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The aim of this study is to report the clinical features, imaging findings including confocal imaging, corneal nerve fiber analysis, and management outcomes in a series of three cases of varicella zoster virus (VZV) reactivation following one dose of coronavirus disease 2019 (COVID-19) vaccination. This was a retrospective and observational study. All the patients who developed uveitis post-vaccination were pooled together. Patients who had VZV reactivation were included. Two cases had polymerase chain reaction positive for VZV from aqueous humor. At the time of presentation, IgG and IgM spike protein antibodies for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) were tested. Out of this pool, three patients with classical features to describe pole-to-pole manifestations were chosen. A 36-year-old lady with post-vaccination sclerokeratouveitis associated with reactivation of herpes zoster ophthalmicus, a 56-year-old lady with post-vaccination acute anterior uveitis associated with herpes zoster ophthalmicus, and a 43-year-old gentleman with post-vaccination acute retinal necrosis were included. We present a possible link between anti-SARS-CoV-2 virus vaccination and varicella zoster reactivation in these patients and also describe the clinical features, imaging findings including confocal imaging, corneal nerve fiber analysis, and management with detailed discussion.
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Purpose: To compare the prevalence of dry eye disease (DED) and assess corneal nerve sensitivity (CNS) in diabetic and non?diabetic patients. To study the association of severity of DED in patients with diabetic retinopathy (DR) and CNS in DED. Methods: A cross?sectional prospective comparative study was conducted on 400 patients attending the ophthalmology OPD. The patients above 18 years of age were divided into two groups—diabetic (T2DM) and non?diabetic. All patients were subjectively assessed for DED based on Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire and objectively, using Schirmer’s II test and Tear Film Break?Up Time (TBUT). Visual acuity assessment, anterior segment, and posterior segment evaluation were done. Results: Considering the SPEED score, Schirmer II values, TBUT values, and Dry Eye Work Shop (DEWS) II diagnostic criteria, mild DED was seen in 23% diabetic and 22.25% non?diabetic groups, moderate DED in 45.75% diabetic and 9.75% non?diabetic groups, and severe DED in 2% diabetic and 1.75% non?diabetic groups. Moderate DED was more common within all grades of DR. CNS was reduced more in diabetic group and also in patients with higher degree of DED. Conclusion: Prevalence of DED is more in the patients with T2DM. CNS was reduced more in patients with T2DM and in patients with moderate DED. Our study also correlated that severity of DR affects the severity of DED.
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Objective:To investigate the changes in the nerve fiber layer of the cornea in patients with demyelinating optic neuritis (DON) and its correlation with visual acuity.Methods:A cross-sectional study. From March 2021 to July 2022, 27 cases (39 eyes) of DON patients diagnosed in the Department of Neurology and Ophthalmology of Beijing Tongren Hospital Affiliated to Capital Medical University were enrolled in this study. According to the serological test results, the patients were divided into aquaporin 4 antibody associated optic neuritis (AQP4-ON group) and myelin oligodendrocyte glycoprotein antibody associated optic neuritis (MOG-ON group), with 15 cases (19 eyes) and 12 cases (20 eyes) respectively. According to previous history of glucocorticoid treatment, the patients were divided into glucocorticoid treated group and non-glucocorticoid treated group, with 17 cases (27 eyes) and 10 cases (12 eyes) respectively. Twenty healthy volunteers (20 eyes) with age- and gender-matched were selected as the control group. All eyes underwent best corrected visual acuity (BCVA) and in vivo confocal microscopy (IVCM) examinations. BCVA was performed using Snellen's standard logarithmic visual acuity chart, which was converted into logarithmic minimum angle resolution (logMAR) visual acuity during statistics. The corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve fiber branch length (CNBL), corneal nerve fiber branch density (CNBD) and the density of corneal dendritic cells (DC) were detected by IVCM examination. Parameter comparison between groups by t-test and Kruskal-Wallis rank sum test. The correlation between logMAR BCVA and pamameters of corneal nerve fibers were analyzed using Spearman analysis. Results:The CNFL, CNFD, and CNBL of the DON group and the control group were (10.67±2.55) mm/mm 2, (57.78±12.35) root/mm 2, (3.27±1.34) mm/mm 2, and (13.74±3.05) mm/mm 2, (70.95±13.14) root/mm 2, and (4.22±1.03) mm/mm 2, respectively; the difference in CNFL, CNFD, and CNBL between the two groups were statistically significant ( t=4.089, 3.795, 2.773; P<0.05). The CNFL, CNBL, and CNBD of the affected eyes in the MOG-ON group and AQP4-ON group were (12.02±2.13) mm/mm 2, (3.80±1.19) mm/mm 2, (47.97±8.86) fibers/mm 2, and (9.25±2.19) mm/mm 2, (2.72±1.19) mm/mm 2, (39.43±13.86) fibers/mm 2, respectively; the differences in CNFL, CNBL, and CNBD between the two groups were statistically significant ( t=-4.002, -2.706, -2.306; P<0.05). The corneal DC density of the patients in the hormone treated group and the non-hormone treated group was (24.43±8.32) and (41.22±9.86) cells/mm 2, respectively. The difference in corneal DC density between the two subgroups was statistically significant ( P<0.001). Correlation analysis showed that there was a significant negative correlation between logMAR BCVA and CNBL and CNFL in patients with DON ( r=-0.422, -0.456; P<0.05). Conclusions:There are different degrees of corneal nerve fiber damage in patients with different types of DON. There was a negative correlation between BCVA and the length of corneal nerve fibers.
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The cornea is a transparent outer layer of the anterior eye segment, innervated by a high density of neural tissue. In the process of corneal innervation, trigeminal ganglion originated corneal nerves traverse different types of corneal cell in the epithelial and stromal layers. Corneal stromal cells, epithelial cells, immune cells, and other cells interact closely to maintain corneal microenvironmental homeostasis. In addition, corneal nerves is associated with the occurrence and development of many ocular surface diseases. Corneal nerves release various active peptides that regulate corneal sensation, maintain epithelial integrity and proliferation, improve wound healing, and manage local inflammation and immune response. This article reviews the advances in the corneal nerve regulation of the ocular surface microenvironment, providing some new ideas for the further study and treatment of corneal nerve-associated diseases.
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Objective:To explore the changes of corneal neuropathy and ocular surface flora in patients with type 2 diabetes, and the correlation between corneal neuropathy and ocular surface flora changes.Methods:According to the results of fundus fluorescein angiography, 65 patients with type 2 diabetes (130 eyes in total) who were treated with insulin alone and without comorbid retinopathy in the Department of Endocrinology, Henan People′s Hospital from March to June 2019 were selected. Sixty-five age-matched normal glucose tolerance subjects (130 eyes in total) were also enrolled. Confocal microscopy was performed and conjunctival sac secretions were collected. Through 16S rRNA analysis and sequencing and PICRUSt bacterial gene function prediction, the relationship between patients with type 2 diabetes and the difference in the degree of corneal neuropathy and the composition of ocular surface flora and function prediction in healthy people were explored, and the correlation between corneal neuropathy and ocular surface flora was analyzed as well.Results:Compared with healthy people, patients with type 2 diabetes have more severe corneal neuropathy, and it was related to the changes in ocular surface flora. Brevibacillus and paenibacillus were significantly positively correlated with the degree of corneal neuropathy ( P<0.05), and enhydrobacter and proteobacteria were significantly negatively correlated with the degree of corneal neuropathy ( P<0.05). PICRUSt analysis showed that the degree of enrichment of metabolism-related genes in the ocular surface flora of patients with type 2 diabetes was significantly changed compared with healthy people. Conclusion:Patients with type 2 diabetes present with more severe corneal neuropathy. The diversity of ocular surface flora and metabolic function have significant changes. The degree of severity corneal neuropathy is related to brevibacillus, paenibacillus, enhydrobacter, and proteobacteria.
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@#AIM: To analyze and study the corneal nerve invasion phenomenon of Bowman's membrane in patients with IIIA lattice corneal dystrophy by confocal laser scanning microscopy. Quantitative analysis of 10a continuous observation image data was performed, followed by self-control studies.<p>METHODS: A total of 10 patients(13 eyes)with IIIA Lattice corneal dystrophy were continuously examined by confocal laser scanning microscopy. The data were observed and analyzed. <p>RESULTS: The normal corneal nerve of Bowman's membrane(Grade 0)of IIIA LCD patients gradually decreased with the prolongation of observation time. The nerves of grade I to V involved(amyloid-wrapped nerve fibers)gradually increased correspondingly. So suggested that the corneal nerve invasion of Bowman's membrane(amyloid deposits)in patients with IIIA LCD were gradually increasing with time. <p>CONCLUSION: In patients with type ⅢA lattice corneal dystrophy, there is a neurotropic phenomenon in Bowman's membrane, which gradually worsens with the aggravation of the lesion. This lesion can explain the recurrent epithelial damage of the IIIA LCD from some degrees. Continuous observation of patients with type IIIA LCD by corneal laser confocal microscopy can well understand the development of the lesion and explain its clinical manifestations.
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@#Corneal confocal microscope(CCM)is a non-invasive instrument for the study of living cornea and is increasingly being used to evaluate corneal nerve plexus and Langerhans cell lesions. This paper reviews the recent advances in corneal nerve plexus and Langerhans cell lesions from the perspective of the use of CCM in the study of systemic diseases such as diabetes mellitus, Sjogren's syndrome, multiple sclerosis, thyroid-associated ophthalmopathy, fibromyalgia, chronic migraine and Parkinson's disease.
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Objective To evaluate the clinical changes of corneal epithelial cells,dendritic cells,endothelial cells and corneal nerves in contralateral eyes of patients with unilateral infectious keratitis.Methods A prospective serial case observation study was conducted in patients with unilateral infectious keratitis from January to August 2018 in the First Affiliated Hospital of Harbin Medical University.The corneal epithelial cells density,dendritic cells density,endothelial cells density,total nerve density,total number of nerves and branch nerve density were analyzed with in vivo confocal microscopy (IVCM),slit lamp microscopy was performed on all subjects to observe the conjunctiva,cornea and anterior chamber.Corneal branch nerve density and total nerve density were compared with the control group by homogeneity test of variance.This study was approved by the Ethics Committee of the First Affiliated Hospital of Harbin Medical University (No.IRB-AF/SC-04/01.0).Results Slit lamp microscopy showed no significant changes in anterior segment of the contralateral uninfected eyes in the 3 groups.The corneal epithelial cells density of uninfected eyes in viral keratitis group,bacterial keratitis group and fungal keratitis group was 1 834 (1 584,2 107),1 905 (1 651,2 332) and 1 859 (1 477,1 995)/mm2,respectively,which were significantly lower than 3 479 (3 080,3 910)/mm2 in the control group,the dendritic cells densities in viral keratitis group and bacterial keratitis group were 175 (139,214)/mm2 and 156 (118,190)/mm2,which were higher than 69(57,76)/mm2 in the control group,the differences were statistically significant (all at P＜0.05).The corneal endothelial cells density of uninfected eyes in viral keratitis group was 1 107(945,1 270)/mm2,which was less than 1 905(1 651,2 332)/mm2 in the bacterial keratitis group and 1 859(1 477,1 995)/mm2 in the fungal keratitis group (both at P＜0.05).The corneal nerve number and total nerve density of uninfected eyes in viral keratitis group were l0(7,11)/mm2 and (1 822.85±622.34) μm/mm2,which were lower than 11 (9,13)/mm2 and (2 340.91±:408.70)μm/mm2 in the bacterial keratitis group,with significant differences between them (P＜ 0.05,P＜ 0.008 3).The morphology of corneal epithelial cells and endothelial cells in each infectious keratitis group was larger than that in the control group,while the morphology and number of dendritic cells in the contralateral eye of patients with viral and bacterial keratitis increased.Conclusions In unilateral uninfected eyes of infectious keratitis,the density of corneal epithelial cells,dendritic cells,endothelial cells and corneal nerves changes correspondingly.There may be a close relationship of corneal immunity and nervous system between the two eyes.
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@#Diabetic retinopathy(DR)is the most common retinal vascular disease, seriously compromising visual function and quality-of-life. Retinal laser photocoagulation is one of the safest, most effective, and economical methods used to treat DR, but is associated with certain side-effects developing at the time of treatment. Given the continuous developments in diagnostic and treatment modalities, the complications associated with the use of traditional single-point lasers are becoming better understood. Today, the clinical demand for multi-point scanning lasers is increasing, but the effectiveness and safety of both treatments require further exploration. Here, we review the effects of laser treatment on vision, fundus fluorescein angiography, the visual field, visual function, macular edema, and the corneal nerve.
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Objective To investigate the relationship between corneal basal nerve change and type 2 diabetic retinopathy based on confocal laser microscopy.Methods Together 118 patients with type 2 diabetes (T2D) were collected in our hospital from February 2016 to February 2017,including 57 patients with diabetic retinopathy (DR group) and 61 patients without DR (NDR group).For comparison,60 healthy volunteers were selected as the control group.And all the subjects were examined by corneal confocal laser microscopy to analyze the relationship between the morphological parameters of the corneal nerve and clinical variables.Results Corneal nerve fiber density,corneal nerve branch density and corneal nerve branch length in DR group were (20.03 ±4.22) · mm-2,(22.01 ± 7.05) · mm-2 and (9.50 ± 1.76) mm ·mm-2,significantly less than those of the control group and NDR group (all P ＜ 0.05);and corneal nerve fiber curvature was (0.30 ± 0.03),significantly higher than that of the control group and NDR group (all P ＜ 0.05);In DR patients,phase Ⅲ patients had smaller the corneal nerve fiber density,corneal nerve branch density and corneal nerve branch length,but the larger corneal nerve fiber curvature than the phase Ⅰ and Ⅱ patients (all P ＜ 0.05);course of disease of DR group was (12.04 ± 2.48) years,which was significantly higher than that of NDR group (P ＜ 0.05),while fasting C peptide and fasting insulin were (1.41 ± 0.58) μg · L-1 and (20.05 ± 7.91) mU · L-1,respectively,significantly lower than those of NDR group (all P ＜ 0.05);The duration of T2D was negatively correlated with the corneal nerve branch density and corneal nerve branch length (r =-0.322,-0.317,all P ＜0.05);Fasting C peptide was positively correlated with the corneal nerve branch density (r =0.298,P ＜ 0.05),and negatively correlated with the corneal nerve curvature (r =-0.311,P ＜ 0.05).Conclusion Patients with T2D retinopathy have abnormal morphology of corneal nerve.And confocal laser scanning microscopy is conducive to the early detection of microvascular disease in T2D patients with a longer course of disease or a low level of fasting C peptide.
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PURPOSE: To investigate the effect of macrophage migration inhibitory factor (MIF) on corneal sensitivity after laser in situ keratomileusis (LASIK) surgery. METHODS: New Zealand white rabbits were used in this study. A hinged corneal flap (160-microm thick) was created with a microkeratome, and -3.0 diopter excimer laser ablation was performed. Expressions of MIF mRNA in the corneal epithelial cells and surrounding inflammatory cells were analyzed using reverse transcription polymerase chain reaction at 48 hours after LASIK. After LASIK surgery, the rabbits were topically given either 1) a balanced salt solution (BSS), 2) MIF (100 ng/mL) alone, or 3) a combination of nerve growth factor (NGF, 100 ug/mL), neurotrophine-3 (NT-3, 100 ng/mL), interleukin-6 (IL-6, 5 ng/mL), and leukemia inhibitory factor (LIF, 5 ng/mL) four times a day for three days. Preoperative and postoperative corneal sensitivity at two weeks and at 10 weeks were assessed using the Cochet-Bonnet esthesiometer. RESULTS: Expression of MIF mRNA was 2.5-fold upregulated in the corneal epithelium and 1.5-fold upregulated in the surrounding inflammatory cells as compared with the control eyes. Preoperative baseline corneal sensitivity was 40.56 +/- 2.36 mm. At two weeks after LASIK, corneal sensitivity was 9.17 +/- 5.57 mm in the BSS treated group, 21.92 +/- 2.44 mm in the MIF treated group, and 22.42 +/- 1.59 mm in the neuronal growth factors-treated group (MIF vs. BSS, p < 0.0001; neuronal growth factors vs. BSS, p < 0.0001; MIF vs. neuronal growth factors, p = 0.815). At 10 weeks after LASIK, corneal sensitivity was 15.00 +/- 9.65, 35.00 +/- 5.48, and 29.58 +/- 4.31 mm respectively (MIF vs. BSS, p = 0.0001; neuronal growth factors vs. BSS, p = 0.002; MIF vs. neuronal growth factors, p = 0.192). Treatment with MIF alone could achieve as much of an effect on recovery of corneal sensation as treatment with combination of NGF, NT-3, IL-6, and LIF. CONCLUSIONS: Topically administered MIF plays a significant role in the early recovery of corneal sensitivity after LASIK in the experimental animal model.
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Animals , Female , Humans , Rabbits , Epithelium, Corneal/drug effects , Interleukin-6/pharmacology , Keratomileusis, Laser In Situ/methods , Leukemia Inhibitory Factor/pharmacology , Macrophage Migration-Inhibitory Factors/genetics , Models, Animal , Nerve Growth Factor/pharmacology , Nerve Regeneration/drug effects , Neurotrophin 3/pharmacology , RNA, Messenger/metabolism , Recovery of Function/drug effects , Sensation/drug effectsABSTRACT
PURPOSE: To investigate the changes of the corneal microstructure of neurosurgically-induced neurotrophic keratitis patients compared to normal human corneas using in vivo confocal microscope (IVCM). METHODS: Ten eyes in the normal control group and 11 eyes in the neurosurgically-induced neurotrophic keratitis patient group were included in the present study. After corneal sensitivity tests were performed, thickness of each layer and number of endothelial cells and stromal keratocytes in the cornea were assessed using IVCM. Morphological characteristics of the corneal nerves were measured by ImageJ software. RESULTS: After analysis of corneal thickness layer by layer, the Bowman's layer was significantly reduced in the neurosurgically-induced neurotrophic keratitis patient group compared with the normal control group (p = 0.016) and the portion of Bowman's layer was significantly reduced in the neurosurgically-induced neurotrophic keratitis patient group compared with the control group (p = 0.024). The nerve fiber length per square-millimeter became significantly shorter compared to the normal control group (p = 0.042). The nerve fiber length per square millimeter showed significant correlations with the number of fibers, number of beading, branching patterns, and nerve tortuosity (p = 0.002, 0.002, 0.013 and 0.034, respectively). The number of endothelial cells and stromal keratocytes, the number of nerve fibers and beading, and the pattern of branching and nerve tortuosity showed no significant differences between the normal and neurosurgically-induced neurotrophic keratitis patient groups. CONCLUSIONS: Our results showed that decreased thickness of Bowman's layer may be related to the decreased corneal nerve distribution, secondary to the dysfunction of trigeminal nerve branch innervating the cornea. The microstructural changes of Bowman's layer can help diagnose the disease and evaluate the current status in neurosurgically-induced neurotrophic keratitis patients.
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Humans , Cornea , Endothelial Cells , Keratitis , Microscopy, Confocal , Nerve Fibers , Neurosurgery , Trigeminal NerveABSTRACT
PURPOSE: To investigate the changes of the corneal microstructure of neurosurgically-induced neurotrophic keratitis patients compared to normal human corneas using in vivo confocal microscope (IVCM). METHODS: Ten eyes in the normal control group and 11 eyes in the neurosurgically-induced neurotrophic keratitis patient group were included in the present study. After corneal sensitivity tests were performed, thickness of each layer and number of endothelial cells and stromal keratocytes in the cornea were assessed using IVCM. Morphological characteristics of the corneal nerves were measured by ImageJ software. RESULTS: After analysis of corneal thickness layer by layer, the Bowman's layer was significantly reduced in the neurosurgically-induced neurotrophic keratitis patient group compared with the normal control group (p = 0.016) and the portion of Bowman's layer was significantly reduced in the neurosurgically-induced neurotrophic keratitis patient group compared with the control group (p = 0.024). The nerve fiber length per square-millimeter became significantly shorter compared to the normal control group (p = 0.042). The nerve fiber length per square millimeter showed significant correlations with the number of fibers, number of beading, branching patterns, and nerve tortuosity (p = 0.002, 0.002, 0.013 and 0.034, respectively). The number of endothelial cells and stromal keratocytes, the number of nerve fibers and beading, and the pattern of branching and nerve tortuosity showed no significant differences between the normal and neurosurgically-induced neurotrophic keratitis patient groups. CONCLUSIONS: Our results showed that decreased thickness of Bowman's layer may be related to the decreased corneal nerve distribution, secondary to the dysfunction of trigeminal nerve branch innervating the cornea. The microstructural changes of Bowman's layer can help diagnose the disease and evaluate the current status in neurosurgically-induced neurotrophic keratitis patients.
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Humans , Cornea , Endothelial Cells , Keratitis , Microscopy, Confocal , Nerve Fibers , Neurosurgery , Trigeminal NerveABSTRACT
Background Femtosecond laser in situ keratomileusis (LASIK) inevitably injury keratocytes and corneal nerve fibers.The research report about postoperative morphological changes of corneal nerve regeneration and keratocytes in femtosecond LASIK is still rare.Objective The aim of this study was to observe the kinetic changes of keratocytes and corneal nerve in corneal flap after femtosecond LASIK.Method Femtosecond laser manufacture corneal flap of LASIK surgery was performed on 60 eyes of 30 patients with refractive error using both femtosecond laser system and excimer laser treatment system.The repair of corneal wound was examined by slit lamp microscope,and the morphology of keratocytes and corneal nerve were observed with confocal microscope 1 week,1month,3 months after surgery,respectively.Results No haze or flap folds were found under the slit lamp microscope from 1 week through 3 months after operation.One week after surgery,the corneal stromal cells at the interface of the corneal flap appeared to be a mild activation status in 42 eyes (70％),but the activated cells gradually reduced with lapse of time.Three months after surgery,mild activation state still was found in 7 eyes (12％).One week after surgery,independent,short (＜50 μm),curved subbasal nerve fibers were exhibited in 7 eyes (12％),and curved filamentous nerve fibers were discovered in 48 eyes (80％) one month after surgery.The nerve fiber length of subbasal nerve was ＞200 μm in 27 eyes (45％) and classes beaded structure appeared 3 months after operation but were still different with preoperative subbasal nerve fibers.One week after the operation,filaments or discontinuous nerve fibers could been seen in 46 eyes (77％) at theinterface,and long nerve fibers or filamentous nerves were visible around the terminal or periphery of nerve fibers in 49 eyes (82％) one month after surgery,and long nerve fibers or filaments of nerve fibers were visible in 57 eyes (95％) 3 months after the surgery.Conclusions Femtosecond LASIK cause wound reaction at cellular level.Corneal nerve fibers recover with the extension of time,but there are still some morphological differences 3 months after surgery from preoperation.
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Background Radiofrequency thermocoagulation is one of the effective therapies for trigeminal neuralgia.Corneal nerve is important substance of radiofrequency thermocoagulation ocular surface,which support the normal structure and function of cornea.Most of corneal nerves come from ophthalmic branch of trigeminal nerve.However,the change of ocular surface microenvironment following radiofrequency thermocoagulation treatment in the patient with trigeminal neuralgiais unclear.Objective This study was to analyze ocular surface change after radiofrequency thermocoagulation therapy in patients with trigeminal neuralgia.Methods Twenty-eight eyes of 28patients with trigeminal neuralgia underwent radiofrequency thermocoagulation therapy were enrolled in this study.The contralateral eyes were regarded as the control group.The central corneal sensitivity,function of lacrimal secretion (Schiemer 1 test),tear break-up time(BUT),corneal fluorescence staining and laser scanning confocal microscopic examination were performed before and after surgery in operative eyes and compared with the fellow eye.Informed consent was obtained before any relevant medical procedure from each patient.Results No significant differences was found before surgery in the central corneal sensitivity,the Schiemer Ⅰ test,BUT,corneal fluorescence staining and densities value of corneal subepithelial nerve plexus between the treating eyes and fellow eyes(Z =-1.511,-1.119,-0.428,-0.378,-0.854; P =0.131,0.263,0.669,0.705,0.393).1n the third day after radiofrequencythermocoagulation therapy,compared with pre-treatment,no significant differences were seen in BUT result,Schirmer Ⅰ test and the score of ocular surface fluorescence staining (Z =-0.620,-0.315,-1.732;P =0.535,0.753,0.083).Corneal sensitivity and subbasal nerve density were lowed 3 days after surgery (Z =-2.708,-2.813 ; P =0.007,0.005).One month after treatment,differences of all indexes mentioned above showed statistical significance between treating eyes and fellow eyes(Z=-3.888,-2.373,-3.311,-2.535 ; P =0.000,0.018,0.001,0.011).The corneal subepithelial nerve was thinner and sparse and dendritic cells on the cornea were found in the eyes received radiofrequency thermocoagulation therapy.Conclusions The secretion of tears and the stability of tear film are poorer and the corneal sensitivity and subbasal nerve density are affected in a certain extent in the eye received radiofrequency thermocoagulation therapy.
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BackgroundWith the number of diabetics increases,people pay more attention to the diabetic keratopathy.The major mechanism leading to diabetic keratopathy is diabetic corneal neuropathy.So it is significant to observe pathologic mechanism of diabetic corneal neuropathy. Objective To investigate the protective effects of edaravone( a free radical scavenger) on corneal nerve of rats with experimental diabetic corneal neuropathy,then explain the effects of oxidative stress in the pathologic mechanism of diabetic corneal neuropathy. Methods Seventy Sprague-Daxley male rats were taken as experimental subjects and 20 of them were used as normal control group.The remaining 50 were induced to be diabetic mellitus by a single intraperitoneal injection of streptozotocin and divided into 2 groups randomly:edaravone treated group and diabetic control group.In the edaravone treated group,edaravone(0.2 g/L) eye drops were used 3 times a day until the animal was killed.Five rats in each group were sacrificed at 6,8,10 and 12 weeks respectively.Then the corneal sensation,number of corneal nerve fibers,morphology,content of malondialdehyde(MDA) and activity of superoxide dismutase(SOD) in the corneal tissue were detected.ResultsIn the diabetic control group,the corneal sensation and the number of corneal nerve fibers were decreased,the density of neural network for cluster was sparse,the nerve activity was decreased,the content of MDA in the corneal tissue was significantly increased,the activity of SOD in the corneal tissue was significantly decreased (P＜0.01 ).Accompany with the course of disease,the above change was obvious day after day.Compared with the diabetic control group,the corneal sensation and the morphological abnormalities in corneal nerve of edaravone group were improved significantly which had the partial branches to the 12th week,the content of MDA in the corneal tissue was significantly decreased,the activity of SOD in the corneal tissue was significantly increased (P＜0.01).Conclusions Edaravone can lower diabetic corneal nerve of rats with experimental diabetic corneal neuropathyinjury,Oxidative stress may be a critical pathologic mechanism of diabetic corneal neuropathy.
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PURPOSE: To evaluate the changes in the clinical signs and symptoms of dry eye syndrome before and after cataract surgery according to the main incision location and the type of artificial tears. METHODS: Twenty-four eyes of 17 patients who underwent phacoemulsification and posterior chamber lens insertion from May 2009 to July 2009 were enrolled in the present study prospectively. The main incision location (temporal or superior incision) was determined according to the axis of astigmatism and the postoperative artificial tears (sodium hyaluronate with or without preservatives) were determined randomly. The tear film break-up time (TF-BUT), Schirmer test, esthesiometer, corneal surface grading with Oxford system and ocular surface disease index (OSDI) questionnaire before and 1, 2 and 6 months after surgery were evaluated. The corneal nerve was also analyzed using corneal confocal microscopy (Confoscan 4, Nidek, Italy) before, and 1 and 6 months after surgery. RESULTS: The TF-BUT was significantly longer (p = 0.010) and the OSDI score was significantly lower (p = 0.007) in the patient group with preservative-free sodium hyaluronate than the group with sodium hyaluronate containing preservatives at 6 months after cataract surgery. There were no statistically significant differences according to the main incision location in the sodium hyaluronate without preservatives group. CONCLUSIONS: Symptoms and several signs of dry eye syndrome triggered by cataract surgery decreased with preservative- free artificial tears compared to tears with preservatives.
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Humans , Astigmatism , Axis, Cervical Vertebra , Cataract , Dry Eye Syndromes , Eye , Hyaluronic Acid , Microscopy, Confocal , Ophthalmic Solutions , Phacoemulsification , Prospective Studies , Surveys and Questionnaires , TearsABSTRACT
Background The ocular nerve of trigeminus is the sensation and nutrition nerve of cornea.Whether trigeminal neuralgia affect the function of ocular surface and the morphology of corneal nerve plexus or not is below understanding.Confocal microscope is a non-invasive method for in vivo corneal examination.Objective This study was to analyze the ocular surface findings and observe the morphology and density of corneal nerve under the confocal microscopy in patients with trigeminal neuralgia.Methods Thirty-three eyes of 33 patients with trigeminal neuralgia were collected from the Department of Pain Management in Henan Provincial People's Hospital.The corneal perceptual sensitivity was examined using corneal aesthesiometer,and the function of lacrimal secretion (Schiemer Ⅰtest),tear break-up time (BUT) were performed to evaluate the influence of trigeminal neuralgia on ocular surface.The change of corneal nerve was observed under the confocal microscopy.The fellow eyes served as controls.The informed consent was obtained from the subjects before any examination.Results The fiber length of corneal perceptual sensitivity was (54.348±6.793)mm and (55.217±6.480)mm in trigeminal neuralgia group and control group without a significant difference between them (t=0.641,P=0.528).No significant differences were found in the mean value of Schiemer Ⅰtest (9.390±6.583mm vs 9.300±5.295mm) and BUT result (6.09±4.177s vs 6.13±4.799s) between trigeminal neuralgia and control group(t=0.070,P=0.945;t=-0.085,P=0.933).The densities value of corneal subepithelial nerve plexus at the nasal,temporal,superior,inferior and central area was insignificantly changed between trigeminal neuralgia group and control group(P=0.840,0.459,0.268,0.120,0.607).Tenuous,bending and circling nerve fibers were seen in corneal stroma under the confocal microscope,while the nerve fibers were strict in controls.Conclusion Trigeminal neuralgia does not dramatically affect eye surface function and corneal subbasal nerve plexus density,but corneal nerve fibers with trigeminal neuralgia are more bending than normal people.
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Background The ultrastructure change and growth of corneal nerve after laser in situ keratomileusis (LASIK) are some influent factors to the stability of tear film and the sensibility of cornea.Some relevant studies are lack up to now.Objective This study is to observe the changes of ultrastructure of corneal epithelium and regeneration of corneal nerve fiber.Methods LASIK was performed on the lateral eyes of 48 New Zealand white rabbits.Rabbit eyes were excavated at instant in postoperation,one day,seven days,one,three and six months after LASIK.Change of corneal ultrastructure and corneal nerve staining were examined under the scanning electron microscope (SEM) and transmmision electron microscope (TEM) at the time points mentioned above.The numbers of microvilli of corneal epithelial cells in different postoperative time were analyzed.10% AuCl was used to evaluate the growth status of corneal nerve in different time after LASIK.Results Irregularity of microvillus of corneal epithelial cells,degrease of cell density were seen under the TEM and some cavities could been observed in the instant of postoperation.The connection abnormality of intercells,dropsy and rupture of microvillus were presented under the SEM,However,the ultrastructure of corneal epithelial cells was almost normal in 7 days after LASIK.The numbers of microvillus in corneal epithelial cells were significantly declined in the postoperative instant group compared with preoperative group (P＜0.05),but no evidently difference was found in postoperative 1 day and 7 days groups compared with preoperative group(P＞0.05).Corneal nerve staining showed that in 1 day after surgery,nerve plexus was deprivation and boundary of nerve injury was clear and nerve fibers were cut off.After one month some reborn nerve fiber grew into the cornea flap.Reborn corneal nerve fiber can be seen at center laser ablation area after six months of LASIK.Conclusion The ultrastructure change of corneal epithelial cells in the early stage after operation may be a important factor causing dry eye symptom following LASIK.The growth fashion of corneal nerve fibers is from the cutting edge to the center of corneal flap.
ABSTRACT
PURPOSE: This study was performed to describe the ultrastructure of stromal nerve fibers in central, mid-peripheral, and peripheral parts of the human cornea by flat serial corneal section. METHODS: Seven samples from fresh normal cornea, derived from eyes with retinoblastoma and eyes from eye bank, were processed for transmission electron microscopic examinations. Flat serial sections reaching from mid-epithelium to the anterior stroma were observed. RESULTS: The myelinated and unmyelinated nerve fibers are alternately arranged and run parallel to the stromal collagen fibers at the periphery of the cornea. The main difference between the limbal and the central cornea is the presence of myelinated nerve fibers in the anterior peripheral stroma. The diameter of the unmyelinated nerve fiber measures between 0.25 and 0.63 micrometer in size. The corneal nerve fibers contain vesicles, mitochondria, and glycogen particles. The peripheral nerve fibers contain both clear and dense vesicles. The nerve fiber is separated by an interval of 0.3 micrometer from the cytoplasmic wall of keratocyte at the center of the cornea. CONCLUSIONS: The majority of the corneal nerve fibers can be classified as C-fibers due to their size. The presence of both clear and dense vesicles within the cytoplasm of the periphery of the cornea suggest that a small portion in the peripheral corneal nerve may be originated from the sympathetic nervous system. A close vicinity between the nerve fibers and keratocyte supports that nerve fibers might modulate the release of growth factors in the regulation of stromal and epithelial metabolism.