In Vivo Confocal Microscopy Parameters Research Articles

Diabetic corneal neuropathy and its relation to the severity of retinopathy in patients with type 2 diabetes mellitus: an in vivo confocal microscopy study.

To investigate corneal neuropathy and corneal nerve alterations in type 2 diabetes mellitus (DM) patients with different diabetic retinopathy (DR) status. A total of 87 eyes of 87 patients with DM and 28 eyes of 28 healthy control subjects were included in the study. DM patients were further classified into 3 groups: patients without DR (NDR), patients with non-proliferative DR (NPDR), and patients with proliferative DR (PDR). PDR patients were classified into 2 groups regarding having undergone retinal argon laser photocoagulation treatment (ALP). Ocular surface disease index score (OSDI), average tear break-up time (A-BUT), corneal sensitivity and cornea nerve fiber length (CNFL), cornea nerve fiber density (CNFD), and cornea nerve branch density (CNBD) of the cornea subbasal nerve plexus (SBNP) were measured using in vivo confocal microscopy (IVCM). OSDI scores increased and A-BUT decreased in DM patients compared to the control group, but no significant difference was found between DM patient groups. Corneal sensitivity decreased in DM patients who developed DR, compared to both the controls and the NDR group. CNFD and CNFL decreased in NPDR and PDR patients compared to controls. CNFD and CNBD decreased in patients who had developed PDR, compared to all three groups. All IVCM parameters decreased with DR progression. IVCM can detect early structural corneal nerve changes in diabetic patients. The presence of DM affects ocular surface parameters, especially in long-term DM patients. Corneal sensitivity loss is increased with the presence of DR. All IVCM parameters decrease with DR development and its progression.

Corneal complications of ocular GvHD

Corneal fluorescein staining is one of the tests recommended to diagnose and grade ocular graft versus host disease (GvHD) according to the International Chronic Ocular GvHD Consensus Group. Despite superficial punctate keratopathy is the most common corneal manifestation, patients with more severe stages may develop corneal neovascularization, sterile corneal ulceration and even perforation. Previous in vivo confocal microscopy (IVCM) studies reported significant microstructural changes in the cornea of patients with ocular GvHD, including a higher density of dendritic cells and globular immune cells, a network of hyper‐reflective activated keratocytes, and a lower density and higher tortuosity of sub‐basal corneal nerves. Dendritic cells act as antigen‐presenting cells, and play a key role in ocular surface immune homeostasis. Thus, their increased density may be indicative of immune activation and inflammation of the ocular surface in patients with ocular GvHD. Interestingly, Kheirkhah et al. reported higher dendritic cell density in patients with DED owing to systemic immune disease (i.e., Sjögren syndrome and ocular GvHD) compared to patients with DED of other origins. Recently, our group employed a fully automated IVCM analysis system to compare corneal sub‐basal nerve plexus in patients with DED owing to both ocular GvHD and Sjögren syndrome and in healthy control subjects. Although overall patients with DED showed lower density of nerve fibres and branches, shorter nerve fibres and higher fibre width compared to healthy controls, no significant difference was observed between patients with ocular GvHD and Sjögren syndrome for all IVCM metrics. In agreement with this observation, other studies reported no significant difference of IVCM parameters in DED patients with and without ocular GvHD after adjusting for clinical severity of dry eye. This suggests that the ocular surface changes observed by IVCM in ocular GvHD may be possibly reflective of the local disease severity rather than the underlying systemic process.

Evaluation of Limbal Stem Cells in Patients With Type 2 Diabetes: An In Vivo Confocal Microscopy Study.

This study aimed to investigate corneal limbus changes in patients with type 2 diabetes mellitus (DM) using in vivo confocal microscopy (IVCM) and explore the correlation between their ocular manifestations and systemic status. Fifty-five patients with type 2 DM and 20 age-matched controls were included. The following IVCM parameters were compared between the 2 groups: palisades of Vogt (POV), corneal epithelial thickness (CET), basal cell density (BCD), subbasal nerve plexus, and dendritic cell density. All subjects underwent blood and urine sampling for laboratory analysis, including fasting blood glucose, glycated hemoglobin, total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, C-reactive protein, urinary albumin-to-creatinine ratio, urine albumin, and urine creatinine. The correlations between IVCM parameters and blood biomarkers were detected. Receiver operating characteristic curve was used for selecting the cutoff value of risk factors for corneal stem cell injury in patients with DM. Compared with controls, patients with DM displayed a significant reduction of POV (superior region, P = 0.033; inferior region, P = 0.003; nasal region, P < 0.001; temporal region, P < 0.001), central CET (44.8 ± 3.6 μm vs. 51.9 ± 3.6 μm, P < 0.001), central corneal BCD (7415.5 ± 563.2 cells/mm 2 vs. 9177.9 ± 977.8 cells/mm 2 , P < 0.001), and peripheral corneal BCD (6181.3 ± 416.5 cells/mm 2 vs. 8576.3 ± 933.2 cells/mm 2 , P < 0.001). Dendritic cell density (41.0 ± 33.7 cells/mm 2 vs. 24.6 ± 7.8 cells/mm 2 , P = 0.001) was significantly higher in the DM group. The following weak correlations were shown between IVCM parameters and blood biomarkers: central corneal BCD was negatively correlated with DM duration (r = -0.3, P = 0.024), TC (r = -0.36, P = 0.007), and LDL (r = -0.39, P = 0.004). The presence of POV in the superior region was negatively correlated with TC (r = -0.34, P = 0.011) and LDL (r = -0.31, P = 0.022). Cutoff values of 1.215 mmol/L for HDL, 1.59 mmol/L for TG, or 4.75 mmol/L for TC were established to distinguish patients with a high risk from a low risk for stem cell damage. Patients with type 2 DM displayed a lower positive rate of typical POV and a decrease in BCD, CET, and subbasal nerve density. The most relevant indicators for stem cell phenotypes were DM duration, TC, and LDL. Lipid status in diabetic patients could be a predictor of risk for developing corneal limbal stem cell deficiency. Further studies with larger sample sizes or basic research are needed to verify the results.

Early marker of ocular neurodegeneration in children and adolescents with type 1 diabetes: the contributing role of polymorphisms in mir146a and mir128a genes

BackgroundEarly ocular neurodegenerative signs of diabetic neuropathy (DN) can be found in children and adolescents with type 1 diabetes (T1D). No data are available on the potential role of polymorphisms in miRNAs genes in predisposing T1D subjects to these signs.AimsTo determine whether MIR146A rs2910164 and MIR128A rs11888095 polymorphisms are associated with early retinal and corneal neurodegenerative changes in pediatric patients with T1D.MethodsA total of 140 T1D children/adolescents underwent spectral domain-optical coherence tomography (SD-OCT) and in vivo confocal microscopy (IVCM) with measurement of retinal and corneal nerve fiber parameters. Risk factors for diabetes complications (diabetes duration, blood pressure, HbA1c) were recorded. Genotyping of rs2910164 and rs1188095 SNPs and genotype–phenotype association analysis were performed.ResultsThe C allele of rs2910164 in MIR146A was associated with higher values of IVCM parameters and minimum rim width (MRW) of the peripapillary region of optic nerve head measured in the retina, whereas the T allele of rs1188095 in MIR128A was associated with a significant impairment of them. Multiple regression analysis showed that MIR146A and MIR128A polymorphisms were significantly associated with corneal nerve fiber length (beta = 0.225 and − 0.204, respectively) and other IVCM parameters, independently from age, diabetes duration, HbA1c and systolic blood pressure percentile. Similar results were found for MRW (beta = 0.213 and − 0.286, respectively).ConclusionsThese results provide new insight into the genetic predisposition to DN showing that two polymorphisms in MIR146A and MIR128A genes could significantly contribute to the development of early ocular preclinical signs of DN.

Characteristics of Toxic Keratopathy, an In Vivo Confocal Microscopy Study.

PurposeToxic keratopathy (TK) involves complex clinical manifestations and is difficult to differentiate from other ocular surface diseases by conventional slit-lamp examination. The challenge faced by clinicians in confidently diagnosing TK cannot be underestimated. This study aimed to explore the microstructural characteristics and diagnostic parameters by in vivo confocal microscopy (IVCM) in TK.MethodsIn this prospective, cross-sectional, comparative study, slit-lamp and IVCM examinations were performed on 20 normal eyes and 54 eyes with TK. Based on slit-lamp imaging, TK subjects were divided into four groups: superficial punctate keratitis (n = 10 eyes), pseudodendritic keratitis (n = 14 eyes), ulcerative keratitis (UK; n = 16 eyes), and ring keratitis (RK; n = 14 eyes). The microstructural characteristics of TK were described according to the following IVCM parameters: basal cell (BC) density, dendritiform cell (DC) density, DC size, corneal nerve fiber (CNF) length, nerve tortuosity, and keratocyte reflectivity. A receiver operating characteristic (ROC) curve model was also formulated to compare the predictive power of BC density, DC density, and CNF length.ResultsTK eyes showed significantly higher values for DC density (45.8 cells/mm2; range, 25.0–100.0) compared with normal eyes (24.0 cells/mm2; range, 20.8–32.3; P = 0.013; DC size (111.0 µm2; range, 92.0–137.8) compared with normal eyes (63.7 µm2; range, 47.7–70.3; P < 0.001); nerve tortuosity (0.08; range, 0.05–0.09) compared with normal eyes (0.04; range, 0.02–0.04; P < 0.001); and keratocyte reflectivity. BC density and CNF length values were found to be significantly less than those for normal controls (both P < 0.001). In all subgroups, CNF length appeared to be significantly lower than that of controls (all P < 0.001), and DC density was only statistically significantly higher in the UK (P = 0.003) and RK (P < 0.001) groups. Corneal fluorescein staining had no correlation with the analyzed IVCM parameters (all P ˃ 0.05). However, the increase in DC density and DC size showed negative correlations to CNF length (density: r = −0.325, P < 0.005; size: r = −0.493, P < 0.005), as well as positive correlations to duration and frequency of topical eye drops and DC size (density: r = 0.361, P < 0.05; size: r = 0.581, P < 0.05). A ROC curve showed that CNF length had the strongest predictive power, with the estimated area under the curve being 0.992 ± 0.008.ConclusionsLower BC density and CNF length, greater DC density and DC size, and greater keratocyte reflectivity were the microstructural characteristics of TK. The role of subbasal nerve, inflammatory response, and limbal stem cells in the progression of TK and the appropriate treatment of different TK stages are future research directions.Translational RelevanceThe evaluation of basal cells, subbasal nerve, and dendritiform cells is helpful to our understanding of the pathological process of TK.

In vivo confocal microscopy study of corneal nerve alterations in children and youths with Type 1 diabetes.

ObjectiveTo determine whether children and youths with Type 1 diabetes (T1D) have early alterations of the corneal subbasal nerve plexus detectable with in vivo confocal microscopy (IVCM) and to investigate the role of longitudinally measured major risk factors for diabetes complications associated with these alterations.MethodsOne hundred and fifty children and youths with T1D and 51 age‐matched controls were enrolled and underwent IVCM. Corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal fiber total branch density (CTBD), and corneal fiber fractal dimension (CNFrD) were measured. Risk factors for diabetes complications (blood pressure, BMI, HbA1c, lipoproteins, urinary albumin‐creatinine ratio) were recorded at IVCM and longitudinally since T1D onset. Unpaired t‐test was used to compare variables between the groups. Multiple regression models were calculated using IVCM parameters as dependent variables and risk factors as independent variables.ResultsAll IVCM parameters, except CTBD, were significantly lower in the T1D patients. Glycometabolic control (HbA1c, visit‐to‐visit HbA1c variability, and mean HbA1c), and blood pressure were inversely correlated with IVCM parameters. Multiple regression showed that part of the variability in CNFL, CNFD, CTBD, and CNFraD was explained by HbA1c, blood pressure percentiles and age at IVCM examination, independent of diabetes duration, BMI percentile and LDL cholesterol. Comparable results were obtained using the mean value of risk factors measured longitudinally since T1D onset.ConclusionsEarly signs of corneal nerve degeneration were found in children and youths with T1D. Glycometabolic control and blood pressure were the major risk factors for these alterations.

Can in vivo confocal microscopy differentiate between sub‐types of dry eye disease? A review

Many studies utilised in vivo confocal microscopy (IVCM) to associate variations in corneal structures with dry eye disease (DED). However, DED is an umbrella term that covers various aetiologies and presentations. This review analyses populations by DED aetiology to determine the relationships between IVCM parameters and specific DED sub-types. It focuses on the most commonly examined structures, sub-basal nerves and dendritic cells. Across the literature, most studies found individuals with immune-mediated DED had lower sub-basal nerve fibre number and density than controls, with smaller differences between non-immune DED and controls. However, wide ranges of values reported across studies demonstrate considerable overlap between DED sub-types and controls, rendering these metrics less helpful when diagnosing an individual patient. Dendritic cell density was considerably higher in individuals with immune-mediated DED than in non-immune DED or controls. As such, dendritic cell density may be a better indicator of DED associated with a systemic immune-mediated process.

Association between alterations of corneal sub-basal nerve plexus analyzed with in vivo confocal microscopy and long-term glycemic variability.

The effect of long-term glycemic variability upon corneal sub-basal nerve plexus (CSNP) morphology analyzed by in vivo confocal microscopy (IVCM) has been poorly investigated in the setting of type 1 diabetes mellitus (T1DM). Our purpose was to analyze the association between morphometric parameters of CSNP and new markers of glycemic variability in a population of patients with T1DM. Forty patients with T1DM underwent: assessment of diabetic neuropathy (DN); analysis of subcutaneous advanced glycated end-products; IVCM scans of CSNP. The fully automated software ACCMetrics was employed to analyze IVCM images and calculate seven corneal nerve parameters. Data of diabetes duration, mean and standard deviation (SD) of either last-year and all-time glycated hemoglobin (HbA1C) were retrieved. Diabetes duration and all-time SD of HbA1C were independently associated with CNFD (R = -0.26, p = 0.01; R = -0.27, p = 0.047 respectively), CNFL (R = -0.12; p = 0.01; R = -0.17, p = 0.01 respectively) and CNFrD (R = -0.001, p = 0.009; R = -0.002, p = 0.007 respectively). The analysis of the association among IVCM parameters and specific subtypes of DN showed that altered cold sensitivity was independently associated with CNFD (B = -0.24, p = 0.01), CNFL (B = -0.46, p = 0.01) and CNFrD (B = -28.65, p = 0.03). All-time SD of HbA1C and disease duration were found to be independent predictors of damage to CSNP in patients with T1DM.

In vivo confocal microscopy and trachomatous conjunctival scarring: Predictors for clinical progression.

In vivo confocal microscopy (IVCM) provides high-resolution images of the ocular surface and has been validated in trachomatous conjunctival scarring. This study used IVCM to identify parameters associated with clinical scarring progression. Prospective cohort study. A total of 800 participants in Northern Tanzania with trachomatous scarring. Participants underwent clinical examination, photography and IVCM at baseline and 24-months. Clinical progression of scarring was defined by comparing baseline and 24-month photographs. Masked grading of IVCM images was used to identify scarring at both time points. Multivariable logistic regression was used to assess factors associated with clinical progression. Risk factors associated with clinical scarring progression. Clinical and IVCM assessment of 800 participants were performed at baseline, with 617 (77.1%) seen at 24-months. Of these, 438 of 617 (71.0%) had gradable IVCM images at both time points and 342 of 438 (78.1%) of these could be graded as showing definite clinical progression or no progression on image comparison. Clinical progression was found to occur in 79 of 342 (23.1%). After adjusting for age and sex, clinical scarring progression was strongly associated with a high IVCM connective tissue organization score at both baseline (odds ratio [OR] = 1.84 for each increase in scarring category; P = .002) and 24-months (OR = 1.60; P = .02). Dendritiform cells present at 24-months were strongly associated with clinical scarring progression after adjustment (OR = 2.62; P = .03). Quantitative IVCM parameters, including connective tissue organization score and the presence of dendritiform cells, are associated with disease progression and may be useful markers in trachoma and other conjunctival fibrotic diseases.

Correlation of corneal immune cell changes with clinical severity in dry eye disease: An in vivo confocal microscopy study

PurposeTo evaluate corneal immune dendritiform cell (DC) changes in dry eye disease (DED) using in vivo confocal microscopy (IVCM) and to correlate IVCM parameters with clinical severity. MethodsThis was a retrospective, cross-sectional study including 300 eyes of 150 DED patients and 49 eyes of 49 age-matched controls. Severity of DED was based on the Dry Eye Workshop (DEWS) classification. IVCM images of subbasal layer of the central cornea were analyzed for DC density and morphology (including number of dendrites per DC, DC size and DC field). ResultsDC density was significantly higher in DED compared to controls (93.4 ± 6.3 vs. 25.9 ± 3.9 cells/mm2; P < 0.001). Morphologically, number of dendrites, DC size and field were significantly larger in DED (3.3 ± 0.1, 106.9 ± 4.7 μm2, 403.8 ± 20.1 μm2 than controls (2.3 ± 0.1, 62.5 ± 5.7 μm2, 241.4 ± 24.4 μm2, P < 0.001). Significantly higher DC density compared to controls was observed as early as Level 1 DED severity (87 ± 10 cells/mm2, p < 0.001. Significant morphological changes in DC were detected for Levels 2 to 4 (p=<0.001, and p =< 0.05) for dendrites and DC field, respectively. Similarly, DC size showed significant increase at DED level 3–4. (p < 0.05). Linear regression analysis showed that both conjunctival and corneal staining were independently associated with DC density, while corneal staining was independently associated with DC morphology. ConclusionDC density and morphology correlated with clinical severity of DED. While, DC density is increased in mild DED, morphological changes are seen only in severe cases. IVCM may be a powerful tool to detect early immune changes and may complement clinical examination in DED.

Evaluation of ocular surface impairment in meibomian gland dysfunction of varying severity using a comprehensive grading scale.

This study aimed to propose a comprehensive grading scale to evaluate different clinical manifestations in patients with varying severity of meibomian gland dysfunction (MGD) and analyze the correlations between the parameters of ocular surface impairment in MGD.A total of 63 patients with MGD were enrolled. Ten specific symptoms were evaluated each with a subjective score and total score was applied to grade the severity of MGD. Thirty-seven patients were diagnosed with mild, 19 with moderate, and 7 with severe MGD. Slit-lamp and keratography were used to assess the signs of ocular surface and meibomian gland (MG). In vivo confocal microscopy (IVCM) was performed to evaluate the corneal nerves and dendritic cells. The differences and correlations between symptoms, signs, and IVCM parameters were analyzed.Dryness, foreign body sensation, asthenopia, and photophobia were the most common and severe symptoms in our patients. The severe MGD group showed worse MG expressibility, Meibum score, Meiboscore, MG score, and higher nerve reflectivity (P < .05). The mild MGD group showed higher nerve density (P < .05). Total symptom score was negatively correlated with nerve density (r = –0.374, P < .05), while positively correlated with nerve reflectivity and dendritic cell density (r = 0.332 and 0.288, respectively, P < .05). MG score was correlated with nerve reflectivity (r = 0.265, P < .05).The comprehensive grading scale was suitable for evaluating clinical manifestations in MGD of varying severity. The relationship between the specific symptoms, signs, and IVCM results concerning whole ocular surface impairment could help elucidate MGD pathophysiology and benefit evaluation or treatment in the future.

The correlation between the microstructure of meibomian glands and ocular Demodex infestation: A retrospective case-control study in a Chinese population.

Meibomian gland dysfunction (MGD) is a common disease in ophthalmic clinic. This study aimed to explore ocular Demodex infestation on the microstructure changes of the meibomian glands (MGs) in patients with MGD by in vivo confocal microscopy (IVCM).We retrospectively reviewed 103 eyes of 52 patients with MGD and 62 eyes of 31 non-MGD patients. All enrolled patients underwent IVCM examination. The following IVCM parameters were recorded: the MG acinar density (MAD), MG acinar longest diameter (MALD), MG acinar shortest diameter (MASD), MG orifice area (MOA), severity of MG fibrosis (MF), MG acinar irregularity (MAI), meibum secretion reflectivity (MSR), inhomogeneous appearance of walls of acinar units (AWI) and periglandular interstices of acinar units (API), and the number of Demodex.The positive rate of Demodex infestation in MGDs was 89.32%, and statistically higher than control group (controls; P < .001). All parameters showed statistically significant differences between MGDs and controls (P < .001), and Demodex-negative group and Demodex-positive group (P < .05) in both MGDs and controls, except MAD (P = .826) in controls. The number of Demodex was positively correlated with MALD, MASD, MF, MAI, MSR, AWI, and API in MGDs and controls (P < .05), and negatively correlated with MAD and MOA in MGDs (P < .05). MOA showed a strong significant correlation with the number of Demodex in controls (P < .001), whereas there was no significant difference between the number of Demodex and the MAD in controls (P = .448).Demodex can cause microstructural changes of MGs, which can cause or aggravate MGD, and the more the number of Demodex infestation, the more serious the structural damage.

In vivo confocal microscopy morphometric analysis of corneal subbasal nerve plexus in dry eye disease using newly developed fully automated system.

To evaluate in vivo confocal microscopy (IVCM) features of corneal subbasal nerve plexus (SNP) in the setting of dry eye disease (DED) using fully automated software "ACCMetrics," and to further investigate its diagnostic performance in discriminating DED patients. IVCM exams of SNP in DED patients and matched control subjects were performed using Heidelberg Retina Tomograph with the Rostock Cornea Module. The following parameters were obtained with ACCMetrics: corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL), corneal nerve total branch density (CTBD), corneal nerve fiber area (CNFA), corneal nerve fiber width (CNFW), and corneal nerve fractal dimension (CNFrD). The Mann-Whitney U test was used to compare variables. Receiver operating characteristic curves with calculations of the area under the curve (AUC) were used to describe the accuracy of IVCM parameters for discriminating DED patients from controls. Thirty-nine DED patients and 30 control subjects were included. Significantly, lower values of CNFD, CNBD, and CNFL and higher value of CNFW were found in DED patients compared to controls (respectively, 20.5 ± 8.7 vs 25.4 ± 6.7n/mm2; 25.6 ± 20.1 vs 37.6 ± 21.5n/mm2; 12.6 ± 4.4 vs 14.5 ± 2.9mm/mm2; 0.021 ± 0.001 vs 0.019 ± 0.001mm/mm2; always p < 0.024). CNFW value had the highest diagnostic power in discriminating DED patients (AUC = 0.828). When the diagnosis of DED was made based on either CNFW or CNBD, the sensitivity was 97.4% and the specificity 46.7%. The software ACCMetrics was able to rapidly detect SNP alterations occurring in the setting of DED and showed good diagnostic performance in discriminating DED patients.

Histopathology manifestation and imaging characteristics of in vivo confocal microscopy for diagnosis of ocular surface squamous neoplasia

Objective: To study the histopathology manifestation and imaging characteristics of in vivo confocal microscopy (IVCM) for diagnosis of ocular surface squamous neoplasia (OSSN) and analyze the reliability of IVCM in differential diagnosis from OSSN cases. Methods: A prospective study. Twenty-three patients (23 eyes) with OSSN were collected from September 2015 to November 2017 in Beijing Tongren Eye center. They were underwent the examinations sequentially as follows: visual examination; slit-lamp microscope examination and ocular surface photography; color fundus image; anterior segment optical coherence tomography examination; IVCM examination and histopathology examination after surgery. With histopathology diagnosis, all subjects were divided into two groups: conjunctival intraepithelial neoplasm (CIN) and squamous cell carcinoma (SCC). Compared with histopathological findings, the IVCM results (cell morphology, cytoplasm and nucleus) of OSSN were analyzed. The difference analysis between the count data of two groups was carried out by the chi square test or Fisher's exact test. Receiver operating characteristic curve and area under the curve (AUC) were used to describe the accuracy of each parameter to differentiate SCC from OSSN. Results: There were 12 males and 11 females among the 23 patients aged (62±15) years. With the histopathological diagnosis, there were 15 cases (15 eyes) in the CIN group and 8 cases (8 eyes) in the SCC group. Eye redness, pain, foreign body sensation and tears were the symptoms of OSSN. There was no significant difference in clinical symptoms between the CIN and SCC groups. The size of tumors and the incidence of trophoblastic vessels in the SCC group were greater than those in the CIN group [8.5(6.5-15.5) mm vs. 5.8(4.0-8.5)mm, Z=4.702,P=0.029; 7/8 vs. 5/15, χ2=6.135, P=0.013). In histopathology, multilayered epithelia with cellular polymorphism, varied cytoplasm staining, and slightly thicker nuclei were observed in the CIN group. The corneal epithelial cells of SCC patients were markedly heterogeneous, and the intercellular bridge structure can be detected. Proliferative cells appeared with spindle shaped cells, nuclear mitotic figures and syncytial cells in the SCC group. The IVCM examination in the CIN group and SCC group showed that the cytoplasm was high and the ratio of nuclear plasma increased. There was no significant difference between the two groups in the size of epithelial cells, cytoplasm reflectivity, and nuclear cytoplasm ratio (P=0.053, 0.108, 0.067). The proportions of nuclear mitotic figures, spindle or chimeric cells, nests of whirlpool cells and the abnormal cells of the superficial stroma layer (8/8, 8/8, 8/8 and 8/8) in the SCC group was higher than those (2/15, 1/15, 4/15 and 0/15) in the CIN group, and the difference was statistically significant (P=0.001, 0.001, 0.003; P<0.001). Among these IVCM parameters, the abnormal cells of the superficial stroma layer had the highest diagnostic ability with the AUC value of 1.000, and the following AUC values were 0.933 for mitotic or double nuclei, 0.901 for spindle or chimeric cells, and 0.867 for the nests of whirlpool cells. Conclusions: The IVCM characteristics of OSSN are the dysplastic cells, hyper-reflective cytoplasm and increased nuclear plasma ratio in the corneal epithelium. Dysplastic cells appearing in the superficial stroma layer, nuclear mitotic figures and nests of vortex cells are the main IVCM parameters to support the malignant change of OSSN lesions. (Chin J Ophthalmol, 2018, 54: 652-660).

In vivo confocal microscopy indicates an inverse relationship between the sub-basal corneal plexus and the conjunctivalisation in patients with limbal stem cell deficiency

Background/aimsLimbal stem cell deficiency (LSCD) is characterised by a marked decrease in limbal stem cells. It is classified primarily using subjective slit-lamp observations. In vivo confocal microscopy (IVCM) can non-invasively...

In Vivo Confocal Microscopy in Dry Eye Disease Associated With Chronic Graft-Versus-Host Disease.

To compare densities of corneal epithelial dendritic cells (DCs), corneal subbasal nerves, and conjunctival epithelial immune cells (EICs) between patients with dry eye disease (DED) with and without graft-versus-host disease (GVHD) using in vivo confocal microscopy (IVCM). This study included 54 patients who had moderate to severe DED either associated with (n = 33) or without (n = 21) chronic GVHD. In addition to evaluating clinical parameters of DED, images obtained by laser-scanning IVCM of the central cornea and superior tarsal conjunctiva were analyzed to measure densities of corneal epithelial DCs, corneal subbasal nerves, and conjunctival EICs. Although there were no significant differences between GVHD and non-GVHD groups in symptom scores, the GVHD group had significantly worse corneal fluorescein staining, tear break-up time, and Schirmer's scores than the non-GVHD group. Corneal epithelial DC density, corneal subbasal nerve density, and conjunctival EIC density were 148 ± 135 cells/mm2, 16.3 ± 6.1 mm/mm2, and 670 ± 267 cells/mm2, respectively, in the GVHD group; and 122 ± 99 cells/mm2, 18.3 ± 5.1 mm/mm2, and 572 ± 271 cells/mm2, respectively, in the non-GVHD group. After adjusting for clinical parameters, including the DED severity, none of the IVCM parameters was significantly different between the GVHD versus non-GVHD groups (P = 0.82, P = 0.21, and P = 0.60, respectively). In GVHD-associated DED, cellular changes in the cornea and conjunctiva observed by IVCM were similar to those seen in patients who have non-GVHD dry eye with the same level of disease severity. Therefore, corneal and conjunctival IVCM findings in GVHD-associated DED are possibly reflective of the local disease (DED) severity rather than the underlying systemic disease process.

Meibomian Gland Alteration in Patients with Primary Chronic Dacryocystitis: An In vivo Confocal Microscopy Study

Purpose: To evaluate meibomian gland (MG) alterations in patients with primary chronic dacryocystitis (PCD) by in vivo confocal microscopy (IVCM), and to correlate the finding with clinical presentation.Methods: Twenty-eight eyes with the diagnosis of PCD and their contralateral unaffected eyes were studied and compared with 27 normal controls. All subjects completed an Ocular Surface Disease Index questionnaire (OSDI) and underwent slit-lamp biomicroscopy examination, tear break-up time (BUT) measurements, fluorescein staining, Schirmer test I, and an IVCM examination of the MG. IVCM parameters, including the MG acinar unit density (MGAUD), periglandular inflammatory cell density (ICD), MG acinar unit longest diameter (MGALD), and MG acinar unit shortest diameter (MGASD) and their correlation with clinical data were analyzed.Results: The mean MG expressibility scores, BUT values, and staining scores were significantly worse in eyes with PCD compared with the contralateral clinically unaffected eyes and controls (p < 0.05). A significant decrease in MGAUD was observed in PCD eyes compared with the controls and the contralateral clinically unaffected eyes. Conversely, the mean ICD and MGASD values were significantly higher in the PCD eyes. There were no significant differences in mean MGALD value between the PCD eyes and the contralateral clinically unaffected eyes. In addition, there were significant changes in the IVCM parameters in the contralateral unaffected eyes compared with the controls, including MGAUD, ICD, MGALD, and MGASD. All IVCM parameters showed a strong, significant correlation with MG dropout grades, MG expressibility, fluorescein staining scores, and OSDI values (all p < 0.05).Conclusions: Patients with unilateral PCD demonstrated significant changes in MG as compared with the contralateral clinically unaffected eyes and controls. The MG function should be closely observed in these patients.

Monitoring the Inflammatory Process in Herpetic Stromal Keratitis: The Role of In Vivo Confocal Microscopy

To investigate the role of in vivo confocal microscopy (IVCM) in the detection of inflammatory activity and follow-up of herpetic stromal keratitis (HSK). Prospective observational cohort study. Thirty-eight patients with active HSK. Within 7 days after diagnosis of active HSK, both eyes of each patient were examined by slit-lamp biomicroscopy and white-light IVCM (Confoscan 4; Nidek Technologies, Padova, Italy). The HSK-affected eyes were followed up at 1, 3, 6, and 12 months, whereas the unaffected fellow eyes were reexamined after 12 months. Three patients did not complete follow-up and were excluded for data analyses. All IVCM examinations were assessed for morphologic alterations characteristic of inflammatory activity and for corneal backscatter. As secondary outcome parameters, best-corrected visual activity (BCVA), central corneal thickness (CCT), intraocular pressure (IOP), and endothelial cell density (ECD) were determined at each study visit. We used repeated-measures analysis of variance to assess changes during the 12-month follow-up period and paired t tests to compare HSK-affected eyes with fellow eyes. Presence of dendriform cells, pseudoguttae, and keratic precipitates, and follow-up of mean corneal backscatter. An increase of dendriform cells and pseudoguttae often accompanied stromal infiltration. Because these IVCM parameters were indiscernible or overlooked at slit-lamp examination, they proved to be excellent indicators of inflammatory activity. At 12 months' follow-up, mean corneal backscatter had decreased significantly by 36%, but still fell outside the normal range in 24 (69%) of the HSK-affected eyes. By using slit-lamp in conjunction with IVCM, we detected 17 recurrences in 14 of 35 patients (40%). Three of these recurrences were missed by slit-lamp, and 6 of these were missed by IVCM. At 12 months' follow-up, BCVA (-9 letters), CCT (-36 μm), and ECD (-313 cells/mm(2)) were significantly lower, whereas IOP (1.8 mmHg) was significantly higher, in HSK-affected eyes compared with fellow eyes. The data presented demonstrate that IVCM is complementary to slit-lamp examination in the follow-up of HSK, particularly because of its power to detect early signs of intracorneal inflammatory activity. Therapy guidance based on morphologic assessment and corneal backscatter measurement by combined IVCM and slit-lamp examination may improve the outcome of HSK. The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Filtering Bleb Functionality: A Clinical, Anterior Segment Optical Coherence Tomography and In Vivo Confocal Microscopy Study

To provide a microscopic and macroscopic analysis by a clinical, in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) assessment of filtering blebs after glaucoma surgery. We retrospectively analyzed 60 eyes of 48 glaucomatous patients by slit-lamp, IVCM, and AS-OCT examinations. Patients were divided into 2 groups: successful blebs (group 1, 16 patients, 27 eyes) were defined as a one-third reduction in preoperative intraocular pressure without antiglaucoma medications and failed blebs (group 2, 32 patients, 33 eyes) as a less than one-third reduction in preoperative intraocular pressure without therapy. The examinations were performed from 1 to 96 months postoperatively. Diffuse or cystic clinical patterns were indicative for good functionality whereas flat or encapsulation was indicative for poor functionality. When comparing successful with failed blebs, the IVCM analysis showed a greater number (P=0.014), density (P=0.009), and total area of epithelial microcysts (P=0.017) and a lower density of connective tissue (P=0.006). The AS-OCT analysis showed a lower degree of bleb wall reflectivity (P<0.001). A significant correlation was found between the clinical and AS-OCT parameters, particularly for the cystic (100%) and diffuse (74%) patterns. All IVCM parameters did correlate well with the bleb functionality whereas, among the AS-OCT parameters, only the bleb wall reflectivity was significantly related to the filtering capability. Clinical and AS-OCT bleb classification showed a significant degree of concordance. As a consequence, simultaneous approach by clinical, microscopic, and tomographic assessment improves the clinician's ability in the postsurgery understanding and management of blebs.