Gastrostomy Exchange With Displacement Into the Jejunum

A 54-year-old female with a gastrostomy tube presented with persistent nausea, vomiting, and abdominal pain. On physical examination, the gastrostomy tube was completely advanced into the abdominal cavity with only the external retention ring and hub on the exterior. The first step in the workup was obtaining a scout radiograph. This imaging was appropriate to show the location of the gastrostomy catheter which was overlying the left upper quadrant. The distal tip was heading in the direction of the left lower quadrant. The course of the gastrostomy catheter did not follow the expected direction of the duodenal C-loop. Proceeding forward, contrast was injected through the existing catheter which showed opacification of the jejunal bowel loops. The patient could now be properly diagnosed with gastroenteric intussusception and proper measures could be taken. Following the injected contrast showing jejunal opacification, a stiff Glidewire was advanced through the existing catheter all the way into the jejunum. Deflation of the balloon and removal of the catheter caused an almost instantaneous change in the course of the Glidewire to the more conventional path following the course of the duodenal C-loop. A sheath was then advanced over the wire which was now shown crossing the midline in the proper gastroduodenojejunal course. The final step was to advance a new 22-French MIC gastrostomy catheter over the Glidewire. The contrast was then injected to demonstrate proper opacification of the rugal folds and gastric fundus. The patient reported an immediate resolution of symptoms and was later discharged.

Deep Learning and Machine Learning Algorithms for Retinal Image Analysis in Neurodegenerative Disease: Systematic Review of Datasets and Models

Purpose

Retinal images contain rich biomarker information for neurodegenerative disease. Recently, deep learning models have been used for automated neurodegenerative disease diagnosis and risk prediction using retinal images with good results.

Methods

In this review, we systematically report studies with datasets of retinal images from patients with neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, and others. We also review and characterize the models in the current literature which have been used for classification, regression, or segmentation problems using retinal images in patients with neurodegenerative diseases.

Results

Our review found several existing datasets and models with various imaging modalities primarily in patients with Alzheimer's disease, with most datasets on the order of tens to a few hundred images. We found limited data available for the other neurodegenerative diseases. Although cross-sectional imaging data for Alzheimer's disease is becoming more abundant, datasets with longitudinal imaging of any disease are lacking.

Conclusions

The use of bilateral and multimodal imaging together with metadata seems to improve model performance, thus multimodal bilateral image datasets with patient metadata are needed. We identified several deep learning tools that have been useful in this context including feature extraction algorithms specifically for retinal images, retinal image preprocessing techniques, transfer learning, feature fusion, and attention mapping. Importantly, we also consider the limitations common to these models in real-world clinical applications.

Translational Relevance

This systematic review evaluates the deep learning models and retinal features relevant in the evaluation of retinal images of patients with neurodegenerative disease.

Programmatically Localizing Diabetic Retinopathy Features in 45-Degree Retinal Photographs Using Anatomical Colocation

Background: The aim in this study was to investigate the localization of diabetic retinopathy features at the posterior pole. Methods: This study extracted diabetic retinopathy feature locations from 757 macula-centered 45-degree fundus photographs in the publicly available DDR dataset. Arteriole and venule locations were also extracted from the RITE (n = 35) and IOSTAR (n = 29) datasets. Images were normalized to collocate optic disc and macula positions, and feature positions were collated to generate a frequency distribution matrix. Sørensen-Dice coefficients were calculated to compare the location of different features. Results: Arterioles occurred in two main, distinct arcuate patterns. Venules showed a more diffuse distribution. Microaneurysms were diffusely located around the posterior pole. Hemorrhages and exudates occurred more frequently at the temporal aspect of the macula. Cotton wool spots occurred in a region approximating the radial peripapillary capillaries. Intraretinal microvascular abnormalities and neovascularization were seen throughout the posterior pole, with neovascularization at the disc (n = 65) being more common than neovascularization elsewhere (n = 46). Venous beading occurred primarily between the first and third bifurcations of the venules. Diabetic retinopathy overall was more frequent in the temporal aspect of the macula. The location of cotton wool spots and exudates showed moderate similarity (0.52) when all data were considered, reducing to low similarity (0.18) when areas of low frequency were removed. Conclusions: Diabetic retinopathy occurs throughout the posterior pole but is more frequent in the temporal aspect of the macula. Understanding the location of diabetic retinopathy features may help inform visual search strategies for diabetic retinopathy screening.

Deep Learning Identifies High-Quality Fundus Photographs and Increases Accuracy in Automated Primary Open Angle Glaucoma Detection

Purpose

To develop and evaluate a deep learning (DL) model to assess fundus photograph quality, and quantitatively measure its impact on automated POAG detection in independent study populations.

Methods

Image quality ground truth was determined by manual review of 2815 fundus photographs of healthy and POAG eyes from the Diagnostic Innovations in Glaucoma Study and African Descent and Glaucoma Evaluation Study (DIGS/ADAGES), as well as 11,350 from the Ocular Hypertension Treatment Study (OHTS). Human experts assessed a photograph as high quality if of sufficient quality to determine POAG status and poor quality if not. A DL quality model was trained on photographs from DIGS/ADAGES and tested on OHTS. The effect of DL quality assessment on DL POAG detection was measured using area under the receiver operating characteristic (AUROC).

Results

The DL quality model yielded an AUROC of 0.97 for differentiating between high- and low-quality photographs; qualitative human review affirmed high model performance. Diagnostic accuracy of the DL POAG model was significantly greater (P < 0.001) in good (AUROC, 0.87; 95% CI, 0.80-0.92) compared with poor quality photographs (AUROC, 0.77; 95% CI, 0.67-0.88).

Conclusions

The DL quality model was able to accurately assess fundus photograph quality. Using automated quality assessment to filter out low-quality photographs increased the accuracy of a DL POAG detection model.

Translational Relevance

Incorporating DL quality assessment into automated review of fundus photographs can help to decrease the burden of manual review and improve accuracy for automated DL POAG detection.

Image harmonization and deep learning automated classification of plus disease in retinopathy of prematurity

Purpose

Retinopathy of prematurity (ROP) is a retinal vascular disease affecting premature infants that can culminate in blindness within days if not monitored and treated. A disease stage for scrutiny and administration of treatment within ROP is "plus disease" characterized by increased tortuosity and dilation of posterior retinal blood vessels. The monitoring of ROP occurs via routine imaging, typically using expensive instruments ($50 to $140 K) that are unavailable in low-resource settings at the point of care.

Approach

As part of the smartphone-ROP program to enable referrals to expert physicians, fundus images are acquired using smartphone cameras and inexpensive lenses. We developed methods for artificial intelligence determination of plus disease, consisting of a preprocessing pipeline to enhance vessels and harmonize images followed by deep learning classification. A deep learning binary classifier (plus disease versus no plus disease) was developed using GoogLeNet.

Results

Vessel contrast was enhanced by 90% after preprocessing as assessed by the contrast improvement index. In an image quality evaluation, preprocessed and original images were evaluated by pediatric ophthalmologists from the US and South America with years of experience diagnosing ROP and plus disease. All participating ophthalmologists agreed or strongly agreed that vessel visibility was improved with preprocessing. Using images from various smartphones, harmonized via preprocessing (e.g., vessel enhancement and size normalization) and augmented in physically reasonable ways (e.g., image rotation), we achieved an area under the ROC curve of 0.9754 for plus disease on a limited dataset.

Conclusions

Promising results indicate the potential for developing algorithms and software to facilitate the usage of cell phone images for staging of plus disease.

An Update on Multimodal Ophthalmological Imaging of Diffuse Choroidal Hemangioma in Sturge-Weber Syndrome

Sturge-Weber syndrome (SWS) is characterized by facial port-wine stains, leptomeningeal hemangiomas, and prominent ocular manifestations such as glaucoma and diffuse choroidal hemangiomas (DCHs). Imaging modalities are critical for diagnosing and longitudinally monitoring DCHs in SWS. Fundus photography is fundamental in assessing both eyes simultaneously, fluorescein angiography and indocyanine green angiography effectively map the retinal and choroidal circulation, and ultrasonography offers essential structural insights into the choroid and retina. NIR imaging reveals subtle retinal pigment changes, often overlooked in standard fundus examination. Enhanced depth imaging spectral domain optical coherence tomography (EDI-SDOCT) and swept-source OCT (SSOCT) improve the visualization of the choroidal-scleral boundary, essential for DCH characterization. The potential of OCT angiography (OCTA) is under exploration, particularly its role in predicting signs of disease progression or worsening, as well as potential new biomarkers such as the choroidal vascularity index (CVI). The present review aims to provide an update on multimodal imaging of DCHs in SWS.

Retinal microvasculature and incident dementia over 10 years: The Three-City-Alienor cohort

Introduction

We explored the longitudinal relationship between retinal vascular features and dementia incidence over 10 years.

Methods

Among 584 participants from the Three-City-Alienor (3C-Alienor) population-based cohort, quantitative retinal vascular features (caliber, tortuosity, fractal dimension) were measured using semi-automated software. Dementia was actively diagnosed over the follow-up period.

Results

One hundred twenty-eight participants (21.9%) developed dementia over a median of 7.1 years. In Cox proportional hazards models adjusted for sociodemographic characteristics, apolipoprotein E (APOE) ε4, and vascular factors, increased retinal arteriolar tortuosity was associated with all-cause dementia (hazard ratio per standard deviation increase, 1.21; 95% confidence interval: 1.02-1.44). Wider retinal calibers and a higher venular tortuosity were associated with mixed/vascular dementia, but not Alzheimer's disease. Fractal dimensions were not associated with dementia.

Discussion

Changes in the retinal microvasculature were associated with dementia risk. More studies are needed to replicate these findings and determine which features might help identify persons at risk at an early stage.

HIGHLIGHTS

The retinal microvasculature might reflect the brain microvasculatureWe explored the association between retinal vascular features and incident dementia584 participants from the Three-City-Alienor cohort were followed-up over 10 yearsIncreased arteriolar tortuosity and venular calibers were associated with dementia riskRetinal imaging might help identify persons at risk of future dementia.

A Rare Case of Cytomegalovirus Retinitis in a Young Immunocompetent Patient

Cytomegalovirus (CMV) is known to be the most common opportunistic infection in immunocompromised cases, and CMV retinitis is the most common ocular manifestation. Severe retinitis with involvement of the macula or retinal necrosis can lead to vision loss. Prompt diagnosis and treatment can restrict the disease's progression. We describe the case of a 30-year-old man who presented with the chief complaint of progressive diminution of vision in both eyes for 15 days. Diminution of vision was associated with fever and skin rashes. The patient had no history of diabetes, hypertension, tuberculosis, ocular trauma, ocular surgery, organ transplant history, history of immunosuppression, or previous drug history except paracetamol tablets for fever. On ocular examination on the day of presentation, the patient's best corrected visual acuity on Snellen's visual acuity chart was 6/12 and 6/24 in the right and left eyes, respectively. Fundus examination revealed a well-defined optic disc with peripapillary flame-shaped hemorrhages with exudates and an epiretinal membrane. On spectral domain optical coherence tomography (SD-OCT), macular edema was 469 µm and 421 µm in the right and left eyes, respectively. On serological examination, only cytomegalovirus IgG came out positive (1196.65 AU/ml). Based on the clinical findings, fundus examination, and lab investigations, the patient was diagnosed as having a systemic CMV infection with CMV retinitis, and treatment was started with intravenous ganciclovir. With timely diagnosis and management, the patient's vision was recovered. This is a rare case report regarding the development of CMV retinitis in a completely immunocompetent individual.

Computer-assisted evaluation of retinal vessel tortuosity in moderate-to-late preterm children

PURPOSE

Since very preterm children often have increased retinal tortuosity that may indicate decisive architectural changes in the systemic microvascular network, we used a new semi-automatic software to measure retinal vessel tortuosity on fundus digital images of moderate-to-late preterm (MLP) children.

METHODS

In this observational case-control study, the global and local tortuosity parameters of retinal vessels were evaluated on fundus photographs of 36 MLP children and 36 age- and sex-matched controls. The associations between birth parameters and parameters reflecting retinal vessel tortuosity were evaluated using correlation analysis.

RESULTS

Even after incorporation of anatomical factors, the global and local tortuosity parameters were not significantly different between groups. The MLP group showed a smaller arteriolar caliber (0.53  ±  0.2) than the controls (0.56  ±  0.2; p  =  0.013). Other local tortuosity parameters, such as vessel length, distance to fovea, and distance to optic disc, were not significantly different between arteries and veins. Tortuosity in both groups was higher among vessels closer to the fovea (r  =  -0.077, p < 0.001) and the optic disc (r  =  -0.0544, p  =  0.009). Global tortuosity showed a weakly positive correlation with gestational age and a weakly negative correlation with birth weight in both groups.

CONCLUSION

MLP patients did not display increased vessel tortuosity in comparison with the controls; however, the arteriolar caliber in the MLP group was smaller than that in children born full-term. Larger studies should confirm this finding and explore associations between cardiovascular and metabolic status and retinal vessel geometry in MLP children.

The Impact of Color Vision Deficiency on the Capability of Ophthalmologists to Diagnose Benign and Malignant Choroidal Tumors

BACKGROUND

Color vision deficiency (CVD) is an under-reported problem among medical personnel, and its impact is still not well characterized. We aim to assess the impact of CVD among ophthalmologists on the accuracy of diagnosing different benign and malignant choroidal lesions.

METHODS

This is a cross-sectional study conducted on ophthalmologists. We used a web-based survey to collect responses through professional ophthalmology society social media. The survey included a set of five images for normal fundus, choroidal nevus, circumscribed choroidal hemangioma, choroidal metastasis, and choroidal melanoma, wherein each image simulated the three main types of CVD: protanopia, deuteranopia, and tritanopia, in addition to a non-simulated image.

RESULTS

Forty-one participants were included, with a mean age of 40 (±9.2) years. They were 28 (68%) men and 13 (32%) women. Participants showed significantly low accuracy for definite diagnosis for circumscribed choroidal hemangioma, nevus, melanoma, and metastasis when the images simulated protanopia and deuteranopia, but not tritanopia. Nevertheless, participants maintained the capability to recognize the nature of the lesions for both simulated and non-simulated images if they were benign or malignant, thereby ensuring immediate referral for specialized care. The exception was with simulated choroidal nevi images, wherein participants incorrectly assigned simulated protanopia and deuteranopia nevi images to malignant lesions.

CONCLUSION

Protanopia and deuteranopia affected the accuracy of diagnosing several choroidal lesions; however, ophthalmologists with those two simulated CVDs were still able to discriminate between benign and malignant tumors.

An evaluation of the use of double-curved endoscopes for gastric gastrointestinal stromal tumors

BACKGROUND

Endoscopic full-thickness resection (EFTR) is a standard treatment method for gastric gastrointestinal stromal tumors (gGISTs). Evidence of the safety and efficacy of a double-curved endoscope (DCE) in EFTR of gGISTs is limited. We aimed to compare the operative outcomes of DCE versus single-curved endoscopes (SCE) in EFTR of gGISTs.

MATERIAL AND METHODS

This retrospective observational study was conducted at four Chinese tertiary institutes. From January 2019 to November 2021, 104 patients who underwent EFTR by SCE (n = 57) or DCE (n = 47) were enrolled. One-to-one propensity score matching (PSM) was performed between the two groups to compare the demographics and operative outcomes.

RESULTS

All gGISTs were resected successfully with no recurrence during follow-up. The median (range) tumor size was 1.2 (0.5, 3.5) cm in DCE and 2.0 (0.6, 4.8) cm in SCE (p < .001), and the procedure time was shorter in the DCE group than in the SCE group (50.0 min vs. 62.0 min, p < .05). After PSM, 41 pairs were selected, and no difference was noted in demographics. The procedure time was also shorter in the DCE group than in the SCE group (50.0 min vs. 55.0 min, p < .05). Subgroup analysis showed that the DCE group had a shorter procedure time in the gastric fundus than the SCE group (47.0 min vs. 55.0 min, p < .05). In multiple linear regression analysis, significant factors related to prolonged procedure time were the type of endoscope of SCE and larger tumor size (p < .05).

CONCLUSIONS

EFTR of gGISTs using DCE is safe and effective. Compared with SCE, DCE had an advantage in terms of operative time, especially in the gastric fundus.

Effect of palmitoylethanolamide on degeneration of a human-derived retinal pigment epithelial cell induced by all-trans retinal

AIM

To study the effect of palmitoylethanolamide (PEA) on apoptosis of retinal pigment epithelial (RPE) cells induced by all-trans retinal (atRAL) and to explore the possible molecular mechanism.

METHODS

CellTiter 96^® Aqueous One Solution Cell Proliferation Assay (MTS) was used to detect the effect of PEA on human-derived retinal epithelial cells (ARPE-19) viability induced by atRAL. A Leica DMi8 inverted microscope was used to observe cell morphology. Reactive oxygen species (ROS) production was evaluated with 2',7'-dichlorodihydrof-luorescein diacetate (H2DCFDA) staining and fluorescence microscopy. Expression of c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), c-Jun, phosphorylated c-Jun (p-c-Jun), Bak, cleaved caspase-3, C/EBP homologous protein (CHOP), and binding (Bip) protein levels were tested by Western blot. Abca4 ^-/- Rdh8 ^-/- mice, mouse models of atRAL clearance defects which displays some symbolic characteristics of dry age-related macular degeneration (AMD) and Stargardt disease (STGD1). In the animal models, PEA was injected intraperitoneally. The full-field electroretinogram was used to detect visual function under scotopic conditions traced from mice. Optical coherence tomography showed reconstitution or thickening of the retinal pigment epithelium layer. Effect of PEA on fundus injury induced by light in Abca4^-/-Rdh8^-/- mice was observed by fundus photography.

RESULTS

PEA ameliorated ARPE-19 cells apoptosis and inhibited ROS (including mitochondrial ROS) production induced by atRAL. PEA improved the retinal functional, prohibited both RPE and photoreceptor from death, ameliorates light-induced fundus impairment in Abca4 ^-/- Rdh8 ^-/- mice. In vitro and in vivo, PEA inhibited JNK, p-JNK, c-Jun, p-c-Jun, Bak, cleaved caspase-3, CHOP, and Bip protein levels induced by all-trans retinal in ARPE-19 cells.

CONCLUSION

PEA has effect on treating RPE cells apoptosis in retinopathy caused by atRAL accumulation. PEA is a potential treatment strategy for dry AMD and STGD1. The molecular mechanism is affecting the ROS-JNK-CHOP signaling pathway partly.

Ocular Manifestations in Pregnancy-Induced Hypertension at a Tertiary Level Hospital in Karnataka, India

Introduction Pregnancy-induced hypertension (PIH) is a hypertensive disorder in pregnancy that occurs after 20 weeks of pregnancy in the absence of previously known hypertension. PIH is a common and serious complication accompanying pregnancy. Pre-eclampsia and eclampsia are multisystem disorders that can involve end organs like kidneys, liver, eyes, haematopoietic system and placenta. Though ocular involvement is not uncommon in PIH, ocular examination is not always done in all cases of PIH. Timely detection of changes in retinal vasculature can be a hint to the underlying changes in the vascular system of the various end organs of the human body including placental circulation. Adequate management of PIH is very important for both fetal and maternal well-being. Aim To evaluate the ocular manifestations in women affected by PIH (mild pre-eclampsia, severe pre-eclampsia and eclampsia) presenting to a tertiary-level hospital. Methodology This was a hospital-based cross-sectional study carried out for a period of one year at a tertiary-level hospital. A total of 120 subjects diagnosed as cases of pre-eclampsia/eclampsia admitted to the eclampsia ward of the obstetric unit formed the study population. After taking history, a detailed ocular examination was done for all patients and the findings were noted. Results The mean age of the study population was 31.91 ± 4.38 years (range 21 to 39 years). The mean gestational age was 30.89 ± 3.98 weeks. Fifty-three (44.17%) were primigravida, 64 (53.33%) were multiparous, and three (2.5%) were grand multiparous. Sixty-two (51.67%) had mild pre-eclampsia, 50 (41.67%) had severe pre-eclampsia and eight (6.67%) had eclampsia. The mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) recorded in the study were 155.32 ± 11.89 mmHg and 104.3 ± 11.41 mmHg respectively. Ocular symptoms were present in 43 (35.83%) participants. Blurring of vision (19.17%) was the commonest ocular symptom observed in the study population followed by photopsia (13.33%), diplopia (9.17%), intermittent loss of vision (5.83%), ocular pain (6.67%), and scotoma (1.67%). Systemic symptoms included headache (11.67%), epigastric pain (3.33%), and nausea (5%). Anterior segment findings like conjunctival congestion, lid edema, and subconjunctival hemorrhage each accounted for 1.67% of the study population. Fundal changes were present in 33.33% of cases. Arteriolar narrowing was the commonest fundal finding amounting to 15.83%, followed by arteriovenous (AV) crossing changes also in 15.83%, cotton wool spots in 5.83%, retinal haemorrhages in 8.33%, papilledema in 2.5%, and choroidal infarcts in 1.67% participants. Grade 1 hypertensive retinopathy was observed in 15.83% of participants, grade 2 in 8.33% of participants, grade 3 in 6.67% of participants and grade 4 in 2.5% of participants. The mean SBP and mean DBP were high among those with fundal changes (163.35 ± 10.25 mmHg and 111.15 ± 10.29 mmHg) compared to those without fundal changes (151.3 ± 10.58 mmHg and 100.88 ± 10.41 mmHg). This was statistically significant. Proteinuria showed significant correlation with retinal changes. Conclusion The retinal vasculature changes correlate with the severity of hypertension, hence, it is very important to seek ophthalmologic opinion for evaluation, diagnosis and prompt management of PIH.

Effect of Highly Active Antiretroviral Therapy on Fundus Images and Retinal Microvessel Diameter in HIV/AIDS Patients

Introduction

We aimed to investigate whether there were changes in fundus picture and retinal microvascularity of patients with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) who were treated with highly active antiretroviral therapy (HAART).

Methods

From July 2015 to November 2016, 130 HIV/AIDS patients were collected by the Yunnan Institute of Traditional Chinese Medicine, including 63 treatment-naïve patients and 67 that received HAART for 12 months. Fundus picture lesions, retinal microvascular diameters, CD4+ T lymphocyte count and HIV-1 plasma viral loads were compared between the two groups. The recruited patients were mainly young and middle-aged, with more males than females. There were no significant differences in smoking history, comorbidities and opportunistic infections between the two groups.

Results

According to the analysis results from SPSS 20.0 software, the number of CD4+ T lymphocytes in the treated patients (563.34±2.56 cells/μL) increased significantly (P=0.009) as compared with untreated patients (451.37±2.10 cells/μL), and the HIV-1 plasma viral load reduced considerably (4794 vs 0 copy/mL, P=0.000). No significant differences were observed from the fundus picture of patients after effective HAART therapy, including the retinal artery diameter, venous diameter and arteriovenous diameter ratio.

Building Clinical Skills Teaching Materials: A Study of Cognitive Task Analysis Versus Free Recall Instruction to Teach Canine Indirect Ophthalmoscopy

Ophthalmoscopy is a core component of a complete ophthalmic examination. Due to its complex technical aspects and patients becoming uncooperative if the procedure is prolonged, it can be a difficult skill for a novice to learn and develop proficiency in. Skills instruction is typically provided by subject matter experts (SMEs) through free recall without an agreed-upon instructional framework. This can lead to unintentional omission of essential steps and knowledge required to perform skills correctly. Cognitive task analysis (CTA) allows for construction of standardized instructional protocols that encompass the knowledge and skills experts apply when performing tasks. The objectives of this study were to (a) develop a CTA-based teaching protocol for canine indirect ophthalmoscopy and (b) compare the steps verbalized or demonstrated by SMEs during free recall instruction versus those ultimately identified by CTA. Four SMEs participated in free recall instructional sessions and interviews used for the development of a CTA-based teaching protocol for novice learners. The CTA-based protocol identified 66 steps and sub-steps considered essential for successfully performing canine indirect ophthalmoscopy. During instructional sessions, SMEs on average failed to verbalize 57.1% of clinical knowledge steps, did not verbalize or demonstrate 68.3% and 9.5% of action steps, and did not verbalize or demonstrate 73.2% and 40.4% of decision steps, respectively. This study demonstrates that SMEs teaching indirect ophthalmoscopy by free recall may unintentionally omit important steps, suggesting that compared with free recall, CTA may generate more comprehensive and thus potentially more effective instructional materials for teaching technical skills in veterinary medicine.

Fundus findings in patients admitted with post COVID-19 sepsis in an intensive care unit

Purpose

COVID-19 infection is being increasingly identified as a risk factor for the development of ocular infections, especially endogenous endophthalmitis. Current studies primarily report cases among survivors, and the overall prevalence, especially amongst patients admitted with active sepsis is unknown. We report on the fundus and systemic findings of inpatients who were being treated for post-COVID-19 systemic secondary infections in a tertiary intensive care unit.

Methods

Retrospective observational study based on chart review.

Results

A total of 24 patients were identified. These included 21 (87.5%) males and 3 (12.5%) females with ages ranging from 33 to 72 years (mean 54.1 years). Pre-existing risk factors included type 2 diabetes mellitus, systemic hypertension, chronic kidney disease, multiple myeloma, and patients on long-term corticosteroid/immunosuppressive treatment. Nine patients (37.5%) died and 15 (62.5%) survived. Of a total of 48 eyes, observed fundus lesions included endogenous endophthalmitis (4 eyes of 2 patients, 8.3%), preretinal hemorrhages (4 eyes of 2 patients, 8.3%), optic disc pallor (2 eyes of 1 patient, 4.1%), moderate non-proliferative diabetic retinopathy (4 eyes of 2 patients, 8.3%), Roth spots (2 eyes of 1 patient, 4.1%), and 2 eyes of 1 patient (4.1%) with evidence of previous pan-retinal photocoagulation.

Conclusion

Two patients had evidence of endogenous endophthalmitis. These findings suggest that the actual incidence of ocular lesions, especially infections is higher than that reported. Fundus examination should form a part of the management protocol for patients being treated for post-COVID-19 systemic infections.

Organisation of the musculature of the rat stomach

The strengths, directions and coupling of the movements of the stomach depend on the organisation of its musculature. Although the rat has been used as a model species to study gastric function, there is no detailed, quantitative study of the arrangement of the gastric muscles in rat. Here we provide a descriptive and quantitative account, and compare it with human gastric anatomy. The rat stomach has three components of the muscularis externa, a longitudinal coat, a circular coat and an internal oblique (sling) muscle in the region of the gastro-oesophageal junction. These layers are similar to human. Unlike human, the rat stomach is also equipped with paired muscular oesophago-pyloric ligaments that lie external to the longitudinal muscle. There is a prominent muscularis mucosae throughout the stomach and strands of smooth muscle occur in the mucosa, between the glands of the corpus and antrum. The striated muscle of the oesophageal wall reaches to the stomach, unlike the human, in which the wall of the distal oesophagus is smooth muscle. Thus, the continuity of gastric and oesophageal smooth muscle bundles, that occurs in human, does not occur in rat. Circular muscle bundles extend around the circumference of the stomach, in the fundus forming a cap of parallel muscle bundles. This arrangement favours co-ordinated circumferential contractions. Small bands of muscle make connections between the circular muscle bundles. This is consistent with a slower conduction of excitation orthogonal to the circular muscle bundles, across the corpus towards the distal antrum. The oblique muscle merged and became continuous with the circular muscle close to the gastro-oesophageal junction at the base of the fundus, and in the corpus, lateral to the lesser curvature. Quantitation of muscle thickness revealed gradients of thickness of both the longitudinal and circular muscle. This anatomical study provides essential data for interpreting gastric movements.

Screening of Common Retinal Diseases Using Six-Category Models Based on EfficientNet

Purpose

A six-category model of common retinal diseases is proposed to help primary medical institutions in the preliminary screening of the five common retinal diseases.

Methods

A total of 2,400 fundus images of normal and five common retinal diseases were provided by a cooperative hospital. Two six-category deep learning models of common retinal diseases based on the EfficientNet-B4 and ResNet50 models were trained. The results from the six-category models in this study and the results from a five-category model in our previous study based on ResNet50 were compared. A total of 1,315 fundus images were used to test the models, the clinical diagnosis results and the diagnosis results of the two six-category models were compared. The main evaluation indicators were sensitivity, specificity, F1-score, area under the curve (AUC), 95% confidence interval, kappa and accuracy, and the receiver operator characteristic curves of the two six-category models were compared in the study.

Results

The diagnostic accuracy rate of EfficientNet-B4 model was 95.59%, the kappa value was 94.61%, and there was high diagnostic consistency. The AUC of the normal diagnosis and the five retinal diseases were all above 0.95. The sensitivity, specificity, and F1-score for the diagnosis of normal fundus images were 100, 99.9, and 99.83%, respectively. The specificity and F1-score for RVO diagnosis were 95.68, 98.61, and 93.09%, respectively. The sensitivity, specificity, and F1-score for high myopia diagnosis were 96.1, 99.6, and 97.37%, respectively. The sensitivity, specificity, and F1-score for glaucoma diagnosis were 97.62, 99.07, and 94.62%, respectively. The sensitivity, specificity, and F1-score for DR diagnosis were 90.76, 99.16, and 93.3%, respectively. The sensitivity, specificity, and F1-score for MD diagnosis were 92.27, 98.5, and 91.51%, respectively.

Conclusion

The EfficientNet-B4 model was used to design a six-category model of common retinal diseases. It can be used to diagnose the normal fundus and five common retinal diseases based on fundus images. It can help primary doctors in the screening for common retinal diseases, and give suitable suggestions and recommendations. Timely referral can improve the efficiency of diagnosis of eye diseases in rural areas and avoid delaying treatment.

Application of Artificial Intelligence in Ophthalmology for the Diagnosis and Treatment of Eye Diseases

In this paper, we present the main aspects of artificial intelligence application in ophthalmology for the diagnosis and treatment of eye diseases on the example of developing a computer system for personalizing retinal laser photocoagulation. Approaches to the automation of eye disease prediction and treatment based on fundus images are described. Four problems of applying the neural network approach are highlighted. Decision support information technology for personalizing laser treatment of diabetic macular edema and identifying prognostic factors of surgical outcome using methods of intellectual analysis of large unstructured data is described. The system allows the doctor to form a plan of optimal coagulation arrangement for retinal laser coagulation for each case, to predict the quality of laser coagulation depending on the initial data on the localization and severity of edema and to improve his skills by comparing the result of coagulation performed and the coagulation plan proposed by the system.

Use of offline artificial intelligence in a smartphone-based fundus camera for community screening of diabetic retinopathy

Purpose:

The aim of the study was to analyse the reliability of an offline artificial intelligence (AI) algorithm for community screening of diabetic retinopathy.

Methods:

A total of 1378 patients with diabetes visiting public dispensaries under the administration of the Municipal Corporation of Greater Mumbai between August 2018 and September 2019 were enrolled for the study. Fundus images were captured by non-specialist operators using a smartphone-based camera covering the posterior pole, including the disc and macula, and the nasal and temporal fields. The offline AI algorithm on the smartphone marked the images as referable diabetic retinopathy (RDR) or non-RDR, which were then compared against the grading by two vitreoretinal surgeons to derive upon the sensitivity and specificity of the algorithm.

Results:

Out of 1378 patients, gradable fundus images were obtained and analysed for 1294 patients. The sensitivity and specificity of diagnosing RDR were 100% (95% CI: 94.72–100.00%) and 89.55% (95% CI: 87.76–91.16%), respectively; the same values for any diabetic retinopathy (DR) were 89.13% (95% CI: 82.71–93.79%) and 94.43% (95% CI: 91.89–94.74%), respectively, with no false-negative results.

Conclusion:

The robustness of the offline AI algorithm was established in this study making it a reliable tool for community-based DR screening.

Acute Retinal Necrosis in an Immunocompetent Patient Treated With Intravitreal Ganciclovir

Acute retinal necrosis (ARN) is an inflammatory syndrome of high clinical concern; untreated or misdiagnosed cases may progress to optic neuropathy or retinal detachment, leading to irreversible blindness. ARN affects men and women equally and is often seen in immunocompromised patients but is also known to present in immunocompetent patients. It is usually due to systemic viral infection with secondary vitreoretinal inflammation. Most commonly, the first-line management of ARN is oral or intravenous antiviral therapy. Here, we report the case of an immunocompetent patient presenting with necrotizing retinopathy secondary to ARN. This patient was treated with oral valacyclovir and then intravenous acyclovir with no improvement. However, intravitreal injection of ganciclovir successfully halted the progression of ARN and led to the preservation of vision in the patient.

A Novel, Smartphone-Based, Teleophthalmology-Enabled, Widefield Fundus Imaging Device With an Autocapture Algorithm

Purpose

Widefield imaging can detect signs of retinal pathology extending beyond the posterior pole and is currently moving to the forefront of posterior segment imaging. We report a novel, smartphone-based, telemedicine-enabled, mydriatic, widefield retinal imaging device with autofocus and autocapture capabilities to be used by non-specialist operators.

Methods

The Remidio Vistaro uses an annular illumination design without cross-polarizers to eliminate Purkinje reflexes. The measured resolution using the US Air Force target test was 64 line pairs (lp)/mm in the center, 57 lp/mm in the middle, and 45 lp/mm in the periphery of a single-shot retinal image. An autocapture algorithm was developed to capture images automatically upon reaching the correct working distance. The field of view (FOV) was validated using both model and real eyes. A pilot study was conducted to objectively assess image quality. The FOVs of montaged images from the Vistaro were compared with regulatory-approved widefield and ultra-widefield devices.

Results

The FOV of the Vistaro was found to be approximately 65° in one shot. Automatic image capture was achieved in 80% of patient examinations within an average of 10 to 15 seconds. Consensus grading of image quality among three graders showed that 91.6% of the images were clinically useful. A two-field montage on the Vistaro was shown to exceed the cumulative FOV of a seven-field Early Treatment Diabetic Retinopathy Study image.

Conclusions

A novel, smartphone-based, portable, mydriatic, widefield imaging device can view the retina beyond the posterior pole with a FOV of 65° in one shot.

Translational Relevance

Smartphone-based widefield imaging can be widely used to screen for retinal pathologies beyond the posterior pole.

A Retrospective Experience of Helicobacter pylori Histology in a Large Sample of Subjects in Northern Italy

Updated data about the prevalence of Helicobacter pylori (H. pylori) and its correlation with histological results are scarce. The aim of our study was to provide current data on the impact of H. pylori in a third-level endoscopy service. We performed a large, retrospective study analyzing the results of all histological samples of gastroscopy from the year 2019. In total, 1512 subjects were included. The prevalence of H. pylori was 16.8%. A significant difference between the prevalence in subjects born in Italy and those from eastern Europe, south America, or Africa was found (p < 0.0001, p = 0.006, and p = 0.0006, respectively). An association was found between H. pylori and active superficial gastritis (p < 0.0001). Current H. pylori and/or a previous finding of H. pylori was related to antral atrophy (p < 0.0001). Fifteen patients had low-grade dysplasia. There were no statistically significant associations with current or past H. pylori infection. One patient presented gastric cardia adenocarcinoma with regular gastric mucosa. One patient, H. pylori positive, was diagnosed with gastric signet ring cell adenocarcinoma in a setting of diffuse atrophy, without metaplasia.. Our study provides updated, solid (biopsy diagnosis and large population) data on the prevalence of H. pylori infection in a representative region of southern Europe.

A case of retinal vascular involvement in a 6-year-old patient with Covid-19

Purpose:

This study evaluated fundus changes in a 6-year-old child who contracted Sars-CoV-2 without developing symptoms of the disease.

Materials and methods:

The patient underwent a complete ophthalmic evaluation, which included assessment of visual acuity with and without correction, extensive ophthalmological examination, cicloplegic refraction by retinoscopy and funduscopic examination, OCT, and angio-OCT examination.

Results:

Fundoscopic examination in a young patient with previous Sars-CoV-2 infection showed marked vascular tortuosity, evident both at the posterior pole and retinal periphery, especially on the arterial vasculature, and cotton wool spots along the retinal vessels, highlightable also at OCT and angio-OCT examination. These alterations persist at a 6-month follow-up.

Conclusions:

In COVID-19 infection, even in asymptomatic pediatric patients, vasculitis develops also affecting the retinal vessels, appreciable on fundus examination. A thorough eye examination in all COVID-19 patients with close follow-up is therefore important. This is the first case report on retinal changes in a pediatric patient.

Teaching Smartphone Funduscopy with 20 Diopter Lens in Undergraduate Medical Education

Purpose

To assess attitudes of pre-clinical undergraduate medical students toward learning smartphone funduscopy (SF) and its appropriateness as a teaching tool.

Patients and Methods

Second year medical students received instruction on direct ophthalmoscopy (DO) and SF; they were then paired with a peer and randomly assigned to perform DO or SF first. The SF technique involved freehand alignment of the axes of the smartphone camera with a condenser lens. Both techniques were done through a maximally dilated pupil. A questionnaire was completed to acquire data on baseline experience, performance of both examination techniques, attitudes, and appropriateness. Statistical significance testing and Bland-Altman analysis were used to determine differences between DO and SF, and a multivariable mixed regression model was fitted to identify any predictors for positive attitudes toward DO or SF.

Results

One hundred thirty-seven (137) individuals completed the study. A similar proportion of students could identify the optic nerve, macula, and vessels using DO and SF. However, self-reported quality scores were higher for DO for the optic nerve (p = 0.006) and macula (p = 0.08). The mean (standard deviation) attempts to identify these major structures were 2.7 (SD 2.3) for DO and 4.5 (SD 2.9) for SF (p < 0.001). Attitudes of students were consistently more positive toward DO across the five questions assessed. A small subset of students had equally positive attitudes toward DO and SF. Improved quality scores were predictive of positive attitudes for both DO and SF. Ultimately, 24% of students preferred SF over DO.

Conclusion

Among inexperienced examiners of the fundus through a dilated pupil, SF is a non-inferior technique to DO in identifying structures. Despite overall favorable attitudes towards the more familiar DO, those students who quickly learned the SF technique had similar satisfaction scores. Teaching SF should be considered in undergraduate medical education.

Whole genome transcriptome analysis of the stomach resected in human vertical sleeve gastrectomy: cutting more than calories

Vertical sleeve gastrectomy (VSG) is a surgical weight loss procedure that resects 80% of the stomach, creating a tube linking the esophagus to the duodenum. Because of the efficacy and relative simplicity of VSG, it is preferred in the United States, with VSG currently at >61% of bariatric surgeries performed. Surprisingly, there has never been a complete molecular characterization of the human stomach greater curvature's fundus and corpus. Here we compare and contrast the molecular makeup of these regions. We performed a prospective cohort study to obtain gastric tissue samples from patients undergoing elective VSG. Paired fundus and corpus samples were obtained. Whole genome transcriptome analysis was performed by RNA sequencing (N = 10), with key findings validated by qPCR (N = 24). Participants were primarily female (95.8%) and White (79.15%). Mean body mass index, body weight, and age were 46.1 kg/m², 121.6 kg, and 43.29 yr, respectively. Overall, 432 gene transcripts were significantly different between the fundus and the corpus (P < 0.05). A significant correlation was found between the RNA sequencing dataset and qPCR validation, demonstrating robust gene expression differences between the fundus and the corpus. Significant genes included progastricsin, acidic chitinase, and gastokine 1 and 2 in both the fundus and the corpus. Of the very highly expressed genes in both regions, 87% were present in both the stomach's fundus and corpus, indicating substantial overlap. Despite significant overlap in the greater curvature gene signature, regional differences exist within the fundus and the corpus. Given that the mechanism of VSG is partly unresolved, the potential that the resected tissue may express genes that influence long-term body weight regulation is unknown and could influence VSG outcomes.

Relationship of motor mechanisms to gastroparesis symptoms: toward individualized treatment

Following a classical paper by Dr. Keith A. Kelly published in this journal, and over the past 40 years, there has been increased understanding of the functions of different regions of the stomach, specifically the fundus, antrum, and pylorus. Several of the important physiological principles were based on in vivo animal studies that led to the appreciation of regional function and control mechanisms. These include the roles of the extrinsic parasympathetic vagal innervation, the gastric enteric nervous system and electrical syncytium consisting of pacemaker cells and smooth muscle cells, and duodenogastric reflexes providing feedback regulation following the arrival of food and hydrogen ions stimulating the release of hormones and vagal afferent mechanisms that inhibit gastric motility and stimulate pyloric contractility. Further insights on the role of regional motor functions in gastric emptying were obtained from observations in patients following diverse gastric surgeries or bariatric procedures, including fundoplication, Billroth I and sleeve gastrectomy, and sleeve gastroplasty. Antropyloroduodenal manometry and measurements of pyloric diameter and distensibility index provided important assessments of the role of antral hypomotility and pylorospasm, and these constitute specific targets for individualized treatment of patients with gastroparesis. Moreover, in patients with upper gastrointestinal symptoms suggestive of gastroparesis, the availability of measurements of gastric accommodation and pharmacological agents to reduce gastric sensitivity or enhance gastric accommodation provide additional specific targets for individualized treatment. It is anticipated that, in the future, such physiological measurements will be applied in patients to optimize choice of therapy, possibly including identifying the best candidate for pyloric interventions.

The significance of anatomic tumor location in gallbladder cancer

BACKGROUND AND OBJECTIVES

Current management guidelines recognize the impact of hepatic versus peritoneal sided gallbladder cancers (GBC) on survival. However, no data exist regarding the significance of anatomic tumor location within the gallbladder.

METHODS

We retrospectively analyzed all GBC that underwent surgical resection with curative intent in our health system from 2007 to 2017. We evaluated the effect of anatomic pathologic tumor location (fundus/body, neck, and multifocal) on clinicopathologic, perioperative, and oncologic outcomes.

RESULTS

About 97 patients met criteria; 63% fundus/body, 22% multifocal, and 15% neck. Compared with fundus/body, neck tumors more frequently presented with preoperative jaundice (53% vs. 13%, p < .001), were smaller (20 mm vs. 30 mm, p = .068) and had significantly more biliary tree invasion (33% vs. 13%, p = .030) on histopathology. Although tumor characteristics (pTNM stage, liver invasion, lymphovascular invasion, prognostic nutritional index, and grade) were similar, neck tumors had significantly higher rates of R0 resection (53% vs. 11%, p < .001). Rates of adjuvant therapy were similar. Median PFS was similar between cohorts (p = .356). However, median overall survival (OS) was significantly shorter in neck (21 months) than fundus/body tumors (NR > 109 months), p = .015.

CONCLUSIONS

Neck tumors were rare, small and more likely to result in jaundice secondary to biliary tree invasion. Despite higher R0 resection rates, these tumors had significantly worse OS.

Fuchs' Uveitis: Is It Different from What We Know?

BACKGROUND

To describe ocular findings in Turkish patients with Fuchs' uveitis (FU).

METHODS

The medical records of FU were retrospectively reviewed.

RESULTS

The study included 281 eyes of 258 patients with FU. There were diffusely spread keratic precipitates (KPs)[(medium sized in 253 (90.0%) eyes, stellate-medium in 28 (10%) eyes)], Koeppe nodules (KN) in 64 (22.8%) eyes and cataract in 129 (45.9%) eyes. There was vitreous infiltration of varying grades in all eyes (100%) with grade 1 haze in 96 (34.2%) eyes, grade 2 haze in 69 (24.6%) eyes, and grade 3 haze in 63 (22.4%) eyes. Stellate-medium KPs were significantly more likely in eyes with KN than in eyes without KN (28.1 vs. 4.6%, p <.001) and in eyes with +3 vitreous haze than in those without +3 vitreous haze (28.6 vs. 4.6%, p <.001).

CONCLUSION

Vitreous involvement is the most frequent posterior segment finding. Posterior involvement is a feature that should not be ignored.Stellate-medium KPs and KN may be an indicator of increased and chronic inflammation.

Quality and Feasibility of Automated Digital Retinal Imaging in the Emergency Department

BACKGROUND

Emergency physicians (EPs) frequently evaluate patients at risk for sight-threatening conditions but may have difficulty performing direct ophthalmoscopy effectively. Digital fundus photography offers a potential alternative.

OBJECTIVE

We sought to assess the performance of an automated digital retinal imaging platform in a real-world emergency department.

METHODS

We performed a prospective, observational study of emergency department patients who were at risk for acute, nontraumatic, posterior segment pathology. Photographs were obtained using an automated digital retinal camera and were subsequently reviewed by an ophthalmologist. We recorded the number of attempts required, total time required, patient comfort, and findings on EP-performed direct ophthalmoscopy, if performed.

RESULTS

Of 123 participants completing the study, 93 (75.6%) had ≥1 eye with a diagnostically useful image, while 29 (23.6%) had no photographs of diagnostic value. The mean number of attempts required to obtain images was 1.45 (range 1-3) and the mean elapsed time required to complete photography was 109.6 s. The mean patient comfort score was 4.6 on a 5-point scale, where 5 was the most comfortable. Direct ophthalmoscopy was performed by an emergency department provider for 19 (15.4%) patients. Acute findings were noted in 14 patients during expert review of fundus photographs, though in only 2 of these cases was direct ophthalmoscopy performed by an EP with only 1 finding ultimately identified correctly.

CONCLUSIONS

Automated digital imaging of the ocular fundus is rapidly performed, is well tolerated by patients, and can be used to obtain diagnostic quality images without the use of pharmacologic pupillary dilation in most emergency department patients who are at risk for acute posterior segment pathology.

Retinal vascular abnormalities in schizophrenia and bipolar disorder: A window to the brain

OBJECTIVES

The examination of retinal microvascular abnormalities through fundus photography is currently the best available non-invasive technique for assessment of cerebral vascular status. Several studies in the last decade have reported higher incidences of adverse cerebrovascular events in Schizophrenia (SCZ) and bipolar disorder (BD). However, retinal microvasculature abnormalities in SCZ and BD have remained under-explored, and no study has compared this aspect of SCZ and BD till date.

METHODS

Retinal Images of 100 SCZ patients, BD patients, and healthy volunteers each were acquired by trained individuals using a non-mydriatic camera with a 40-degree field of view. The retinal images were quantified using a valid semi-automated method. The average of left and right eye diameters of the venules and arterioles passing through the extended zone between 0.5 and 2 disc diameters from the optic disc were calculated.

RESULTS

The groups differed significantly with respect to average diameters of both retinal venules (P < 0.001) and retinal arterioles (P < 0.001), after controlling for age and sex. Both SCZ and BD patients had significantly narrower arterioles and wider venules compared to HV. There were also significant differences between SCZ and BD patients; patients with BD had narrower arterioles and wider venules.

CONCLUSION

Considering the affordability and easy accessibility of the investigative procedure, retinal microvascular examination could serve as a potential screening tool to identify individuals at risk for adverse cerebrovascular events. The findings of the current study also provide a strong rationale for further systematic examination of retinal vascular abnormalities in SCZ and BD.

The grey fovea sign of macular oedema or subfoveal fluid on non-stereoscopic fundus photographs

PURPOSE

To describe the grey fovea sign of fovea-involving macular oedema or subretinal fluid accumulation in red-free fundus photography.

METHODS

A test set of 91 digital fundus photographs of good quality from 100 consecutive eyes in 72 patients with diabetic retinopathy or central serous chorioretinopathy was composed by one of the investigators and evaluated by four masked observers. The photographs were graded as to whether a normal dark fovea was present or absent. The reference method was foveal thickness measurement using optical coherence tomography (OCT).

RESULTS

Eyes graded as having a grey fovea on fundus photographs (n = 67) had a median foveal thickness of 279 μm (interquartile range 130 μm), whereas eyes graded as having a normal dark fovea (n = 24) had a median foveal thickness of 238 μm (interquartile range 44.5 μm, p = 0.025).

CONCLUSION

The absence of a dark fovea on red-free greyscale fundus photographs is a sign of foveal thickening or detachment that can be reliably recognized by graders when using OCT as the reference diagnostic method. Awareness of the grey fovea sign may facilitate fundus photographic screening for maculopathy because its absence is a reliable sign that no foveal oedema or detachment is present. Its presence may indicate that such conditions are present, but it can also be induced by various other conditions, for which reason it should prompt further investigations by OCT.

Correlation of ultra-widefield fundus autofluorescence patterns with the underlying genotype in retinal dystrophies and retinitis pigmentosa

PURPOSE

Ultra-widefield fundus autofluorescence (UW-FAF) allows the characterization of the peripheral retinal features of vitreoretinal diseases. The purpose of this study was to examine possible genotypic/phenotypic correlations of UW-FAF patterns in patients with a variety of retinal dystrophies and retinitis pigmentosa (RP).

METHODS

An IRB-approved retrospective consecutive case series study was performed of genetically characterized retinal dystrophy or RP patients who underwent UW-FAF imaging. UW-FAF was performed with the Optos 200Tx system. Clinical variables, genotypic analysis, and phenotypic characteristics were reviewed.

RESULTS

Seventeen patients were identified who had identified mutations in retinal dystrophy or RP genes and who also had undergone UW-FAF. Three patients had X-linked RP with RPGR mutations. Six patients had autosomal dominant RP (four with RHO mutations and one with a PRPF31 mutation, and one with RDS/PRPH2 mutation). Four patients had autosomal recessive RP (four with USH2A mutations). Three patients had Leber Congenital Amaurosis (LCA) with mutations including CRB1, CEP290, and RPGRIP1. Macular hyperautofluorescence was noted in all patients. A ring of hyperautofluorescence was clear in patients with RHO and USH2A mutations, and patients with USH2A mutations demonstrated a second ring of hyperautofluorescence. In the periphery, patients with RHO or RPGR mutations exhibited hyperautofluorescence with patchy areas of hypoautofluorescence. Patients with USH2A mutations had a distinctive pattern of diffuse and homogeneous peripheral hypoautofluorescence.

CONCLUSION

UW-FAF may provide important information to facilitate diagnosis and further research is needed to better characterize this technology as an imaging biomarker for genotype association in retinal dystrophies and RP.

Comparison between indocyanine green angiography and fluorescein angiography in normal cats

OBJECTIVE

To study a new approach to indocyanine green (ICG) angiography for contrasting the ocular fundus in cats.

ANIMALS STUDIED

Six healthy laboratory cats.

PROCEDURES

Fluorescein (FLUO) and ICG angiography were performed using an infrared-sensitive charged coupled device-equipped fundus camera on sedated cats.

RESULTS

At 12.3 ± 3.4 s after ICG administration, the choroidal arteries could be seen extending radially from the optic disk. The choroidal veins became apparent at 16.2 ± 4.1 s alongside the choroidal arteries. Gradual fading of the choroidal vessels began 5.8 ± 1.5 min postdye administration and diffuse fluorescence of the fundus appeared. Diffuse fluorescence of the optic disk faded at about 18.8 ± 2.9 min. Mean arterial blood pressure at 1 and 3 min after ICG administration showed no significant change when compared to pre-administration (P > 0.05). However, 5 min (P = 0.054) and 10 min (P < 0.05) postadministration, a significant drop in blood pressure occurred. The time lapse between FLUO administration and its appearance in the ocular fundus was 15.7 ± 3.8 s. Retinal veins became apparent at 22.0 ± 3.6 s alongside retinal arteries. At 31.2 ± 4.1 s, full venous fluorescence was visualized throughout the entire fundus.

CONCLUSIONS

While FLUO angiography shows only the retinal vessels, ICG angiography enabled visualization of the choroidal vasculature. ICG angiography provides clear resolution while remaining reliable and simple; thus, a combination of ICG and FLUO angiography shows promise as a diagnostic aid for clinical evaluation of various chorioretinal diseases in cats.

Use of Ocular Coherence Tomography in Children With Idiopathic Intracranial Hypertension-A Single-Center Experience

BACKGROUND

Idiopathic intracranial hypertension is a disorder characterized by elevated intracranial pressure without an identifiable etiology. Detection of papilledema may be challenging and leads to diagnostic uncertainty in evaluating a child for possible idiopathic intracranial hypertension. Ocular coherence tomography has the potential to add accuracy to the diagnosis of idiopathic intracranial hypertension. The goal of the present study was to determine if there was a relationship between severity of papilledema (as determined by direct ophthalmoscopy and confirmed by fundus photography) and measures of ocular coherence tomography in a pediatric population with idiopathic intracranial hypertension.

METHODS

Thirteen pediatric patients were recruited prospectively after diagnosis of either definitive idiopathic intracranial hypertension (with papilledema) or possible idiopathic intracranial hypertension (without papilledema) at Children's Hospital of Michigan over a period of one year. Clinical data and results of initial ocular coherence tomography and visual field testing were collected and statistically analyzed.

RESULTS

The Frisén scale of papilledema significantly correlated with average retinal nerve fiber layer thickness of each eye (r = 0.633, P = 0.02 in right eye and r = 0.868, P = 0.001 in left eye). The retinal nerve fiber layer thickness (mean ± SD) was significantly higher in the definitive group than in the possible group (189 ± 65 μm vs 104 ± 10 μm in right eye, 165 ± 42 μm vs 106 ± 9 μm in left eye, P < 0.01 in both eyes).

CONCLUSIONS

Ocular coherence tomography may be used as a supplementary method to aid in the reliable detection of papilledema in evaluating a child for idiopathic intracranial hypertension.

Automated construction of arterial and venous trees in retinal images

While many approaches exist to segment retinal vessels in fundus photographs, only a limited number focus on the construction and disambiguation of arterial and venous trees. Previous approaches are local and/or greedy in nature, making them susceptible to errors or limiting their applicability to large vessels. We propose a more global framework to generate arteriovenous trees in retinal images, given a vessel segmentation. In particular, our approach consists of three stages. The first stage is to generate an overconnected vessel network, named the vessel potential connectivity map (VPCM), consisting of vessel segments and the potential connectivity between them. The second stage is to disambiguate the VPCM into multiple anatomical trees, using a graph-based metaheuristic algorithm. The third stage is to classify these trees into arterial or venous (A/V) trees. We evaluated our approach with a ground truth built based on a public database, showing a pixel-wise classification accuracy of 88.15% using a manual vessel segmentation as input, and 86.11% using an automatic vessel segmentation as input.

Interaction of aqueous leaf extract of Aegle marmelos (L.) Corr. with cholinergic, serotonergic and adrenergic receptors: an ex vivo study

Objectives:

The aim was to study interaction of aqueous leaf extract of Aegle marmelos (AM) with cholinergic, serotonergic, and adrenergic receptor systems using appropriate rat tissues-ileum, fundus and tracheal chain, respectively.

Materials and Methods:

Cumulative concentration-response curves (CRC) were constructed at various doses on each tissue for AM and respective standard agonist. The CRC was again plotted in presence and absence of respective standard antagonist to confirm the interaction of receptor system and AM.

Results:

AM induced concentration-dependent contractions in isolated rat ileum (0.2–6.4 mg/ml) and fundus (0.2–3.2 mg/ml) that were inhibited significantly (P < 0.05) in the presence of atropine (10⁻⁷ M) and ketanserin (10⁻⁶ M), respectively. The relaxant effect, produced by AM (0.2 mg/ml) on carbachol (10⁻⁵ M) precontracted rat tracheal chain, was also inhibited significantly (P < 0.05) by propranolol (1 ng/ml).

Conclusion:

It may be concluded that AM possesses agonistic activity on cholinergic, serotonergic and adrenergic receptors.

A rare presentation of pigmented paravenous retinochoroidal atrophy

A 21-year-old female patient presented with gradual progressive loss of vision in both eyes of 12 years duration. Funduscopic examination revealed bone-spicule pigmentation and choroidal and retinal pigment epithelium atrophy along the vascular arcades, with macular involvement in both eyes. The patient was diagnosed with pigmented paravenous retinochoroidal atrophy which is rare disease, uncommon in females, more commonly affecting the paravascular fundus. Very few cases of macular involvement have been reported.

A computational modeling for the detection of diabetic retinopathy severity

Prolonged diabetes ultimately leads to Diabetic Retinopathy (DR) which is one of the leading causes of preventable blindness in the world. Through advanced image analysis techniques are used for abnormalities detection in retina that define and correlate the severity of DR. A thorough study is done in this area in recent past years and on the basis of these studies we have developed a computer based prediction model that is used to determine the severity of DR. To identify severity DR, we have analyzed the human eye image. We have extracted some important features from human eye image i.e. Blood Artery, Optical disc, Exudates. Based on these image and data we have designed an automated system for the determination of DR severity. This automated DR severity assessment methods can be used to predict the clinical case and conditions when young clinicians would agree or disagree with their more experienced fellow members. The algorithms described in this study may be used in clinical practice to validate or invalidate the diagnoses. Algorithms or method developed here may also be used for pooling diagnostic knowledge for serving mankind. Here we have described a computational based low cost retinal diagnostic approach which can aid an ophthalmologist to quickly diagnose the various stages of DR. This system can accept retinal images and can successfully detect any pathological condition associated with DR.

Conversion of the Kowa RC-2 camera to a digital version, instructions for use, and postprocessing of the images

OBJECTIVE

To describe a means of converting the Kowa RC-2 camera to a digital version.

PROCEDURE

The optic (OP) and the film portions (FP) of the Kowa RC-2 were separated. The lateral rails were unscrewed from the front plate of the FP. The front plate was detached from the FP. The plate was fixed to an anodized aluminum plate (AAP). The rails were screwed back onto the front plate. This system was reattached to the OP by means of the rails. A T2-E mount ring was screwed onto the AAP and fixed to a digital camera body (DCB). A flash sync extension cord was used to connect the flash cable of the Kowa to the DCB. The images obtained with the converted Kowa were inverted horizontally and vertically using image processing software.

RESULTS

The images obtained with the converted Kowa RC-2 were identical in format to those using the film version with a circular image surrounded by a black rectangle. The imaged ocular structures were accurately depicted, appearing upside down and reversed on the LCD screen. The DCB was set to manual mode and focus. The shutter speed was initially set to 1/250 s, and the ISO was adjusted based on the ocular structure being photographed. An extra filter had to be placed over the light source to dim the light when imaging reflective fundi.

CONCLUSION

The converted digital version of the Kowa RC-2 as described provides an affordable means of obtaining high-quality images of various ocular structures.

Orientation of the uterine fundus in reference to the longitudinal axis of the body: a 3-dimensional sonographic study

OBJECTIVES

The aim of this pilot study was to measure the angle of rotation of the uterus at the fundus from horizontal using 3-dimensional sonography in women presenting for annual gynecologic examinations.

METHODS

A total of 51 patients participated in the study. All patients underwent transvaginal sonography, and 3-dimensional volumes were acquired. The cervicouterine angle and the angle of rotation at the fundus were measured.

RESULTS

The uteri were noted to be anteverted in 64.7%, retroverted in 25.5%, and euverted in 9.8%. They were noted to be pointing toward the right side of the pelvis in 49.0%, to the left side in 39.2%, and at the midline in 11.8%. The median cervicouterine angle was 122° (interquartile range [IQR], 105°-137°). The median angle of rotation at the fundus away from horizontal in either a clockwise or counterclockwise direction on the transverse B-plane was 10.4° (IQR, 7.1°-19.0°), with a maximal angle of 43°, and on the coronal C-plane, it was 10.0° (IQR, 3.0°-20.0°), with a maximal angle of 43°. Noneuverted uteri were more likely to be rotated at the fundus.

CONCLUSIONS

Our study reveals that, contrary to traditional thinking, the uterus can be rotated at the fundus in relation to the body (z-axis) along the longitudinal axis of the cervical canal.

Exploration of the Visual System: Part 2: In Vivo Analysis Methods: Virtual-Reality Optomotor System, Fundus Examination, and Fluorescent Angiography

The mouse has emerged as an animal model for many diseases. At IRO, we have used this animal to understand the development of many eye diseases and treatment of some of them. Precise evaluation of vision is a prerequisite for both these approaches. In this unit we describe three ways to measure vision: testing the optokinetic response, and evaluating the fundus by direct observation and by fluorescent angiography. Curr. Protoc. Mouse Biol. 2:207-218 © 2012 by John Wiley & Sons, Inc.

Combined use of high-reflective index vitrectomy meniscus contact lens and a noncontact wide-angle viewing system in vitreous surgery

Background:

The aim of this study was to assess the combined use of a high-reflective index vitrectomy (HHV) meniscus contact lens and a noncontact wide-angle viewing system in vitreous surgery.

Methods:

Twenty-three gauge vitrectomy was performed with combined use of a HHV meniscus contact lens and a noncontact wide-angle viewing system. When delicate manipulation of the retina such as internal limiting membrane peeling was performed, only the HHV meniscus lens was used.

Results:

Advantages of this combination procedure include the ability to observe the peripheral fundus image, easy access to the posterior pole without exchange of the contact lens when needed, keeping the corneal surface wet covered by a contact lens, and the good view afforded during fluid–air exchange.

Conclusion:

Combined use of a HHV meniscus contact lens and a noncontact wide-angle viewing system is useful for vitreous surgery. It has the advantages of both contact and noncontact wide-angle viewing systems.

The impact of asthma on the gastrointestinal tract (GIT)

The gastrointestinal tract (GIT) of vertebrates is composed of several distinct compartments and glands as well as an extensive mucosal surface. Its primary function is that of chemical and physical digestion of food and the absorption of nutrients; however, due to its continual antigen exposure, the GIT also has an important defensive immunological function. The GIT's immunological participation is facilitated by the mucosa-associated lymphoid tissues, thought to share the mucosal immunological system with the respiratory mucosa-associated lymphoid tissues. As a result of this shared mucosal immunity, it has been hypothesized that bronchial asthma may be able to affect the body's GIT in the same pathophysiological manner as the airways and lungs. Here we discuss the link between bronchial asthma and pathophysiological features in the GIT - including leukocyte influx, goblet cell alterations, fibrosis, and epithelial and villous atrophy.

Automatic detection of microaneurysms and hemorrhages in digital fundus images

An efficient approach for automatic detection of red lesions in ocular fundus images based on pixel classification and mathematical morphology is proposed. Experimental evaluation of the proposed approach demonstrates better performance over other red lesion detection algorithms, and when determining whether an image contains red lesions the proposed approach achieves a sensitivity of 100% and specificity of 91%.

Risk factor analysis of 167 patients with high myopia

AIM

To analyze the risk factors of age, sex, course, best corrected visual acuity (BCVA), diopter and fundus features of high myopes with progressive high myopia.

METHODS

A total of 167 patients with high myopes were categorized into four groups: group 1, age 10-29 years; group 2, age 30-49 years; group 3, age 50-69 years and group 4, age 70-89 years. The refractive errors of all patients were measured without cycloplegia with an autorefractometer. Data of the spherical equivalent (SE) of the refractive errors in diopters (D) and fundus examined by direct ophthalmoscope were used in statistical analysis.

RESULTS

The number of female was statistically larger than that of male (P<0.01), also the disease course was correlated to the age. The visual acuity of high myopes significantly decreased as they grew older including the higher incidence of lacquer cracker, submacular hemorrhage, Fuchs spots, chorioretinal atrophy.

CONCLUSION

Female maybe a risk factor of high myopia, advanced age is an important factor of visual acuity decreased. High myopes ought to be treated early to delay the progress of myopia and development of macular degeneration.

Smooth muscle 5-HT2A receptors mediating contraction of porcine isolated proximal stomach strips

1. The aim of this study was to characterize the 5-HT receptors involved in the 5-HT-induced contraction of longitudinal muscle (LM) strips of porcine proximal stomach. This was done in a classical organ bath set-up for isotonic measurement. 2. The concentration-contraction curve to 5-HT was not modified by 5-HT(3) and 5-HT(4) receptor antagonism. Methysergide, ketanserin and mesulergine antagonized the curve to 5-HT. Concomitantly, increasing concentrations of ketanserin and mesulergine progressively revealed a biphasic nature of the 5-HT curve. Ketanserin antagonized the low-affinity receptor while it did not modify the high-affinity receptor. 3. Tetrodotoxin did not influence the concentration-contraction curve to 5-HT neither in the absence nor presence of ketanserin, indicating that nerves are not involved. 4. Ketanserin competitively antagonized the monophasic concentration-response curve to alpha-Methyl-5-HT, yielding a Schild slope that was not significantly different from unity. After constraining the Schild slope to unity, a pK(B) estimate of 8.23+/-0.90 was obtained. This affinity estimate of ketanserin closely approximates previously reported affinities at 5-HT(2A) receptors. 5. In the presence of ketanserin (0.1 microM; exposing the high-affinity receptor), a wide range of 5-HT receptor antagonists covering all 5-HT receptors known, was tested. Only methysergide and ritanserin inhibited the response to 5-HT, thus expressing affinity for the high-affinity receptor. This did not reveal the identity of the receptor involved. 6 It can be concluded that 5-HT induces pig proximal stomach (LM) contraction via 5-HT(2A) receptors located on smooth muscle. A ketanserin-insensitive phase of contractions could not be characterized between the actually known classes of 5-HT receptors with the pharmacological tools that were used.