Blogging for medical education - a personal view

Medical education has evolved considerably from didactic and lecture-based to self-directed, especially with the rise of online platforms. While large organisations may commission or create entire customised courses for online learning, the individual teacher has a more modest and immediately accessible tool with which to disseminate information to students and other learners: blogging

Prevalence of co-existent neoplasia in clinically diagnosed pterygia in a UK population

INTRODUCTION: Ocular surface squamous neoplasia (OSSN) and pterygia share risk factors and co-exist in only a minority of cases. Reported rates of OSSN in specimens sent as pterygium for histopathological analysis vary between 0% and nearly 10%, with the highest rates reported in countries with high levels of ultraviolet light exposure. As there is a paucity of data in European populations, the aim of this study was to report the prevalence of co-existent OSSN or other neoplastic disease in clinically suspected pterygium specimens sent to a specialist ophthalmic pathology service in London, United Kingdom. METHODS: We performed a retrospective review of sequential histopathology records of patients with excised tissue submitted as suspected “pterygium” between 1997 and 2021. RESULTS: In total, 2061 specimens of pterygia were received during the 24-year period, with a prevalence of neoplasia in those specimens of 0.6% (n = 12). On detailed review of the medical records of these patients, half (n = 6) had the pre-operative clinical suspicion of possible OSSN. Of those cases without clinical suspicion pre-operatively, one was diagnosed with invasive squamous cell carcinoma of the conjunctiva. CONCLUSION: In this study, rates of unexpected diagnoses are reassuringly low. These results may challenge accepted dogma, and influence future guidance for the indications for submitting non-suspicious pterygia for histopathological analysis

Iris extramedullary hematopoiesis in choroidal melanoma

PURPOSE: Extramedullary hematopoiesis (EMH) usually occurs in patients with loss of bone marrow hematopoietic function, and in a vast majority of cases, it involves the liver, the spleen, or the lymph nodes. We report EMH in the iris of patients enucleated for choroidal melanoma (CM). METHODS: We report a series of three patients with CM, two treated with primary enucleation and one with secondary enucleation. RESULTS: Histopathology revealed EMH in the iris of all patients. CONCLUSION: EMH of the iris can be associated with CM in the absence of any hematological or systemic disorders. To the best of our knowledge, our work is the first report of this abnormal histopathological finding

Solitary Iris Plasmacytoma With Anterior Chamber Crystalline Deposits

PURPOSE: To report a case of solitary iris plasmacytoma successfully treated with ruthenium plaque radiotherapy. METHODS: A 44-year-old white woman presented with pain in the right eye and raised intraocular pressure. Her medical history included breast cancer treated 11 years earlier with lumpectomy, lymph node clearance, chemotherapy, and radiotherapy. On examination, the right iris had a tan-colored mass with crystalline deposits visible on the mass surface and on the corneal endothelium. The fundus and left eye were normal. An anterior segment ultrasound scan showed a mass with mixed internal echogenicity and internal blood flow. RESULTS: An iris biopsy showed an infiltrate of plasma cells. Immunohistochemistry for kappa and lambda light chains demonstrated lambda light chain restriction. Systemic hematologic investigations including complete blood count, serum paraproteins, bone marrow biopsy, and full-body magnetic resonance image were normal. The monoclonal plasma cell infiltrate was consistent with a solitary iris plasmacytoma. The mass was treated with ruthenium plaque radiotherapy. After 4 years of follow-up, the mass remained regressed, and no systemic myeloma has developed. CONCLUSIONS: Iris plasmacytoma is rare and should prompt systemic evaluation to rule out multiple myeloma. Solitary iris plasmacytoma can be successfully treated with plaque radiotherapy

Immunohistochemical characterization of feline lymphoplasmacytic anterior uveitis

OBJECTIVE: To characterize the immune cells present in different forms of feline anterior uveitis. SAMPLES: Eyes were obtained from 49 cats diagnosed with chronic idiopathic lymphoplasmacytic anterior uveitis, 7 cats with feline infectious peritonitis (FIP), and 9 cats euthanized for nonocular disease. METHODS: H&E sections were scored on the level of infiltrate in the anterior uvea. Immunohistochemistry was performed for FoxP3, CD3, and IL-17A, and positive cells were quantified in multiple images of each sample. A generalized estimating equation tested for an association between the level of inflammation and the prevalence of these cell types. RESULTS: Cells stained positive for IL-17A in idiopathic uveitis but not in FIP samples. We found significantly fewer FoxP3+and CD3+cells in low-grade compared with high-grade inflammation in idiopathic uveitis or FIP samples (P values all <.005), but no difference between FIP and high-grade samples. CONCLUSIONS: Idiopathic, but not FIP-associated, uveitis appears to have Th17 cell involvement. The numbers of FoxP3+and CD3+T-cells present appear directly correlated; thus, the severity of disease does not appear directly determined by the numbers of regulatory cells

Detection of extrascleral extension in uveal melanoma with histopathological correlation

PURPOSE: Uveal melanoma is the most common primary intraocular malignancy. Extrascleral extension (ESE) is rare, but associated with an increased rate of orbital recurrence and an overall poor prognosis. Clinical studies show low rates when compared with histological studies. Due to the prognostic importance of ESE, we sought to compare our clinical, intraoperative, and histological detection rates. DESIGN: A retrospective cross-sectional case series. METHODS: A list of eyes enucleated for uveal melanoma was compiled from the admissions records of the London Ocular Oncology Service during the 28-month period, i.e. January 2010-April 2012. The surgical and clinical notes of patients with histopathology proven ESE were reviewed to determine when it was first diagnosed or suspected. The subsequent management of these cases is discussed. RESULTS: A total of 16 out of 174 (9%) eyes had histologically proven ESE. Eight of 16 cases were detected preoperatively at clinical examination, including the use of ocular ultrasound, 3 of 16 were discovered intra-operatively, and 5 of 16 deemed microscopic ESE, were first detected on histological examination. Seven of 7 (100%) of cases with anterior ESE were detected clinically by slit lamp biomicroscopy, while only 1 out of 9 (11%) of cases with posterior ESE was detected preoperatively with ultrasound. CONCLUSIONS: Slit lamp biomicroscopy is sensitive for detecting anterior ESE. Most posterior ESE is microscopic, but macroscopic posterior ESE may also be missed by B-scan ocular ultrasound. Orbital surgeons should be suspicious of clinically undetected posterior ESE, and consider adjuvant orbital radiotherapy in cases with macroscopic ESE

Late Solitary Extraocular Recurrence from Previously Resected Iris Melanoma.

Purpose To report on cases of late extraocular relapse of previously resected iris melanoma, without concurrent intraocular recurrence. Design Retrospective case series. Methods A retrospective chart review of 4 patients diagnosed with late subconjunctival relapse of previously resected iris melanoma. Results Three females and one male underwent iris tumour resection and presented to our service with suspicious conjunctival lesions at a median of 22 years later (mean: 21). None showed intraocular relapse. Treatment of the conjunctival tumours included excisional biopsy (n=4) followed by cryotherapy (n=3) and/or brachytherapy (n=3). In all cases, histopathology confirmed malignant melanoma, with no intraepithelial component or associated melanosis. Genetic sequencing (n=3) showed wildtype BRAF and NRAS in all. GNA11 mutation was found in 1 case. On array CGH (n=3), gain of 6p was found in 2 cases and gain of 8 in 2. Overall, findings were strongly suggestive of a diagnosis of late extraocular relapse from previously resected iris melanoma. In a median of 2.5 years (mean: 7.7) from the subconjunctival relapse, no further episodes of intra/extraocular recurrence were recorded, and all patients were free from distant metastasis. Conclusions Patients undergoing iris melanoma resection are at risk of developing late solitary extraocular relapse even over 30 years after surgery. In the absence of an intraocular component, diagnosis may be challenging, as tumours mimic a primary conjunctival lesion. Management by excisional biopsy followed by adjuvant therapy was successful, and histopathology and genetic analysis supported a diagnosis of extraocular uveal tumour spread rather than a primary conjunctival tumour

Associations with photoreceptor thickness measures in the UK Biobank.

Spectral-domain OCT (SD-OCT) provides high resolution images enabling identification of individual retinal layers. We included 32,923 participants aged 40-69 years old from UK Biobank. Questionnaires, physical examination, and eye examination including SD-OCT imaging were performed. SD OCT measured photoreceptor layer thickness includes photoreceptor layer thickness: inner nuclear layer-retinal pigment epithelium (INL-RPE) and the specific sublayers of the photoreceptor: inner nuclear layer-external limiting membrane (INL-ELM); external limiting membrane-inner segment outer segment (ELM-ISOS); and inner segment outer segment-retinal pigment epithelium (ISOS-RPE). In multivariate regression models, the total average INL-RPE was observed to be thinner in older aged, females, Black ethnicity, smokers, participants with higher systolic blood pressure, more negative refractive error, lower IOPcc and lower corneal hysteresis. The overall INL-ELM, ELM-ISOS and ISOS-RPE thickness was significantly associated with sex and race. Total average of INL-ELM thickness was additionally associated with age and refractive error, while ELM-ISOS was additionally associated with age, smoking status, SBP and refractive error; and ISOS-RPE was additionally associated with smoking status, IOPcc and corneal hysteresis. Hence, we found novel associations of ethnicity, smoking, systolic blood pressure, refraction, IOPcc and corneal hysteresis with photoreceptor thickness

An ENU-Induced Mutation of Nrg1 Causes Dilated Pupils and a Reduction in Muscarinic Receptors in the Sphincter Pupillae

BACKGROUND: N-ethyl-N-nitrosourea (ENU)-induced mutagenesis is a powerful tool for the study of gene function and the generation of human disease models. A large number of mouse mutants obtained by ENU-induced mutagenesis with a variety of phenotypes have been recovered. However, after genetic confirmation testing, only approximately 50% of the abnormal phenotypes were found to be heritable. METHODOLOGY/PRINCIPAL FINDINGS: A mouse mutant, Dp1, with a dilated pupil phenotype was induced with an N-ethyl-N-nitrosourea (ENU) mutagenesis strategy. Sequence analysis for Nrg1 reveals a G>A base substitution that flanks exon E59, encoding for an EGFβ domain, in the 5' splice donor site. The mutation affects but does not abolish the splicing of EGFβ-type Nrg1 mRNA in Dp1 mice and produces several different transcripts by activating other, cryptic splice sites. These types of protein isoforms are expected, and the result shows that, in the mutant, the effect is a decrease in but not an elimination of the high affinity EGFβ-type Nrg1 isoforms. This is partially compensated for by an increase in expression of the low affinity alpha forms or inactive proteins, suggesting that the mutation results in a hypomorphic allele. Interestingly, genetic model testing shows that Dp1 is a mutation that results in a dilated pupil phenotype that is inherited with very low penetrance when heterozygous and with complete penetrance when homozygous. Pharmacological and immunohistochemical tests show a reduction of muscarinic (M) receptors in the sphincter pupillae of Dp1 mice, which is a major cause of dilated pupils. CONCLUSIONS/SIGNIFICANCE: This study is the first report of an Nrg1 mutation being associated with a dilated pupil phenotype and the reduction of M receptors. This report may help in establishing more mutant mouse lines and models of human genetic disease and can be applied to other organisms. Dp1 mice are a valuable resource for the further clarification of Nrg1 biological function