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PURPOSE: To evaluate the biomechanical and tomographic outcomes of keratoconus patients up to four years after corneal crosslinking (CXL). METHODS: In this longitudinal retrospective-prospective single-center case series, the preoperative tomographic and biomechanical results from 200 keratoconus eyes of 161 patients undergoing CXL were compared to follow-up examinations at three-months, six-months, one-year, two-years, three-years, and four-years after CXL. Primary outcomes included the Corvis Biomechanical Factor (CBiF) and five biomechanical response parameters obtained from the Corvis ST. Tomographically, the Belin-Ambrósio deviation index (BAD-D) and the maximal keratometry (Kmax) measured by the Pentacam were analyzed. Additionally, Corvis E-staging, the thinnest corneal thickness (TCT), and the best-corrected visual acuity (BCVA) were obtained. Primary outcomes were compared using a paired t-test. RESULTS: The CBiF decreased significantly at the six-month (p < 0.001) and one-year (p < 0.001) follow-ups when compared to preoperative values. E-staging behaved accordingly to the CBiF. Within the two- to four-year follow-ups, the biomechanical outcomes showed no significant differences when compared to preoperative. Tomographically, the BAD-D increased significantly during the first year after CXL with a maximum at six-months (p < 0.001), while Kmax decreased significantly (p < 0.001) and continuously up to four years after CXL. The TCT was lower at all postoperative follow-up visits compared to preoperative, and the BCVA improved. CONCLUSION: In the first year after CXL, there was a temporary progression in both the biomechanical CBiF and E-staging, as well as in the tomographic analysis. CXL contributes to the stabilization of both the tomographic and biomechanical properties of the cornea up to four years postoperatively.
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Although the safety of phakic intraocular lenses (pIOLs) has been continuously improved over 70-years of development, high endothelial cell losses can occur even with current pIOL models. Numerous studies have demonstrated that the distance of a pIOL to the corneal endothelium plays a crucial role in the extent of endothelial cell loss. For this reason alone, higher endothelial cell loss tends to be observed with anterior chamber lenses than with posterior chamber lenses. Adequate preoperative anterior chamber depth is essential, at least for iris-fixed pIOLs, in order to ensure a safe distance from the endothelium. However, the anterior chamber becomes shallower with age and therefore it may be useful to consider patient age in the safety criteria. Although endothelial cell loss is generally low with current pIOL models, regular monitoring of the endothelial cell density remains essential due to large interindividual differences in patients with pIOLs. If the endothelial cell loss is greater than expected and the follow-up visits confirm the trend, the pIOL should be explanted without delay. The endothelial reserve should be considered on an individual basis by taking into account patient age, physiological endothelial cell loss, and loss due to further surgery. With careful indication and long-term patient care, pIOLs remain a safe treatment option.
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Pérdida de Celulas Endoteliales de la Córnea , Lentes Intraoculares Fáquicas , Humanos , Pérdida de Celulas Endoteliales de la Córnea/etiología , Pérdida de Celulas Endoteliales de la Córnea/patología , Endotelio Corneal/patología , Resultado del Tratamiento , Medicina Basada en la EvidenciaRESUMEN
In modern ophthalmic surgery, an intraocular lens (IOL) is commonly implanted into the patient's eye with an IOL injector. Many injectors are available, showing various technological differences, from the early manually loaded injector systems to the modern preloaded injectors. This review aims to give a concise overview of the defining characteristics of injector models and draws attention to complications that may occur during IOL implantation. One can differentiate injectors according to their preoperative preparation (manually loaded or preloaded), their implantation mechanism (push-type or screw-type or combined or automated), the size of the nozzle tip, the presence of an insertion depth control feature, and the injector's reusability. Potential complications are IOL misconfigurations such as a haptic-optic adhesion, adherence of the IOL to the injector plunger, an overriding plunger, uncontrolled IOL rotation, a trapped trailing haptic, or damage to the IOL. Additionally, during IOL implantation, the nozzle can become damaged with scratches, extensions, cracks, or bursts to the tip. While these complications rarely produce long-term consequences, manufacturers should try to prevent them by further improving their devices. Similarly, surgeons should evaluate new injectors carefully to ensure the highest possible surgical safety.
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Implantación de Lentes Intraoculares , Lentes Intraoculares , Humanos , Implantación de Lentes Intraoculares/instrumentación , Implantación de Lentes Intraoculares/métodos , Implantación de Lentes Intraoculares/efectos adversos , Diseño de Equipo , Análisis de Falla de Equipo , Diseño de PrótesisRESUMEN
In recent decades, technical advancements in lens surgery have considerably improved safety and refractive outcomes. This has led to a much broader range of indications for refractive lens exchange (RLE). Effective restoration of uncorrected distance and near visual acuity is possible with modern presbyopia correcting intraocular lenses (IOLs). Hyperopic patients who are fully presbyopic were identified as ideal candidates for RLE. For myopic patients, an increased risk of retinal detachment has been reported, which leads to a higher threshold to perform RLE in this patient group. The most frequent postoperative complications include posterior capsular opacification, deviation from the target refraction and cystoid macular edema. Thus, adequate planning of surgery, careful patient selection, as well as comprehensive counseling are crucial for successful RLE.
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Lentes Intraoculares , Humanos , Resultado del Tratamiento , Presbiopía/cirugía , Presbiopía/terapia , Implantación de Lentes Intraoculares/métodos , Agudeza Visual , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Medicina Basada en la EvidenciaRESUMEN
Cataract is among the leading causes of visual impairment worldwide. Innovations in treatment have drastically improved patient outcomes, but to be properly implemented, it is necessary to have the right diagnostic tools. This review explores the cataract grading systems developed by researchers in recent decades and provides insight into both merits and limitations. To this day, the gold standard for cataract classification is the Lens Opacity Classification System III. Different cataract features are graded according to standard photographs during slit lamp examination. Although widely used in research, its clinical application is rare, and it is limited by its subjective nature. Meanwhile, recent advancements in imaging technology, notably Scheimpflug imaging and optical coherence tomography, have opened the possibility of objective assessment of lens structure. With the use of automatic lens anatomy detection software, researchers demonstrated a good correlation to functional and surgical metrics such as visual acuity, phacoemulsification energy, and surgical time. The development of deep learning networks has further increased the capability of these grading systems by improving interpretability and increasing robustness when applied to norm-deviating cases. These classification systems, which can be used for both screening and preoperative diagnostics, are of value for targeted prospective studies, but still require implementation and validation in everyday clinical practice.
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Catarata , Cristalino , Facoemulsificación , Humanos , Estudios Prospectivos , Fotograbar/métodos , Catarata/diagnóstico , Agudeza Visual , Facoemulsificación/métodosRESUMEN
Intravitreal injections (IVIâs) have gained increased popularity in the past decades and are used to treat a multitude of ailments. In 2010, the total number of IVIâs surpassed the number of cataract surgeries performed, making it the most common procedure in ophthalmology. As the number of injections increases, so does the number of injected-related complications. While complications in the posterior segment, such as retinal detachment or endophthalmitis, are detrimental to visual function and have therefore been well documented, IVIâs can also lead to complications in the anterior segment. These include hyphema, inflammation of the sterile anterior segment (incidence rate of 0.05 to 1.1% depending on the drug), implant migration with corneal decompensation (incidence rate of 0.43%), iatrogenic lens damage (incidence rate of 0.07%), accelerated cataract formation (up to 50% for steroids and 10.9% for anti-VEGF), and an increased complication rate during subsequent cataract surgery (up to 4% per IVI). Most of these complications occur immediately and have a good prognosis if treated correctly. However, the increased risk of complications during subsequent surgery demonstrates that IVIâs can also have long-term complications, a topic that needs to be explored further in future research projects.
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Segmento Anterior del Ojo , Inyecciones Intravítreas , Humanos , Inyecciones Intravítreas/efectos adversos , Segmento Anterior del Ojo/diagnóstico por imagen , Hipema/etiología , Catarata/inducido químicamente , Endoftalmitis/etiología , Complicaciones Posoperatorias/etiologíaRESUMEN
PURPOSE: The smaller incision, new-generation implantable miniature telescope is a novel implant to optimize vision in retinal patients with central vision loss. Using Miyake-Apple techniques we visualized the device implantation, repositioning, and explantation, while noting capsular bag dynamics. METHODS: Using the Miyake-Apple technique, we assessed capsular bag deformation after successful implantation of the device in human autopsy eyes. We assessed rescue strategies for converting a sulcus implantation to a capsular implantation and explantation strategies. We noted the occurrence of posterior capsule striae, zonular stress, and the haptics' arc of contact with the capsular bag after implantation. RESULTS: Acceptable zonular stress was observed during the successful implantation of the SING IMT. When it was implanted in the sulcus, one could reposition the haptics into the bag with two spatulas using counter-pressure in an effective strategy despite inducing tolerable, medium zonular stress. A similar technique, in reverse, allows safe explantation without damaging the rhexis or the bag, while inducing similar medium, tolerable zonular stress. In all eyes we examined, the implant considerably stretches the bag, inducing a capsular bag deformation and posterior capsule striae. CONCLUSION: The SING IMT can be safely implanted without significant zonular stress. In sulcus implantation and explantation, repositioning of the haptic is achievable without perturbing zonular stress using the presented approaches. It stretches average-sized capsular bags to support its weight. This is achieved by an increased arc of contact of the haptics with the capsular equator.
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Cápsula del Cristalino , Lentes Intraoculares , Malus , Humanos , Implantación de Lentes Intraoculares/métodos , Cápsula del Cristalino/cirugía , Prótesis e Implantes , CapsulorrexisRESUMEN
OBJECTIVE: To compare the optic-haptic interaction of different hydrophobic acrylic IOLs after using six preloaded injectors. METHODS: We reviewed the video-recordings of procedures on a total of 388 eyes that underwent phacoemulsification and intraocular lens (IOL) implantation. For six preloaded injectors: multiSert (Hoya Surgical Optics) [System 1], TECNIS Simplicity (Johnson & Johnson Vision) [System 2], TECNIS iTec (Johnson & Johnson Vision) [System 3], AutonoMe (Alcon, Laboratories) [System 4], Bluesert (Carl Zeiss Meditec) [System 5], and Prosert (OphthalmoPro GmbH) [System 6], we noted in each case the time of IOL delivery and made a descriptive observation of IOL insertion and optic-haptic-interaction. RESULTS: We defined standard haptic behavior where the haptics emerged "folded" from the injector and quickly recovered their pre-implantation appearance. The incidence where the leading haptic emerged in a deformed way for System 1 was 20%, System 2: 19%, System 3: 14%, System 4: 56%, System 5: 24% and System 6: 5%. For trailing haptic deformed behavior, the incidence was 36%, 6%, 4%, 8%, 18% and 2%, respectively for Systems 1 to 6. Optic-haptic adhesion occurred in 2% of cases for System 1, 44% for System 2, 52% for System 3, 48% for System 4, and 11% for System 6 (P < 0.05). Adhesion was not found with System 5. CONCLUSIONS: We observed different deformed behavior for leading and trailing haptics in the six preloaded systems, some systems had as much as 52% optic-haptic adhesion.
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Extracción de Catarata , Cápsula del Cristalino , Lentes Intraoculares , Facoemulsificación , Humanos , Tecnología Háptica , Cápsula del Cristalino/cirugía , Implantación de Lentes Intraoculares/métodos , Facoemulsificación/métodos , Diseño de PrótesisRESUMEN
BACKGROUND: To compare the clinical outcomes of bilateral implantation of enhanced intermediate function intraocular lenses (IOLs) and standard monofocal IOLs. METHODS: In this prospective, randomized, comparative controlled study, we compared the visual outcomes of patients who underwent bilateral cataract surgery at the Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, with either enhanced monofocal IOLs (Tecnis Eyhance, ICB00, Johnson and Johnson Vision Care, Inc) (Group 1) or standard monofocal IOLs (Tecnis, ZCB00, Johnson and Johnson Vision Care, Inc) (Group 2). The assessment included monocular and binocular uncorrected distance visual acuity (UDVA), uncorrected intermediate (UIVA at 60 cm) and near (UNVA at 40 cm) visual acuity, uncorrected defocus curves, contrast sensitivity testing (CST), and reading speed test using Quality of vision was evaluated using the Visual Function Questionnaire (VFQ-25). RESULTS: At 3-months postoperatively, monocular and binocular outcomes of UIVA and UNVA were statistically significantly better in Group 1 (P < 0.05). The binocular uncorrected defocus curve of Group 1 showed statistically significantly better outcomes at vergence ranges of -1.5 to -4.0 D (P < 0.05). Significantly higher reading speed test was also observed in Group 1 in all ranges tested (1.0 to 0.1 LogMAR) (P < 0.05). There were no statistically significant differences in CST between groups. CONCLUSIONS: Bilateral implantation of enhanced monofocal IOLs provided better vision at intermediate and near distances compared to standard monofocal IOLs, while maintaining good distance vision and contrast sensitivity.
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Lentes Intraoculares , Facoemulsificación , Humanos , Implantación de Lentes Intraoculares , Estudios Prospectivos , Satisfacción del Paciente , Sensibilidad de Contraste , República de Corea , Diseño de PrótesisRESUMEN
Early (< 3 months) intraocular lens (IOL) dislocation occurs due to insufficient fixation in the capsular bag, while late dislocation (≥ 3 months) is due to increasing insufficiency of the zonular apparatus. Iris-fixated IOL (IFIOL) and suture- or sutureless-fixated scleral IOL (SFIOL) are currently the most commonly used methods when IOL exchange is indicated. Different methods of scleral fixation with or without sutures have been described. The most important techniques are summarised in this paper. IFIOL and SFIOL allow comparable visual outcomes but differ in their risk profile. The decision of which method to use should be made case by case and in accordance with the surgeon's preference.
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Cápsula del Cristalino , Lentes Intraoculares , Humanos , Implantación de Lentes Intraoculares/métodos , Iris/cirugía , Causalidad , Esclerótica/cirugía , Técnicas de Sutura , Estudios Retrospectivos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugíaRESUMEN
Despite all the progress in cataract and refractive lens surgery, refractive surprise is common in clinical practice. A significant postoperative refractive error is particularly annoying - and contributes to the patient's dissatisfaction with the procedure and the surgeon - when a multifocal IOL, an EDOF-IOL or a toric IOL has been implanted. The relatively new technology of intraoperative aberrometry offers the surgeon the option to intraoperatively measure the eye and its refraction, either directly after lens extraction and/or following IOL implantation. Currently, three different systems are available. In a number of studies, the technology has shown a better refractive predictability than preoperative biometry. Besides giving an evaluation of the prototype of a new intraoperative aberrometer, the I-O-W-A system, we also present our results on the influence of the kind of anaesthesia chosen and of two different IOL designs on the predictability of intraoperative aberrometry.
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Extracción de Catarata , Lentes Intraoculares , Facoemulsificación , Humanos , Implantación de Lentes Intraoculares/métodos , Agudeza Visual , Refracción OcularRESUMEN
Simultaneous implantation of a monofocal or monofocal toric intraocular lens (IOL) into the capsular bag and a multifocal IOL into the ciliary sulcus, referred to as duet procedure, allows us to create multifocality that is more easily reversible than the implantation of a capsular bag-fixated multifocal IOL. The optical quality and results after the duet procedure are equivalent to those of a capsular bag-fixated multifocal IOL. Patients who cannot tolerate the side effects of multifocal optics or who develop an ocular condition leading to loss of function such as age-related macular degeneration (AMD) or glaucoma in the course of their lives may benefit from the reversibility of the procedure.
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Cápsula del Cristalino , Lentes Intraoculares , Facoemulsificación , Humanos , Implantación de Lentes Intraoculares/métodos , Agudeza VisualRESUMEN
Opacification of intraocular lenses (IOLs) due to material changes is a serious complication that can compromise the good visual outcomes of uncomplicated cataract surgery. In hydrophobic acrylic IOLs, opacification can result from glistening formation, while in hydrophilic acrylic IOLs, there is a risk of calcification due to the formation of calcium phosphates within the polymer. Over time, various methods have been developed to investigate calcification in hydrophilic acrylic IOLs. The aim of this article is to provide an overview of standard histological staining and models used to simulate IOL calcification. Histological staining can be used to detect calcification and assess the extent of crystal formation. The development of in vivo and in vitro replication models has helped to identify the underlying pathomechanisms of calcification. In vivo models are suitable for assessing the biocompatibility of IOL materials. Bioreactors as an in vitro model can be used to investigate the kinetics of crystal formation within the polymer. The replication of IOL calcification under standardized conditions using electrophoresis allows for the comparison of different lens materials with respect to the risk of calcification. The combination of different analytical and replication methods can be used in the future to further investigate the pathomechanisms of calcium phosphate crystal formation and the influence of risk factors. This may help to prevent calcification of hydrophilic acrylic IOLs and associated explantation and complications.
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Calcinosis , Extracción de Catarata , Lentes Intraoculares , Facoemulsificación , Humanos , Implantación de Lentes Intraoculares , Complicaciones Posoperatorias/etiología , Lentes Intraoculares/efectos adversos , Extracción de Catarata/efectos adversos , Calcinosis/diagnóstico , Calcinosis/etiologíaRESUMEN
Fungal keratitis due to Fusarium species is a rare but serious ocular disease. Due to its rapid progression, often late diagnostic confirmation as well as limited topical treatment options, this is potentially sight threatening. Increasing contact lens use and global climate change have been suggested to be factors leading to an increase in cases of fusarium keratitis, even in regions with moderate climate. Early recognition and initiation of antimycotic treatment, as well as early surgical treatment by penetrating keratoplasty are decisive for the outcome.
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BACKGROUND: Due to its invasive nature, cataract surgery can lead to inflammatory processes in the posterior segment, which can result in prolonged recovery times, reduced functional outcomes, and late-onset complications. The aim of the current study was to identify wherever phacoemulsification parameters play a role in choroidal thickness change following cataract surgery. METHODS: This prospective single-center study enrolled 31 patients (31 eyes) scheduled to undergo routine cataract surgery. Patients with previous ocular surgeries, pathologies or general disorders affecting vision were excluded. Patients were examined preoperatively, as well as 1, 4, and 12 weeks after surgery. Corrected distance visual acuity (CDVA), intraocular pressure (IOP) as well as cumulative dissipated energy (CDE), ultrasound time (UT), and fluids used during surgery were recorded. Subfoveal choroidal thickness was measured manually by two masked independent experts using enhanced depth imaging (EDI) optical coherence tomography (OCT). Furthermore, cataract density was automatically calculated using a custom MATLAB script and an anterior segment OCT. RESULTS: Subfoveal choroidal thickness increased significantly (p < 0.001, Student's paired sample t-test) and continuously during the 12-week-long follow-up period. Both the nuclear lens density and the improvement in CDVA correlated significantly with this increase (r = 0.413, p = 0.021 and r = 0.421, p = 0.018, respectively). Neither the CDE (r = 0.334, p = 0.071), the UT (r = 0.102, p = 0.629), the amount of fluid used (r = 0.237, p = 0.27) nor the decrease in IOP (r = - 0.197, p = 0.288) showed any significant correlation with the choroidal swelling. CONCLUSION: Cataract surgery leads to an increase in subfoveal choroidal thickness. While no statistically significant correlation to the phacoemulsification parameters could be established, this might be because of a selection bias due to the technological constraints of the OCT. Nevertheless, the choroid might play a central role in early- and late-onset complications.
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Catarata , Oftalmología , Humanos , Tomografía de Coherencia Óptica/métodos , Estudios Prospectivos , Coroides/diagnóstico por imagen , Coroides/patología , Catarata/diagnóstico por imagen , Catarata/complicacionesRESUMEN
BACKGROUND: Keratoconus is a bilateral, yet asymmetric disease. In rare cases, the second eye may show no signs of tomographic changes. The purpose of this study was to analyze the biomechanical characteristics in tomographically regular keratoconus fellow eyes. MATERIALS AND METHODS: This retrospective, consecutive case series analyzed 916 eyes of 458 patients who presented to our keratoconus clinic between November 2020 and October 2022. Primary outcome measures included best-corrected visual acuity (BCVA), tomographic Scheimpflug analysis using Pentacam AXL (Oculus, Wetzlar, Germany), and biomechanical assessment using Corvis ST (Oculus, Wetzlar, Germany). Tomographic changes were assessed via analysis of the anterior and posterior curvature, K-max, thinnest corneal thickness (TCT), the Belin/Ambrosio Deviation Display (BAD-D), and the ABCD-Grading. Biomechanical changes were analyzed using Corvis Biomechanical Index (CBI) and Tomographic Biomechanical Index (TBI). RESULTS: Of 916 eyes, 34 tomographically regular fellow eyes (7.4%) were identified and included in the analysis. Overall, the mean BCVA was - 0.02 ± 0.13 logMAR. Tomographic analysis showed mean K-max of 43.87 ± 1.21 D, mean TCT of 532 ± 23 µm, and mean BAD-D of 1.02 ± 0.43. Biomechanical analysis demonstrated mean CBI of 0.28 ± 0.26 and mean TBI of 0.34 ± 0.30. While normal CBI-values were observed in 16 (47%) of 34 eyes, only 13 eyes (38%) showed a regular TBI and only 7 eyes (21%) showed regular TBI and CBI. The sensitivity of CBI and TBI to detect a tomographically normal keratoconus fellow eye was 53% and 62%, respectively. CONCLUSION: A highly asymmetric corneal ectasia with regular tomographic finding in a fellow eye is rare among keratoconus patients. In such cases, a biomechanical analysis may be useful in detecting early signs of corneal ectasia. In our analysis, the TBI showed high sensitivity for detecting a biomechanical abnormality in tomographically regular fellow eyes.
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Queratocono , Humanos , Queratocono/diagnóstico por imagen , Córnea/diagnóstico por imagen , Estudios Retrospectivos , Topografía de la Córnea/métodos , Paquimetría Corneal , Dilatación Patológica , Curva ROC , Fenómenos Biomecánicos , ElasticidadRESUMEN
Differentiating between various intraocular lens (IOL) changes can be a challenge. In particular, certain IOL models carry the risk of late postoperative calcification. A major cause of IOL exchange surgery could be avoided if appropriate modifications were made during the IOL manufacturing process. The use of a hydrophilic acrylate carries the risk of IOL calcification, especially when a secondary procedure, such as a pars plana vitrectomy or other procedures using gas or air, is performed. In secondary IOL calcification, there is a wide range of opacification patterns, which are usually located in the centre on the anterior surface of the IOL or sometimes elsewhere. Often, granular deposits accumulate just below or on the surface of the IOL, leading to significant deterioration in visual quality and eventually requiring IOL exchange surgery. Therefore, in the case of eyes requiring secondary surgical intraocular intervention in the future, the use of hydrophilic IOLs should be critically evaluated. With regard to hydrophobic IOL materials, there are clear differences in the susceptibility to the formation of glistenings. Over time, there has been a significant decrease in glistening formation over the past 30 years due to optimisation of the material. With hydrophobic IOLs, special care should also be taken to avoid mechanical damage. In general, the only treatment option for functionally-impairing IOL opacification is surgical lens exchange, which carries potential risks of complications. In cases with a low degree of functional impairment, and especially in eyes with additional ocular diseases, it may be difficult to weigh the risk of additional surgery against the potential benefit. In some cases, it may be more appropriate not to perform an IOL exchange despite the IOL opacification. Recent visualisation methods that allow high-resolution analysis of the opacities in vivo and in vitro may be used in the future to estimate the functional effects of various IOL material changes on the optical quality.
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Calcinosis , Lentes Intraoculares , Facoemulsificación , Humanos , Diagnóstico Diferencial , Implantación de Lentes Intraoculares , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Ojo Artificial/efectos adversos , Calcinosis/etiologíaRESUMEN
PURPOSE: The injection of high-viscosity silicone oil lengthens injection time. New polyimide cannulas offer a greater inner diameter than conventional metal cannulas at the same gauge. We compared the injection time for polyimide and metal cannulas at 23 G for a variety of silicone oils including a 12,500-mPas prototype oil. METHODS: In this laboratory study, injection time was measured three times per cannula and per oil. Warming the oil before injection to up to 42°C was also evaluated. Finally, the feasibility of polyimide cannulas was tested in vitrectomized porcine eyes. RESULTS: The 23-G polyimide cannula mostly decreased injection times. The time to inject 5 mL of Siluron Xtra and Siluron 5000 decreased by 6:02 (76.9%) minutes (483 vs. 121 seconds) and 12:01 (74.7%) minutes (973 vs. 252 seconds), respectively. Although the 23-G metal cannula failed to inject 12,500 mPas oil, 5 mL was injected in 10:21 minutes using the polyimide cannula. Prewarming Siluron 5000 to 42°C lowered the injection time by 9.0% and by 12.1% when using the metal or polyimide cannula, respectively. CONCLUSION: Polyimide cannulas allow a clinically relevant decrease in injection time. They may not only shorten surgery time but could also ease the use of next-generation ultra-high-viscosity silicone oils. Prewarming silicone oil leads to decreased injection times.
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Aceites de Silicona , Cirugía Vitreorretiniana , Cánula , Humanos , Tempo Operativo , ViscosidadRESUMEN
PURPOSE: Human photoreceptors are sensitive to infrared light (IR). This sensitivity can be used as a novel indicator of retinal function. Diabetic retinopathy patients were assessed using in vivo two-photon excitation and compared their scotopic IR threshold with that of healthy patients. METHODS: Sixty-two participants, 28 healthy and 34 with diabetic retinopathy, underwent a comprehensive eye examination, where visual acuity and contrast sensitivity were assessed. Infrared thresholds were measured in the fovea and parafovea following 30-minute dark adaptation. A two-photon excitation device was used with integrated pulsed laser light (1,045 nm) for sensitivity testing and scanning laser ophthalmoscopy for fundus imaging. RESULTS: The mean Snellen visual acuity of diabetic patients (6/7.7) was worse than that of the healthy patients (6/5.5), which was significantly different (P < 0.001). Disease patients had decreased contrast sensitivity, especially at 6 and 18 cycles/degree. The mean retinal sensitivity to IR light in eyes with diabetic retinopathy (11.6 ± 2.0 dB) was significantly (P < 0.001) lower than that in normal eyes (15.5 ± 1.3 dB). CONCLUSION: Compared with healthy control subjects, the IR light sensitivity of diabetic patients was significantly impaired. Two-photon measurements can be used in the assessment of retinal disease, but further studies are needed to validate IR light stimulation in various stages of diabetic retinopathy.
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Adaptación a la Oscuridad/fisiología , Retinopatía Diabética/fisiopatología , Rayos Infrarrojos , Fotofobia/fisiopatología , Células Fotorreceptoras/fisiología , Agudeza Visual , Retinopatía Diabética/diagnóstico , Femenino , Fóvea Central/diagnóstico por imagen , Fóvea Central/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Oftalmoscopía/métodos , Fotofobia/diagnóstico , Proyectos Piloto , Pruebas del Campo Visual/métodosRESUMEN
BACKGROUND: To assess the optical behavior of a new diffractive intraocular lens (IOL) and compare its performance to that of an established extended-depth-of-focus (EDOF) IOL. METHODS: This study assessed the Proming EDOF Multifocal AM2UX [Eyebright Medical Technology (Beijing) Co., Ltd., China] and the AT LARA 829MP [Carl Zeiss Meditec, Germany]. An experimental set-up with 0.01% fluorescein solution and monochromatic light (532 nm) was used to visualize the IOLs' ray propagation. In addition, the optical quality of the IOLs was assessed by measuring the modulation transfer function (MTF) values at 50lp/mm and 3.0 and 4.5 mm apertures on the optical bench OptiSpheric® IOL PRO II [Trioptics GmbH, Germany]. RESULTS: The ray propagation of the two IOLs showed two distinct foci. Light intensity assessment revealed that both IOLs allocate more energy to primary than secondary focus. At 3.0 mm pupil, the MTF values at 50lp/mm for the primary focus were 0.39 and 0.37, and for the secondary focus, 0.29 and 0.26 for the AT LARA and Proming IOLs, respectively. At 4.5 mm pupil, the single-frequency MTF for the primary focus was 0.51 and 0.24 and for the secondary focus 0.21 and 0.15 for the AT LARA and Proming IOLs, respectively. CONCLUSIONS: When tested with an aberration-free model cornea under monochromatic conditions, the Proming behaved as a low-add bifocal lens; however, its properties did not differ much from the well-established AT LARA EDOF IOL. The AT LARA outperformed the Proming at low defocus (up to 2D), while the latter demonstrated better image quality in the 2-3D range.