Pseudophakic corneal edema caused by Descemet membrane detachment using high-resolution swept-source OCT imaging.

Background: Small Descemet membrane detachments after cataract surgery are relatively common and most cases do not require any secondary surgical intervention and can be treated conservatively. However, in case of advanced Descemet membrane detachment (DMD), it needs to be recognized and treated appropriately. The advent of anterior segment imaging using optical coherence tomography (OCT) technology has made diagnosing pathologies of the anterior segment accurate and time efficient and has proven as an invaluable tool to guide decision making. Case presentation: A 71-year-old patient presented after complicated cataract surgery with decreased visual acuity and cloudy vision. On examination, best corrected visual acuity was 1.5 logMAR. A high-resolution swept-source OCT (Anterion, Heidelberg Engineering, Heidelberg, Germany) was used to better evaluate and visualize the extent of DMD. An anterior chamber gas bubble was injected to reattach the Descemet membrane (DM) to the corneal stroma. The success of the surgery was visualized using the high-resolution swept-source OCT. This revealed a completely attached Descemet membrane. Conclusions: Clinically, it can be difficult to distinguish the etiology of epithelial and stromal edema post cataract surgery. This case demonstrated the clinical usefulness using high resolution swept source imaging to guide clinical decision making in evaluating timing and treatment success of pneumodescemetopexy after complicated cataract surgery.

Through-focus performance and off-axis effects in aspheric monofocal intraocular lenses.

This study aimed to determine the through-focus performance and the effect of misalignment on the optical quality of different aspheric monofocal intraocular lenses (IOLs). To this end, optical quality was assessed in three IOL models with different optic surfaces: standard aberration neutral model and two spherical aberration (SA) correcting, one of which utilizes higher-order aspheric terms. The optical quality was measured by means of the modulation transfer function at 3- and 4.5-mm pupils and under monochromatic and polychromatic light with different corneal SA. The optically derived range of vision and tolerance to misalignment were also tested. The study demonstrated that the type of IOL surface affects the monofocal implant's performance. Although a standard primary-SA correction may improve scotopic image quality, misalignment may diminish this advantage. The higher-order aspheric surface used to correct SA provided an improved performance against decentration and offered a higher optical quality than the aberration-neutral design when tested in a model eye. The latter, however, demonstrated a high tolerance to misalignment, offering a slight extension of the range of vision, potentially resulting from uncorrected optical aberrations.

Polypseudophakia: from "Piggyback" to supplementary sulcus-fixated IOLs.

Polypseudophakia, the concept of using a second intraocular lens (IOL) to supplement an IOL that has already been placed in the capsular bag, was first used as a corrective measure where the power requirement was higher than that of available single IOLs. Subsequently, the technique was modified to compensate for post-operative residual refractive errors. In these early cases, an IOL designed for the capsular bag would be implanted in the sulcus.  Although these approaches were less than ideal, alternative means of correcting residual refractive errors were not without their limitations: IOL exchange can be traumatic to the eye and is not easily carried out once fibrosis has occurred, while corneal refractive surgical techniques are not suitable for all patients. Piggyback implantation was the term first coined to describe the use of two IOLs, placed together in the capsular bag. The term was later extended to include the procedure where an IOL designed for the capsular bag was placed in the sulcus. Unfortunately, the term piggyback has persisted even though these two approaches have been largely discredited. Intraocular lenses are now available which have been specifically designed for placement in the ciliary sulcus. As these newer IOLs avoid the many unacceptable complications brought about by both types of earlier piggyback implantation, it is time to employ a new terminology, such as supplementary IOL or secondary enhancement to distinguish between the placement of an unsuitable capsular bag IOL in the sulcus and the implantation of an IOL specifically designed for ciliary sulcus implantation. In addition to minimising possible complications, supplementary IOLs designed for the sulcus have expanded the options available to the ophthalmic surgeon. With these new IOLs it is possible to correct presbyopia and residual astigmatism, and to provide temporary correction of refractive errors in growing, or unstable, eyes. This article aims to review the literature available on supplementary IOL implantation in the ciliary sulcus and to summarise the evidence for the efficacy and safety of this intervention. KEY MESSAGES: What is known Polypseudophakia has been used for over 30 years to correct hyperopia or residual refractive error, but early techniques were associated with significant complications. What is new The development of specially designed sulcus-fixated supplementary IOLs significantly reduces the risks associated with these procedures, and has also opened up new opportunities in patient care. The reversibility of the procedure allows patients to experience multifocality, and to provide temporary and adjustable correction in unstable or growing eyes. The terms "secondary enhancement" or "DUET" to describe supplementary IOL implantation are preferential to "piggyback".

Functional Outcomes After Refractive Lens Exchange With Implantation of a Glistening-Free Diffractive Trifocal Intraocular Lens.

PURPOSE: To evaluate visual outcomes and patient-reported results after bilateral femtosecond-laser-assisted refractive lens exchange (RLE) with the implantation of a diffractive trifocal intraocular lens. DESIGN: Prospective interventional case series. METHODS: A study of 27 patients (54 eyes) implanted with the Clareon PanOptix (Alcon) multifocal intraocular lens during femtosecond-laser-assisted RLE in a university hospital setting. The uncorrected (UDVA) and corrected (CDVA) distance visual acuity, uncorrected (UIVA) and distance-corrected (DCIVA) intermediate visual acuity at 60 cm, uncorrected (UNVA) and distance-corrected (DCNVA) near visual acuity at 40 and 33 cm were evaluated at 3 months postoperatively and compared with the preoperative values. In addition, we assessed the postoperative defocus curve, mesopic and photopic contrast sensitivity, and patient-reported spectacle independence. RESULTS: The mean postoperative binocular UDVA was -0.02 ± 0.06 logMAR and CDVA was -0.11 ± 0.05 logMAR. The UIVA was -0.07 ± 0.05 logMAR and DCIVA was -0.07 ± 0.07 logMAR. The UNVA at 40 cm was 0.03 ± 0.09 logMAR and DCNVA was -0.02 ±â€¯0.06 logMAR; and, at 33 cm UNVA was 0.14 ± 0.10 logMAR and DCNVA was 0.11 ± 0.08 logMAR. In comparison to the preoperative binocular CDVA (-0.12 ± 0.08 logMAR), no statistically significant change was observed (P = 1.0), while all the other binocular visual acuities improved (P < .01). In the mean binocular defocus curve, the visual acuity was better than 0.10 logMAR in the range between +0.5 D and -3.0 D. The mean contrast sensitivity was within the normal range, and most patients reported complete spectacle independence. CONCLUSIONS: The RLE surgery improved uncorrected visual acuity at far, intermediate, and near distances without negatively affecting the CDVA. Patients achieved a high level of spectacle independence.

[Correction of aphakia in cases of insufficient capsular bag stability]. / Aphakiekorrektur bei unzureichender Kapselsackstabilität.

A variety of situations can lead to the need for an alternative method of intraocular lens (IOL) fixation if implantation in the capsular bag is not possible. Depending on the situation, sulcus-fixated IOLs, iris-fixated IOLs (IFIOLs) and scleral-fixated IOLs (SFIOLs) are available. With SFIOLs, a distinction is made between suture-fixated and sutureless-fixated techniques. This paper summarizes the advantages and disadvantages of the different approaches, including the newer methods of sutureless SFIOLs. The decision on a specific approach in the individual case depends on both the individual circumstances of the patient and the experience of the surgeon.

Refractive Lens Exchange: A Review.

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.

Anterior Segment Complications Following Intravitreal Injection.

Intravitreal injections (IVI s) have gained increased popularity in the past decades and are used to treat a multitude of ailments. In 2010, the total number of IVI s 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, IVI s 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 IVI s can also have long-term complications, a topic that needs to be explored further in future research projects.

Characterisation of Intraocular Lens Injectors.

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.

Vertical implantable collamer lens as a novel method to increase rotational stability.

PURPOSE: We investigated the vertical implantation of a toric implantable collamer lens (ICL) and compared the rotational stability with that of horizontal implantation. METHODS: This matched comparative study retrospectively reviewed and analyzed data from patients who underwent ICL implantation from 2003-2022 by 1:1 matching vertical and horizontal (V and H toric groups, respectively) implantation patients according to preoperative astigmatism, spherical equivalent, sulcus-to-sulcus, anterior chamber depth, and ICL size. Visual acuity, manifest refraction, vaulting, and rotation were measured 3 months postoperatively. RESULTS: We included 646 eyes (323 each in the V and H toric groups). No statistically significant difference was observed between groups in postoperative visual acuity, refractive error, and astigmatism. Vaulting was lower in the V toric group. (P < 0.001). The mean lens rotation in the V toric group was less than that in the H toric group (1.11 ± 2.84° versus 3.02 ± 10.34°, P = 0.001). The proportion of eyes in the V and H toric groups showing ≥10° of rotation was 2.5% (8 eyes) and 6.5% (21 eyes), respectively (P = 0.014). Despite repositioning from rotation, three (0.9%) and eight (2.5%) eyes required removal owing to lens re-rotation in the V and H toric groups, respectively. CONCLUSION: Toric ICL vertical implantation showed good rotational stability, and appropriate visual acuity correction results with relatively low vaulting. This procedure therefore presents an effective novel method that could replace horizontal toric ICL implantation.

Corneal High-Order Aberrations in Fuchs Endothelial Corneal Dystrophy and Subclinical Corneal Edema.

PURPOSE: High-order aberrations (HOAs) are known to be increased in corneas with Fuchs endothelial dystrophy (FECD) and are associated with visual impairment. This case series aimed to analyze whether tomographic changes in FECD affect the HOA in the early period of the disease. METHODS: In this retrospective single-center case series, 144 eyes of 85 patients were included, of which 78 eyes of 47 patients with FECD with slit-lamp biomicroscopically visible guttae but no visible corneal edema served as the study-cohort. According to Sun et al, included eyes were divided into 2 groups: group 0 (n = 28; no subclinical corneal edema) and group 1 (n = 50; subclinical corneal edema). A total of 66 healthy eyes of 38 patients served as control group. Mean values and standard deviations were calculated for the root mean square (RMS), coma, trefoil and spherical aberrations (SA) of the cornea (C), the anterior surface (CF), and the posterior surface (CB). RESULTS: Statistically significant differences (P < 0.001) in the RMS HOA (group 0: 0.209 ± 0.044 µm, group 1: 0.372 ± 0.122 µm) and in coma (group 0: 0.082 ± 0.054 µm, group 1: 0.214 ± 0.101 µm) and SA (group 0: -0.130 ± 0.038 µm, group 1: -0.176 ± 0.074 µm) of the CB were found in eyes in group 1 versus those in group 0. There were no statistically significant differences in HOA between the control group and eyes in group 0. CONCLUSIONS: FECD eyes with subclinical corneal edema demonstrated significant increase in RMS, coma, and SA of the CB. Tomographic analysis, therefore, helps in visual impairment assessment, disease progression, and decision-making for early endothelial keratoplasty in patients with FECD.

Inter-zonal epithelial thickness differences for early keratoconus detection using optical coherence tomography.

PURPOSE: To develop and test a parameter for early keratoconus screening by quantifying the localized epithelial thickness differences in keratoconic eyes. METHODS: The cross-sectional study included 189 eyes of 116 subjects in total: 86 eyes of 54 keratoconus patients with bilateral ectasia and 40 eyes of 20 healthy subjects in the parameter-development dataset and 42 eyes of 21 keratoconus patients with asymmetric ectasia and 21 eyes of 21 healthy subjects in the parameter-validation dataset. Epithelial thickness maps were obtained using anterior segment optical coherence tomography and the inter-zonal epithelial thickness differences were calculated. The developed parameter was tested in keratoconus patients with asymmetric ectasia. RESULTS: Compared to healthy controls, the inferior-temporal and global inter-zonal epithelial thickness differences were higher not only in eyes with tomographically significant keratoconus (median [interquartile range] of 4.42 [3.13] µm vs. 0.78 [0.42] µm, p < 0.001, and 3.05 [1.51] µm vs. 1.07 [0.26] µm, p < 0.001, respectively), but also in tomographically normal keratoconus fellow eyes (1.36 [0.85] µm vs. 0.78 [0.42] µm, p = 0.005, and 1.31 [0.32] µm vs. 1.07 [0.26] µm, p = 0.01, respectively). The inferior-temporal inter-zonal epithelial thickness differences had an area under the receiver operating characteristic curve (95% confidence interval) of 0.991 (0.972-1) for detecting tomographically significant keratoconus and 0.749 (0.598-0.901) for differentiating between tomographically normal keratoconus fellow eyes and healthy controls. CONCLUSIONS: The inter-zonal epithelial thickness differences are increased in keratoconus fellow eyes which still have a normal Scheimpflug corneal tomography, and therefore may serve as a useful parameter to detect early ectatic changes.

[Complex optical systems for individualized correction of presbyopia]. / Komplexe Optiksysteme für eine individualisierte Presbyopiekorrektur.

A multitude of available intraocular lens (IOL) models enable a personalized approach to presbyopia correction in order to meet each patient's needs. This review article discusses more complex approaches which can be useful in selected cases. The concept of reversible trifocality enables correction of presbyopia using a supplementary intraocular lens (IOL), which can be removed if necessary (e.g., intolerance to multifocal optics). The use of capsulotomy-fixated IOLs enables high precision for positioning of the lens and better stability compared to conventional capsular bag-fixated IOLs, which can be particularly advantageous in multifocal optics. The mix and match concept enables a combination of different IOLs with various optical principles to achieve the desired binocular effect. Binocular IOL systems, which consist of two complementary IOLs, can be seen as a further development of the mix and match concept. Knowledge of the available options and their application can further improve correction of presbyopia.

[Optical benchtop evaluation of special intraocular lens optics]. / Optische Bank-Evaluierung für spezielle Intraokularlinsenoptiken.

Intraocular lenses (IOL) featuring complex optical designs can pose a challenge in understanding their performance, which may hinder making an informed decision when selecting suitable lenses for patients. This underlines the importance of collecting optical quality data of IOLs and making them available. The deployment of benchtop systems for IOL testing offers not only insights into the design features of various IOL solutions but also provides a platform for objective comparisons of special optics designs, including information about their susceptibility to photic phenomena. Recent advances in IOL testing have improved the ability to predict functional effects on visual acuity and contrast sensitivity from objective optical quality metrics. This, for instance, can be used to study monofocal lenses and the impact of asphericity on vision and IOLs tolerance to misalignment. Monofocal-plus IOLs consistently show only a slight improvement in the depth of focus when tested on the optical bench and in clinical settings. Although the pupil dependence found in this technology may limit the advantages of monofocal-plus over standard monofocal technology to extend the range of vision, it is the key to reduce photic phenomena. Refractive and diffractive extended depth of focus (EDOF) IOLs can effectively enhance intermediate vision, with the latter offering a slightly broader depth of focus but potentially increasing the risk of dysphotopsia. However, the limitation of EDOF IOLs is that they often fail to deliver spectacle independence for reading, which can be overcome by trifocal technology. Still, the available trifocal IOLs differ in their location of intermediate and near foci and the susceptibility to produce glare effects. Therefore, the knowledge from optical benchtop testing of IOLs can support optimizing the IOL selection by aligning the patient's visual needs with the IOL's properties, setting the right expectations, and assessing the risk profile for the occurrence of photic phenomena, potentially leading to improved decision-making.

[Overview of intraocular lenses with optics for correcting presbyopia]. / Übersicht über Intraokularlinsen mit Presbyopie-korrigierenden Optiken.

BACKGROUND: In recent years intraocular lenses (IOLs) for correcting presbyopia have been significantly improved and diversified. There are currently many different IOL models based on a wide variety of optical designs. OBJECTIVE: The wide variety of available IOL solutions to correct presbyopia can be challenging for surgeons and patients. In everyday practice, the question is which IOL is best for which patient. MATERIAL AND METHODS: This overview describes and categorizes the currently available implants. The respective optical properties are analyzed and clinical study results are discussed, in particular those evaluating visual performance and the occurrence of photic phenomena. RESULTS: Monofocal-plus IOLs provide improved intermediate visual acuity with optimal distant visual acuity and minimal photic phenomena. Extended depth of field (EDoF) IOLs extend the depth of field through different optical principles and provide good distant and intermediate visual acuity. Trifocal lenses enable the greatest independence from spectacles at the price of a higher probability of dysphotopsia. CONCLUSION: The selection of the most suitable IOL for correction of presbyopia requires a balance between the patient's visual needs and possible side effects. An adequate knowledge of the currently available implants allows a patient-oriented selection of IOLs.

Biomechanical changes following corneal crosslinking in keratoconus patients.

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.

Intraocular lens calcification in a patient with Ehlers-Danlos syndrome.

Introduction: Calcification of hydrophilic intraocular lenses (IOL) is a rare complication following cataract surgery. Secondary calcification is described as due to host factors or changes in the IOL environment and uveitis, proliferative diabetic retinopathy and sequelae of ocular surgery are recognised potentiators. The impact of systemic connective tissue disease on IOL opacification is yet to described. Purpose: To describe the clinical presentation and management of a young patient, with a rare subtype of Ehlers-Danlos syndrome, who presented with secondary IOL calcification 14 years after primary IOL insertion. Observations: Floret-like lesions were observed on the IOL surface. Positive staining for calcification was observed with Alizarin red and von Kossa method on laboratory analysis. Conclusions and importance: Patients with systemic connective tissue disease, such as a subtype of Ehlers-Danlos, may present with secondary IOL calcification many years after primary lens insertion. This poses an additional consideration when implanting IOLs in these patients.Good visual acuity can be achieved with IOL exchange.