Interpretable deep learning for diagnosis of fungal and acanthamoeba keratitis using in vivo confocal microscopy images.

Infectious keratitis refers to a group of corneal disorders in which corneal tissues suffer inflammation and damage caused by pathogenic infections. Among these disorders, fungal keratitis (FK) and acanthamoeba keratitis (AK) are particularly severe and can cause permanent blindness if not diagnosed early and accurately. In Vivo Confocal Microscopy (IVCM) allows for imaging of different corneal layers and provides an important tool for an early and accurate diagnosis. In this paper, we introduce the IVCM-Keratitis dataset, which comprises of a total of 4001 sample images of AK and FK, as well as non-specific keratitis (NSK) and healthy corneas classes. We use this dataset to develop multiple deep-learning models based on Convolutional Neural Networks (CNNs) to provide automated assistance in enhancing the diagnostic accuracy of confocal microscopy in infectious keratitis. Densenet161 had the best performance among these models, with an accuracy, precision, recall, and F1 score of 93.55%, 92.52%, 94.77%, and 96.93%, respectively. Our study highlights the potential of deep learning models to provide automated diagnostic assistance for infectious keratitis via confocal microscopy images, particularly in the early detection of AK and FK. The proposed model can provide valuable support to both experienced and inexperienced eye-care practitioners in confocal microscopy image analysis, by suggesting the most likely diagnosis. We further demonstrate that these models can highlight the areas of infection in the IVCM images and explain the reasons behind their diagnosis by utilizing saliency maps, a technique used in eXplainable Artificial Intelligence (XAI) to interpret these models.

A case of Candida albicans-induced fungal keratitis in a Chihuahua dog - with a focus on optical coherence tomographic features.

A 4-year-old Chihuahua dog was referred for bilateral corneal ulcers. Slightly raised white fluorescein-positive plaque-like corneal lesions in both eyes appeared as intense hyperreflective areas with posterior shadowing on optical coherence tomography (OCT). Based on corneal cytology and culture, Candida albicans-induced fungal keratitis was diagnosed. Despite treatment, on OCT, endothelial plaques, increased stromal infiltration thickness, vertical shapes of the ulcer edge, and necrotic stromal space were judged to be aggravation of the disease, and surgery was performed. Conjunctival grafting surgery with topical 1% voriconazole effectively resolved fungal keratitis. OCT can provide detailed and objective information related to the disease prognosis.

A Structure-Aware Convolutional Neural Network for Automatic Diagnosis of Fungal Keratitis with In Vivo Confocal Microscopy Images.

Fungal keratitis (FK) is a common and severe corneal disease, which is widely spread in tropical and subtropical areas. Early diagnosis and treatment are vital for patients, with confocal microscopy cornea imaging being one of the most effective methods for the diagnosis of FK. However, most cases are currently diagnosed by the subjective judgment of ophthalmologists, which is time-consuming and heavily depends on the experience of the ophthalmologists. In this paper, we introduce a novel structure-aware automatic diagnosis algorithm based on deep convolutional neural networks for the accurate diagnosis of FK. Specifically, a two-stream convolutional network is deployed, combining GoogLeNet and VGGNet, which are two commonly used networks in computer vision architectures. The main stream is used for feature extraction of the input image, while the auxiliary stream is used for feature discrimination and enhancement of the hyphae structure. Then, the features are combined by concatenating the channel dimension to obtain the final output, i.e., normal or abnormal. The results showed that the proposed method achieved accuracy, sensitivity, and specificity of 97.73%, 97.02%, and 98.54%, respectively. These results suggest that the proposed neural network could be a promising computer-aided FK diagnosis solution.

Transcutaneous retrobulbar injection of amphotericin B in rhino-orbital-cerebral mucormycosis: a review.

Mucormycosis is an aggressive and potentially fatal invasive fungal infection. The most common form of mucormycosis is rhino-orbital-cerebral mucormycosis (ROCM). While it is commonly seen in immunocompromised patients, it is also known to affect healthy individuals. The global disease burden of ROCM has increased significantly following the surge in cases during the COVID-19 pandemic. Endoscopic sinus debridement, systemic antifungal therapy, and control of the underlying immunosuppressive condition are essential for the management of ROCM. Orbital involvement, however, presents a challenge to clinicians. Intervention strategies that have been described to treat orbital disease include orbital exenteration, conservative orbital debridement with or without irrigation with amphotericin B and transcutaneous retrobulbar injection of amphotericin B (TRAMB). Currently, there is a lack of clarity regarding the indications and outcomes of TRAMB as a treatment modality. In this review, the drug formulations used, the complications, and outcomes of previously described cases that have used TRAMB in cases of ROCM are discussed. Favorable outcomes following TRAMB depend on appropriate patient selection and radiological evidence of the orbital burden of the disease. This review aims to familiarize clinicians with objective parameters for patient selection for TRAMB, namely the extent of the disease, the clinical features, and radiological findings; viz. the clinical interpretation of areas of contrast uptake and those of necrosis. TRAMB can be considered as a viable option in select cases of orbital mucormycosis where exenteration or debridement are not indicated, or when there is limited orbital disease.

Differentiation of Active Corneal Infections from Healed Scars Using Deep Learning.

PURPOSE: To develop and evaluate an automated, portable algorithm to differentiate active corneal ulcers from healed scars using only external photographs. DESIGN: A convolutional neural network was trained and tested using photographs of corneal ulcers and scars. PARTICIPANTS: De-identified photographs of corneal ulcers were obtained from the Steroids for Corneal Ulcers Trial (SCUT), Mycotic Ulcer Treatment Trial (MUTT), and Byers Eye Institute at Stanford University. METHODS: Photographs of corneal ulcers (n = 1313) and scars (n = 1132) from the SCUT and MUTT were used to train a convolutional neural network (CNN). The CNN was tested on 2 different patient populations from eye clinics in India (n = 200) and the Byers Eye Institute at Stanford University (n = 101). Accuracy was evaluated against gold standard clinical classifications. Feature importances for the trained model were visualized using gradient-weighted class activation mapping. MAIN OUTCOME MEASURES: Accuracy of the CNN was assessed via F1 score. The area under the receiver operating characteristic (ROC) curve (AUC) was used to measure the precision-recall trade-off. RESULTS: The CNN correctly classified 115 of 123 active ulcers and 65 of 77 scars in patients with corneal ulcer from India (F1 score, 92.0% [95% confidence interval (CI), 88.2%-95.8%]; sensitivity, 93.5% [95% CI, 89.1%-97.9%]; specificity, 84.42% [95% CI, 79.42%-89.42%]; ROC: AUC, 0.9731). The CNN correctly classified 43 of 55 active ulcers and 42 of 46 scars in patients with corneal ulcers from Northern California (F1 score, 84.3% [95% CI, 77.2%-91.4%]; sensitivity, 78.2% [95% CI, 67.3%-89.1%]; specificity, 91.3% [95% CI, 85.8%-96.8%]; ROC: AUC, 0.9474). The CNN visualizations correlated with clinically relevant features such as corneal infiltrate, hypopyon, and conjunctival injection. CONCLUSIONS: The CNN classified corneal ulcers and scars with high accuracy and generalized to patient populations outside of its training data. The CNN focused on clinically relevant features when it made a diagnosis. The CNN demonstrated potential as an inexpensive diagnostic approach that may aid triage in communities with limited access to eye care.

[Correlation of inflammatory cells and corneal nerve damage in fungal keratitis on in vivo confocal microscopy].

Objective: To investigate the relationship between inflammatory cell infiltration and nerve damage in patients with fungal keratitis at different degrees of severity. Methods: Retrospective study. A total of 44 consecutive patients (44 eyes) with fungal keratitis in Beijing Tongren Hospital Affiliated to Capital Medical University from January 2017 to December 2019 were selected as the patient group, including 30 males and 14 females, with an age of (58.3±11.5) years old. Twenty healthy people (20 eyes) were included as control group. Slit-lamp microscopy was performed to observe the corneal ulcer. According to the diameter of corneal ulcer, patients were divided into mild, moderate and severe groups. With in vivo confocal microscopic ,the images were obtained from the epithelial layer to the endothelial layer in the central cornea and superior, inferior, nasal and temporal peripheral cornea. Parameters of the maximum density of fungal hyphae, the maximum depth of hyphal infiltration, the density, area and length of dendritic cells (DCs), the nerve density, and the number and curvature of nerve trunks were collected. The Kruskal-Wallis test, Wilcoxon test, and Spearman correlation analysis were used for analyses. Results: On confocal microscopy, many uniform, highly reflective, segment-like structures in parallel or staggered rows were detected in the cornea, with a certain degree of physiological curvature and branching. Quantitative analysis of hyphal density found that the median rating of hyphal density was 2.6 (2.0, 3.0), mainly with medium to large amounts of hyphae. Most hyphae were 100-150 µm in depth (18 cases, 40.9%), and the maximum depth of hyphae in 95.5% (42 cases) of patients was within 300 µm. The hyphal invasion depth in the mild group was 89.4 (50.5, 106.8) µm, in the moderate group was 133 (122, 203) µm, and in the severe group was 135 (74, 151) µm. As the severity of the disease increased, the depth of hyphal invasion increased (F=4.248, P=0.001). Compared with the control group, the DC density [166 (81.3, 212.5) vs. 24.0 (20.8, 32.3) cells/µm2], area [441.3 (291.9, 529.5) vs. 63.7 (47.7, 70.3) µm2] and length [68.3 (39.4, 91.0) vs. 9.2 (7.0, 11.3) µm] increased in patients (W=493.5, 500.0, 500.0; P<0.01). The nerve density [5 398.3 (3 202.7, 6 828.3) vs. 19 171.8 (17 558.8, 21 550.4) µm/mm2; t=-14.448, P<0.01] and the length [692.7 (402.0, 925.1) vs.2 138.4 (1 940.4, 2 597.2) µm; t=-11.930, P<0.01] and number [2.9 (2.0,3.0) vs. 6.0 (5.5,7.0); t=-8.282, P<0.01] of nerve trunks in patients decreased. There were strong negative correlations between the nerve density, the number of nerve trunks, and the DC density (r=-0.555, -0.466; P<0.01). Conclusions: The depth of fungal hypha invasion in patients with fungal keratitis is mainly concentrated in the epithelial layer and superficial stroma layer. The density of mature dendritic cells in the lesion area was negatively correlated with the density and number of subbasal nerves. The density of subbasal nerves decreased as the increase of the severity of the lesion. (Chin J Ophthalmol, 2021, 57: 580-588).

Endothelial Biopsy for the Diagnosis and Management of Culture-Negative Retrocorneal Fungal Keratitis With the Assistance of Optical Coherence Tomography Imaging.

PURPOSE: To report a case of a culture-negative deep fungal corneal infection that was diagnosed after histopathology of an anterior segment optical coherence tomography-guided endothelial biopsy. METHODS: A 22-year-old woman with history of contact lens wear and concomitant topical steroid use presented with a mid-stromal corneal infiltrate that failed to respond to oral acyclovir and topical fortified antibiotics. Although cornea stains, cultures, and confocal microscopy showed negative results, there was high clinical suspicion for fungal keratitis. After 2 months on topical natamycin, oral voriconazole, and serial intrastromal and intracameral voriconazole injections, the infiltrate enlarged and deepened. Imaging with anterior segment optical coherence tomography revealed that the infection had progressed to an endothelial plaque. RESULTS: Diagnostic endothelial biopsy was performed in the operating room. Cultures showed again negative results, whereas histopathology of the removed specimen revealed fungal elements. The postoperative edema at the site of the biopsy resolved over the course of 4 weeks, and a posterior stromal scar formed. Serial intrastromal and intracameral voriconazole injections were continued for the first postoperative month. At the 1-year and the 3-year follow-up examinations, the patient's vision was 20/20 without recurrence. CONCLUSIONS: Intraoperative scraping of the endothelial plaque and histopathologic evaluation of the specimen proved to be of utmost importance for definitive diagnosis and resolution of the culture-negative deep fungal infection in this case. This young patient's cornea was retained and vision remains excellent.

A deep learning approach in diagnosing fungal keratitis based on corneal photographs.

Fungal keratitis (FK) is the most devastating and vision-threatening microbial keratitis, but clinical diagnosis a great challenge. This study aimed to develop and verify a deep learning (DL)-based corneal photograph model for diagnosing FK. Corneal photos of laboratory-confirmed microbial keratitis were consecutively collected from a single referral center. A DL framework with DenseNet architecture was used to automatically recognize FK from the photo. The diagnoses of FK via corneal photograph for comparing DL-based models were made in the Expert and NCS-Oph group through a majority decision of three non-corneal specialty ophthalmologist and three corneal specialists, respectively. The average percentage of sensitivity, specificity, positive predictive value, and negative predictive value was approximately 71, 68, 60, and 78. The sensitivity was higher than that of the NCS-Oph (52%, P < .01), whereas the specificity was lower than that of the NCS-Oph (83%, P < .01). The average accuracy of around 70% was comparable with that of the NCS-Oph. Therefore, the sensitive DL-based diagnostic model is a promising tool for improving first-line medical care at rural area in early identification of FK.

Optical coherence tomography features of retinal lesions in Chinese patients with endogenous Candida endophthalmitis.

BACKGROUND: To evaluate the optical coherence tomography (OCT) features of retinal lesions in Chinese patients with endogenous Candida endophthalmitis (ECE). METHODS: We performed a retrospective review of patients diagnosed with ECE at one medical center. The medical records of the patients including predisposing risk factors, treatment and visual acuity were reviewed. And we focused on the analysis of OCT images of retinal lesions before and after treatment. RESULTS: A total of 16 Chinese patients (22 eyes) were included in this study. The most frequent predisposing risk factors were intravenous use of corticosteroids or antibiotics, lithotripsy for urinary calculi, and diabetes. After treatment, visual acuity was improved in 13 (59.1%) of the 22 eyes, and remained the same in the other 9 (40.9%) eyes. Pre-treatment OCT images obtained at presentation were available for 17 of the 22 eyes. Four types of the OCT manifestations of retinal lesions were identified: type 1 (subretinal macular lesions), type 2 (lesions are located in the inner retinal layer), type 3 (lesions involve the full-thickness retina and accompanied with macular edema), type 4 (sub-inner limiting membrane lesions). Pre-treatment OCT imaging of the 17 eyes revealed five as type 1, four as type 2, six as type 3, and two as type 4. After treatment, OCT images revealed epiretinal membrane and subretinal fibrosis as the most common post-treatment complications of ECE. Epiretinal membrane was detected in 2/4 type 2 lesions, in 4/6 type 3 lesions, and in 1/2 type 4 lesions, while subretinal fibrosis was mainly seen in type 1 lesions (4/5). Among the types, visual prognosis was best in eyes with type 2 lesions. CONCLUSIONS: In this case series, the OCT manifestations of retinal lesions in ECE could be classified into four types. The post-treatment OCT manifestations were different in four types of lesions. We preliminarily found that the OCT morphology of retinal lesions was associated with the visual prognosis of ECE.

Coccidioidomycosis Chorioretinitis.

Coccidioidomycosis is an invasive fungus found primarily in the soil of Southwestern United States, Mexico, and Central America. Primary disease mostly presents as a pulmonary disease although multiple organ systems can be affected through lymphohematogenous dissemination, with ocular seeding extremely rare. When present, the anterior segment structures are most commonly affected. Isolated choroid and/or vitreal disease has been reported infrequently. This is a case of chorioretinitis with vitreal involvement.

Risk factors and outcomes of patients with ocular involvement of candidemia.

BACKGROUND: Ocular involvement of candidemia can result in serious complications, including vision loss. This study investigated the risk factors for ocular involvement in patients with candidemia and the outcomes of treatment. METHODS: Episodes of candidemia in hospitalized adults who underwent ophthalmic examinations within 2 weeks of candidemia onset between January 2014 and May 2017 were retrospectively reviewed. Their demographic characteristics, antifungal treatments, and visual outcomes were evaluated. RESULTS: During the study period, 438 adults were diagnosed with candidemia, with 275 (62.8%) undergoing ophthalmic examinations within 2 weeks. Of these 275 patients, 59 (21.5%) had fundoscopic abnormalities suggestive of ocular involvement, including 51 with chorioretinitis and eight with Candida endophthalmitis. Eleven patients were symptomatic. Persistent candidemia (adjusted odd ratio [aOR], 2.55; 95% confidence interval [CI], 1.29-5.08; P = 0.01), neutropenia during the preceding 2 weeks (aOR, 2.92; 95% CI, 1.14-7.53; P = 0.03), and C. albicans infection (aOR, 2.15; 95% CI, 1.09-4.24; P = 0.03) were independently associated with ocular involvement. Among the 24 patients with neutropenia, 41.7% had ocular involvements at the initial examination. Ophthalmologic examination even before the neutrophil recovery was positive in one-third of neutropenic patients. Out of the 37 patients in whom ocular outcomes after 6 weeks were available, 35 patients showed favorable or stable fundoscopic findings. Two patients had decreased visual acuity despite the stable fundoscopic finding. CONCLUSION: Neutropenia within two weeks of candidemia was a risk factor for ocular involvement. More than 80 percent of patients with ocular involvements were asymptomatic, emphasizing the importance of routine ophthalmic examinations. The median 6 weeks of systemic antifungal treatment resulted in favorable outcomes in 89.2% of patients.

Anterior Segment Optical Coherence Tomography Images in Microsporidial Keratoconjunctivitis.

PURPOSE: To describe the findings of anterior segment optical coherence tomography (AS-OCT) in patients with microsporidial keratoconjunctivitis. METHODS: The observational study included 13 eyes from 13 patients. Slit-lamp photography and AS-OCT were performed using the Swept source OCT before corneal scraping. All cases were positive for Gram-chromotrope (modified trichrome) staining for Microsporidia spp. RESULTS: Three significant AS-OCT findings were observed. First, hyperreflective dots were limited to the epithelial layers of the cornea, and second, there were no extensions into the stromal layer in all cases. Last, hyperreflective dots slightly raised above the epithelial surface were observed in most cases (12/13%, 92.3%). CONCLUSIONS: AS-OCT represents an alternative, noninvasive tool to diagnose microsporidial keratoconjunctivitis, especially if corneal scraping is not possible.

Cellular morphological changes detected by laser scanning in vivo confocal microscopy associated with clinical outcome in fungal keratitis.

HRT3 in vivo confocal microscopy (IVCM) images may indicate clinical outcome, but few studies have analysed this in fungal keratitis (FK). Adults with FK (diameter ≥3 mm) presenting to Aravind Eye Hospital, India from 2012-3 were enrolled prospectively. IVCM was performed at baseline, days 7, 14 and 21 post-enrolment (+/- 3 days where possible). Specific morphologies were identified in IVCM images by a grader masked to microbiology and clinical outcome (defined as good: healed/improving, or poor: enlarged ulcer, perforation or transplant/glue). Associations with final visit outcome assessed using logistic regression. 143 FK participants were enrolled; 87 had good outcome, 56 had poor outcome. Poor outcomes were associated with stellate interconnected cellular processes with no visible nuclei (OR 2.28, 95% CI: 1.03-5.06, p = 0.043) in baseline IVCM images, and fungal filaments (OR 6.48, 95% CI:2.50-16.78, p < 0.001) or honeycomb distribution of inflammatory cells (OR 5.24, 95% CI: 1.44-19.06, p = 0.012) in final visit images. Fungal filaments (OR 3.61, 95% CI:1.64-7.95, p = 0.001), stromal dendritiform cells (OR 2.88, 95% CI:1.17-7.11, p = 0.022), or stellate cellular processes with no visible nuclei (OR 2.09, 95% CI:1.14-3.82, p = 0.017) were associated with poor outcome if not in baseline but present in final visit images. IVCM can reveal morphological changes associated with clinical outcome.

The incidence of endophthalmitis or macular involvement and the necessity of a routine ophthalmic examination in patients with candidemia.

BACKGROUND: The incidence of ocular candidiasis (OC) in patients with candidemia varies across different reports, and the issue of whether routine ophthalmoscopy improves outcomes has been raised. This study investigated the incidence of OC and evaluate whether the extent of OC impacts the clinical outcomes. METHODS: This retrospective study included non-neutropenic patients with candidemia who underwent treatment at one of 15 medical centers between 2010 and 2016. Chorioretinitis without other possible causes for the ocular lesions and endophthalmitis was classified as a probable OC. If signs of chorioretinitis were observed in patients with a systemic disease that causes similar ocular lesions, they were classified as a possible OC. RESULTS: In total, 781 of 1089 patients with candidemia underwent an ophthalmic examination. The prevalence of OC was 19.5%. The time from the collection of a positive blood culture to the initial ophthalmic examination was 5.0 ± 3.9 days in patients with OC. The leading isolate was Candida albicans (77.9%). Possible OC was associated with unsuccessful treatments (resolution of ocular findings) (odds ratio: 0.354, 95% confidence interval: 0.141-0.887), indicating an overdiagnosis in patients with a possible OC. If these patients were excluded, the incidence fell to 12.8%. Endophthalmitis and/or macular involvement, both of which require aggressive therapy, were detected in 43.1% of patients; a significantly higher incidence of visual symptoms was observed in these patients. CONCLUSION: Even when early routine ophthalmic examinations were performed, a high incidence of advanced ocular lesions was observed. These results suggest that routine ophthalmic examinations are still warranted in patients with candidemia.

Spectral Domain Anterior Segment Optical Coherence Tomography in Fungal Keratitis.

PURPOSE: To evaluate the use of spectral domain anterior segment optical coherence tomography (SD-ASOCT) in fungal keratitis. METHODS: Fifty eyes of 50 patients with fungal keratitis were recruited. Serial ASOCT was performed on days 0, 7, 14, 21, 28, 42, and 56. Corneal thickness (CT) in the infiltrate area, infiltrate thickness (IT), and infiltrate width were measured at each follow-up. The presence of any specific feature on ASOCT was evaluated. RESULTS: Mean CT and IT at presentation were 650.5 ± 108 µm and 401.1 ± 91 µm, which reduced significantly at each follow-up [on days 7, 14, 28, and 42; 626.8 ± 113 µm (P < 0.001) and 367.3 ± 94 µm (P = 0.002), 601.4 ± 109 µm and 344.7 ± 94 µm (P < 0.001), 544.8 ± 103 µm and 305.1 ± 80 µm (P < 0.001), and 522.8 ± 97 µm and 291.4 ± 79 µm (P < 0.001), respectively]. The mean CT and scar depth at complete healing were 496.3 ± 101 µm and 283.2 ± 77 µm, respectively. In 10/50 (20%) eyes, the posterior border of the cornea was not clearly visible because of posterior shadowing; therefore, IT was measured along the maximum visible area of hyperreflectivity, whereas CT was measured just adjacent to the area of shadowing. The infiltrate width was measured in 35 eyes, and the mean values at days 0, 7, 14, 28, 42, and 56 were 5.5 ± 0.8 mm, 4.6 ± 0.7 mm, 4.4 ± 0.6 mm, 4.2 ± 0.6 mm, 4.1 ± 0.6 mm, and 4.1 ± 0.6 mm, respectively. A satellite lesion and endothelial plaque were seen in 30% (15/50) and 44% (22/50) eyes, respectively. CONCLUSIONS: ASOCT is a useful adjunct in monitoring fungal keratitis especially in cases with deep stromal involvement and endothelial plaques. In addition, it also provides insight into the activity of keratitis.

Two-photon microscopy of fungal keratitis-affected rabbit cornea ex vivo using moxifloxacin as a labeling agent.

Two-photon microscopy (TPM) is a three dimensional (3D) microscopic technique based on nonlinear two-photon fluorescence, which has been tested as an alternative to reflectance confocal microscopy (RCM) for detecting fungal keratitis via optical imaging. Although TPM provided images with better contrast than RCM for fungal keratitis, its imaging speed was relatively low because of weak intrinsic signal. Moxifloxacin, a Food and Drug Administration (FDA)-approved antibiotic, was recently used as a cell-labeling agent for TPM. In this study, moxifloxacin was used to label fungal cells for TPM imaging of fungal keratitis models. Fungal cell suspensions and ex vivo fungal keratitis-affected rabbit corneas were prepared using two types of fungal pathogens, Aspergillus fumigatus and Candida albicans, and TPM imaging was performed both with and without moxifloxacin treatment. Fungal cells with enhanced fluorescence were clearly visible by TPM of moxifloxacin-treated fungal cell suspensions. TPM of moxifloxacin-treated fungal keratitis rabbit corneas revealed both the infecting fungal cells and corneal cells similar to those observed in TPM without moxifloxacin treatment, albeit with approximately 10-times enhanced fluorescence. Fungal cells were distinguished from corneal cells on the basis of their distinct morphologies. Thus, TPM with moxifloxacin labeling might be useful for the detection of fungal keratitis at the improved imaging speed.

In Vivo Confocal Microscopy Cellular Features of Host and Organism in Bacterial, Fungal, and Acanthamoeba Keratitis.

PURPOSE: To determine cellular features of fungal (FK), Acanthamoeba (AK), and bacterial keratitis (BK) using HRT3 in vivo confocal microscopy (IVCM). DESIGN: Prospective observational cross-sectional study. METHODS: Eligible participants were adults with microbiologically positive FK, AK, or BK, of size ≥ 3 mm, attending Aravind Eye Hospital from February 2012 to February 2013. Exclusion criteria were descemetocele or perforation. At presentation, IVCM imaging was performed, then corneal scrapes were obtained for culture/light microscopy. An experienced grader (masked to microbiology/clinical features) assessed IVCM images for presence/absence of normal keratocyte-like morphology, stellate interconnected cells with/without visible nuclei, dendritiform cells (DFCs), inflammatory cells in a honeycomb distribution, and organism features. Statistical significance was assessed by logistic regression, adjusted for age, sex, ulcer size, and symptom duration. Main outcome measures were presence/absence of IVCM features in FK, AK, BK. RESULTS: A total of 183 participants had FK, 18 AK, 17 BK. Acanthamoeba appeared as bright spots (16/18, 89%), double-walled cysts (15/18, 83%), or signet rings (3/18, 17%), and often formed clusters after topical steroid use (univariable odds ratio [OR] 9.98, 95% confidence interval [CI] 1.02-97.96, P = .048). BK was associated with bullae in anterior stroma (OR 9.99, 95% CI: 3.11-32.06, P < .001). Honeycomb distribution of anterior stromal inflammatory cells was associated with FK (univariable OR 2.74, 95% CI: 1.01-7.40, P = .047). Aspergillus ulcers were associated with stromal DFCs (OR 11.05, 95% CI: 1.49-82.13, P = .019) and Fusarium ulcers with stellate appearance of interconnected cell processes with nuclei (OR 0.24, 95% CI: 0.09-0.65, P = .005). CONCLUSION: Specific cellular and structural features observed using IVCM in microbial keratitis may be associated with organism.

SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY FINDINGS IN ENDOGENOUS CANDIDA ENDOPHTHALMITIS AND THEIR CLINICAL RELEVANCE.

PURPOSE: To describe vitreal, retinal, and choroidal features of eyes affected by Endogenous candida endophthalmitis (ECE) analyzed by spectral domain optical coherence tomography (SD-OCT) and to evaluate their clinical impact. METHODS: Medical records and SD-OCT images from eyes diagnosed with ECE at four retina and uveitis tertiary referral centers were retrospectively evaluated. Spectral domain optical coherence tomography images were analyzed to evaluate the structural changes occurring in the vitreous, the retina, and the choroid in areas involved by ECE. Baseline and final best-corrected visual acuity were correlated with SD-OCT findings. RESULTS: Fifteen eyes from nine patients were enrolled. Vitreous involvement (vitreous cells, posterior hyaloid thickening) was detected in 13/15 eyes. Peculiar hyper-reflective preretinal aggregates obscuring the underlying retina because of a shadowing effect ("rain-cloud" sign) were noticed in all eyes with vitreous involvement. Two patterns of retinal and choroidal findings were identified: the first (six eyes) confined within the inner retinal layers (Intraretinal Pattern), the second (nine eyes) involving both retina (full thickness) and choriocapillaris (Chorioretinal Pattern). None of the eyes showed both patterns. None of the eyes, regardless the pattern, showed choroidal thickening. Baseline best-corrected visual acuity was not associated with OCT pattern (P = 0.09). On the contrary, final best-corrected visual acuity was significantly higher in patients showing Intraretinal Pattern (∼20/25, 0.06 ± 0.08 LogMAR) than in subjects with Chorioretinal Pattern (∼20/50, 0.44 ± 0.30 LogMAR) (P = 0.01). CONCLUSION: Endogenous candida endophthalmitis showed peculiar features on SD-OCT. Two distinct patterns of chorioretinal involvement influencing the final best-corrected visual acuity were identified. Spectral domain optical coherence tomography could be useful in the diagnosis, management, and outcome prediction in ECE.

Diagnostic Imaging and Invasive Fungal Diseases in Children.

Invasive fungal disease (IFD) is a life-threatening condition, especially in immunocompromised children. The role of diagnostic imaging in children at risk for an IFD is multifactorial, including initially detecting it, evaluating for dissemination of infection beyond the primary site of disease, monitoring the response to antifungal therapy, and assessing for potential relapse. The objective of this review was to synthesize the published literature relevant to the use of various imaging modalities for the diagnosis and management of IFD in children.

In vivo confocal microscopic characteristics of microsporidial keratoconjunctivitis in immunocompetent adults.

BACKGROUND/AIMS: To describe in vivo confocal microscopy (IVCM) features of microsporidial keratoconjunctivitis in immunocompetent adult patients. METHODS: Patients suspected clinically to be suffering from microsporidial keratoconjunctivitis (ie, presence of unilateral follicular and/or papillary conjunctivitis in conjunction with multifocal, coarse corneal epitheliopathy) were subjected to IVCM with the Rostock Cornea Module of the Heidelberg Retinal Tomograph 3, and combined potassium hydroxide and calcofluor white (KOH+CFW) staining of the corneal scrapings, to detect the microsporidial spores. Detection of spores in corneal scrapings was considered as being confirmatory for microsporidial infection. RESULTS: Of a total of 10 patients screened, 8 patients (7 male, 1 female) demonstrated the presence of oval, non-budding microsporidial spores which fluoresced bluish white on combined KOH+CFW staining. IVCM in seven of these eight patients demonstrated multiple rosette-like clusters/plaque of epithelial cells, within which hyper-reflective, pinpoint oval intracellular bodies (similar to the spores seen on microbiological staining) were present. One patient who had been on prolonged treatment with topical steroids showed the presence of the oval bright bodies scattered diffusely within the epithelial cells, without rosette formation. CONCLUSIONS: In microsporidial keratoconjunctivitis, IVCM is able to detect presence of bright, ovoid spore-like structures in the epithelial layers. Epithelial rosette formation is another characteristic feature seen in a majority of these patients. These features may be used as a reliable screening tool for starting therapy, precluding the need for corneal scrapings in a majority of patients.