Bilateral morphometric analysis of corneal sub-basal nerve plexus in patients undergoing unilateral cataract surgery: a preliminary in vivo confocal microscopy study

2020 ◽  
pp. bjophthalmol-2019-315449 ◽  
Author(s):  
Giuseppe Giannaccare ◽  
Federico Bernabei ◽  
Marco Pellegrini ◽  
Fabio Guaraldi ◽  
Federica Turchi ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Cataract Surgery ◽  
Nerve Fibre ◽  
Fibre Length ◽  
Nerve Plexus ◽  
In Vivo Confocal Microscopy ◽  
Corneal Nerve ◽  
Branch Density ◽  
Unilateral Cataract

AimsTo evaluate bilateral morphometric changes of corneal sub-basal nerve plexus (CSNP) occurring after unilateral cataract surgery by in vivo confocal microscopy (IVCM) images analysed with automated software.MethodsIVCM was performed before (V0) and 1 month after surgery (V1) in both operated eyes (OEs) and unoperated eyes (UEs) of 30 patients. Thirty age and sex-matched subjects acted as controls. Corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), corneal nerve fibre length (CNFL), corneal nerve total branch density (CTBD), corneal nerve fibre area (CNFA), corneal nerve fibre width, corneal nerve fractal dimension (CNFrD) and dendritic cells density were calculated.ResultsMean CNFD, CNBD, CNFL, CTBD, CNFA and CNFrD significantly decreased at V1 versus V0 in both eyes (respectively, 15.35±7.00 vs 21.21±6.56 n/mm2 in OEs and 20.11±6.69 vs 23.20±7.26 in UEs; 13.57±12.16 vs 26.79±16.91 n/mm2 in OEs and 24.28±14.88 vs 29.76±15.25 in UEs; 9.67±3.44 mm/mm2 vs 13.49±3.42 in OEs and 12.53±3.60 vs 14.02±3.82 in UEs; 22.81±18.77 vs 42.25±24.64 n/mm2 in OEs and 38.06±20.52 vs 43.93±22.27 in UEs; 0.0040±0.0021 vs 0.0058±0.0020 mm2/mm2 in OEs and 0.0049±0.0016 vs 0.0057±0.0019 in UEs; 1.418±0.058 vs 1.470±0.037 in OEs and 1.466±0.040 vs 1.477±0.036 in UEs; always p<0.049).ConclusionPatients undergoing cataract surgery exhibit bilateral alterations of CSNP. This finding could have broad implications in the setting of sequential cataract surgery.

scholarly journals In Vivo Confocal Microscopy Evaluation in Patients with Keratoconus

2022 ◽  
Vol 11 (2) ◽  
pp. 393
Author(s):  
Alvin Wei Jun Teo ◽  
Hassan Mansoor ◽  
Nigel Sim ◽  
Molly Tzu-Yu Lin ◽  
Yu-Chi Liu
Keyword(s):  
Confocal Microscopy ◽  
Nerve Regeneration ◽  
Nerve Fibre ◽  
Ex Vivo ◽  
Fibre Length ◽  
In Vivo Confocal Microscopy ◽  
Corneal Sensitivity ◽  
Mechanical Removal ◽  
Cellular Changes

Keratoconus is the most common primary corneal ectasia characterized by progressive focal thinning. Patients experience increased irregular astigmatism, decreased visual acuity and corneal sensitivity. Corneal collagen crosslinking (CXL), a minimally invasive procedure, is effective in halting disease progression. Historically, keratoconus research was confined to ex vivo settings. In vivo confocal microscopy (IVCM) has been used to examine the corneal microstructure clinically. In this review, we discuss keratoconus cellular changes evaluated by IVCM before and after CXL. Cellular changes before CXL include decreased keratocyte and nerve densities, disorganized subbasal nerves with thickening, increased nerve tortuosity and shortened nerve fibre length. Repopulation of keratocytes occurs up to 1 year post procedure. IVCM also correlates corneal nerve status to functional corneal sensitivity. Immediately after CXL, there is reduced nerve density and keratocyte absence due to mechanical removal of the epithelium and CXL effect. Nerve regeneration begins after 1 month, with nerve fibre densities recovering to pre-operative levels between 6 months to 1 year and remains stable up to 5 years. Nerves remain tortuous and nerve densities are reduced. Corneal sensitivity is reduced immediately postoperatively but recovers with nerve regeneration. Our article provides comprehensive review on the use of IVCM imaging in keratoconus patients.

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

2020 ◽  
pp. 112067212096412
Author(s):  
Marco Pellegrini ◽  
Stefano Sebastiani ◽  
Lorenzo Tucci ◽  
Giuseppe Giannaccare ◽  
Simona Moscatiello ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Glycemic Variability ◽  
Diabetes Duration ◽  
Nerve Plexus ◽  
Cold Sensitivity ◽  
In Vivo Confocal Microscopy ◽  
Corneal Nerve ◽  
Automated Software

Purpose: 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. Methods: 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. Results: 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). Conclusions: All-time SD of HbA1C and disease duration were found to be independent predictors of damage to CSNP in patients with T1DM.

scholarly journals Laser scanning in vivo confocal microscopy (IVCM) for evaluating human corneal sub-basal nerve plexus parameters: protocol for a systematic review

BMJ Open ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. e018646 ◽  
Author(s):  
Manikkuwadura Eranda Harshan De Silva ◽  
Alexis Ceecee Zhang ◽  
Amalia Karahalios ◽  
Holly Rose Chinnery ◽  
Laura Elizabeth Downie
Keyword(s):  
Systematic Review ◽  
Confocal Microscopy ◽  
Laser Scanning ◽  
Meta Analysis ◽  
Nerve Plexus ◽  
Cochrane Library ◽  
Published Data ◽  
In Vivo Confocal Microscopy ◽  
Corneal Nerve

IntroductionLaser scanning in vivo confocal microscopy (IVCM) enables non-invasive, high-resolution imaging of the cornea. In recent years, there has been a vast increase in researchers using laser scanning IVCM to image and quantify corneal nerve parameters. However, a range of methodological approaches have been adopted. The primary aim of this systematic review is to critically appraise the reported method(s) of primary research studies that have used laser scanning IVCM to quantify corneal sub-basal nerve plexus (SBNP) parameters in humans, and to examine corneal nerve parameters in healthy individuals.Methods and analysisA systematic review of primary studies that have used laser scanning IVCM to quantify SBNP parameters in humans will be conducted. Comprehensive electronic searches will be performed in Ovid MedLine, Embase and the Cochrane Library. Two reviewers will independently assess titles and abstracts, and exclude studies not meeting the inclusion criteria. For studies judged eligible or potentially eligible, full texts will be independently assessed by two reviewers to determine eligibility. A third reviewer will resolve any discrepancies in judgement. Risk of bias will be assessed using a custom tool, covering five methodological domains: participant selection, method of image capture, method of image analysis, data reporting and other sources of bias. A systematic narrative synthesis of findings will be provided. A multilevel random-effects meta-analysis will be performed for corneal nerve parameters derived from healthy participants. This review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.Ethics and disseminationAs this review considers published data, ethical approval is not required. We foresee that this synthesis will serve as a reference for future studies, and can be used to inform best practice standards for using IVCM in clinical research. A manuscript reporting the results of the review will be published and may also be presented at scientific conferences.

scholarly journals Corneal confocal microscopy detects small fibre neurodegeneration in Parkinson's disease using automated analysis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sze Hway Lim ◽  
Maryam Ferdousi ◽  
Alise Kalteniece ◽  
Lewis Kass-Iliyya ◽  
Ioannis N. Petropoulos ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Confocal Microscopy ◽  
Nerve Fibre ◽  
Fibre Length ◽  
Mean Difference ◽  
Nerve Branch ◽  
Corneal Confocal Microscopy ◽  
Corneal Nerve ◽  
Branch Density

AbstractWe studied the utility of corneal confocal microscopy (CCM) in detecting a reduction in corneal nerve parameters in a large cohort of patients with Parkinson’s disease (PD) compared to controls using a fully automated potentially scalable method of analysis. We also assessed if CCM parameters are related to the severity and sub-type of PD. 98 participants with PD and 26 healthy controls underwent CCM with automated corneal nerve quantification, MDS-UPDRS III, Hoehn and Yahr scale, Montreal Cognitive Assessment, Parkinson’s Disease Questionnaire-39 and PD subtype assessment. Corneal nerve fibre density (mean difference: − 5.00 no/mm2, 95% confidence interval (CI) [− 7.89, − 2.12], p = 0.001), corneal nerve branch density (mean difference: − 10.71 no/mm2, 95% CI [− 16.93, − 4.48], p = 0.003), corneal total branch density (mean difference: − 14.75 no/mm2, 95% CI [− 23.58, − 5.92], p = 0.002), and corneal nerve fibre length (mean difference: − 2.57 mm/mm2, 95% CI [− 4.02, − 1.12], p = 0.001) were significantly lower in PD participants compared to controls. There was no correlation between corneal nerve parameters and duration, severity or subtype of PD, cognitive function or quality of life. CCM with automated corneal nerve analysis identifies nerve fibre damage and may act as a biomarker for neurodegeneration in PD.

scholarly journals Validation of the Use of Automated and Manual Quantitative Analysis of Corneal Nerve Plexus Following Refractive Surgery

Diagnostics ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 493 ◽  
Author(s):  
Jia Ying Chin ◽  
Lily Wei Yun Yang ◽  
Angel Jung Se Ji ◽  
Mario Nubile ◽  
Leonardo Mastropasqua ◽  
...  
Keyword(s):  
Nerve Fibre ◽  
Refractive Surgery ◽  
Fibre Length ◽  
Observer Agreement ◽  
Nerve Branch ◽  
Lenticule Extraction ◽  
Manual Methods ◽  
Corneal Nerve ◽  
Branch Density

Following refractive surgery, the cornea is denervated and re-innervated, hence a reproducible tool to objectively quantify this change is warranted. This study aimed to determine the repeatability and reproducibility of corneal nerve quantification between automated (ACCMetrics) and manual software (CCMetrics) following refractive surgery. A total of 1007 in vivo confocal microscopy images from 20 post-small incision lenticule extraction (SMILE) or post-laser-assisted in situ keratomileusis (LASIK) patients were evaluated by two independent observers using CCMetrics for corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fibre length (CNFL). Intra-observer and inter-observer reproducibility and repeatability, as well as agreement and correlation between the measurements obtained by ACCMetrics and CCMetrics, were assessed. We found that CNFL demonstrated the best intra- and inter-observer agreement followed by CNFD (intra-class correlation coefficient (ICC) = 0.799 and 0.740, respectively for CNFL; 0.757 and 0.728 for CNFD). CNBD demonstrated poorest intra- and inter-observer ICC. There was an underestimation in ACCMetrics measurements compared to CCMetrics measurements, although the differences were not significant. Our data suggested that both automated and manual methods can be used as reliable tools for the evaluation of corneal nerve status following refractive surgery. However, the measurements obtained with different methods are not interchangeable.

An in vivo confocal microscopy study of corneal changes in pseudoexfoliation syndrome

2018 ◽  
Vol 29 (5) ◽  
pp. 555-560 ◽  
Author(s):  
Luca Terracciano ◽  
Michela Cennamo ◽  
Eleonora Favuzza ◽  
Litasova Julia ◽  
Orsola Caporossi ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Anterior Segment ◽  
Senile Cataract ◽  
Nerve Plexus ◽  
Pseudoexfoliation Syndrome ◽  
Control Group ◽  
In Vivo Confocal Microscopy ◽  
Corneal Sensitivity ◽  
Corneal Layer

Purpose: To evaluate, through the in vivo confocal microscopy, the pathological changes of each corneal layer in eyes affected by pseudoexfoliation syndrome. Methods: We studied 40 eyes of 40 patients with diagnosis of unilateral senile cataract associated with pseudoexfoliation syndrome and 40 eyes of 40 control subjects with senile cataract without pseudoexfoliation syndrome. All patients underwent a complete ophthalmic examination including best corrected visual acuity, slit-lamp examination, corneal sensitivity measurement using a Cochet-Bonnet nylon thread esthesiometer, and anterior segment optical coherence tomography (Visante OCT, Carl Zeiss Meditec AG, Germany); in vivo confocal microscopy of corneal sections (endothelium, stroma, sub-basal nerve plexus, and superficial and basal epithelium) was performed with the ConfoScan 4.0 (Nidek, Japan). Results: In pseudoexfoliation syndrome group, the mean corneal sensitivity was 44.1 ± 1.3 mm and in the control group was 55.6 ± 4.7 mm. The corneas of the eyes with pseudoexfoliation syndrome were significantly less sensitive than those of control group eyes (p < 0.001). Pseudoexfoliation syndrome eyes had a lower nerve density and less nerve beadings and a higher degree of tortuosity in sub-basal plexus compared to the control group. The cell density of epithelial and endothelial layers was significantly lower in pseudoexfoliation syndrome eyes than controls. In 80% of pseudoexfoliation syndrome eyes, we found activated keratocytes and inflammatory cells in the anterior stroma. Conclusion: Our study demonstrates the morpho-structural corneal alterations in eyes affected by pseudoexfoliation syndrome, using corneal in vivo confocal microscopy as a non-invasive and high-reproducible technique to evaluate pathophysiology of each corneal layer; the sub-basal nerve plexus alterations are correlated with the lower corneal sensitivity.

Image Reconstruction of the Subbasal Nerve Plexus with In Vivo Confocal Microscopy

2011 ◽  
Vol 52 (9) ◽  
pp. 5022 ◽  
Author(s):  
Stephan Allgeier ◽  
Andrey Zhivov ◽  
Franz Eberle ◽  
Bernd Koehler ◽  
Susanne Maier ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Confocal Microscopy ◽  
Nerve Plexus ◽  
In Vivo Confocal Microscopy ◽  
Subbasal Nerve Plexus
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