equivalent (SEQ) also declined from -11.4 ± 1.5 D to -2.1 ± 0.8 D. The CDVA improved from 0.80 ± 0.32 to 0.18 ± 0.10 log MAR (P < 0.001). No intraoperative complications were identified. Postoperative complications included IOL decentration (12.5%), vitreous hemorrhage (7.5%), IOL slippage (5%), IOL tilt (5%), and retinal detachment (RD) (5%). Further surgical procedures were necessary for only four cases (10%), all of which had positive outcomes. IOL tilting and slippage occurring at average ages of 18 and 19 years, respectively. No other complications, such as hypotony, elevated intraocular pressure (IOP), corneal edema, iritis, IOL dislocation, cystoid macular edema (CME) or endophthalmitis, were reported.ConclusionsThe Yamane technique has proven effective and safe for treating subluxated lenses in Egyptian patients with Marfan Syndrome, resulting in improved visual acuity with minimal complications, mostly minor and manageable. Comprehensive fundus examinations before and after surgery are essential for promptly identifying retinal breaks and reducing the risk of retinal detachment. IOL tilting and slippage are more common in younger patients.

Pain during prolonged sitting in subjects with patellofemoral pain in Dutch physical therapy clinics: an online questionnaire-based analysis

ObjectivesThis study aimed to describe (1) differences between subjects with patellofemoral pain (PFP) with and without pain during prolonged sitting (PDPS), (2) minimum knee flexion angle and time to onset/disappearance of PDPS and (3) differences between those with PDPS at smaller/greater flexion angles and with fast/slow onset and disappearance of PDPS.DesignPatient-reported online questionnaire.SettingPrivate physical therapy clinics in the Netherlands between May 2021 and March 2023.Participants87 participants (61 (70%) females, mean age 22.0 years (IQR 4.0), body mass index 23.1 (4.7)).Outcome measuresVisual Analogue Scale for worst pain (VAS-W) and sitting pain (VAS-W sitting), the Anterior Knee Pain Scale (AKPS), knee flexion angle to provoke PDPS and time to onset/disappearance of PDPS.Results63 of 87 (72%) participants reported PDPS. Participants with PDPS experienced bilateral symptoms of PFP more frequently (71% vs 46%, p=0.44) and scored 12 points lower on the AKPS (p&lt;0.001). Most participants (85%) reported a minimum knee flexion angle of ≥90°, median time to PDPS onset of 16–20 min and 6–10 min for disappearance. Participants experiencing PDPS at smaller flexion angles exhibited higher VAS-W and VAS-W sitting scores (7.0 (1.0), 6.8 (1.1)) than those at greater flexion angles (5.0 (3.0), for both) (p=0.002, p=0.001). Participants with fast onset of PDPS reported higher VAS-W and VAS-W sitting scores (7.0 (2.0), 6.0 (2.0)) than those with slow onset (5.0 (3.0), 5.0 (4.0)) (p&lt;0.001, p=0.025).ConclusionsParticipants with PDPS reported higher levels of disability than those without. PDPS was typically induced at knee flexion of ≥90°, with delayed onset/disappearance. Higher pain levels were reported by those experiencing PDPS at smaller knee flexion angles or with faster onset. Future research should explore the mechanisms of PDPS and develop targeted interventions to improve long-term outcomes.

A Filter Calibration Method for Laser-Scanned Weld Toe Geometries

The scanning of weld seams can be used to evaluate the local weld toe geometry for fatigue assessments. Laser scanned weld seam profiles often contain noise which complicates the accurate measurement of the weld toe geometry. For that reason, filtering of the scanned data is necessary. The issue at hand is that a filtering method can significantly affect the measurement results. Therefore, a calibration of the filter input parameters is needed. In this study, a calibration method for filtered laser-scanned weld profiles is presented by using artificial weld toe geometries. The adjustment of different filter functions is achieved by using an optimization method on predefined weld toes with an artificial noise. The resulting input data for the filter functions is tested on a real specimen to verify the method. Through the calibration method it is possible to achieve satisfactory measurement results with precisely set input parameters for the filter functions. The most suitable filter functions for the measurement of the weld toe are the Gaussian and the Lowpass filter. Both functions are adequate as a universally applicable filter. For the evaluation of the measurement results of the radii and angles, a tolerance range is introduced, which is defined by the theoretically minimum measurable radii and angles. Using an adjusted Lowpass filter and a point distance of 0.07 mm set by the laser scanner, a measurement within the tolerance range of 0.2 mm is achievable for the weld toe radius. For the weld toe angle, the tolerance range of 1.5° is achieved for the majority of measurements.

Reading Performance Following Contralateral Implantation of an Extended Depth of Focus (EDOF) IOL and a Hybrid EDOF Multifocal IOL.

To assess objective reading performance at intermediate and near distances using the Salzberg Reading Desk (SRD) (SRD Vision) in patients with cataract who underwent the implantation of a diffractive extended depth of focus intraocular lens (EDOF IOL) in the dominant eye and a hybrid multifocal EDOF IOL in the non-dominant eye. This prospective, non-comparative, interventional study included 46 eyes of 23 patients with cataract who underwent bilateral cataract surgery with implantation of the DFR00V Tecnis Synergy IOL (Johnson & Johnson Surgical Vision) in the non-dominant eye and the DXR00V Tecnis Symfony OptiBlue IOL (Johnson & Johnson Surgical Vision) in the dominant eye. At postoperative 6 months, the Salzburg Reading Desk was used to assess distance-corrected reading performance at near and intermediate distances. Although the monocular reading acuity at the preferred intermediate distance was statistically significantly better in the eyes implanted with the DXR00V IOL, it was better with the DFR00V IOL at preferred near distances. The mean binocular distance-corrected preferred intermediate and near reading acuity was 0.07 ± 0.09 (20/23) and 0.13 ± 0.09 (20/27) logarithm of the minimum angle of resolution, respectively. Other parameters of reading performance, such as reading speed, reading distance, reading time, and smallest scale log print size, were similar between the two IOL groups when assessed monocularly. Implanting a DFR00V IOL in the non-dominant eye and a diffractive DXR00V IOL in the dominant eye resulted in excellent binocular reading acuity and speed at intermediate and near distances. [J Refract Surg. 2024;40(11):e778-e782.].

Predictability of Keratorefractive Lenticule Extraction Is Equal to Variance of Preoperative Manifest Refraction Measurement.

To compare variance of manifest refraction (MR) measurement and variance of refractive outcomes after keratorefractive lenticule extraction (KLEx) in the same cohort. This was a retrospective study of consecutive patients attending at least three preoperative refractions before undergoing KLEx. All manifest refractions were performed according to a standard protocol. Additionally, automated refraction, spectacles prescription, wavefront refraction, and tomography/topography were also considered when determining the treatment refraction. Variance of postoperative outcomes was compared to variance of MR measurement. The difference in MR of 153 eyes between the first and last preoperative visit showed a mean pairwise absolute difference of 0.22 ± 0.22 diopters (D) (range: 0.00 to 1.25 D) in spherical equivalent (SE). The 95% limit of agreement (LoA) was within 0.73 D for sphere, 0.60 D for cylinder, and 0.61 D for SE. Standard deviation (SD) for corrected distance visual acuity (CDVA) was 0.06 logarithm of the minimum angle of resolution (logMAR) and the 95% LoA was within 1.3 Snellen lines. The differences between reproducibility of the two last preoperative MR and the variance of postoperative outcomes after KLEx (ie, the isolated repeatability of corneal lenticule extraction) was SD of 0.13 D for sphere, cylinder, and SE, and 11 degrees in axis, respectively. Predictability of KLEx was equal to variance of refraction measurement. Isolated repeatability of the laser treatment was better than the reproducibility of MR. Thus, the authors have shown for the first time that precision of KLEx has reached such a level today that further improvement is limited by MR measurements. [J Refract Surg. 2024;40(11):e814-e823.].

Non-inferiority of Cataract Surgery in a Stand-Alone Unidirectional Airflow System Versus in a Conventional Operating Room: A Retrospective Study.

To demonstrate the non-inferiority of a stand-alone unidirectional airflow system, the SurgiCube (Surgi-Cube International BV), for cataract surgery compared to a conventional operating theater (OT). This was a retrospective and comparative cross-sectional study conducted at the Rothschild Foundation, Paris, France. All patients who underwent cataract surgery using the SurgiCube between February 2020 and February 2023 were included and compared to a separate group of patients with cataract surgery performed in a conventional OT and under topical anesthesia during the same period. Patients with less than 1 month of follow-up after surgery were excluded. We collected relevant information from the patient's medical records. Main outcome measures, incidence of endophthalmitis, intraoperative and postoperative complication incidence, 1-month logarithm of minimum angle of resolution (logMAR) visual acuity and intraocular pressure, and operating times were analyzed. A total of 1,901 eyes in the SurgiCube group were compared to 5,474 eyes in the OT group. The occurrence of endophthalmitis was 0.05% (n = 1) in the SurgiCube group versus 0.07% (n = 4) in the OT group (P = 1.00; odds ratio = 0.72 [95% CI = 0.01 to 7.28]). The percentage of procedures with at least one perioperative complication was 2.6% in the SurgiCube group and 2.7% in the OT group (P = .87; odds ratio = 0.96 [95% CI = 0.68 to 1.34]). The percentage of procedures with a postoperative complication was 6.31% in the SurgiCube group and 6.6% in the OT group (P = .59; odds ratio = 0.94 [95% CI = 0.75 to 1.17]. Average visual acuity at 30 days was 0.04 logMAR in the SurgiCube group and 0.07 logMAR in the OT group (P = .62). The average operating times were 16.8 and 19.7 minutes for the SurgiCube and OT groups, respectively (P < .001). The average occupation room times were 26.2 and 32.3 minutes for the SurgiCube and OT groups, respectively (P < .001). Cataract surgery in the SurgiCube seems to be non-inferior to cataract surgery in a conventional OT. [J Refract Surg. 2024;40(11):e884-e891.].

Clinical Comparison of a Small-Aperture Intraocular Lens Versus a Monofocal Control.

To evaluate range of visual acuity, visual quality, and safety of the IC-8 small-aperture (SA) intraocular lens (IOL) (Apthera; Bausch & Lomb, Inc) in patients with cataract. This was a prospective, multicenter, open-label, parallel-group, non-randomized, examiner-masked, 12-month clinical study conducted at 21 sites in the United States. Included patients (N = 453) received either the SA IOL (targeted to -0.75 diopters) in one eye and a monofocal or monofocal toric IOL (targeted to plano) in the fellow eye (SA IOL group, n = 343) or bilateral monofocal/monofocal toric IOLs (control group, n = 110). At 6 months, the SA IOL group achieved superior binocular uncorrected intermediate and near visual acuity (P < .0001) and equivalent binocular uncorrected distance visual acuity versus the control group. In SA IOL eyes, 99.1% achieved monocular corrected distance visual acuity of 0.3 logarithm of the minimum angle of resolution or better. The SA IOL and control groups had comparable binocular photopic and mesopic contrast sensitivities at 6 months both with and without glare. The SA IOL group reported few visual symptoms overall, although at higher rates than in the control group. The SA IOL group exhibited improved intermediate and near vision, comparable distance vision and binocular contrast sensitivities, and few visual symptoms or adverse events versus the bilateral monofocal/monofocal toric IOL group, suggesting that the SA IOL is an effective option for presbyopia correction at the time of cataract surgery. [J Refract Surg. 2024;40(11):e824-e835.].

Evaluation of Long-term Rotational Stability and Functional Performance of Two Toric Multifocal IOL Models Beyond 5 Years.

To assess visual outcomes and stability of lens alignment more than 3 years after implanting either the AT Lisa Tri Toric (Carl Zeiss Meditec) or the Acrysof IQ Restor Toric (Alcon Laboratories, Inc) intraocular lens (IOL). Patients who had received either the AT Lisa Tri Toric or the Acrysof IQ Restor Toric IOL were included in the study. The average follow-up period was 5.4 years for the AT Lisa Tri Toric group and 7.9 years for the Acrysof IQ Restor group. The examinations covered included: subjective refraction, monocular and binocular corrected and uncorrected visual acuity at far (4 m), intermediate (75 cm), and near (40 cm) distances, binocular best-corrected defocus curve analysis (4 m), contrast sensitivity evaluation, assessment of IOL axial position, and presence of positive dysphotopsia. A total of 42 eyes were evaluated. Both groups exhibited good long-term lens axial stability. The AT Lisa Tri Toric group had a mean misalignment of 4.8 ± 3.2° from the preoperatively determined axis, whereas the Acrysof IQ Restor Toric group had an average misalignment of 5.4 ± 4.5° (no statistically significant difference, P = .578). Mean achieved spherical equivalent was -0.19 ± 0.36 diopters (D) for the AT Lisa Tri Toric group and 0.15 ± 0.39 D for the Acrysof IQ Restor Toric group. In the AT Lisa Tri Toric group, 18 eyes (72%) achieved an uncorrected distance visual acuity of 0.10 logarithm of the minimum angle of resolution (20/25 Snellen) or better, compared to 15 eyes (88%) in the Acrysof IQ Restor Toric group. Overall, 21 eyes (84%) in the AT Lisa Tri Toric group and 14 eyes (83%) in the Acrysof IQ Restor Toric group achieved a postoperative spherical equivalent refraction between -0.50 and +0.50 D. Both the AT Lisa Tri Toric and the Acrysof IQ Restor Toric IOLs showed good long-term stability and functional outcomes. They proved to be effective options for restoring vision at far, intermediate, and near distances, providing a viable solution for presbyopia correction even several years after implantation. [J Refract Surg. 2024;40(11):e845-e853.].

Use of selective laser capsulotomy for mature white cataracts: Initial experience in Indian eyes.

To report the initial experience of performing capsulotomy in eyes with mature white cataracts using selective laser capsulotomy (SLC) in Indian eyes. This was a prospective, noncomparative, open-label study. All adults presenting to our institution with mature cataracts whose pupils dilated >6 mm and who were willing for phacoemulsification were invited to participate. During surgery, after staining the anterior capsule with a proprietary trypan blue, the CAPSULaser device (Excel-Lens Inc, Los Gatos, CA, USA) was used to create a capsulotomy of size ranging from 5 to 5.5 mm and phacoemulsification was carried out. The primary outcome was the size, centration, and continuity of the capsulotomy edge at the end of the surgery. Secondary outcomes were the surgical time for capsulotomy, capsulotomy centration on the intraocular lens (IOL) at 3 months, and adverse effects. Thirty eyes were studied of 30 patients who were recruited with a mean age of 66.4 ± 8.3 years, of which 17 (57%) were men. The intraoperative size of capsulotomy was the same as intended in all eyes and the edges were smooth. None of the eyes experienced any visible capsular tears or run out events; one had a capsular tag. The time for capsulotomy including capsular staining was 3 ± 0.23 min. All IOLs were well centered at 3 months with a capsulotomy size remaining the same. The endothelial cell count had dropped by 8% at 3 months post-op, and the vision improved significantly to 0.03 log of minimum angle of resolution. None of the eyes experienced any intraoperative complications or laser-induced adverse effects. SLC was a safe and effective technique providing precise, well-centered anterior capsulotomies in mature white cataracts.

Effects and safety of combined corneal collagen crosslinking and intrastromal corneal ring segment treatment in patients with keratoconus: a retrospective study

PurposeTo evaluate the safety and efficacy of different time-point combinations of intrastromal corneal ring segment (ICRS) implantation using femtosecond technology) and corneal collagen crosslinking (CXL) for the treatment of moderate-to-severe keratoconus (KCC).MethodsThis study included 69 eyes of 69 patients with keratoconus who underwent ICRS and CXL treatment at an Eye Hospital between March 2020 and March 2023. The patients were divided into two groups: Group 1 (n = 33 eyes of 33 patients), which received ICRS and CXL treatment in one session, and Group 2 (n = 36 eyes of 36 patients), which included treatment with ICRS for at least 6 months following CXL application. Preoperative and postoperative evaluations included visual acuity, autorefractometer refraction, corneal tomographic measurements using the Sirius (CSO) Scheimpflug camera and the TONOREF™ III device, and documentation of observed complications. Uncorrected visual acuity (UCVA) and best-corrected spectacle visual acuity (BCVA) were measured in each eye individually, and visual acuity was assessed using the logarithm of the minimum angle of resolution (logMAR).ResultsIn Group 1, mean UCVA improved from 0.81 ± 0.34 to 0.45 ± 0.25 (p < 0.01), and mean BCVA improved from 0.76 ± 0.35 to 0.38 ± 0.20 (p < 0.01). In Group 2, mean UCVA improved from 0.71 ± 0.32 to 0.43 ± 0.30 (p < 0.01), and mean BCVA improved from 0.65 ± 0.25 to 0.31 ± 0.23 (p < 0.01). Both groups showed significant reductions in manifest spherical and cylindrical refraction (p < 0.01). Group 1 exhibited greater reductions in maximum keratometry (Kmax), flat keratometry (K1), steep keratometry (K2) (p < 0.05), and astigmatic aberration compared with group 2 (p < 0.01). The use of simultaneous or separate CXL and ICRS does not significantly increase the incidence of complications.ConclusionsBoth combined and separate CXL and ICRS treatments resulted in significant improvement in UCVA and BCVA and reduced manifest refraction. Although improvements were observed in groups 1 and 2 in terms of K1, K2, and Kmax at 6 months, the improvements were more pronounced in Group 1. These results highlight the potential benefits of simultaneous ICRS + CXL treatment and underscore the importance of optimising the timing of CXL treatment to achieve the best visual outcomes.

Ten-Year Follow-Up After Descemet Membrane Endothelial Keratoplasty.

To examine clinical results up to 10 years after Descemet Membrane Endothelial Keratoplasty (DMEK) and Triple-DMEK. Prospective study including 201 eyes, of which 54 eyes [38 DMEKs and 16 Triple-DMEKs; Fuchs endothelial dystrophy (n = 45), pseudophakic bullous keratopathy (n = 9)] reached the minimum follow-up of 5 years and were followed up for up to 10 years. We evaluated best-corrected visual acuity (BCVA, logarithm of the minimum angle of resolution [logMAR]), endothelial cell density (ECD, cells/mm2), minimal central corneal thickness (CCT, μm), central retinal thickness (μm), rebubbling, graft survival and re-DMEK rate, chamber angle alterations, and incidence of glaucoma. Fifty-four eyes had a 5-year and 37 eyes an 8- to 10-year follow-up. Mean follow-up was 94.4 ± 12.1 months. Best-corrected visual acuity increased from 0.6 ± 0.3 logMAR to 0.1 ± 0.2 logMAR at 6 months (P ≤ 0.001) and was 539 ± 54 μm at long term. Endothelial cell density decreased from 2488 ± 320.9 (donor) to 980.1 ± 437 cells/mm2 with an average ECD loss/year of 4% and did not correlate with BCVA. Central corneal thickness decreased from 596.9 ± 82.2 μm to 498.6 ± 24.3 μm at 12 months (P ≤ 0.001) and remained stable (P = 1.000). Mean rebubbling rate was 0.3 ± 0.5/eye and did not correlate with BCVA. Eight eyes (14.8%) received at least 1 rebubbling. Primary graft failure/rejection rate was 1.5%/0% within the first postoperative year, and secondary graft failure rate was 12.4% at 7 years. Eight eyes (preoperative n = 3, de novo n = 5) had open-angle glaucoma without chamber angle changes (14.8%, P ≤ 0.001). Although ECD decreases continuously in the long-term follow-up, excellent visual acuity can be preserved 10 years after DMEK and Triple-DMEK. The final outcome can be estimated 6 months after surgery.

Simple Epithelial Transplantation for Ocular Surface Reconstruction After Severe Ocular Burn Injury.

To manage ocular surface complications and recover conjunctival and corneal epithelia after unilateral severe chemical burn. We performed simple conjunctival epithelial transplantation (SCET) to obtain renewal of fornix and bulbar-tarsal conjunctiva epithelium, followed by simple limbal epithelial transplantation (SLET) to recover limbal function and epithelial corneal surface. Slit-lamp examination, fluorescein staining, in vivo confocal microscopy, Kheirkhah grading system for symblepharon severity, Wong-Baker FACES Pain Rating Scale, and best-corrected visual acuity were assessed before surgery, at 1 to 3 months after SCET and SLET, and thereafter at 6 to 12 to 36 months. Two patients with unilateral burn injuries underwent surgery. Eye mobility and fornix reconstruction were promptly achieved, and conjunctival epithelium with goblet cells was observed on the bulbar and tarsal conjunctiva 3 months after SCET. After SLET, corneal epithelium and cornea-conjunctiva transition zone were observed at 3 and 6 months, respectively. From before surgery to 6 months after SLET, symblepharon improved from grade IVa2 and IIIb2 to Ic0 and Ib0, the Wong-Baker FACES Pain Rating Scale changed from grade 6 and 4 to 0, and best-corrected visual acuity upgraded from 1.40 and 1.10 logarithm of the minimum angle of resolution to 0.5 logarithm of the minimum angle of resolution, in patient 1 and 2, respectively. After 3 years, results remained stable. SCET effectively healed the bare conjunctival area relieving subjective symptoms and discomfort. Sequential SCET and SLET showed to be feasible in restoring a normal ocular surface with long-lasting results suggesting the aim in patients with severe ocular burn is not merely corneal epithelium renewal but also the regeneration of ocular surface homeostasis.

Off-Centered DMEK Grafts: Impact and Resolution.

The aim of this study was to assess the outcomes of off-centered Descemet membrane endothelial keratoplasty (DMEK) grafts compared to descemetorhexis. This is a retrospective case series of DMEK procedures conducted between June 2022 and July 2023 with postoperative graft decentration, characterized by a gap between the graft and descemetorhexis edge. Eight eyes of 8 patients met the inclusion criteria. The average gap between the descemetorhexis edge and DMEK graft was 911.2 μm (range 306-1468). The resulting focal peripheral edema overlying the gap resolved in all cases, with a median time of 3 months. Best-corrected visual acuity improved from 0.49 (±0.26) logarithm of the minimum angle of resolution to 0.01 (±0.02) logarithm of the minimum angle of resolution at 12 months (P = 0.003). Central corneal thickness decreased from 646.5 (±177.8) μm to 473.7 (±29.6) μm at 12 months (P = 0.05). One eye, in the overlapped area of host-donor Descemet membranes, had small peripheral partial graft detachment less than one-third of graft surface area. No eyes required graft rebubbling. A larger descemetorhexis to DMEK gap showed a trend toward longer resolution times (P = 0.06). Focal edema in the inferonasal periphery took longer to recover compared with the nasal position (P = 0.01). Larger descemetorhexis to DMEK gaps did not significantly influence the longitudinal visual acuity trend (P = 0.75). Decentered DMEK, characterized by a gap between the graft and descemetorhexis edge, leads to focal stromal edema that diminishes over time, with no impact on final visual acuity.

Corneal Endothelial Keratoprosthesis EndoArt in Patients with Glaucoma at High Risk of Graft Failure After Keratoplasty.

The novel endothelial keratoprosthesis EndoArt improves corneal edema by reducing the inflow of aqueous humor into the cornea. We assessed the early outcome after EndoArt implantation in patients at a high risk of graft failure after keratoplasty. This retrospective study included 14 patients with high-risk eyes owing to at least one of the following risk factors for graft failure after keratoplasty: multiple previous surgeries (glaucoma surgery, keratoplasty) and recurrent intraocular inflammation because of uveitis, aniridia, or anterior synechia. After descemetorhexis, the EndoArt keratoprosthesis was placed on the posterior stroma, secured with a gas bubble and 1 to 3 transcorneal holding sutures. Best spectacle-corrected visual acuity and central corneal thickness were calculated preoperatively and postoperatively. In addition, detachment of the keratoprosthesis and the need for additional gas injections (rebubbling) were analyzed. Octafluoropropane (C3F8) 12% in 11 patients and sulfur hexafluoride 20% in 3 patients were used to attach EndoArt. Detachments requiring at least 1 rebubbling occurred in 8 eyes. Preoperative best spectacle-corrected visual acuity was 1.6 (±0.6) logarithm of the minimal angle of resolution and improved to 1.3 (±0.6) after 12 weeks. Preoperative central corneal thickness (771.8 μm ± 157) significantly decreased postoperatively in all patients (622.1 μm ± 184.7 [P = 0.025] and 562.8 μm ± 183.6 [P = 0.012] after 6 and 12 weeks, respectively). EndoArt improved visual acuity and significantly reduced corneal thickness within 3 months postoperatively, subjectively, but not statistically significantly. The rebubbling rates in this cohort with an altered anterior segment anatomy were relatively high. Patients at a high risk of graft failure may benefit from this novel endothelial keratoprosthesis.

Optical parameter design model of hemispherical laser retroreflector arrays for satellite laser ranging

A laser retroreflector array (LRA) with multiple retroreflectors is used to directionally reflect an incident laser beam and aims to enhance the received signal strength into laser ranging ground stations. A comprehensive mathematical equation of the received photons is established by modelling the LRA far field diffraction intensity (FFDI) and the satellite velocity aberration position. Based on this received photon model, a novel method on designing the dihedral angle offset and the aperture of retroreflectors is proposed, which maximizes the received photon under the minimal elevation angle of the ground station. Taking the hemispherical structure parameters of Chinese HY-2 satellite LRA and the specification parameters of the Shanghai Astronomical Observatory, the optimal aperture and the dihedral angle offset of the HY-2 laser retroreflectors are 17 mm and 1.6″, respectively. These two optimal optical parameters make the received photon under the elevation angle of 0° reach ∼0.9 count per laser shot. Until now, ∼851,400 successful observations have been successfully obtained by global ground stations since the first launch of HY-2 satellite series in 2011, which guarantees the high-precise orbit determination of HY-2 satellite series.

Interaction law between mining stress and fault activation and the effect of fault dip angle in longwall working face

Study of the interaction between fault activation and mining stress evolution in the longwall working face is helpful to provide a targeted area for fault type heavy mine pressure disaster control. Combining theoretical analysis, physical and numerical simulation, the mechanical mechanism of fault activation is analyzed, the interaction law between mining stress and fault activation is studied, and the influence of fault dip angle on the evolution of fault activation and mining stress is discussed. The minimum critical dip angles α of normal and reverse fault activation are π/4 + φ/2 and π/4-φ/2, respectively. During the mining process, the activation position of the fault surface, the peak values of stress and displacement gradually increase and transfer from the high position of the fault to the low position, and the peak value of the advance abutment pressure reaches the maximum at the fault. The advancing distance of the working face required for fault activation gradually decreases with the decrease of the fault dip angle, and the peak elevation area of the working face gradually increases with the decrease of the fault dip angle. Combined with the on-site microseismic monitoring results, it can be seen that when the working face is about 20 m away from the fault, the stress and energy increase sharply, which is the main control area of the impact disaster.

Human Amniotic Membrane: A Seal for Complex Retinal Detachments.

To evaluate the efficacy of human amniotic membrane (hAM) transplantation for complex retinal detachments (RD). A retrospective analysis of consecutive patients who underwent vitreoretinal surgery with hAM transplantation for complex RD was conducted. The indications included high myopic macular hole (MH)-associated RD (n=5), traumatic large macular tears (n=4), combined RD with MH due to cicatricial retinopathy of prematurity (n=2) and severe retinitis (n=1), and morning glory syndrome (n=1). Surgical procedures, anatomical and functional results, and complications were noted. Thirteen eyes of 13 patients with a median age of 7 years (range, 0-65 years) were included. The follow-up was 15 months (range, 6-30 months). All eyes achieved MH sealing. Sealing occurred after a single surgery in 75% of eyes, while 25% required a second surgery due to hAM contraction/dislocation. The retina was attached and silicone oil could be removed in 92% of eyes during follow-up. The mean logarithm of the minimum angle of resolution visual acuity increased from 2.08±0.49 to 1.78±0.70 (p=0.07). Optical coherence tomography showed good integration of the hAM grafts with the retina, albeit without discernible retinal layer differentiation in any case. Amniotic membrane grafting appears to be promising for anatomical sealing of MHs and posterior retinal tears in complex RDs such as those associated with degenerative myopia, severe trauma, tractional membranes, and retinal shortening, where conventional surgical techniques are likely to fail. Further research is needed to clarify the regenerative potential and functional capacity of hAM grafts in severe retinal pathologies.

Scleral buckling in retinal detachment due to retinal dialysis - A vitreoretina fellow's perspective.

To analyze the efficacy of scleral buckling in the hands of vitreo-retina (VR) fellows under training in eyes with retinal detachment associated with retinal dialysis and analyze the patient and retinal characteristics in these eyes. We carried out a retrospective consecutive case review at a tertiary eye care center in North India. Records of all the patients who had undergone scleral buckling (SB) for retinal dialysis-associated rhegmatogenous retinal detachment by VR fellows (with less than 2 years' experience) between January 2017 and January 2020 were reviewed. Fifty-three eyes of 53 patients with a mean age of 20.77 years were analyzed. Of the patients, 73.58% were males. History of eye trauma was present in 71.69% patients. A total of 21 residents operated these 53 eyes. SB was able to achieve retinal attachment in a single surgery in 84.9% (45/53) eyes. Mean preoperative best corrected visual acuity was 1.9 ± 1.05 log of minimum angle of resolution (logMAR), which improved postoperatively to 1.07 ± 0.72 logMAR (P < 0.001). Surgical success rate was 85.71% (24/28) in eyes with no proliferative vitreoretinopathy (PVR), 66.66% (2/3) in eyes with PVR-A, 91.66% (11/12) in eyes with PVR-B, and 80% (8/10) in eyes with PVR-C1. Fifty-two eyes had a single dialysis and one eye had two separate dialysis. Six eyes had giant retinal dialysis (dialysis greater than 3 clock hours) and all were due to trauma. Five patients had retinal dialysis in the fellow eye and were diagnosed with bilateral idiopathic retinal dialysis. Scleral buckling is a safe and effective management for retinal dialysis retinal detachment even in the hands of VR fellows under training.

Evaluation of Medically Reversible Limbal Stem Cell Deficiency.

To evaluate the clinical characteristics and treatment strategies of limbal stem cell deficiency (LSCD) patients managed with medical therapy. The study included 29 eyes of 21 patients with LSCD who were managed medically at Ege University Faculty of Medicine, Department of Ophthalmology between May 2013 and May 2023. LSCD stages before and after medical treatment were recorded according to the LSCD staging system published by the International LSCD Working Group. The medical records of patients showing improvement in LSCD stage with medical treatment without surgical intervention were evaluated. The mean age was 35.5±23.8 years (range, 5-71 years) with a male-to-female ratio of 6:15. The primary etiology of LSCD was ocular rosacea in 12 patients (57.1%), marginal keratitis in the setting of blepharitis in 8 patients (38.1%), and topical medication toxicity in 1 patient (4.8%). The mean baseline best corrected visual acuity (BCVA) was 0.25±0.26 logarithm of the minimum angle of resolution (logMAR) (range, 0-1 logMAR). Pre-treatment LSCD stage was stage 1A in 5 eyes (17.2%), stage 1B in 12 eyes (41.4%), stage 1C in 4 eyes (13.8%), stage 2A in 4 eyes (13.8%), and stage 2B in 4 eyes (13.8%). Complete regression of LSCD was achieved in 6 eyes (20.7%) with medical treatment addressing the primary etiology. In the remaining eyes, after medical treatment, the severity of LSCD decreased below the surgical threshold, which is considered stage 2B. The mean final BCVA was 0.07±0.1 logMAR (range, 0-0.4 logMAR). This study highlights that LSCD can be completely or partially reversible with appropriate management, especially in cases with underlying limbal niche dysfunction, where inflammation plays a significant role. Although limbal stem cell transplantation is considered the main treatment approach for LSCD, localized and early-stage LSCD can be effectively managed medically without the need for surgical intervention.