Intrastromal Keratolimbal Epithelial Cysts: Congenital and Postsurgical. / Intrastromale keratolimbale Epithelzysten: kongenital und postoperativ.

Two very rare cases of intrastromal keratolimbal epithelial cysts are reported. Firstly, an enlarging congenital cyst in a 9-year-old boy, and secondly, a recurrent postsurgical cyst in an 18-year-old female patient. Both cases presented with a limbal cyst, continuing into the corneal stroma as a whitish mass up to the optical axis. The indication for surgery was stabilization of visual acuity in case one and improvement of cosmetic aspects in case two. In the first case, a small part of the cyst was opened at the limbus and the whitish material in the cyst was flushed out. In the second case, anterior lamellar keratectomy over the whole cyst was performed with subsequent application of mitomycin C. Immunohistochemical analysis revealed cytokeratin 19-positive epithelial cells in both cysts. Therefore, an implantation of conjunctival epithelium into the sclera seems to be responsible for the respective keratolimbal cyst. Postsurgically, satisfying cosmetic and functional results were obtained in both cases, with follow-ups of 4 and 9 months. Keratolimbal cysts have rarely been described in the literature. In most cases, a conjunctival epithelial implantation occurs following surgery or trauma and very rarely congenitally. After simple aspiration of the cyst's content, a rapid recurrence is often observed, so that partial or - if possible - complete removal of the anterior cyst wall is recommended, as shown in our cases.

Current Practice in the Treatment of Epithelial and Melanocytic Tumours with Interferon-α2b: A Survey of Tertiary Eye Centres in Germany.

PURPOSE: To evaluate the standard of care, in particular the use of topical or subconjunctival interferon-α2b, in treating ocular surface squamous neoplasia or melanocytic tumours in tertiary eye centres in Germany. METHODS: A survey containing 14 questions was sent to 43 tertiary eye centres in Germany. The questions addressed the surgical and medical management of ocular surface squamous neoplasia and melanocytic tumours (primary acquired melanosis and malignant melanoma), as well as the clinical experiences and difficulties in prescribing off-label interferon-α2b eye drops and subconjunctival injections. RESULTS: Twenty-four tertiary eye centres responded to the survey. Eighty-three percent of centres had used interferon-α2b in their clinical practice and 25% prescribed it as the first-line cytostatic agent following surgical excision of ocular surface squamous neoplasia, while 10% would do so for melanocytic tumours. Correspondingly, the majority of respondents selected mitomycin C as their first-line agent. Side effects were uncommon with topical interferon-α2b eye drops but were more frequently reported after subconjunctival interferon-α2b injections. In total, eight centres had experience with interferon-α2b injections. The most significant obstacles perceived by ophthalmologists when prescribing interferon-α2b were its high cost and the reimbursement thereof. CONCLUSION: Off-label mitomycin C was the preferred adjuvant therapy for epithelial and melanocytic tumours, with interferon-α2b being the standard second-line option. Interferon-α2b has predominantly been used to treat ocular surface squamous neoplasia and, to a lesser extent, melanocytic tumours at German tertiary eye centres. Following its market withdrawal, supply shortages of interferon-α2b are likely to have a profound impact on patient care and their quality of life.

Implementing Regulation (EU) 2017/746 of 5 April 2017 on In vitro Diagnostic Medical Devices (IVDR) in Medical Laboratories, especially in Ophthalmopathology. / Zur Umsetzung der Verordnung (EU) 2017/746 vom 5. April 2017 über In-vitro-Diagnostika (IVDR) in medizinischen Laboratorien, insbesondere in der Ophthalmopathologie.

The European Commission revised Directive 98/79/EC on in vitro diagnostic medical devices (IVDD) to improve patient safety and take appropriate account of technical progress. With the new Regulation (EU) 2017/746 of April 5, 2017 on in vitro diagnostic medical devices (IVDR), high standards for the quality and safety of in vitro diagnostic medical devices (IVD) apply within the European Union. The IVDR is primarily aimed at manufacturers and suppliers of IVDs, but also has significant implications for medical diagnostic laboratories. Its application is mandatory as of May 26, 2022. IVD are classified into four risk classes A to D according to their intended purpose and the associated risks. For the first time, EU-wide legal requirements are formulated for products manufactured in-house. Any medical laboratory that uses "laboratory-developed tests" (LDT), or modifies or uses CE-IVD products outside the manufacturer's specifications, becomes a manufacturer itself and IVDR Article 5 (5) applies in its entirety. Production and use of LDT must then be performed within the framework of appropriate QM systems. The health care facility must comply with certain provisions (standards), in Germany the Rili-BÄK is to be mentioned here. LDT are subject to the safety and performance requirements listed in Annex 1 to the IVDR, including the requirement for validation prior to first use, while commercial CE-IVD products only require verification. Regulation (EU) 2022/112 of January 25, 2022, provides for staggered transition periods of up to six years for some of these requirements, but it is expected that many laboratories will switch from LDT to commercial CE-marked IVD products because ultimately this will be more resource-efficient for them. In this article, we describe the requirements for medical diagnostic laboratories resulting from the IVDR and offer solution concepts for their implementation in smaller, especially ophthalmopathology laboratories.

[Conjunctival Degeneration and Neoplasia]. / Bindehautdegenerationen und -neoplasien.

Conjunctival tumors result from gain of tissue, which can be either degenerative or neoplastic, but also inflammatory. In this article, degenerative (pterygium and pinguecula) as well as benign and malignant neoplastic conjunctival changes (epithelial, melanocytic and vascular tumors, choristomas as well as metastases) are discussed with regard to pathogenesis, symptoms, diagnostics and current status of treatment.

Histological Diagnosis of Ocular and Periocular Tuberculosis 1945 - 2020. / Histologisch diagnostizierte okuläre und periokuläre Tuberkulose von 1945 bis 2020.

BACKGROUND: Ocular tuberculosis is a rare but important differential diagnosis for inflammatory conditions of all eye tissues, including the ocular surface and adnexa. Tissue diagnostics may prove challenging as some ocular tissues are difficult to biopsy and the detection of pathogens may be insensitive. We were interested in how many cases in the archive of the ophthalmopathological laboratory had been diagnosed with (peri)ocular tuberculosis since 1945. MATERIALS AND METHODS: Retrospective analysis of historical records and specimens of the ophthalmopathology laboratory of the eye department at Freiburg university hospital. Systematic re-evaluation of available slides for presence of granuloma, necrosis, giant cells, acid fast bacteria, and chronic as well as acute inflammation, plus comparison of current and historic evaluations. In addition, we describe a recent case with tuberculoma of the iris. RESULTS: There were 50,418 records archived since 1945, of which 23 specimens taken from 22 patients had been diagnosed as (peri)ocular tuberculosis. Of these, 22 (96%) were archived and available for re-interpretation. Four specimens (17%) had been excised from children. The most common tissues were enucleated eye globes (10/23, 44%), followed by the lacrimal sac (5/23, 22%) and conjunctiva (2/23, 9%). The most frequent histopathological findings were granulomas (23/23, 100%), chronic inflammation (22/23, 96%), giant cells (21/23, 91%), and necrosis (14/23, 61%). An acute inflammatory response was found in 4/23 specimens (17%). Ziehl-Neelsen stains for acid-fast bacteria had been performed in five cases, of which three were positive (60%). The greatest discrepancy between current and historical findings related to the presence of necrosis (59% consensus). In other findings, the consensus was high (78 - 96%). In a recent case of a patient with wasting syndrome attributed to lymphoma, histopathological workup of an iris tumour led to the diagnosis of tuberculosis. CONCLUSION: Ocular tuberculosis is a rare but important histopathological differential diagnosis. In the available specimens, the classic finding of necrotizing inflammation was rarest and showed least consensus on histological re-evaluation. Other typical findings, such as giant cells and a predominantly lymphocytic infiltrate, are sometimes not found even with proven presence of Mycobacterium tuberculosis. They should not be considered essential in cases where there is strong clinical suspicion.

Merkel Cell Carcinoma of the Upper Eye Lid with Atypical Clinical Appearance. / Merkel-Zell-Karzinome des Oberlides mit ungewöhnlichem klinischem Erscheinungsbild.

Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine skin tumor that occurs mainly in the sun-exposed head and neck region, but rarely in the eyelid region. Early lymphogenic spread often leads to locoregional metastases, which is why early diagnosis is crucial. Classically, periocular MCC presents as a reddish-livid nodule in elderly patients, a visual diagnosis. However, given its low incidence and variable appearance, diagnosis can also be challenging. In both cases presented here, the MCC presented as a skin-colored swelling. In patient 1, the tumor showed a partially deep subaponeurotic localization and mimicked a B-cell lymphoma histopathologically, whereas in patient 2 it imitated a diffuse chalazion clinically. After immunohistochemical characterization and exclusion of metastases, the initial clinically benign appearing lesions in both patients were classified as CK20 negative MCC. The extensive upper eyelid defects were reconstructed by Cutler-Beard plastic surgery, a particular challenge in patient 1 given the oculus unicus situation. Our two cases demonstrate that Merkel cell carcinomas not only manifest as deep red cherry-shaped tumors, but can be skin-colored and mimic benign changes when atypical in location or infiltration pattern.

Comparison of two Schwann Cell-Containing Orbital Tumors: Schwannoma and Ganglioneuroma. / Gegenüberstellung zweier Schwann-Zell-haltiger orbitaler Tumoren: Schwannom und Ganglioneurom.

Orbital tumors comprise a variety of diseases, although tumors of the peripheral nerves are rare. Of these, schwannoma is considered the most common entity, consisting histopathologically almost exclusively of Schwann cells. Another benign tumor containing Schwann cells is ganglioneuroma. Here, ganglion cells are histopathologically apparent in addition to the Schwann cell-containing stroma. Ganglioneuroma belongs to the group of neuroblastic tumors and can occur anywhere in the pathway of sympathetic ganglion cells. In this report, we present the disease courses as well as the findings of two patients with different orbital tumors. In both cases, the diagnosis was only confirmed by histopathological examination. The first patient had a schwannoma with cystic degeneration and the second patient had a ganglioneuroma, both tumor entities which occur only rarely in the orbit. Commonalities and differences are discussed.

Ectopic thyroid tissue in the iris: a case report.

BACKGROUND: Ectopic thyroid tissue in the iris, also known as a thyroid glandular epithelial choristoma of the iris, has only been described twice in the literature. In both cases it remained asymptomatic. CASE PRESENTATION: A 67-year-old female patient presented for the first time in mid-2017 with corneal endothelial decompensation, with a history of complicated cataract surgery and IStent® implantation. Slit lamp microscopy showed endothelial decompensation, pseudophakia, anterior synechiae and a whitish iris tumour adhering to the endothelium. The latter had existed since childhood. Given these findings, reduced visual acuity of hand movement perception and an intraocular pressure of 23 mmHg, we performed a keratoplasty combined with an en bloc resection of the iris tumour at 9 o'clock and sector iridectomy at the end of 2019. Histological and immunohistological examination of the iris tumour unexpectedly revealed thyroid tissue. After the procedure described above, the patient had an increase in visual acuity while the graft stayed clear and the eye showed no evidence of tumour recurrence or other complications. CONCLUSIONS: We report a third case of ectopic thyroid tissue in the iris. Both previous cases remained asymptomatic, whereas in our case, size and location of the ectopic thyroid tissue contributed to a more complex cataract surgery resulting in endothelial decompensation. Therefore, in such cases appropriate patient information should be provided prior to cataract surgery. Furthermore, careful histological examination and examination of the thyroid is important to exclude malignant diagnoses such as a metastasis of a follicular thyroid carcinoma.

Spiroplasma species as a rare cause of congenital cataract and uveitis: a case series.

BACKGROUND: To date, only four cases of ocular spiroplasma infection have been reported in the entire ophthalmic literature. We add two more cases to raise awareness of this sight-threatening congenital disease that manifests as cataract with ocular inflammation. CASE PRESENTATION: Both infants were referred for cataracts associated with ocular inflammation. Case 1, a 3-week-old neonate presented with unilateral cataract, ocular inflammation and elevated intraocular pressure. Case 2 was a 3-month-old infant with bilateral cataract and panuveitis. Lensectomies with or without vitrectomy and subsequent analyses of the specimens were performed. Transmission electron microscopy and multiplex polymerase chain reaction or 16 s rRNA gene polymerase chain reaction revealed spiroplasma species. CONCLUSIONS: Spiroplasma as a very rare cause for congenital cataract might be underdiagnosed. We recommend performing polymerase chain reaction to probe for spiroplasma species in congenital cataracts with an inflammatory component.

Gelatinous Drop-Like Corneal Dystrophy - 2 Clinical Cases. / Gelatinöse Hornhautdystrophie ­ 2 Verlaufsdarstellungen.

Gelatinous drop-like corneal dystrophy is a very rare autosomal recessive disease classified as an epithelial and subepithelial corneal dystrophy. Patients typically present under the age of 20 with drop-like corneal lesions showing high corneal fluorescein uptake. Their disease course is typically protracted and prone to frequent relapses. The condition is caused by a dysfunction of the epithelial barrier, leading to protein deposits most likely originating from tear fluid. Histology typically shows subepithelial amyloid deposits with corresponding defects of Bowman's layer and epithelial atrophy. Where topical lubricating and anti-inflammatory therapy proves insufficient, penetrating allogenic limbokeratoplasty can be considered in a curative approach. In this report, we present disease courses of 2 unrelated patients. Current findings on pathogenesis are discussed.

[Teleophthalmology Using Whole Slide Imaging (WSI): Clinical-Pathological Correlation Even Without Own Histological Laboratory]. / Teleophthalmopathologie mittels Whole Slide Imaging (WSI): klinisch-pathologische Korrelation auch ohne eigenes histologisches Labor.

Telepathology has experienced enormous growth over the last two decades due to significant advances in IT and has led to the introduction of innovative solutions for digital imaging in ophthalmology. Whole Slide Imaging (WSI), where conventional glass slides are fully scanned, offers a wide range of applications, including remote (conciliary) diagnostics, second opinions, (remote) teaching and research and presentation. In addition to qualified and experienced personnel, a comparatively expensive basic equipment has so far also been an essential requirement. The focus ophthalmology at the Eye Centre in Freiburg is able to involve a de facto unlimited number of users and consulting partners (also overseas) in the digital microscopy of identical sections independent of location, device and time. This is done simply by using the internet. This procedure has proven to be very successful and opens up completely new avenues, not only for correct diagnosis (clinical-pathological correlation), but also for education and training. Preparation and distribution of further histological slides in addition to the scanned slide is not required for small specimens with scant material, for example, nor is it necessary to purchase microscopes for the participants if funds are lacking or the infrastructure is unsuitable. When dealing with transferring data, it is essential to comply with data protection regulations.

RNA Sequencing of Formalin-Fixed and Paraffin-Embedded Tissue as a Complementary Method in Ophthalmopathology. / Die RNA-Sequenzierung von formalinfixiertem und in Paraffin eingebettetem Gewebe als ergänzende Methode der Ophthalmopathologie.

The high-throughput method of "Next Generation Sequencing" (NGS) allows cost-effective decoding of the nucleotide sequences of millions of RNA molecules in a sample. This makes it possible to determine the number of distinct RNA molecules in tissues or cells and to use these data to draw conclusions. The entirety of RNAs, in particular mRNAs (messenger RNAs) as potential precursors of proteins, provides a comprehensive insight into the functional state of the cells and tissues under investigation. In addition to cell cultures or unfixed tissue, formalin-fixed and paraffin-embedded (FFPE) tissue can also be analysed for this purpose using specific methods. In this overview, the methodological strategy and its application to the field of ophthalmic histopathology are presented.

[Deep Learning in Pathology: Applications and Challenges in Ophthalmic Pathology]. / Deep Learning in der Pathologie: Anwendungsmöglichkeiten und Herausforderungen in der Ophthalmopathologie.

INTRODUCTION: Deep learning has received increasing attention in recent years and is used in many different areas. Since image analysis is a strength of deep learning, it would be obvious to use it for histopathological questions too. Our goal is to identify possible deep learning approaches from general pathology which could be used in ophthalmic pathology. In addition, the data of the past year will be used to estimate the proportion of potentially interesting cases and the necessary technical effort. METHODS: Firstly, a literature search for deep learning models and their possible applications in the field of pathology was carried out. In order to estimate the potential benefit, technical challenges and feasibility, the number of suitable ophthalmopathology cases in our lab in 2019 for the identified models was determined and put in relation to the resulting amount of data and the scanning time. RESULTS: We identified 7 areas of particular interest: determination of regions of interest (ROI), classification of histological images in scoring systems, mapping of tumor fractions, differentiation of different types of inflammation, differentiation of various cutaneous tumors, classification of lymphomas and prediction of patient outcome-based on tumor histology. Within one year, a total of 831 cases (43%) would have been suitable for the above models. The creation of whole slide images (WSI) for all histological cases would have required a storage capacity of 630 GB with a scanning time of 35 h. CONCLUSION: There are several deep learning approaches which are also interesting for ophthalmic pathology. Most of them would have to be specially trained for the ophthalmopathological aspects. To be able to apply deep learning approaches, it is necessary to have a good IT infrastructure with the possibility to create and permanently store WSI, and this seems to be technically feasible. Future studies should focus on the specific practical implementation of current deep learning possibilities for ophthalmic pathology.