A case of eyelid neuroma with recurrent ptosis

Purpose

We report a rare case of eyelid neuroma, discovered nine years after external levator advancement, presenting with recalcitrant ocular foreign body sensation and pain, persistent corneal epithelial defect, followed by corneal scarring, and ptosis.

Observations

An 85-year-old man with a history of multiple skin cancers presented with left ptosis, epiphora and recalcitrant eye pain. Nine years prior to presentation, he underwent excision of melanoma in situ of the left forehead, followed by simultaneous forehead reconstruction and left external ptosis repair. At presentation, he had left ptosis and left superior corneal scarring. Eversion of the eyelid demonstrated the presence of a nodule at the superior border of the tarsus. The patient underwent simultaneous excisional biopsy of the lesion and posterior ptosis repair by Müller muscle conjunctival resection (MMCR). He experienced postoperative resolution of pain, ptosis and epiphora. Histopathologic examination demonstrated the presence of a foreign body granuloma alongside a neuroma.

Conclusions

This case highlights the importance of thorough eyelid exam in individuals with ocular surface disease. We review herein the pathophysiology and histopathology of eyelid neuroma.

Ensemble neural network model for detecting thyroid eye disease using external photographs

PURPOSE

To describe an artificial intelligence platform that detects thyroid eye disease (TED).

DESIGN

Development of a deep learning model.

METHODS

1944 photographs from a clinical database were used to train a deep learning model. 344 additional images ('test set') were used to calculate performance metrics. Receiver operating characteristic, precision-recall curves and heatmaps were generated. From the test set, 50 images were randomly selected ('survey set') and used to compare model performance with ophthalmologist performance. 222 images obtained from a separate clinical database were used to assess model recall and to quantitate model performance with respect to disease stage and grade.

RESULTS

The model achieved test set accuracy of 89.2%, specificity 86.9%, recall 93.4%, precision 79.7% and an F1 score of 86.0%. Heatmaps demonstrated that the model identified pixels corresponding to clinical features of TED. On the survey set, the ensemble model achieved accuracy, specificity, recall, precision and F1 score of 86%, 84%, 89%, 77% and 82%, respectively. 27 ophthalmologists achieved mean performance of 75%, 82%, 63%, 72% and 66%, respectively. On the second test set, the model achieved recall of 91.9%, with higher recall for moderate to severe (98.2%, n=55) and active disease (98.3%, n=60), as compared with mild (86.8%, n=68) or stable disease (85.7%, n=63).

CONCLUSIONS

The deep learning classifier is a novel approach to identify TED and is a first step in the development of tools to improve diagnostic accuracy and lower barriers to specialist evaluation.

Orbital mantle cell lymphoma presenting as myasthenia gravis

A 69-year-old man, previously treated with pyridostigmine for myasthenia gravis (manifesting as ptosis and diplopia) was evaluated for several concomitant bilateral anterior orbital masses. Imaging revealed 3 discrete, solid masses within and around the orbits. An incisional biopsy demonstrated atypical lymphocytes positive for CD20 and Cyclin-D1, consistent with mantle cell lymphoma. The patient received induction chemotherapy with a rituximab-based regimen. He experienced resolution of his diplopia and ptosis after one cycle of chemotherapy and achieved complete remission of the orbital masses and myasthenia symptoms after 6 cycles. Myasthenia gravis is most commonly associated with thymoma, but may also be observed with other malignancies. Recognition that orbital lymphoma may coexist with myasthenia gravis will help in expediting the diagnosis of future cases and in guiding treatment decisions.

The role of tissue resection length in the determination of post-operative eyelid position for Muller's muscle-conjunctival resection surgery

PURPOSE

To investigate the relationships between pre-operative marginal reflex distance (MRD), tissue resection length, phenylephrine response, and change in MRD with surgery for a cohort of individuals undergoing Muller's muscle conjunctival resection (MMCR) surgery.

METHODS

All cases of MMCR surgery performed over a 13-year period at a single institution were screened for entry. Individuals with adequate photographic documentation and follow up were included. Patients with previous or concurrent upper eyelid, orbital or eyebrow disease of surgery were excluded. Marginal reflex distance (MRD) was calculated based on photographs utilizing public domain software. Data was plotted for inspection and appropriate statistical tests were performed.

RESULTS

During the study period 198 eyes fit criteria for analysis. A loose association between tissue resection length and change in MRD with surgery was found (r = 0.176, p < 0.05); this relationship was not significant in ANOVA analysis (p = 0.367). There was a strong association between MRD change with surgery and pre-operative MRD (r = 0.498, p < 0.01). Approximately 28% of the sample responded to 2.5% phenylephrine drop instillation with a greater than 2 mm increase in MRD. The response to phenylephrine was strongly associated with pre-operative MRD (r = -0.441, p < 0.01). A regression on change in MRD with surgery with tissue resection, phenylephrine response >2 mm and pre-operative MRD as variables revealed a model with pre-operative MRD as the only significant predictor (p < 0.01).

CONCLUSION

Tissue resection length and phenylephrine response play small roles relative to pre-operative MRD in the determination of change in MRD with MMCR surgery.

Rad51 ATP binding but not hydrolysis is required to recruit Rad10 in synthesis-dependent strand annealing sites in S. cerevisiae

Several modes of eukaryotic of DNA double strand break repair (DSBR) depend on synapsis of complementary DNA. The Rad51 ATPase, the S. cerevisiae homolog of E. coli RecA, plays a key role in this process by catalyzing homology searching and strand exchange between an invading DNA strand and a repair template (e.g. sister chromatid or homologous chromosome). Synthesis dependent strand annealing (SDSA), a mode of DSBR, requires Rad51. Another repair enzyme, the Rad1-Rad10 endonuclease, acts in the final stages of SDSA, hydrolyzing 3' overhanging single-stranded DNA. Here we show in vivo by fluorescence microscopy that the ATP binding function of yeast Rad51 is required to recruit Rad10 SDSA sites indicating that Rad51 pre-synaptic filament formation must occur prior to the recruitment of Rad1-Rad10. Our data also show that Rad51 ATPase activity, an important step in Rad51 filament disassembly, is not absolutely required in order to recruit Rad1-Rad10 to DSB sites.

Caspase-1 dependent IL-1β secretion is critical for host defense in a mouse model of Chlamydia pneumoniae lung infection

Chlamydia pneumoniae (CP) is an important human pathogen that causes atypical pneumonia and is associated with various chronic inflammatory disorders. Caspase-1 is a key component of the ‘inflammasome’, and is required to cleave pro-IL-1β to bioactive IL-1β. Here we demonstrate for the first time a critical requirement for IL-1β in response to CP infection. Caspase-1^−/− mice exhibit delayed cytokine production, defective clearance of pulmonary bacteria and higher mortality in response to CP infection. Alveolar macrophages harbored increased bacterial numbers due to reduced iNOS levels in Caspase-1^−/− mice. Pharmacological blockade of the IL-1 receptor in CP infected wild-type mice phenocopies Caspase-1-deficient mice, and administration of recombinant IL-1β rescues CP infected Caspase-1^−/− mice from mortality, indicating that IL-1β secretion is crucial for host immune defense against CP lung infection. In vitro investigation reveals that CP-induced IL-1β secretion by macrophages requires TLR2/MyD88 and NLRP3/ASC/Caspase-1 signaling. Entry into the cell by CP and new protein synthesis by CP are required for inflammasome activation. Neither ROS nor cathepsin was required for CP infection induced inflammasome activation. Interestingly, Caspase-1 activation during CP infection occurs with mitochondrial dysfunction indicating a possible mechanism involving the mitochondria for CP-induced inflammasome activation.

Chlamydia pneumoniae infection induced allergic airway sensitization is controlled by regulatory T-cells and plasmacytoid dendritic cells

Chlamydia pneumoniae (CP) is associated with induction and exacerbation of asthma. CP infection can induce allergic airway sensitization in mice in a dose- and time-dependent manner. Allergen exposure 5 days after a low dose (mild-moderate), but not a high dose (severe) CP infection induces antigen sensitization in mice. Innate immune signals play a critical role in controlling CP infection induced allergic airway sensitization, however these mechanisms have not been fully elucidated. Wild-type, TLR2-/-, and TLR4-/- mice were infected intranasally (i.n.) with a low dose of CP, followed by i.n. exposure to human serum albumin (HSA) and challenged with HSA 2 weeks later. Airway inflammation, immunoglobulins, eosinophils, and goblet cells were measured. Low dose CP infection induced allergic sensitization in TLR2-/- mice, but not in TLR4-/- mice, due to differential Treg responses in these genotypes. TLR2-/- mice had reduced numbers of Tregs in the lung during CP infection while TLR4-/- mice had increased numbers. High dose CP infection resulted in an increase in Tregs and pDCs in lungs, which prevented antigen sensitization in WT mice. Depletion of Tregs or pDCs resulted in allergic airway sensitization. We conclude that Tregs and pDCs are critical determinants regulating CP infection-induced allergic sensitization. Furthermore, TLR2 and TLR4 signaling during CP infection may play a regulatory role through the modulation of Tregs.

PTEN expression is down-regulated in liver tissues of rats with hepatic fibrosis induced by biliary stenosis

The gene phosphatase and tensin homolog deleted on chromosome 10 (PTEN) codes for a tumor-suppressor phospholipid phosphatase. Deletion, mutation or abnormal expression of PTEN is commonly found in many kinds of malignant tumors. At the time of this study, though, the role of PTEN expression in the pathology of hepatic fibrosis remains unclear. In this study, we investigate the dynamic expression of PTEN in a rat model of hepatic fibrosis, with special emphasis on the activation and proliferation of hepatic stellate cells (HSC) in vivo. The rat model of hepatic fibrosis used in this study employed common bile duct ligation. At four time points, the expression of PTEN in hepatic tissues and activated HSC in rat liver tissues was measured by immunohistochemical staining, Western blotting, real-time fluorescent quantitative PCR and immunofluorescence confocal laser scanning microscopy, respectively. Further, alpha-smooth muscle actin (alpha-SMA), an activated HSC marker in rat liver tissues, was detected by immunohistochemical staining. This study showed that aggravation of hepatic fibrosis led to gradually decreasing expression of PTEN in the hepatic tissues. Further, as hepatic fibrosis worsens, PTEN-expressing activated HSC accounts for an increasingly smaller percentage of all activated HSC. In contrast, the percentage of alpha-SMA-expressing HSC cells increases significantly. In conclusion, expression of PTEN mRNA and protein is down-regulated in fibrogenic rat liver tissue, and its expression in HSC in vivo also decreases with progression of fibrosis. Thus, these results show that the dynamic expression of PTEN in hepatic tissues negatively correlates with activation and proliferation of HSC.

Rad10 exhibits lesion-dependent genetic requirements for recruitment to DNA double-strand breaks in Saccharomyces cerevisiae

In the yeast Saccharomyces cerevisiae, the Rad1–Rad10 protein complex participates in nucleotide excision repair (NER) and homologous recombination (HR). During HR, the Rad1–Rad10 endonuclease cleaves 3′ branches of DNA and aberrant 3′ DNA ends that are refractory to other 3′ processing enzymes. Here we show that yeast strains expressing fluorescently labeled Rad10 protein (Rad10-YFP) form foci in response to double-strand breaks (DSBs) induced by a site-specific restriction enzyme, I-SceI or by ionizing radiation (IR). Additionally, for endonuclease-induced DSBs, Rad10-YFP localization to DSB sites depends on both RAD51 and RAD52, but not MRE11 while IR-induced breaks do not require RAD51. Finally, Rad10-YFP colocalizes with Rad51-CFP and with Rad52-CFP at DSB sites, indicating a temporal overlap of Rad52, Rad51 and Rad10 functions at DSBs. These observations are consistent with a putative role of Rad10 protein in excising overhanging DNA ends after homology searching and refine the potential role(s) of the Rad1–Rad10 complex in DSB repair in yeast.

Response of rhesus serum high density lipoproteins to cycles of diet-induced hypercholesterolemia

Two male rhesus monkeys underwent cyclical feeding of a hypercholesterolemic diet (2% cholesterol, 25% coconut oil) and a low-fat Purina monkey chow diet. During the latter diet, high density lipoprotein (HDL) exhibited two components with peak densities of d = 1.081 g/ml and 1.109 g/ml named HDLL and HDLH, respectively. During the initial hypercholesterolemic stage, except for apo A-II which remained unchanged, there was a transient rise in HDL (mainly HDLL) as well as in HDL cholesterol and apo A-I, all reaching maximal values after about 2 weeks from the onset of the diet. The two HDL species changed neither in size nor density as compared to their baseline counterparts, but had a comparatively higher content in cholesteryl ester and lesser amounts of triglycerides and phospholipids as compared to the normocholesterolemic animal. With the development of overt hypercholesterolemia (plasma cholesterol levels above 400 mg/dl), both HDL particles increased in density due to the loss of surface components (phospholipids and unesterified cholesterol) and core triglycerides with only minor changes in protein and cholesteryl ester contents. At this stage, the same two animals exhibited significant changes in the size and buoyant density of LDL. When returned to a normal Purina chow diet, the animals' serum cholesterol levels declined rapidly to normal levels; normalization of the HDL distribution also occurred but at a comparatively later time (26 weeks). Our studies indicate that the two HDL subsets characteristic of the normocholesterolemic rhesus monkey undergo significant changes in buoyant density as a function of the stage of hypercholesterolemia and that changes in concentration and size mainly affect the HDLL subspecies. At levels of plasma cholesterol below 400 mg/dl, this cholesterol increment is reflected by a significant increase in the number of the HDL subspecies without the overt participation of the low density lipoprotein classes characteristic of the advanced hyperlipidemic stage. Since we previously reported that greatly increased levels of cholesteryl esters enriched low density lipoproteins, beta-VLDL (very low density lipoprotein) and pre-beta-VLDL during overt diet-induced hypercholesterolemia, it is apparent that cholesterol is distributed differently among lipoprotein particles containing either apo A-I, apo B, or apo E depending on its concentration in plasma.