Background:
To expand the existing knowledge on the rare clinical entity of linear interstitial keratitis.

History and Signs:
This case series includes four healthy patients aged 10, 18, 20, and 21 years at the initial referral to our ophthalmology department at the University Hospital Zurich in Switzerland. All patients reported a sudden onset of painful red eye, with only Case 3 using corrective contact lenses. In the acute phase, all patients were suspected of having unilateral keratitis with conjunctival injection, corneal epithelial defects, and linear stromal opacities, with Case 2 additionally showing anterior chamber reaction and Case 3 exhibiting nummular keratitis. In each patient, we performed diagnostic corneal swabs for common bacteria, fungi, and viruses, all of which were inconclusive. We further assessed autoimmune serological markers and screened for HIV, hepatitis B and C, and syphilis in Cases 1, 3, and 4, and performed in vivo confocal microscopy in Case 2. While infectious screening was negative, we detected antinuclear antibodies in Cases 3 and 4.

Therapy and Outcome:
Case 1 displayed recurrent keratitis, ultimately leading to corneal perforation after mild ocular trauma, which we treated conservatively using bandage contact lenses with topical and systemic antibiotic coverage. At a follow-up five years after the initial presentation, the corrected visual acuity deteriorated from 0.6 LogMAR to 0.5 LogMAR. Case 2 showed pan-stromal corneal inflammation on in vivo confocal microscopy. In Cases 3 and 4, there was no clinical evidence of underlying rheumatologic disease. We treated all three patients using topical antibiotics, lubricating and corticosteroid-containing eye drops, and in Cases 2 and 4 additional antiviral agents due to initially suspected herpetic origin. The corrected visual acuity deteriorated from 0 LogMAR to 0.3 LogMAR in Case 2 and improved from 0.3 LogMAR in Case 3 and 0.6 LogMAR in Case 4 to 0 LogMAR in both patients.

Conclusions:
Linear interstitial keratitis remains a rare entity. It seems to preferably affect adolescent patients. Future research should include autoimmune workup to reveal unknown causal relationships. Long-term patient follow-up is paramount to detect disease recurrence and activity, finally minimizing the risk for corneal rupture.

Background: To develop a fast and frugal decision tree to identify keratoconus patients most likely to benefit visually from the combination of corneal cross-linking with topography-guided photorefractive keratectomy (named CXL plus).
Methods: The outcome of interest was an improvement of uncorrected distance visual acuity (UDVA) by at least two lines at the 12 months follow-up. Preoperative and 12 months follow-up data from patients who received CXL plus (n=96) and CXL only (n=96) were used in a recursive partitioning approach to construct a frugal tree with three variables ("corneal thickness (>/< 430 um)", "patient interest in CXL plus (yes/no)", and "tomographic cylinder ( < / > 3 D)"). In addition, we estimated the probability of the outcome from a multivariate logistic regression model for each combination of variables used in the decision tree.
Results: In the complete sample, 101/192 (52.6%) patients improved by at least two lines in the 12 months follow-up. Patients affirmative in all three answers had a 75.6% (34/45) probability of gaining at least two lines of improvement in UDVA by CXL plus. The statistical model estimated a 66.0% probability for a successful outcome.
Conclusions: A fast and frugal tree consisting of three variables can be used to select a patient group with a high likelihood to benefit from CXL plus. The tree is useful in the preoperative counseling of keratoconus patients contemplating the CXL plus option, an intervention that is not fully covered by many health insurances.

PURPOSE: To evaluate potential advantages of supplemental oxygen in of epi-off customized CXL.
SETTING: Prospective observational study at the Department of Ophthalmology, University Hospital Bern, Switzerland
METHODS: Forty eyes of 40 patients with documented progressive keratoconus were treated with epi-off customized CXL using 15 mW/cm2 and maximal energy levels of 10 J/cm2. Twenty eyes were treated in an atmospheric (21% O2) environment, while 20 eye were treated in a hyperoxic environment (>90% O2) and followed for 1 years. Analyzed parameters were Scheimpflug tomographies, endothelial cell count, BSCVA and anterior segment OCT.
RESULTS: Keratoconus progression was halted in all eyes. Kmax regression in the supplemental oxygen subgroup was significantly greater compared to the normoxic subgroup (-3.4 vs. -0.8 D). High flattening (>4D) was observed in 8 eyes (40%) in the hyperoxic vs. 1 eyes (5%) in the normoxic subgroup. BSCVA increased in both groups, however, significantly more in the supplementary oxygen subgroup. Densitometry peaked in both groups by month 3 and reached preoperative values in the normoxic subgroup, but not completely in the supplementary oxygen subgroup. Demarcation lines were observed significantly deeper using CXL with supplemental oxygen (334 vs 230 microns).
CONCLUSIONS: Supplementary oxygen optimizes the effect and outcome of epi-off CXL with 15mW/cm2. Flattening, corneal regularization and visual acuity improvement go along with an increased haze formation and deeper demarcation line depth using supplemental oxygen.

Purpose: To assess the safety of epithelium-off corneal cross-linking (epi-off CXL) in an office-based setting.

Setting: ELZA Institute, Zurich, Switzerland

Methods: We compared the complication rates of epithelium-off corneal cross-linking (epi-off CXL) performed in an office-based setting to those of epi-off CXL performed in an operating room. Consecutive epi-off CXL procedures (n=511), performed by a single surgeon in a procedure room at the ELZA Institute, Zurich, Switzerland.

Results: No cases of postoperative infectious keratitis were observed, and sterile infiltrates occurred in 10/511 (1.95%) of patients, all of whom responded well to topical steroid therapy. Delayed epithelialization (>7 days) occurred in 14/511 (2.74%) patients. No other adverse events were noted.
Conclusions: Office-based epi-off CXL does not seem to be associated with an increased complication risk when compared to operating room settings.

Purpose: To present a case series of rare and severe complications after corneal collagen cross-linking (CXL) of keratoconus patients.

Methods: Single-center descriptive case series covering the period of 2015 to 2022 at the Department of Ophthalmology at the University Hospital Zurich, Switzerland.

Results: We present four eyes of four patients that showed severe unusual complications within the first month after corneal cross-linking (CXL). Three patients had been treated with the classic epithelium-off “Dresden protocol” (30 minutes riboflavin followed by 30 minutes UV exposition). One patient had been treated with the accelerated epithelium-off protocol (30 minutes riboflavin, followed by 10 minutes UV exposition). One patient presented with an extensive corneal edema due to rubbing the eye after treatment. Two patients showed a bacterial infectious keratitis due to Streptococcus pneumoniae and Staphylococcus hominis, Micrococcus luteus, Streptococcus epidermidis respectively. The latter of the two patients showed an extensive infectious, crystalline keratopathy. The fourth patient showed a severe ulcerative lesion where no infectious cause could be found. Therefore, an autoimmune keratolytic process had to be suspected. Apart from the corneal edema which resolved ad integrum, the other complications resulted in permanent corneal scarring and thinning. One patient needed an emergency amniotic transplant.

Conclusion: Severe complications after CXL remain rare. Most common causes are complications that are not directly associated with the treatment as such. Those indirect complications occur after the treatment during the healing course of the epithelium. Associations with the therapeutic contact lens and with inappropriate patient behavior are often suspected. Correctly performed corneal scrapings with repeated microbiological analysis and a detailed patient history are essential for establishing the correct diagnosis especially in complicated cases that do not respond to standard therapeutic regimes. This case series supports the efforts that are currently taken to improve the CXL technique in a way that postoperative complications are further reduced.

Background: Measuring and controlling intraocular pressure (IOP) are the basis of the follow-up and the treatment of glaucoma. Self-tonometry has been proposed as an alternative to measure IOP more precisely throughout the entire day. The novel EYEMATE-SC sensor is implanted in the suprachoroidal space to enable contactless continual IOP monitoring. The aim of the present study was to investigate the 1-year safety, performance and accuracy of the EYEMATE-SC in primary open-angle glaucoma (POAG) patients undergoing simultaneous non-penetrating glaucoma surgery (NPGS).

Methods: In this prospective, multicenter, open-label, single-arm, interventional clinical trial, 24 eyes of 24 POAG patients who were due to undergo NPGS (canaloplasty or deep sclerectomy) were enrolled. An EYEMATE-SC sensor was implanted during NPGS. Goldmann applanation tonometry (GAT) measures were compared with the sensors’ IOP measures at all post-operative visits during 12 months. Device position and adverse events were recorded throughout the follow-up.
Results: 15 eyes underwent canaloplasty and 9 underwent deep sclerectomy. Successful implantation of the sensor was achieved in all eyes with no reported intraoperative difficulties. Through the 12-month follow-up, no device migration, dislocation or serious device-related complications were recorded. A total of 536 EYEMATE-SC measures were pairwise included in the IOP agreement analysis. The overall mean difference between GAT and EYEMATE-SC measurements was 0.8 mmHg (limits of agreement (CI 95%, LoA): -5.1 and 6.7 mmHg). The agreement gradually improved and from 3-month post-operatively until the end of the follow-up, the mean difference was -0.2 mmHg (LoA: -4.6 and 4.2 mmHg) over a total of 264 EYEMATE-SC measures, and 100% of measures were within ± 5 mmHg of GAT.

Conclusions: The EYEMATE-SC sensor was safe and well-tolerated throughout 12 months. Moreover, it allowed accurate continuous IOP monitoring.

Introduction:
To evaluate 5-year treatment outcomes of XEN gel stent implantation in patients with open angle glaucoma.
Methods:
In this prospective, single-centre interventional study, XEN implantation either alone or combined with phacoemulsification (Phaco + XEN) was performed on consecutive eyes with uncontrolled intraocular pressure (IOP) or disease progression despite medical treatment.
Main outcome measures:
Surgical success was defined as ’complete’ when 60-month unmedicated IOP was ≤15 mmHg with a relative IOP reduction ≥ 20% from medicated baseline, while the definition of qualified success allowed no more medications than at baseline. Secondary outcomes included mean IOP reduction, changes in ocular hypotensive medications and rates of reoperations.
Results:
Out of 170 eyes initially included, 80 eyes (53.7%) of 68 patients completed the 5-year follow-up and were included in the data (XEN: n = 17; Phaco + XEN: n = 63) after 46.3% were lost to follow-up. Mean age was 78.1 ± 9.1 years, and 69.8% were female. Mean medicated IOP decreased from 19.8 ± 7.0 mmHg (19.9 ± 7.8 [XEN] vs. 20.1 ± 7.6 mmHg [Phaco + XEN]) at baseline to 12.6 ± 3.1 mmHg (12.6± 3.1 [XEN] vs. 12.7 ± 3.1 [Phaco + XEN]) at 5 years (±37.0%; p < 0.001). Medications decreased from 2.0 ± 1.3 (2.0 ± 1.3 [XEN] vs. 2.0 ± 1.3 [Phaco + XEN]) to 0.8 ± 0.5 (0.8 ± 1.1 [XEN] vs. 0.8 ± 1.1 [Phaco + XEN]) (±60%; p < 0.001). Needling revision was performed in 39 eyes (49%), and 19.4% underwent reoperations.
Conclusion:
At 5 years, XEN gel stent implantation achieved clinically significant IOP and medication reduction. The procedure carries a substantial rate of needling and re-operations.

Hintergrund
Für Kataraktpatienten mit Astigmatismus ist das Einsetzen von torischen Intraokularlinsen (IOL) eine sichere und effektive Methode, um eine Emmetropie zu erzielen. Dabei ist die exakte Ausrichtung der Linse entlang des berechneten Meridians essentiell für eine effektive Astigmatismus-Korrektur. Das Ziel dieser Studie ist die Auswertung der Daten mittels deskriptiver Statistik. Der primäre Fokus liegt dabei auf den refraktiven Ergebnissen und somit der Überprüfung der Ausrichtungsgenauigkeit von torischen IOL mit dem Zeiss Callisto System.

Patienten und Methoden
Für die Studie wurden insgesamt 106 Augen von 72 Patienten ausgewertet, welche zwischen Januar 2019 bis Dezember 2020 eine Kataraktoperation mit Implantation einer torischen IOL im Kantonsspital Winterthur (KSW) erhalten haben. Die präoperative Biometrie und intraoperative Markierung der Implantationsachse wurde mittels Zeiss Callisto System durchgeführt. Die postoperativen Kontrollen erfolgten nach einem Tag, nach einer Woche und nach 4 Wochen im KSW oder beim zuweisenden Augenarzt. Für die Auswertung wurden nur die Daten der 4-wöchigen Kontrolle verwendet.

Ergebnisse
In 64 Augen (60%) wurde eine Zeiss AT Torbi 709 M und MP sowie in 42 Augen (40%) eine PhysIOL Ankoris toric yellow IOL implantiert. Bei 46 Augen wurde der unkorrigierte postoperative Visus nicht erfasst. Von den übrigen 60 Augen beträgt der mediane unkorrigierte postoperative Visus 0.9 (0.8 bis 1.0 [IQR]). Dabei konnte bei 48% der Augen eine Emmetropie und bei 92% ein Visus ≥ 0.6 erzielt werden. Der postoperative Zylinder beträgt im Median 0.5 Dioptrien (0.25 bis 0.75). Der Median des postoperativen Zylinders abzüglich des Zylinders der Zielrefraktion ist 0.33 (0.17 bis 0.64).

Schlussfolgerungen
Das Zeiss Callisto Systems ist eine effektive Methode mit sehr guten klinischen Ergebnissen, um torische Intraokularlinsen entlang der Implantationsachse auszurichten.

Purpose: The objective of this study was to record the axial corneal strain field in the cornea that resulted directly after creating a stromal tunnel as well as after implanting an intracorneal ring segment (ICRS).

Setting: Swiss federal institute of technology

Methods: Freshly enucleated porcine eyes were obtained and assigned either to ICRS implantation, to tunnel creation only or to virgin control. Immediately after manual tunnel creation and ICRS positioning, respectively, the entire eye globe was mounted within a customized holder and intraocular pressure (IOP) was adjusted to 15 mmHg. Then, IOP was increased in steps of 1 mmHg to 20 mmHg and decreased again. At each step, an optical coherence tomography volume scan was recorded. Displacements between subsequent scans were retrieved using a vector-based phase difference method. The induced corneal strain in axial direction was determined by taking the axial gradient. In addition, corneal surface was detected and sagittal curvature maps computed.

Results: Corneal tissue presented a localized compressive strain in the direct vicinity of the stromal tunnel, which was independent of the sign of IOP change. The central and peripheral (exterior to the ICRS) cornea demonstrated compressive strains upon IOP increase, and tensile strains upon IOP decrease. ICRS induced an annular shaped tensile strain at its inner border, particularly during IOP increase. The compressive strains close to the tunnel remained with ICRS implantation. Corneal curvature changes were limited to the corneal regions subjected to strain.

Conclusions: Tunnel creation and ICRS implantation induce localized strains in cornea regions that coincide with those of refractive changes[ETN1] [SK2] , suggesting that corneal strain and curvature are directly related. Studying corneal strain in response to surgical intervention may provide new insights on underlying working principles.

Objective:
To develop a hybrid information system (HIS) for patients and to investigate whether it leads to an improved information process before cataract surgery compared to the status quo.
Methods:
We applied the outcome-based "Design Science Methodology" from the field of information technology research and developed HIS for the eye clinic at Lucerne Cantonal Hospital. We evaluated the relative advantage of HIS based on five statements (speed, quality, simplicity, effectiveness, control) presented for evaluation on a 7-point Likert scale per statement for patients and treating eye surgeons in a survey.
Results:
The implementation of the HIS leads to a clearly perceived relative advantage over the previous status quo of information process among patients and treating eye surgeons. 52 patients with a mean age of 73 years (46% female) clearly perceive a relative advantage of the HIS over the status quo mean = 6.36, SD = 0.72). 16 eye surgeons with a mean age of 43.4 years (37.5% female) and with 10.4 years of surgical experience, also rate the HIS positively (mean = 4.94, SD= 1.0).
Conclusion:
The results of this work show the perceived relative advantage of the developed HIS. The provision of information prior to cataract surgery is improved, resulting in shared decision making between the ophthalmologist and the patient. The work also contributes to the field of digital health by demonstrating the benefits of hybrid information delivery and how it significantly supports the reach and effectiveness of everyday healthcare providers. The HIS is not only promising in the context of cataract surgery, but can be used for various other diseases in ophthalmology as well as other surgical medical disciplines to achieve the goal of shared decision making.

Purpose: To assess the usability and image quality of a smartphone adapter for direct slit lamp imaging.
Methods: Single-center, prospective, clinical study conducted at the Department of Ophthalmology at the University Hospital Zurich, Switzerland. The participant group consisted of 23 doctors and 3 medical students. The control group consisted of 1 ophthalmic photographer. Both groups took images of the anterior segment and the fundus of the same proband. The control group used professional photo equipment. The participant group used an iPhone 11 mounted on the slit-lamp via a removable smartphone adapter (Custom Surgical GmbH). Acquisition time was defined as the mean time required for mounting the adapter, taking the picture, dismounting and export the images to the management software. A questionnaire was taken by all participants. The quality of all pictures was graded independently by 2 blinded ophthalmologists on a scale from 0 (low) to 10 (high quality). Images with a score ≥7.0 were considered as good as the reference images.
Results: Mean acquisition time for anterior segment and fundus imaging was 155 and 173 seconds respectively for the participant group and 100 and 136 seconds for the control group. No statistical correlation (Spearman Rho) was found between acquisition time and the participants’ ophthalmological experience. On a scale from 0 (difficult) to 10 (easy), the mean subjective difficulty grade for taking a picture of the anterior segment was 8.2/10 and for the fundus photo 6.7/10. No statistical correlation was found between ophthalmological experience of the participant and subjective difficulty. The average quality of the anterior segment images (7.4/10) was rated as good as the reference image. The quality of the fundus photos was slightly lower (6.3/10). Acquisition time and image quality were not statistically correlated.
Conclusion: Slit lamp imaging with the presented smartphone adapter provides high quality imaging of the anterior segment. Posterior segment imaging remains challenging in terms of image quality. The adapter constitutes a cost-effective, portable, easy to use solution for recording ophthalmic photos and videos. It can facilitate clinical documentation and communication among colleagues and with the patient outside regular consultation hours. Direct slit-lamp imaging allows to save time and increases the independence of ophthalmologists on patient mobility and on availability of photographic staff.

Background. Optic neuritis usually leads to reduced color-sensitivity. Most often the change of red color, so called red desaturation, is tested in clinical routine. The aim of this study was to test the feasibility of the Reddesa chart, a new red desaturation test based on polarization, as a screening method for optic neuropathy.
Methods: A total of 20 patients with unilateral optic neuritis and 20 healthy controls were included in this prospective pilot study. Ophthalmological examination included assessment of best corrected visual acuity (BCVA), slit lamp examination, fundoscopy, testing of relative afferent pupillary defect (RAPD) and red desaturation with the red cup test and the Reddesa chart.
Results: The mean BCVA in the optic neuritis group was 0.76±0.36 in the affected eye (95% of eyes with RAPD, 75% of eyes with difference in the Reddesa test) and 1.28±0.24 in the healthy eye, whereas in the control group BCVA was 1.14±0.11 in the right eye and 1.15±0.14 in left eye (none of the eyes with RAPD or abnormal Reddesa test). In our study, the Reddesa test showed a sensitivity of 75% and a specificity of 100% for detecting optic neuritis.
Conclusion: The Reddesa chart is a feasible screening test for optic neuritis in a clinical setting. In comparison to the red cap test, it has the advantage of quantifying red sensitivity. The relatively low specificity of the Reddesa chart in our study might be due to the relatively high number of patients with only mild optic neuritis.

Purpose:
29 y women, refugee from Erithrea, underweighed, presents with a giant orbital cystic lesion. Imaging reveals suspicion of a rare orbital Echinococcus cyst.
Further history shows hepatitis and also a pregnancy of 8 weeks and opens discussion of best surgical and anti-parasitic management for mother and child.

Methods:
We present the important preoperative interdisciplinnary planning in a pregnant patient, the surgical procedure, and the risk of a surgical excision of a giant orbital Echinococcus cyst.

Discussion:
Early surgery was strongly pushed by the infectiologist. Antiparasite medication was planned to administrate around the surgery to prevent spreading. As the eye was already blind and risks of surgery and medication for mother and unborn were high, we planned surgery after birth and and since the mother was underweighed and weak after birth we waited 4 months so it was also possible to breast feed. The decision was taken together with the patient and the future mother and familiy. It revealed to be reasonable for the patient and the baby as the patient reacted with serious vomiting to the antiparacit treatment.
Surgical approach was through a lateral and anterior orbitotomy. Approaching the most vulnerable area of the cystic attachment to the dura as a last step as the rupture is expected at this place. Once the lesion is ruptured, the further dissection is more difficult and the systemic spreading starts and needs to be minimized by keeping it planned. Therefore antiparasit therapy was started already 3 days before surgery.

Conclusion:
We show, that in this case postponing surgical excision of an orbital Echinococcus cyst till after birth and breast feeding is preferable for the patient and the baby.

Purpose
To describe 3 cases of periocular Amyloidosis and describe the management of this rare condition and its systemic risks and implications.

Clinical Cases
Case 1: A 38-year-old otherwise healthy female patient was sent with a unilateral right upper eyelid lesion and secondary ptosis. The biopsy revealed AL-amyloidosis. The systemic work-up was inconspicuous.
Case 2: A 79-year-old woman sent by her ophthalmologist due to epiphora and palpebral laxity for possible correction. The subtarsal conjunctiva was thickened and dark red with multiple suffusions in the periocular region. The further history revealed a known systemic amyloidosis and the biopsy confirmed the conjunctival involvement.
Case 3: A 67-year-old man with a known systemic Myeloma, who suffered from recurrent spontaneous palpebral hematomas. In the course of his disease was diagnosed with a systemic AL-amyloidosis.

Discussion
The amyloidosis can affect almost all organs as a systemical or as a localized disease. The ocular amyloidosis is rare and can affect almost any tissue. Symptoms depend on the affected area. A final diagnosis requires a biopsy. A systemic examination is needed as a systemic illness can be fatal in cases associated with systemic haematological malignancies, multiple myeloma and involvement of the liver and kidney.

Conclusions
Although rare, the ocular amyloidosis should not be missed due to its systemic risks and implications. An interdisciplinary work-up is important to rule out an underlying systemic and possibly fatal disease.

Purpose: Firework-related ocular injuries (FWROI) are a major cause of preventable visual impairment. This study aimed to analyze the occurrence and outcome of FWROI in Switzerland.

Methods: This retrospective multicenter study included patients with FWROI from seven centers in Switzerland from January 2009 to August 2020. Demographic information, type of injuries, medical and surgical treatments, the best corrected visual acuity (BCVA) at baseline and end of follow-up, occurrence and type of secondary complications, and duration of hospitalization were analyzed.

Results: A total of 105 patients (119 eyes) with a mean age of 27.1 ± 15.9 years were included in the study (71.4% male patients; 29.5% underage). Most injuries occurred around New Year’s Eve (32.4%) and the Swiss national holiday on 1 August (60.9%). The most common anterior segment findings were conjunctival or corneal foreign bodies (58%), whereas Berlin’s edema was the most common posterior segment finding (11.4%). Globe ruptures were found in four patients. The mean BCVA in all patients at first presentation was 0.4 ± 0.8 logMAR and improved to 0.3 ± 0.8 logMAR at last follow-up. A primary surgical intervention was performed in 48 eyes (40.3%). Hospitalization directly after the trauma was necessary for 18 patients for a mean of 5.8 ± 4.1 days, and a total of 4.9 ± 7.6 follow-up visits were needed.

Conclusion: This study provides the first data on FWROI in Switzerland, which are helpful for further preventive and educational programs and comparisons with other countries.