A Multicenter Study Validates the WHO 2022 Classification for Conjunctival Melanocytic Intraepithelial Lesions With Clinical and Prognostic Relevance.

Several nomenclature and grading systems have been proposed for conjunctival melanocytic intraepithelial lesions (C-MIL). The fourth "WHO Classification of Eye Tumors" (WHO-EYE04) proposed a C-MIL classification, capturing the progression of noninvasive neoplastic melanocytes from low- to high-grade lesions, onto melanoma in situ (MIS), and then to invasive melanoma. This proposal was revised to the WHO-EYE05 C-MIL system, which simplified the high-grade C-MIL, whereby MIS was subsumed into high-grade C-MIL. Our aim was to validate the WHO-EYE05 C-MIL system using digitized images of C-MIL, stained with hematoxylin and eosin and immunohistochemistry. However, C-MIL cases were retrieved from 3 supraregional ocular pathology centers. Adequate conjunctival biopsies were stained with hematoxylin and eosin, Melan-A, SOX10, and PReferentially expressed Antigen in Melanoma. Digitized slides were uploaded on the SmartZoom platform and independently scored by 4 ocular pathologists to obtain a consensus score, before circulating to 14 expert eye pathologists for independent scoring. In total, 105 cases from 97 patients were evaluated. The initial consensus diagnoses using the WHO-EYE04 C-MIL system were as follows: 28 benign conjunctival melanoses, 13 low-grade C-MIL, 37 high-grade C-MIL, and 27 conjunctival MIS. Using this system resulted in 93% of the pathologists showing only fair-to-moderate agreement (kappa statistic) with the consensus score. The WHO-EYE05 C-MIL system (with high-grade C-MIL and MIS combined) improved consistency between pathologists, with the greatest level of agreement being seen with benign melanosis (74.5%) and high-grade C-MIL (85.4%). Lowest agreements remained between pathologists for low-grade C-MIL (38.7%). Regarding WHO-EYE05 C-MIL scoring and clinical outcomes, local recurrences of noninvasive lesions developed in 8% and 34% of the low- and high-grade cases. Invasive melanoma only occurred in 47% of the cases that were assessed as high-grade C-MIL. This extensive international collaborative study is the first to undertake a comprehensive review of the WHO-EYE05 C-MIL scoring system, which showed good interobserver agreement and reproducibility.

Lapatinib dysregulates HER2 signaling and impairs the viability of human uveal melanoma cells.

Uveal melanoma (UM) is the principal type of intraocular malignancy in adults. Up to 50% of UM patients develop metastatic disease with very poor survival. There are few drugs available to treat the primary or metastatic UM. This study was undertaken to evaluate the anti-cancer effect of lapatinib and corroborate the potential of HER2 inhibition in the treatment of UM. The anti-UM activity of lapatinib was assessed using cell viability, cell death and cell cycle analysis, and its anti-metastatic actions were evaluated using would healing, invasion and colony formation assays. Immunoblotting was used to substantiate the actions of lapatinib on apoptotic and HER2 signaling. The anti-UM activity of lapatinib was further evaluated in a UM xenograft mouse model. Lapatinib decreased the viability of four UM cell lines (IC50: 3.67-6.53 µM). The antiproliferative activity of lapatinib was corroborated in three primary cell lines isolated from UM patient tumors. In UM cell lines, lapatinib promoted apoptosis and cell cycle arrest, and strongly inhibited cell migration, invasion and reproductive cell growth. Lapatinib dysregulated HER2-AKT/ERK/PI3K signalling leading to the altered expression of apoptotic factors and cell cycle mediators in UM cell lines. Importantly, lapatinib suppressed tumourigenesis in mice carrying UM cell xenografts. Together the present findings are consistent with the assertion that HER2 is a viable therapeutic target in UM. Lapatinib is active in primary and metastatic UM as a clinically approved HER2 inhibitor. The activity of lapatinib in UM patients could be evaluated in future clinical trials.

Subretinal peripapillary biopsy-proven sarcoidosis: a case report.

BACKGROUND: To report a case of a subretinal, unilateral, peripapillary granuloma that was diagnosed as sarcoidosis by a 27-gauge pars plana vitrectomy subretinal biopsy. Sarcoidosis is a chronic idiopathic granulomatous inflammatory disease, that has ocular involvement in 10-80% of patients. It is often mistaken for many other primary ocular diseases because the condition can involve any structure in or around the eye. Previous case reports of peripapillary sarcoidosis have either been limited to the choroid or presented with additional ocular and systemic signs, hence have not required an intraocular biopsy. CASE PRESENTATION: A 54-year-old Filipino male presented with a 6-month history of painless blurred vision in his right eye. Fundus examination revealed a large white peripapillary lesion. Enhanced-depth imaging optical coherence tomography confirmed the subretinal location of the mass. Indocyanine green angiography demonstrated absolute hypofluorescent blockage with satellite lesions. A whole-body positron emission tomography scan demonstrated widespread lymphadenopathy, but investigations including an inguinal lymph node biopsy were inconclusive. Following growth of the peripapillary lesion and worsening vision, a 27-gauge pars plana vitrectomy subretinal biopsy was performed which confirmed sarcoidosis. He was treated with oral corticosteroids and transitioned to long term immunotherapy with methotrexate. CONCLUSIONS: Sarcoidosis can present in the subretinal space, around the optic nerve without other ocular findings.

An Open-Source AI Framework for the Analysis of Single Cells in Whole-Slide Images with a Note on CD276 in Glioblastoma.

Routine examination of entire histological slides at cellular resolution poses a significant if not insurmountable challenge to human observers. However, high-resolution data such as the cellular distribution of proteins in tissues, e.g., those obtained following immunochemical staining, are highly desirable. Our present study extends the applicability of the PathoFusion framework to the cellular level. We illustrate our approach using the detection of CD276 immunoreactive cells in glioblastoma as an example. Following automatic identification by means of PathoFusion's bifocal convolutional neural network (BCNN) model, individual cells are automatically profiled and counted. Only discriminable cells selected through data filtering and thresholding were segmented for cell-level analysis. Subsequently, we converted the detection signals into the corresponding heatmaps visualizing the distribution of the detected cells in entire whole-slide images of adjacent H&E-stained sections using the Discrete Wavelet Transform (DWT). Our results demonstrate that PathoFusion is capable of autonomously detecting and counting individual immunochemically labelled cells with a high prediction performance of 0.992 AUC and 97.7% accuracy. The data can be used for whole-slide cross-modality analyses, e.g., relationships between immunochemical signals and anaplastic histological features. PathoFusion has the potential to be applied to additional problems that seek to correlate heterogeneous data streams and to serve as a clinically applicable, weakly supervised system for histological image analyses in (neuro)pathology.

The multi-kinase inhibitor afatinib serves as a novel candidate for the treatment of human uveal melanoma.

PURPOSE: Uveal melanoma (UM) is the most common intraocular malignancy in adults with a poor prognosis and a high recurrence rate. Currently there is no effective treatment for UM. Multi-kinase inhibitors targeting dysregulated pro-tumorigenic signalling pathways have revolutionised anti-cancer treatment but, as yet, their efficacy in UM has not been established. Here, we identified the multi-kinase inhibitor afatinib as a highly effective agent that exerts anti-UM effects in in vitro, ex vivo and in vivo models. METHODS: We assessed the anti-cancer effects of afatinib using cell viability, cell death and cell cycle assays in in vitro and ex vivo UM models. The signaling pathways involved in the anti-UM effects of afatinib were evaluated by Western blotting. The in vivo activity of afatinib was evaluated in UM xenograft models using tumour mass measurement, PET scan, immunohistochemical staining and TUNEL assays. RESULTS: We found that afatinib reduced cell viability and activated apoptosis and cell cycle arrest in multiple established UM cell lines and in patient tumour-derived primary cell lines. Afatinib impaired cell migration and enhanced reproductive death in these UM cell models. Afatinib-induced cell death was accompanied by activation of STAT1 expression and downregulation of Bcl-xL and cyclin D1 expression, which control cell survival and cell cycle progression. Afatinib attenuated HER2-AKT/ERK/PI3K signalling in UM cell lines. Consistent with these observations, we found that afatinib suppressed tumour growth in UM xenografted mice. CONCLUSION: Our data indicate that afatinib activates UM cell death and targets the HER2-mediated cascade, which modulates STAT1-Bcl-xL/cyclin D1 signalling. Thus, targeting HER2 with agents like afatinib may be a novel therapeutic strategy to treat UM and to prevent metastasis.

The application of natural compounds in uveal melanoma drug discovery.

OBJECTIVES: Uveal melanoma (UM) is the most common primary intraocular tumour in adults. UM has a poor overall prognosis and ~50% of patients progress to metastatic disease that has a median survival of 5.2 months. There are currently no proven pharmacological treatments for primary or metastatic UM. Research efforts continue to seek new agents. Many natural compounds have shown promising anti-UM activity in in-vitro and/or in-vivo studies. This review summarises the current findings for natural compounds that may be potentially useful in treating UM. KEY FINDINGS: Literature suggests that natural compounds, such as pristimerin, picropodophyllin, oridonin, zeaxanthin, withaferin and FR-900359, may be promising candidate compounds to treat UM. Most of these compounds have demonstrated satisfactory efficacy in inhibiting in-vitro UM cell growth. SUMMARY: The evidence regarding the anti-UM effects of natural compounds is mainly limited to in-vitro studies; to date, only a small number of these agents have been evaluated in vivo. The molecular mechanisms underpinning the anti-UM properties of these compounds remain largely undefined. Further studies are required to evaluate the in-vivo anticancer activity, appropriate dosage regimen and safety of natural compounds that could be developed for use in UM.

The unfolded protein response and the biology of uveal melanoma.

Uveal melanoma (UM) is a highly metastatic ocular cancer that arises from the melanocytes of the uveal tract (the choroid, ciliary body and iris). Despite a growing understanding of UM biology, effective systemic treatments are currently lacking and the cancer has an extremely poor prognosis. Therefore, identifying novel agents that act by new tumorigenic mechanisms in UM is essential to address this unmet clinical need. Endoplasmic reticulum (ER) stress occurs when misfolded proteins accumulate in the organelle, and the unfolded protein response (UPR) is the cellular mechanism that is activated so that cells may adapt to the situation. Dysregulated UPR signalling has been detected in UM tumors and has been associated with an increase in immune evasion and metastatic activity. A number of established and novel oncology drugs act in part by modulating ER stress and the UPR. The induction of protein-folding stress and the UPR could be a novel approach for the development of new therapeutics in UM. Further studies are now warranted to understand the mechanisms and consequences of UPR signalling in UM.

Biopsy for molecular risk stratification in uveal melanoma: Yields and molecular characteristics in 119 patients.

BACKGROUND: Prognostic cytological and molecular features of uveal melanoma have been well researched and are essential in management. Samples can be obtained in vivo through fine needle aspirate biopsy, vitrector cutter, forceps or post-enucleation for off-site testing. This study aims to examine cytological and chromosome microarray yields of these samples. METHODS: A retrospective cohort analysis of 119 uveal melanoma biopsies submitted to our laboratory. Samples included those taken in vivo (n = 57) and post-enucleation (n = 62). Patient and tumour features were collected including age, sex, primary tumour location, basal diameter and tumour height. Prognostic outcomes measured include cell morphology, chromosomal status and immunohistochemistry. RESULTS: Post-enucleation biopsies accounted for just over half of our samples (52%). Post-enucleation samples had a more successful genetic yield than in vivo biopsies (77% vs. 50%, p = 0.04) though there was no difference for cytological yields. There was no difference in cytological or microarray yields between instruments. The vitrector biopsy group had the smallest tumour thickness (5 mm vs. 10 mm [fine-needle aspirate biopsy], p = 0.003). There was a strong correlation between monosomy 3, BAP1 aberrancy and epithelioid cell type in post-enucleation samples (Tb  = 0.742, p = 0.005). However, epithelioid morphology was not associated with either monosomy 3 (p = 0.07) or BAP1 aberrancy (p = 0.24) for in vivo biopsies. CONCLUSIONS: All three biopsy instruments provide similar cytological yields as post-enucleation sampling, although post-enucleation samples had a more successful chromosome microarray yield. Epithelioid cytomorphology alone is insufficient for prognostication in in vivo biopsies, immunohistochemistry would be a useful surrogate test.

Development of new therapeutic options for the treatment of uveal melanoma.

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Important cytogenetic and genetic risk factors for the development of UM include chromosome 3 monosomy, mutations in the guanine nucleotide-binding proteins GNAQ/GNA11, and loss of the BRACA1-associated protein 1 (BAP 1). Most primary UMs are treated conservatively with radiotherapy, but enucleation is necessary for large tumours. Despite the effectiveness of local control, up to 50% of UM patients develop metastasis for which there are no effective therapies. Attempts to utilise the targeted therapies that have been developed for the treatment of other cancers, including a range of signal transduction pathway inhibitors, have rarely produced significant outcomes in UM. Similarly, the application of immunotherapies that are effective in cutaneous melanoma to treat UM have also been disappointing. Other approaches that have been initiated involve proteasomal inhibitors and histone deacetylase inhibitors which are approved for the treatment of other cancers. Nevertheless, there have been occasional positive outcomes from these treatments in UM. Moreover, combination approaches in UM have also yielded some positive developments. It would be valuable to identify how to apply such therapies efficiently in UM, potentially via individualised tumour profiling. It would also be important to characterise UM tumours to differentiate the potential drivers of progression from those in other types of cancers. The recent identification of novel kinases and metastatic genes in UM tumours makes the development of new UM-specific treatments feasible.

PathoFusion: An Open-Source AI Framework for Recognition of Pathomorphological Features and Mapping of Immunohistochemical Data.

We have developed a platform, termed PathoFusion, which is an integrated system for marking, training, and recognition of pathological features in whole-slide tissue sections. The platform uses a bifocal convolutional neural network (BCNN) which is designed to simultaneously capture both index and contextual feature information from shorter and longer image tiles, respectively. This is analogous to how a microscopist in pathology works, identifying a cancerous morphological feature in the tissue context using first a narrow and then a wider focus, hence bifocal. Adjacent tissue sections obtained from glioblastoma cases were processed for hematoxylin and eosin (H&E) and immunohistochemical (CD276) staining. Image tiles cropped from the digitized images based on markings made by a consultant neuropathologist were used to train the BCNN. PathoFusion demonstrated its ability to recognize malignant neuropathological features autonomously and map immunohistochemical data simultaneously. Our experiments show that PathoFusion achieved areas under the curve (AUCs) of 0.985 ± 0.011 and 0.988 ± 0.001 in patch-level recognition of six typical pathomorphological features and detection of associated immunoreactivity, respectively. On this basis, the system further correlated CD276 immunoreactivity to abnormal tumor vasculature. Corresponding feature distributions and overlaps were visualized by heatmaps, permitting high-resolution qualitative as well as quantitative morphological analyses for entire histological slides. Recognition of more user-defined pathomorphological features can be added to the system and included in future tissue analyses. Integration of PathoFusion with the day-to-day service workflow of a (neuro)pathology department is a goal. The software code for PathoFusion is made publicly available.

Intraocular solitary extramedullary plasmacytoma presenting as unilateral anterior and intermediate uveitis preceded by refractory glaucoma.

BACKGROUND: Solitary extramedullary plasmacytoma (SEP) is a localised proliferation of monoclonal plasma cells involving soft tissue with no or minimal bone marrow involvement and no other systemic evidence of multiple myeloma. Intraocular involvement is exceedingly rare. CASE PRESENTATION: We report a 78-year-old man who was referred with glaucoma in the right eye. He subsequently developed anterior chamber (AC) inflammation and refractory glaucoma then dense vitritis. A vitrectomy was performed with the biopsy revealing numerous plasma cells with atypical findings. In conjunction with the flow cytometry results, and a systemic work up excluding multiple myeloma, a diagnosis of SEP was made. The patient was treated with ocular external beam radiotherapy with resolution of the intraocular inflammation and control of the intraocular pressure. He remains well with no local recurrence and no development of multiple myeloma over a follow up period of 2.5 years. CONCLUSIONS: This is the first case report of SEP presenting as intraocular inflammation without a uveal tract mass.

The In Vivo Correlation between Retinal Pigment Epithelium Thickness and Quantitative Fundus Autofluorescence in a White Population.

PURPOSE: To investigate the influence of age on the thickness of the retinal pigment epithelium (RPE)/Bruch's membrane (BM) complex and the quantitative autofluorescence (qAF) and to study the possible correlation existing between these 2 parameters in a healthy White population. DESIGN: Cross-sectional, observational study. PARTICIPANTS: Healthy White volunteers aged 18 to 65 years. METHODS: All subjects underwent spectral domain OCT (SD-OCT) and qAF imaging with the Heidelberg HRA-Spectralis (Heidelberg Engineering, Heidelberg, Germany). Spectral domain OCT images were analyzed using the in-built graph-based automatic segmentation algorithm for single retinal layer identification to assess RPE/BM complex thickness in vivo. The thickness values of both inner and outer rings of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid, generated by the software using the "RPE" segmentation, were averaged to obtain a single RPE/BM complex thickness value in each eye. Quantitative autofluorescence images were also evaluated using a dedicated software. The qAF values of 8 subfields forming a ring centered onto the fovea were collected and averaged to obtain a single qAF value (qAF8) in each eye. The correlation among the RPE/BM complex thickness, the qAF value, and the age of the subjects was investigated. MAIN OUTCOME MEASURES: The in vivo correlation between RPE/BM complex thickness and qAF. RESULTS: A total of 105 eyes from 105 subjects (mean age, 42.1 ± 13.9 years; range, 18-65) were included in the analysis. The mean RPE/BM complex thickness significantly increased with age (r = 0.33, P = 0.0006). The values of qAF also positively increased with age (P < 0.0001). A significant correlation was found between qAF and RPE/BM complex thickness (r = 0.27, P = 0.004). After adjusting for age, iris color, and gender, the correlation remained significant only for subjects aged less than 40 years (P = 0.009). CONCLUSIONS: BM complex thickness was significantly co/BM complex thickness increased with age in a healthy White population. A similar increase was found for qAF values. After adjusting for age and iris color, qAF and RPE/BM complex thickness were still correlated in subjects aged less than 40 years. The RPE/BM complex thickness could reflect the lipofuscin/melanolipofuscin accumulation in normal subjects, adding great interest in RPE cell biology.

Validation of the Newly Proposed World Health Organization Classification System for Conjunctival Melanocytic Intraepithelial Lesions: A Comparison with the C-MIN and PAM Classification Schemes.

PURPOSE: We sought to compare the sensitivity, specificity, accuracy, and interobserver agreement of the two most commonly used classification systems for conjunctival melanocytic intraepithelial lesions with the new World Health Organization (WHO) classification. DESIGN: Retrospective case series and evaluation of classification systems. METHODS: We reviewed the pathology and medical records of all patients who underwent a primary biopsy procedure for conjunctival primary acquired melanosis (PAM) at Wills Eye Hospital between 1974 and 2002 who had ≥36 months of follow-up. Data collected included age, sex, clinical findings, recurrence, and progression to melanoma. Twelve ophthalmic pathologists analyzed scanned hematoxylin and eosin-stained virtual microscopic slides using 3 classification systems: PAM, conjunctival melanocytic intraepithelial neoplasia, and the WHO 4th edition classification of conjunctival melanocytic intraepithelial lesions. Observer agreement, sensitivity, specificity, and diagnostic accuracy of each classification system were assessed. RESULTS: There were 64 patients who underwent 83 primary excisions with cryotherapy for conjunctival PAM who had adequate tissue for histopathologic evaluation. The interobserver agreement in distinction between the low- and high-grade lesions was 76% for PAM, 67% for conjunctival melanocytic intraepithelial neoplasia, and 81% for WHO classification system. Low-grade lesions provided the greatest interpretative challenge with all 3 classification systems. The 3 classification systems had comparable accuracy of 81%-83% in their ability to identify lesions with potential for recurrence. CONCLUSIONS: This study highlights the comparable strengths and limitations of the 3 classification systems for conjunctival melanocytic intraepithelial lesions and suggests that the simplified WHO classification scheme is appropriate for evaluation of these lesions.

The distribution of toxic metals in the human retina and optic nerve head: Implications for age-related macular degeneration.

OBJECTIVE: Toxic metals are suspected to play a role in the pathogenesis of age-related macular degeneration. However, difficulties in detecting the presence of multiple toxic metals within the intact human retina, and in separating primary metal toxicity from the secondary uptake of metals in damaged tissue, have hindered progress in this field. We therefore looked for the presence of several toxic metals in the posterior segment of normal adult eyes using elemental bioimaging. METHODS: Paraffin sections of the posterior segment of the eye from seven tissue donors (age range 54-74 years) to an eye bank were examined for toxic metals in situ using laser ablation-inductively coupled plasma-mass spectrometry, a technique that detects multiple elements in tissues, as well as the histochemical technique of autometallography that demonstrates inorganic mercury, silver, and bismuth. No donor had a visual impairment, and no significant retinal abnormalities were seen on post mortem fundoscopy and histology. RESULTS: Metals found by laser ablation-inductively coupled plasma-mass spectrometry in the retinal pigment epithelium and choriocapillaris were lead (n = 7), nickel (n = 7), iron (n = 7), cadmium (n = 6), mercury (n = 6), bismuth (n = 5), aluminium (n = 3), and silver (n = 1). In the neural retina, mercury was present in six samples, and iron in one. Metals detected in the optic nerve head were iron (N = 7), mercury (N = 7), nickel (N = 4), and aluminium (N = 1). No gold or chromium was seen. Autometallography demonstrated probable inorganic mercury in the retinal pigment epithelium of one donor. CONCLUSION: Several toxic metals are taken up by the human retina and optic nerve head. Injury to the retinal pigment epithelium from toxic metals could damage the neuroprotective functions of the retinal pigment epithelium and allow toxic metals to enter the outer neural retina. These findings support the hypothesis that accumulations of toxic metals in the retina could contribute to the pathogenesis of age-related macular degeneration.

CUTICULAR DRUSEN: Risk of Geographic Atrophy and Macular Neovascularization.

PURPOSE: Cuticular drusen (CD) have been associated with manifestations of age-related macular degeneration such as atrophy and neovascularization in the macula. In this study, eyes with CD were followed and investigated for the estimated 5-year risk of progression to sequelae of age-related macular degeneration such as geographic atrophy (GA) and macular neovascularization (MNV). METHODS: A consecutive series of patients with CD were followed for the development of GA and MNV. Whenever possible, they were also studied retrospectively. The patients with CD were categorized into three phenotypic groups. Phenotype 1: eyes had concentrated, densely populated CD in the macular and paramacular area, Phenotype 2: eyes showed scattered CD in the posterior fundus, and Phenotype 3: involved eyes with CD mixed with large drusen (>200 µm). The 5-year incidence of progression was then estimated using a Kaplan-Meier estimator. RESULTS: A total of 63 eyes from 38 patients (35 women with a mean age at presentation of 58.9 ± 14.2 years) were studied and followed for a mean of 40 ± 18 months. Thirteen patients had single eyes with GA (84.5%; 11/13) or MNV (15.5%; 2/13) in one eye at presentation and were subsequently excluded. Geographic atrophy developed in 19.0% (12/63) of eyes and MNV in 4.8% (3/63) of eyes. The cumulative estimated 5-year risk of GA and MNV was 28.4% and 8.7%, respectively. The estimated 5-year incidence of MNV or GA was 12.6%, 50.0%, and 51.6% in Phenotype 1, Phenotype 2, and Phenotype 3, respectively (P = 0.0015, log-rank test). No difference in risk was found in the development of GA or MNV (P = 0.11) between the subgroup of patients presenting with GA or MNV in their fellow eye and those with both eyes included. CONCLUSION: When patients with CD are followed longitudinally, there was a significant risk of progression to GA or MNV for Phenotype 2 and Phenotype 3. Patients with CD are commonly first diagnosed in the fifth decade of life, and there is a female predominance. Clinicians should use multimodal imaging to detect and be aware of the risk of progression to manifestations of GA and MNV. These risks of GA and MNV suggest that patients with CD may be part of the overall spectrum of age-related macular degeneration.

Lipid-Producing Ciliochoroidal Melanoma with Expression of HMG-CoA Reductase.

Uveal melanoma (UM) is the commonest primary intraocular malignancy in adults. There is limited published data on lipid production in UM. Here, we describe the clinical, histological, immunohistochemical, and molecular findings in a ciliochoroidal melanoma with lipid production and expression of the enzyme HMG-CoA reductase. This case highlights an unusual UM tumour phenotype with a high-risk molecular metastatic profile and discusses tumour lipogenesis and activation of the mevalonate pathway as a potential therapeutic target in managing lipidised ciliochoroidal UM.

Shedding light on melanins within in situ human eye melanocytes using 2-photon microscopy profiling techniques.

Choroidal melanocytes (HCMs) are melanin-producing cells in the vascular uvea of the human eye (iris, ciliary body and choroid). These cranial neural crest-derived cells migrate to populate a mesodermal microenvironment, and display cellular functions and extracellular interactions that are biologically distinct to skin melanocytes. HCMs (and melanins) are important in normal human eye physiology with roles including photoprotection, regulation of oxidative damage and immune responses. To extend knowledge of cytoplasmic melanins and melanosomes in label-free HCMs, a non-invasive 'fit-free' approach, combining 2-photon excitation fluorescence lifetimes and emission spectral imaging with phasor plot segmentation was applied. Intracellular melanin-mapped FLIM phasors showed a linear distribution indicating that HCM melanins are a ratio of two fluorophores, eumelanin and pheomelanin. A quantitative histogram of HCM melanins was generated by identifying the image pixel fraction contributed by phasor clusters mapped to varying eumelanin/pheomelanin ratio. Eumelanin-enriched dark HCM regions mapped to phasors with shorter lifetimes and longer spectral emission (580-625 nm) and pheomelanin-enriched lighter pigmented HCM regions mapped to phasors with longer lifetimes and shorter spectral emission (550-585 nm). Overall, we demonstrated that these methods can identify and quantitatively profile the heterogeneous eumelanins/pheomelanins within in situ HCMs, and visualize melanosome spatial distributions, not previously reported for these cells.

Primary Choroidal Lymphoma Diagnosed with 27-Gauge Pars Plana Vitrectomy Choroidal Biopsy.

BACKGROUND: Currently, transvitreal fine-needle aspiration biopsy is the most widely used tissue biopsy technique in cases of suspected intraocular lymphoma due to its relative simplicity and low trauma. The small sample produced, however, may be inadequate for diagnostic and prognostic analyses due to mechanical artefacts, insufficient material, or sampling errors. Small case series have demonstrated choroidal biopsy via vitrectomy to be safe and effective. With smaller-gauge vitrectomy instruments, visual recovery is rapid, and post-operative inflammation and conjunctival scarring is minimised. Furthermore, smaller-gauge instrumentation does not appear to affect the diagnostic yield of biopsies for intraocular lymphoma in vitro. We report a case of primary choroidal lymphoma successfully diagnosed with 27-gauge pars plana vitrectomy choroidal biopsy. CASE PRESENTATION: A 72-year-old female presented with a 6-month history of painless blurred vision in her right eye. Fundus examination revealed a large pale choroidal mass centred on the posterior pole with overlying exudative retinal detachment. Enhanced depth imaging optical coherence tomography revealed a markedly thickened choroid with an undulating appearance. B-scan ultrasonography demonstrated diffuse, smooth thickening of the choroid, and retrobulbar extrascleral hypoechoic nodules. A 27-gauge pars plana vitrectomy was performed and choroidal biopsy taken. Histopathologic, immunohistochemical, and flow cytometry studies confirmed a diagnosis of extranodal marginal zone B-cell lymphoma. Systemic workup found no evidence of systemic lymphoma. As such, the patient was diagnosed with primary choroidal lymphoma. She underwent intensity-modulated external beam radiotherapy with subsequent resolution of disease. CONCLUSIONS: Primary choroidal lymphoma can be safely and effectively diagnosed via 27-gauge vitrectomy choroidal biopsy.