3D Mapping of the DMEK Detachment Area from OCT Scans of the Anterior Segment of the Eye - Clinical Applications. / 3D-Kartierung der DMEK-Abhebungsfläche aus OCT-Scans des vorderen Augensegmentes mit klinischen Anwendungen.

Graft detachment is the most common complication after Descemet membrane endothelial keratoplasty (DMEK). To assess the amount of graft detachment, precision is limited when using slit-lamp biomicroscopy. Detachment of DMEK grafts can be assessed automatically on anterior segment optical coherence tomography (AS OCT) images and allows visualization of the area and volume of detachment using 3D maps. This article provides an overview of its applications such as accurately assessing the course of natural graft attachment, identification of potential risk factors for detachment and evaluation of the long-term effect of graft detachment. The 3D map of DMEK detachment may support researchers and clinicians in precise quantification of the area and volume of graft detachment even in large data sets, and the intuitive, fast and reliable evaluation.

Comparison of Pre- and Post-DMEK Keratometry and Total Keratometry Values for IOL Power Calculations in Eyes Undergoing Triple DMEK.

PURPOSE: To evaluate prediction accuracy of pre- and post-DMEK keratometry (K) and total keratometry (TK) values for IOL power calculations in Fuchs endothelial corneal dystrophy (FECD) eyes undergoing DMEK with cataract surgery (triple DMEK). METHODS: Retrospective cross-sectional multicenter study of 55 FECD eyes (44 patients) that underwent triple DMEK between 2019 and 2022 between two centers in USA and Europe. Swept-source optical coherence tomography biometry (IOLMaster 700) was used for pre- and post-DMEK measurements. K and TK values were used for power calculations with ten formulae (Barrett Universal II (BUII), Castrop, Cooke K6, EVO 2.0, Haigis, Hoffer Q, Hoffer QST, Holladay I, Kane, and SRK/T). Mean error, mean absolute error (MAE), standard deviation, and percentage of eyes within ±0.50/±1.00 diopters (D) were calculated. Studied formulae were additionally adjusted using a method published previously (IOLup1D Method), which increases the IOL power by 1D. While both eyes from the same patient were considered for descriptive statistics, we restricted to one eye per individual (44 eyes for statistical comparisons. RESULTS: MAEs for all formulae were lower for post-DMEK K and TK than pre-DMEK K and TK by an average of 0.24 and 0.47 D, respectively. The lowest MAE was 0.49 D for Kane using post-DMEK TK, and the highest MAE was 1.05 D for BUII using pre-DMEK TK. Most IOLup1D formulae had lower MAEs than pre-DMEK K and TK formulae. CONCLUSIONS: The IOLup1D Method should be used instead of pre-DMEK K and TK values for triple DMEK in FECD eyes. Using post-DMEK TK values for cataract surgery after DMEK provides better refractive accuracy than any of the three studied methods used for triple DMEK procedures.

Supine Positioning for Graft Attachment After Descemet Membrane Endothelial Keratoplasty: A Randomized Controlled Trial.

PURPOSE: The Supine Positioning for Descemet Membrane Endothelial Keratoplasty Attachment (SUPER-DMEK) trial assessed the efficacy of prolonged supine head positioning on graft attachment. DESIGN: Randomized controlled trial. METHODS: Participants with Fuchs' dystrophy were randomized to 5 days of supine head positioning (intervention) or to 1 day (control). Participants, surgeons, and investigators were masked until the day after surgery. Adherence to the allocated intervention was monitored using a head sensor. Main outcome measures were area and volume of graft detachment (coprimary end points) 2 weeks after surgery quantified using a validated neural network for image segmentation on anterior segment optical coherence tomography images, and repeat air injection (rebubbling), subjective visual function, and adverse events (secondary end points). RESULTS: A total of 86 participants received the allocated intervention (35 eyes intervention and 51 eyes control). In the intention-to-treat analysis, the mean area of graft detachment was 28.6% in the intervention arm and 27.5% in the control arm (adjusted between-arm difference, 1.3; 95% CI, -8.7 to 11.4; P = .80). Results for volume of detachment and as-treated analyses based on head position sensor data indicated no potentially clinically relevant effect of prolonged supine positioning on graft attachment. Results were not compatible with a relevant treatment effect on rebubbling or subjective visual function. Adverse events, most commonly back pain, were more common and more severe with the intervention. CONCLUSIONS: In this randomized controlled trial, graft attachment was not improved with prolonged supine head positioning. Prolonged supine positioning frequently caused back pain. Prolonged supine positioning after Descemet membrane endothelial keratoplasty for Fuchs' dystrophy may not be needed in routine practice.

Indications, techniques, and graft survival of mini and corneo-scleral tectonic keratoplasties: A retrospective single-center case series.

PURPOSE: Tectonic keratoplasties (TK) are used to treat corneal and scleral perforations and to prevent the loss of the eye. In this study, we retrospectively analyzed indications, surgical procedures, and outcomes of eccentric mini and corneo-scleral tectonic keratoplasties with respect to anatomical survival and clear graft survival rates to identify risk factors for graft failure. METHODS: This retrospective study includes 33 eccentric mini (graft diameter <6 mm) and/or corneo-scleral TK of 32 consecutive patients of a total of 41 TK carried out between 2005 and 2020 in the Eye Center, University of Freiburg, Germany, making up 0.7% of all keratoplasties performed during this period (n = 5557). Patient and graft specific data were extracted from medical files. Anatomical survival-defined as achieving integrity of the globe without further surgical interventions-and clear graft survival-defined as persisting graft clarity-were estimated using the Kaplan-Meier method. We also fitted Cox proportional hazard models to account for factors influencing anatomical and clear graft survival. RESULTS: Median duration of anatomical success was 72.5 months (95% confidence interval (CI) 18.1-infinite (inf.)) and median duration of clear graft survival was 29.6 months (95% CI 12.5-Inf.). The 1-year survival rate for anatomical survival was 67.6% (95% CI 52.2% - 87.6%) and for clear graft survival 66.4% (95% CI 50.5%- 87.1%). No enucleation was necessary during this time-period. Non-inflammatory primary causes (n = 14) presented a trend towards better anatomical survival rates (median remained above 0.75 during follow-up) compared to inflammatory primary causes (n = 19, median 18.1 months (95% CI 2.8 - inf.)) and longer clear graft survival (median 29.6 months (95% CI 12.5 - inf.) versus 13.1 months (95% CI 3.2 - inf.)). Corneo-scleral grafts (n = 18) compared to corneal grafts (n = 15) showed a trend towards better anatomical survival (more than 50% of eyes did not fail during follow-up period (95% CI 21.9-Inf. months) versus 18.1 months (95% CI 2.4-Inf.)) and clear graft survival (median 29.6 months (95% CI 12.6-Inf.) versus 6.2 months (95% CI 2.8-Inf.)). Old age (n = 11, 75.2 - 90.1 years) compared to young age (n = 11, 6.2 - 60.2 years) was the only hazard ratio (hazard ratio 0.04 (95% CI 0.002-0.8)) that reached the level of significance (p = 0.03). CONCLUSION: Eccentric TK is helpful in the successful treatment of a variety of severe eye diseases. Patients at young age, with pre-existing inflammatory conditions or corneal TK are at higher risk for anatomical failure as well as clear graft failure and therefore need to be monitored closely.

Needs and Satisfaction Analysis of Patients and Referring Physicians in an Outpatient Cataract Service. / Bedarfs- und Zufriedenheitsanalyse von Patienten und Zuweisenden eines ambulanten Kataraktangebots.

BACKGROUND: To ensure efficient use of resources within outpatient services, constant patient flow is vital. This can be achieved by addressing the wishes and needs of all relevant stakeholders. MATERIALS AND METHODS: The present study aims to show how the needs and present satisfaction of patients and referring physicians can be determined in the context of an outpatient cataract service. It presents the conclusions that can be drawn for the design of the service. To assess needs and satisfaction, we developed a patient questionnaire and a referring physician questionnaire. Promoters and detractors for referral were identified following the concept of the net promoter score, a market research instrument. RESULTS: 339 (38%) patients and 26 (45%) referring physicians of the main referring group answered the questionnaires. The most important characteristics for referring physicians were quality of treatment, patient satisfaction, and communication in case of queries as well as speed of sending the doctor's letter. When making their decision on a cataract centre, the patients prioritised professional reputation, previous experience with the clinic, and recommendation of their ophthalmologist as well as customary appointment scheduling. CONCLUSION: The two groups influence each other's recommendation or choice. Simultaneous analysis of patients and referring physicians is therefore essential. Overall, patients and referring physicians are highly satisfied with the cataract service of the university medical centre. Beyond that, however, various potentials for improvement could be identified. In summary, this report describes a comprehensive approach to assess needs and satisfaction of patients and referring physicians in an outpatient clinic trying to sustainably improve patient care.

[Training concept for personnel in a university outpatient clinic: development and evaluation of a structured introductory training concept]. / Einarbeitungskonzept für Mitarbeiter:innen einer Hochschulambulanz: Entwicklung und Evaluation eines strukturierten Einarbeitungskonzeptes.

BACKGROUND: The training of new employees is crucial for effective interaction and commitment to the company. OBJECTIVE: Development and evaluation of a structured induction into the process flows of a university outpatient clinic. MATERIAL AND METHODS: We developed and tested a two-stage model for getting to know staff, premises, nursing and medical process flows, and learning examination techniques: Participants went through all stages of an outpatient clinic visit as fictitious patients and subsequently evaluated learning success by self-assessment of general (process-related) and specific (examination-related) competencies in writing and in a feedback interview. RESULTS: In this study, 11 residents, 8 operating room nursing staff, and 6 students underwent the training program. The self-assessed level of competence before and after the run-through as well as the extent of the increase in competence varied depending on the stage and professional group. Residents and students experienced a specific increase in general competences (both 98%; nursing personnel 64%). Specific competence gains for residents were particularly evident in becoming familiar with important process-related interfaces between the occupational groups, in software and examination techniques, and in improved orientation in the outpatient clinic (competence gain at 83% of stages). Operating room nursing staff benefited most from improved communication with staff. CONCLUSION: An increase in general competence can be achieved by a structured training with little time expenditure for different professional groups and facilitates, especially the start for new residents. For maximum specific competence gain, an outpatient clinic run tailored to the employee's field of activity seems desirable.

Cataract Surgery-Indications, Techniques, and Intraocular Lens Selection.

BACKGROUND: Opacification of the lens of the eye (cataract) is usually due to aging. It is a painless, progressive condition that affects contrast and color perception and alters refraction, leading to visual loss that may be total. In cataract surgery, the turbid lens is replaced by an artificial lens. An estimated 600 000 to 800 000 such procedures are performed in Germany each year. METHODS: This review is based on pertinent publications retrieved by a selective search in PubMed, including meta-analyses, Cochrane reviews, and randomized controlled clinical trials (RCTs). RESULTS: Cataract is the most common reversible cause of blindness around the world (approximately 95 million people). The surgical replacement of a turbid lens with an artificial lens is usually carried out under local anesthesia. The standard technique for fragmentation of the nucleus of the lens is ultrasonic phacoemulsification. RCTs have not shown the superiority of the femtosecond laser over phacoemulsification for this purpose so far. The spectrum of artificial intraocular lenses, aside from the conventional type with a single focus, include lenses with multiple foci, extended-depth-of-focus (EDOF) lenses, and astigmatism-correcting lenses. CONCLUSION: In Germany, cataract surgery is usually performed on an outpatient basis under local anesthesia. Artificial lenses with various additional functions are available nowadays; the choice of lens depends on the needs of the individual patient. Patients must be adequately informed about the advantages and disadvantages of the different lens systems.

Long-Term Outcomes of Excimer Laser-Assisted Penetrating Keratoplasty Using a Commercially Available Laser System - A Retrospective Case Series.

BACKGROUND: Favorable functional outcomes have been reported after excimer laser-assisted penetrating keratoplasty (EXL PKP). But this technique has not been widely adopted, and there are reports on EXL PKP from only a very limited number of institutions. Some of these results refer to operations carried out with laser systems that are not commercially available. In this retrospective case series, we report the long-term outcome of EXL PKP using the Schwind Amaris 500E laser system. MATERIAL AND METHODS: This retrospective consecutive case series included 30 eyes of 29 patients who had undergone EXL PKP between 2010 and 2013. Primary outcome measures were topographic astigmatism and visual acuity. Secondary outcome measures were the rates of graft rejection and graft failure, and the rate of grafts with an endothelial cell density below 500 cells/mm2. Survival analyses were carried out for the following endpoints: visual acuity, rate of graft rejection, and rate of grafts with endothelial cell densities higher than 500 cells/mm2. RESULTS: The median interquartile range (IQR) duration of follow-up was 45 (36) months. The indications for PKP were keratoconus (n = 21), corneal scarring (n = 6), Fuchs endothelial dystrophy (n = 1), and corneal dystrophy other than Fuchs endothelial dystrophy (n = 2). The median (IQR) topographic astigmatism at the end of the follow-up period was 5.3 (2.9) D. Forty-five months after surgery, 73% of all eyes had a visual acuity better than 0.3 LogMAR. The rate of graft rejection after 45 months of follow-up was 32%. All eyes maintained endothelial cell densities higher than 500 cells/mm2. There was no graft failure. CONCLUSIONS: EXL PKP is a safe and effective surgical procedure. No general conclusions can be drawn on the refractive outcome of EXL PKP. Potential advantages, such as a higher degree of graft-host congruity, that could possibly improve the refractive outcome should be weighed against the higher costs of EXL PKP.

Diurnal Variation in Straylight in Patients With Fuchs Endothelial Corneal Dystrophy and Controls.

PURPOSE: The goal of this study was to investigate diurnal changes in intraocular straylight in relation to other corneal parameters and subjective complaints in patients with Fuchs endothelial dystrophy and healthy controls. METHODS: This is a prospective study conducted in 2 tertiary care hospitals in Germany and the Netherlands. Patients with Fuchs endothelial dystrophy (n = 71) and healthy controls (n = 34) were included. Patients with Fuchs dystrophy were grouped by the presence of subjective complaints and measured over multiple time points during the day. Measurements included intraocular straylight using the C-Quant and corneal thickness and backscatter using a Scheimpflug camera. A separate group of healthy controls was measured intensively with repeated straylight measurements directly after waking. An exponential decay model was used to model the diurnal change. RESULTS: Healthy controls showed an average straylight baseline of 1.17 log(s) with an increase in straylight after waking of 0.22 log(s). In the repeated measurements subgroup, the increase in morning straylight lasted for 22 minutes. Patients with Fuchs dystrophy showed a morning increase in straylight of 0.21 log(s) present up to 4 hours after waking before reaching an average baseline of 1.30 log(s). Straylight was positively correlated with anterior corneal backscatter, r = 0.21, P = 0.022, and corneal thickness, r = 0.46, P < 0.01. CONCLUSIONS: Healthy eyes experience a diurnal straylight increase similar to patients with Fuchs dystrophy in intensity. However, in Fuchs dystrophy, the resolution of increased straylight is prolonged over multiple hours compared with minutes in healthy eyes. This suggests pathological exacerbation of a physiological diurnal change. This mechanism can play a role in subjective complaints experienced by patients with Fuchs dystrophy.

[The economic importance of individual health services (IGeL) in ophthalmology over time: survey results from 2010 and 2020]. / Die wirtschaftliche Bedeutung von Individuellen Gesundheitsleistungen (IGeL) in der Augenheilkunde über die Zeit: Umfrageergebnisse aus 2010 und 2020.

BACKGROUND: Individual health services (IGeL) enable patients to receive medical services not covered by social health care; however, there is no central data collection on IGeL in Germany. OBJECTIVE: This study illustrates the spectrum of IGeL provided in the field of ophthalmology as an example of the importance of IGeL in Germany based on survey results. MATERIAL AND METHODS: Nationwide, 10% of ophthalmologists in private practice were randomly selected in this anonymous survey in 2010 and 2020 while in 2020 in addition to the randomized 10% of ophthalmologists the same ophthalmologists from 2010 were contacted. By means of a written questionnaire, ophthalmologists were asked about their practice structure, total revenue from IGeL as well as the frequency and price of specific IGeL. RESULTS: Income from IGeL was estimated at an average of 21% of the regular service volume in 2010 and 23% in 2020. Glaucoma IGeL and medical report IGeL were offered by almost all ophthalmologists and glaucoma screening being performed most frequently with an average frequency of over 150 examinations/month. IGeL, such as HRT IGeL were offered by significantly fewer ophthalmologists in 2020 than in 2010, while IGeL based on other technological procedures such as glaucoma OCT were offered more frequently in 2020. CONCLUSION: The volume of IGeL provided in established ophthalmological practices was stable between 2010 and 2020. The range of services offered in 2020 compared to 2010 reflects a dynamic change associated with the entry of new technologies into routine care.

[Corneal endothelial cell photography: comparison of smartphones]. / Korneale Endothelzellfotografie: Vergleich von Smartphones.

BACKGROUND: The documentation of ophthalmologic findings using smartphone photography can confirm diagnoses and enable follow-up assessments in outpatient care. Photographing corneal endothelial cells using a smartphone on a slit lamp is complex for both smartphone and examiner. Smartphone models differ in their ability to quickly and safely take images of the corneal endothelium. AIM OF THIS WORK: In this paper different smartphone models are presented with respect to their applicability for corneal endothelial cell photography and success factors for good smartphone imaging are described. MATERIAL AND METHODS: In a cross-sectional study, a selection of 16 different smartphone models were compared with respect to their use in corneal endothelial cell photography. The smartphones were attached to the slit lamp eyepiece using an adjustable adapter. It was tested whether high-quality endothelial cell images of healthy subjects could be obtained within 3 min using the standard photo app of the respective smartphone. In addition, the subjective difficulty of creating the image was recorded. Factors contributing to successful imaging of corneal endothelial cells were summarized in a figure. RESULTS AND DISCUSSION: Distinct differences regarding feasibility and quality of endothelial cell photography were detected between the different smartphones. Not every smartphone is suitable for endothelial cell photography.

Graft Detachment after Descemet Membrane Endothelial Keratoplasty with and without Cataract Surgery.

Purpose: To evaluate graft detachment after Descemet membrane endothelial keratoplasty (DMEK) in pseudophakic eyes and DMEK combined with cataract surgery (triple DMEK). Design: Analysis of 3 single-center prospective cohort studies and 1 randomized controlled trial. Participants: Participants with Fuchs' endothelial corneal dystrophy. Methods: A validated neural network for image segmentation quantified graft detachment on anterior segment OCT (AS-OCT) images 3 days after DMEK and at the 2-week postoperative visit. Area and volume of graft detachment were compared between DMEK only and triple DMEK using generalized estimating equation models and adjusting for participant age and the size of the air bubble. Main Outcome Measures: Area and volume of DMEK graft detachment. Results: Among 207 participants with 270 eyes included, 75 pseudophakic eyes had DMEK only and 195 eyes had triple DMEK. A total of 147 eyes had less than one third of detachment at day 3. In 139 of these eyes (95%), detachment was still less than one third at the 2-week scan, indicating that postoperative graft detachment at 2 weeks occurred mainly in eyes with early detachment. When superimposing all 3-dimensional maps from 2 weeks after surgery, the central graft was mainly attached and detachment was located at the graft margin. The mean area of graft detachment decreased from 28% in DMEK only and 38% in triple DMEK to 16% in DMEK only and 25% in triple DMEK at the 2-week postoperative visit. At 2 weeks, the mean area of detachment was 1.85-fold higher (95% confidence interval [CI], 1.34-2.56) and the mean volume was 2.41-fold higher (95% CI, 1.51-3.86) in triple DMEK compared with DMEK. A total of 46 eyes received rebubbling procedures, with 7 eyes (9%) in the DMEK group and 39 eyes (20%) in the triple DMEK group (adjusted risk ratio, 3.1; 95% CI, 1.3-7.1), indicating that rebubbling was more common in eyes undergoing triple DMEK. Conclusions: Automated segmentation of AS-OCT images allowed precise quantification of graft detachment over time and identified DMEK combined with cataract surgery as a risk factor. Frequency of operative follow-up might be guided by extent of detachment in the first postoperative days after DMEK.

Corneal Oedema: Aetiology, Diagnostic Testing, and Treatment.

Corneal oedema results from an underlying pathology, which can be diverse in origin, and may be mechanical, dystrophic, or inflammatory, and affect any layer of the cornea. Diagnostic tools such as Scheimpflug imaging and anterior segment optical coherence tomography have standardised quantification of corneal oedema and have become important aids in clinical practice. Timely diagnosis and treatment are key to preventing irreversible damage to the corneal ultrastructure, such as anterior corneal fibrosis or endothelial cell damage. The oedema usually resolves quickly when the underlying cause has been addressed. Symptomatic treatment using hyperosmolar agents has failed to show any benefits in oedema resolution or improvement in visual acuity compared to placebo. In contrast, rho-associated protein kinase (ROCK) inhibitors offer a promising option for medical treatment in cases of endothelial dysfunction, but their safety and efficacy must be further validated in large scale clinical trials. Until then, endothelial or penetrating keratoplasties remain the mainstay treatment where structural changes to the cornea have occurred.

[Online examination course instead of classroom teaching: adaptation of medical student teaching during the COVID-19 pandemic]. / Online-Untersuchungskurs statt Präsenzveranstaltung: Anpassung der studentischen Lehre im Medizinstudium während der COVID-19-Pandemie.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic restricted face-to-face interactions of medical students and teachers. OBJECTIVE: To develop and evaluate an online course for ophthalmology examination techniques for medical students and to determine the impact of the course on the practical objective structured clinical examination (OSCE). MATERIAL AND METHODS: The online examination course was developed as a video-based tutorial according to the SMART (specific, measurable, activating, reasonable, time-bound) principle covering all topics of the National Competency-based Catalogue of Learning Objectives for Medical Education and made available to medical students in the ophthalmology course. At the end of the semester the students graded the online examination course on an ordinal scale from 1 (strongly agree) to 6 (strongly disagree) anonymously and were asked for comments. The grades of the OSCE (range 1-5) were compared with the OSCE results of the previous semester. RESULTS: Of the 164 students 67 participated in the online evaluation (41%). The students reported to be well-prepared for the OSCE (mean grade 2.0; SD 1.0). In the future, 70% of the students would prefer combined online and on-site teaching (47 out of 67 students). Among all 164 students, the mean OSCE results were excellent (mean grade 1.1; SD 0.2) and comparable to the previous semester (mean grade among 166 students, 1.1; SD 0.2; two-sided t-test, p = 0.86). CONCLUSION: The online course on ophthalmology examination techniques allowed medical students to prepare for the OSCE. Beyond the COVID-19 pandemic, online teaching options can support on-site teaching.

Scrolling of the Donor Cornea in Dependence of Temperature and Osmolarity for Descemet Membrane Endothelial Keratoplasty. / Rollung der Spenderhornhaut in Abhängigkeit von Temperatur und Osmolarität für die Descemet Membrane endothelial Keratoplasty.

BACKGROUND: After preparation of a graft for Descemet membrane endothelial keratoplasty (DMEK), the diameter of the graft's scroll varies significantly. In particular, narrow scrolls may complicate DMEK surgery. In this study we investigated how temperature, osmolarity, and deswelling of the donor tissue influence scrolling diameter. MATERIAL AND METHODS: In this study we examined donor corneas that could not be used for transplantation. The diameter of the DMEK donor scrolls was measured after graft preparation by reflected light microscopy under different conditions: (1) The diameter of the roll was measured in Ringer's solution at temperatures of 5 °C, 24 °C and 35 °C. (2) To study the effect of different culture conditions we used 6% dextran-containing medium for 10 min, 20 min, 16 h and 24 h, and hyper- and hypoosmolar fluids (5% NaCl or aqua dest) for 5 min each. RESULTS: The median donors age was 62 years. The median endothelial cell density of the donor corneas was 1679 cells/mm2. The median diameter of the DMEK scroll was 1.35 mm in Ringer's solution at 24 °C (IQR, 1.04 - 1.89). In Ringer's solution at different temperatures, the scrolling diameter changed between 0.02 mm and 0.29 mm. The change in osmolarity resulted in a difference of 0.02 mm to 0.46 mm. Deswelling with dextran resulted in a change of scrolling diameter between 0.02 mm and 0.09 mm. SUMMARY: In this experimental case series, the diameter of the DMEK scroll did not change due to changes of temperature, osmolarity or deswelling. Influencing the graft's scroll to standardize and simplify the DMEK surgery remains an interesting goal for future studies.

Hyperosmolar Eye Drops for Diurnal Corneal Edema in Fuchs' Endothelial Dystrophy: A Double-Masked, Randomized Controlled Trial.

PURPOSE: The Eye Drops for Early Morning-Associated Swelling (EDEMAS) trial assessed the efficacy of hyperosmolar eye drops on corneal edema resolution. DESIGN: Double-masked, randomized controlled trial of hyperosmolar eye drops. PARTICIPANTS: Participants with Fuchs' dystrophy scheduled for Descemet membrane endothelial keratoplasty. METHODS: One eye was randomized to hyperosmolar eye drops (treatment); the fellow eye was randomized to artificial tears (placebo). After baseline examination in the afternoon, corneas were examined using Scheimpflug tomography after eye opening in the morning. Participants received eye drops twice. Imaging was repeated every 30 minutes up to 4 hours. MAIN OUTCOME MEASURES: Decrease in central corneal thickness 1 hour after eye opening (primary end point), corneal thickness, subjective visual function, glare, visual acuity, and adverse events (AEs) (secondary end points). RESULTS: A total of 68 participants received the allocated intervention (59 eyes received treatment; 55 eyes received placebo). All eyes had stromal edema; none had epithelial edema. Corneal thickness was 626 µm in the treatment arm and 622 µm in the placebo arm after eye opening, indicating an early morning edema compared with baseline of +21 µm and +24 µm, respectively. Decrease in corneal thickness after 1 hour was -10.5 µm in the treatment arm (95% confidence interval [CI], -12.8 to -8.2) and -11.2 µm (95% CI, -13.6 to -8.9) in the placebo arm (between-arm difference, 0.7 µm, 95% CI, -2.0 to 3.5; P = 0.59), indicating no clinically relevant effect of hyperosmolar eye drops on early morning corneal edema. Results were not compatible with a relevant treatment effect on corneal thickness, visual acuity, and glare over the entire course of the study. Increase in subjective visual function was less rapid in the treatment arm than in the placebo arm. Adverse events, most commonly burning after eye drop application, were more common with treatment (30 eyes) than placebo (1 eye; risk difference, 49 percentage points; 95% CI, 36-62). CONCLUSIONS: In this double-masked, randomized controlled trial, resolution of early morning stromal edema was not accelerated by hyperosmolar eye drops, which more frequently caused AEs. These results are not compatible with a clinically relevant effect of hyperosmolar eye drops and do not support their routine use.

Rotational alignment of corneal endothelial grafts and risk of graft detachment after Descemet membrane endothelial keratoplasty: a double-masked pseudo-randomized study.

PURPOSE: The posterior cornea is rotationally asymmetric, and Descemet membrane endothelial keratoplasty (DMEK) grafts preferentially scroll vertically. This prospective study assessed whether graft attachment after DMEK differed depending on the rotational alignment of the donor graft in the recipient eye. METHODS: Pseudo-randomization and blinding of the graft orientation in the recipient's eye were possible by procedural separation: (1) The eye bank recorded the position of an orientation marker in the donor cornea; (2) the surgeon preparing the DMEK graft recorded an upside-down marker relative to the eye bank marker; and (3) the surgeon assessed the position of the upside-down marker in the recipient after DMEK. Surgeons were masked towards the eye bank marker. Using mixed-effects models, we assessed graft attachment relative to the rotational alignment of the donor graft. RESULTS: Postoperatively, the graft was not fully attached in 59 of 179 eyes (33%). A second air fill (rebubbling) was performed in 11%. The graft axis was in line with the recipient cornea axis in 40%, oblique in 28% and orthogonal in 32%. We did not detect an elevated risk of incomplete attachment (odds ratio [OR], 1.16; 95% CI, 0.61-2.20), risk of rebubbling (OR, 1.25; 95% CI, 0.47-3.31) or larger areas of graft detachment in non-aligned grafts compared to aligned grafts. CONCLUSION: Rotational alignment was not strongly associated with the risk of incomplete graft attachment, although modestly elevated risks cannot be ruled out. Efforts are needed to reduce the need for rebubbling after DMEK and to identify modifiable risk factors for graft detachment.