Research ArticleIn Vivo Confocal Microscopy of Cornea in Patients with Terrien’sMarginal Corneal Degeneration

Ting Chen,1,2 Qiangxiang Li ,3 Xiangbo Tang ,1 Min Liao ,1 and Hua Wang 1

1Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China2Department of Ophthalmology, Xiangya Changde Hospital, Changde, Hunan Province, China3Hunan Provincial People’s Hospital, Changsha, Hunan Province, China

Correspondence should be addressed to Hua Wang; wanghua1026@hotmail.com

Received 21 April 2019; Accepted 27 June 2019; Published 11 July 2019

Academic Editor: Marta Sacchetti

Copyright © 2019 Ting Chen et al. *is is an open access article distributed under the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*is study was aimed at observing the morphological changes of the cornea with ocular in vivo confocal microscopy (IVCM) inpatients with Terrien’s marginal degeneration (TMD). Ten patients (20 eyes) with TMD treated in the Department of Oph-thalmology, Xiangya Hospital, and 10 healthy controls (20 eyes) were included in the current study. A detailed slit lamp mi-croscopy, anterior segment photography, and corneal IVCM examination were performed for each eye.*e density of central andmarginal corneal epithelial cells, stromal cells, and subepithelial nerve fibers was compared between the two groups using theWilcoxon rank sum test. Compared with the control group, the corneal epithelial and endothelial cells in the TMD group showedgranular highly reflective substances and thinner subepithelial nerve fibers. *e uneven dot-like highly reflective substanceswithout cell structures appeared in the stromal layer of the cornea. *e density of central and marginal corneal epithelial cells,stromal cells, and subepithelial nerve fibers was lower in the TMD group (p< 0.05), and they were negatively correlated withseverity of the disease (p< 0.05). Our study demonstrated that the density of corneal epithelial cells, stromal cells, and sensoryplexus nerve fibers was significantly reduced in the TMD group. *e pathological changes were more obvious in the marginalcornea, and it is correlated with severity of the disease.

1. Introduction

Terrien’s marginal degeneration (TMD) is a chronic andbilateral marginal keratopathy [1], mainly characterized bysulcus thinning of corneal margins, corneal stromal atro-phy, and lipid deposition, often accompanied by cornealneovascularization. It progresses to corneal staphylomaand eventually corneal perforation in its advanced period.*e onset age of TMD patients is 10–70 years old, about 2/3of which are middle-aged men about 40 years old. *eduration of the disease can be up to 10–30 years. *e lesionin the corneal limbus was mostly seen at 9–3 o’clock po-sitions, and the upper corneal limbus is the most commonsite for initial lesions, fast development, and later perfo-rations. Although TMD could progress to advanced stages,severe symptoms like red eyes, eye pain, and cornealperforation are rarely found. *e main manifestation ofthis disease is the gradual decrease of visual acuity. With the

progression of TMD, the cornea became thinner and ex-panded. *e curvature of the cornea and the converseastigmatism gradually increased, which led to a progressivedecline of the patients’ visual acuity.*e exact pathogenesisremains unknown; however, it is commonly believed thatTMD is associated with the following factors: (a) immunediseases, (b) nutritional disorders and degenerative dis-eases, (c) inflammatory diseases, and (d) abnormalitysecondary to the composition of tears [2].

At present, the objective examination methods of TMDin the clinic include ultrasound biomicroscopy of the an-terior segment, optical coherence tomography (OCT) of theanterior segment, corneal topography, and IVCM exami-nation. Among all the above-mentioned methods, IVCM isthe only one that can observe the normal and pathologicalcorneal characteristics at the living corneal cell level. Atpresent, there are only a few reports that IVCM is used toobserve TMD. Some studies have found that TMD had

HindawiJournal of OphthalmologyVolume 2019, Article ID 3161843, 8 pageshttps://doi.org/10.1155/2019/3161843

mailto:wanghua1026@hotmail.comhttps://orcid.org/0000-0003-2575-0951https://orcid.org/0000-0003-4525-4445https://orcid.org/0000-0002-9508-8265https://orcid.org/0000-0003-4612-7528https://creativecommons.org/licenses/by/4.0/https://doi.org/10.1155/2019/3161843

hyperreflective substances deposition in the corneal epi-thelium, abnormal aberration of nerve fibers, activation ofstromal cells, no cellular structural substances, and de-position of lipid layer particles by IVCM [3, 4]. However, noprevious studies have reported the correlation of IVCMfindings and the severity of TMD or compared the patho-logical changes between the central and marginal cornea.

*e clinical diagnosis for some early and atypical cases isdifficult, which results in poor therapeutic effect in severecases. In the present study, we investigated the cornealcharacteristic pathological changes of TMD on the in vivolevel of cells by IVCM, which provides a clinical basis forclarifying the pathogenesis of TMD and meanwhile providesa sensitive and specific detection method for the clinicaldiagnosis and follow-up of TMD patients.

2. Subjects and Methods

2.1. Subjects. Patients diagnosed with TMD for the first timefrom July 2015 to June 2017 in the Department of Oph-thalmology, Xiangya Hospital, Central South University,were included in the study. No gender or age restrictionswere applied. Patients with history of ocular surgery, othercorneal lesions by any causes, systemic diseases, immunesystem diseases, and psychological or mental illness wereexcluded from the study. Meanwhile, ten healthy volunteersmatched by age and gender with no ocular or systemicdiseases were recruited as controls.

2.2. Evaluation for Severity of Disease. Patients with TMDwere classified into Stage I, Stage II, Stage III, and Stage IV bythe Francois staging method [5, 6]. Stage I: Infiltration Period:the gray-white turbidity at the corneal margin parallel to thecorneal limbus was accompanied with the neovascularizationin the superficial cornea. Stage II: Degeneration Period: thesulcus shape of the cornea was thinned, and there was lipiddeposition in the sulcus. Stage III: Swelling Period: the corneain the lesion zone became thinner to form one or morebulging zones with a width of 1.5–3mm or above, andmeanwhile, the significant astigmatism against the rule wasfound. Stage IV: Keratoconus Period: the lesion protrudedforward to form the keratoconus, which may be prone tocorneal perforation (Figure 1) [5, 6].

2.3. Inspection Methods

2.3.1. Slit Lamp Microscopy (Keeler Optics). *e anteriorsegment was checked using a slit lamp.

2.3.2. Anterior Segment Photography (Topson BG4). *ecorneal photos were taken before and after corneal fluo-rescein staining.

2.3.3. Corneal IVCM Examination. An in vivo laser confocalmicroscope (Heidelberg Engineering, Laser class1) was usedto perform IVCM. For each eye, different layers of cornealcells in both the central and peripheral cornea as well as the

corneal subepithelial sensory plexus were scanned. All ex-aminations were finished by one skilled physician with thesame machine. *e most affected portion of the cornea in allpatients was examined.

2.4. Measurement of Cell Density. *e random numbermethod was used to select 3 frames of pictures randomly ateach level, each frame of picture was divided into 36 equalparts on average, and the random number method was usedto select 10 equal parts randomly. *e average corneal celldensity was calculated using the built-in cell countingsoftware [7]. *e principle of cell counting was as follows:only the complete number of cells; when the cell is pressedon the grid line, only count the upper line, not the lower line,only the right line, not the left line.

2.5. Measurement of the Density of Subepithelial Nerve Fibers.At least 3 images of subepithelial nerve fibers were randomlyselected for analysis in each case. *e density of nerve fibers(the total length of nerve fibers in a picture) was measured bysemiautomatic neural analysis and the tracking system(Neuron J) [8]. *e data obtained from Neuron J wereconverted into the corneal subepithelial nerve density (μm/mm2) according to the image size and pixel conversion unit.Because the size of each image is 384 pixels× 384 pixels, theactual size is 400 μm× 400 μm, so it is 1 μm� 0.96 pixels.*erefore, the conversion formula is as follows: cornealsubcutaneous nerve density (μm/mm2)� total length of nervefiber [μm]/4002×1,000,000� total length of nerve fiber [pix]/0.96× 6.25 [9].

2.6. Statistical Analysis Method. *e experiment resultsunderwent a descriptive statistical analysis based on thesoftware SPSS 22.0 (IBM, Armonk, NY). After the normalitytest, the data of two groups showed a skewed distribution.*erefore, the median (median, M)± quartile spacing(quartile, Q) was taken to describe the central location anddispersion of the statistical data.*eWilcoxon rank sum testwas used to compare the density of central and marginalcorneal cells and subepithelial nerve fibers between the TMDgroup and control group. It is also used to compare thedensity of corneal cells and subepithelial nerve fibers in thecentral and marginal cornea in the TMD group. *eSpearman rank correlation method was used to analyze thecorrelation between the density of corneal cells and sub-epithelial nerve fibers and the severity of the disease. p< 0.05was considered to have statistical significance.

3. Results

3.1. General Characteristics. *ere were six TMD femalepatients and four TMD male patients, with a mean age of51.9± 20.3 years. Among them, eight patients had binoculardisease, accounting for 80% of the group. *ere were threepatients (5 eyes) with TMD in the Stage-I period, threepatients (5 eyes) with TMD in the Stage-II period, twopatients (4 eyes) with TMD in the Stage-III period, and two

2 Journal of Ophthalmology

patients (4 eyes) with TMD in the Stage-IV period (Figure 1).*e control group included 4 male and 6 female, aged 17–75 years, with a mean age of 49.0± 24.3 years.

3.2. Change of Corneal Cell Morphology in TMDPatients by IVCM

3.2.1. Epithelial Layer. *e corneal epithelial layer in themarginal and central cornea of both eyes in 10 TMD patientsshowed a decrease in cell density (p< 0.05) compared withcontrols. *ey also displayed a blurred boundary and de-position of dot-like and massive highly reflective substances.*e lesion wasmore severe in themarginal cornea comparedwith the central cornea (p< 0.05) (Figure 2).

3.2.2. Subepithelial Nerve Plexus. *e affected eyes of 10TMD patients showed a significant decrease in the density ofsubepithelial nerve fibers (p< 0.05) compared with controls.We could see a bent nerve trend, thinned nerve fibers, andeven an absence of subepithelial nerve fibers in severe pa-tients. *e activation of dendritic cells was found in thenerve fiber layer of some patients, and dot-like, massive, orcord-like lipid-like particles were found locally.*e lesion inthe corneal marginal zone was more severe than that in thecorneal central zone (p< 0.05) (Figure 2).

3.2.3. Corneal Stroma. *e corneal stroma of TMD patientsshowed a variety of morphological changes by IVCM, in-cluding stromal neovascularization, bright cell nuclei, en-hanced cytoplasmic reflex, activated stromal cells, a decreaseor absence of stromal cells, dot-like, needle-like, highlyreflexive, and uneven fiber tissue without cell structures.Besides, the morphological change was more significant inthe marginal corneal stromal zone than that in the centralcorneal zone (p< 0.05) (Figure 2).

3.2.4. Endothelial Layer. *e corneal endothelial cells of 11eyes in TMD patients showed dot-like reflections andblurred boundaries of endothelial cells, accounting for 55%of all cases (Figure 2).

3.2.5. Langerhans Cells. A large number of dendritic acti-vated Langerhans cells were found in the Bowmanmembraneand subepithelial nerve plexus of two TMD patients (4 eyes),accounting for 20% of all cases. A large number of inactivatedLangerhans cells without dendritic were found in the Bow-man membrane and subepithelial nerve plexus of one TMDpatient (1 eye), accounting for 5% of all cases (Figure 2).

3.3.Density ofCornealCells andDensity of SubepithelialNerveFibers. *e density of central and marginal corneal epi-thelial cells; superficial, medium, and deep stromal cells; andsubepithelial nerve fibers in patients of TMD group wassignificantly lower than that of the control group, and thedifference was statistically significant (p< 0.05); no signifi-cant difference was found in the density of endothelial cellsbetween the two groups (p> 0.05). In the TMD group, thedensity of epithelial cells; anterior, medium, and deepstromal cells; and subepithelial nerve fibers in the centralcornea was significantly higher than that in the marginalcornea, and the difference was statistically significant(p< 0.05). However, no significant difference was found inthe density of endothelial cells between the two groups(p> 0.05) (Tables 1–4).*e density of corneal epithelial cells;superficial, medium, and deep stromal cells; and sub-epithelial nerve fibers in TMD patients was negativelycorrected with the severity of the disease (Table 5).

4. Discussion

Marginal corneal degeneration, also known as Terrien’scorneal degeneration (TMD), was first reported by Trumpy

(a) (b) (c) (d) (e)

Figure 1: Anterior segment photography of TMD at various stages. (a) Normal eyes; (b) TMD at Stage I: the gray-white turbidity at thecorneal margin parallel to the corneal limbus (black arrow); (c) TMD at Stage II: the sulcus shape of the cornea was thinned, and there waslipid deposition in the sulcus (white arrow); (d) TMD at Stage III: the cornea in the lesion zone became thinner to form one or more bulgingzones with a width of 1.5–3mm or above (red arrow); (e) TMD at Stage IV: the marginal cornea was further thinned (blue arrow), withprotruded central cornea.

Journal of Ophthalmology 3

Epithelium Subepithelialnerve fibersAnteriorstroma

Mediumstroma Deep stroma Endothelium

Figure 2: Corneal structures under IVCM. a1–a6 are the central corneal structures of TMDpatients, b1–b6 are the central corneal structuresof the controls, c1–c6 are the marginal corneal structures of TMD patients, and d1–d6 are the marginal corneal structures of the controls.e density of epithelial cells in the central and marginal cornea of TMD patients was decreased, the cell boundaries were blurred, and thedot-like highly reective substances appeared; the density of the subepithelial nerve ber plexus was signicantly reduced and evendisappeared (blue arrow), while the density of inactivated Langerhans cells (green arrow) and activated Langerhans cells (black arrow) wasincreased. e number of anterior, medium, and deep stromal cells of the cornea was decreased, the dot-like (yellow arrow), needle-like(white arrow), and aky highly reective substances without cell structures (red arrow) were presented, and the boundaries of endothelialcells were blurred.

Table 1: Comparison of the density of central corneal cells between Terrien’s marginal degeneration patients and the control group (M±Q).

Group CaseDensity of central corneal cells

Epithelium Anterior stroma Medium stroma Deep stroma EndotheliumTMD group 10 5068.0± 1185.0 477.5± 744.0 250.0± 510.0 250.0± 529.0 2686.5± 314.0Control group 10 5930.0± 924.0 688.0± 519.0 521.5± 476.0 484.0± 465.0 2864.0± 422.0z value — −11.436 −4.962 −6.889 −4.072 −1.876p value —

in 1881 as “corneal hyaline degeneration” and described byTerrien in 1990. Suveges and associates demonstrated TMDas a disease of asymmetric progression in both eyes, whileAustin and Brown classified TMD into quiescent period andadvanced period through the histological presence of in-flammation in TMD patients. Moreover, many researchersbelieved that inflammation played a key role in the pro-gression of TMD and the inflammatory cells could promotethe progression of TMD. TMD has been recognized to acertain extent, but it is still restricted to understand the tissueand cytological features of TMD. TMD presents no specificchanges in pathological morphology, and it is mainlycharacterized by sulcus thinning of noninflammatory cor-neal stroma in the lesion zone, accompanied by superficialneovascularization and lipid deposition. With integralcorneal epithelium, the epithelial cells can proliferate tomore than 10 layers, accompanied by abnormal proliferationof basal membrane tissues. Historically, the cytologic ex-amination of TMD could only rely on the pathologic andother invasive examination methods. *e invention andapplication of IVCM made it possible to perform thenoninvasive biopsy of corneal conjunctival lesions at thecellular level. However, there are still few studies on thecharacteristic pathological changes of TMD using IVCM.

IVCM is an instrument equipped with the laser scanningdevice based on the ordinary microscope imaging, and ituses the laser to stimulate the fluorescence probe to perform

the in vivo noninvasive examination and obtain the fluo-rescence images of cells or cell structures within tissuesthrough image processing of the computer. IVCM has beenwidely applied in many fields, such as cell biology, micro-biology, and neurobiology, and its application field hasgradually expanded from the basic disciplines to the clinicalapplications. IVCM is also getting popularity in ophthal-mology, and the IVCM can be used in almost all lesionsinvolving the ocular surface to observe the microstructurechange of the ocular surface resulted from the lesions. *econcept of confocal microscopy was first patented byMarvinMinsky in 1957 to study the brain neural cells [10]. *e firstin vivo images of the human cornea were obtained byCavanaugh et al. in 1989. *ey demonstrated the confocalvisualization of the epithelium, basal lamina, Bowman layer,stromal nerves, pre-Descemet membrane, and endotheliumin the living cornea. In 1994, James Hill invented the tandemocular scanning device, IVCM. *us far, three main com-mercial confocal systems have been developed for in vivocorneal imaging: the tandem scanning confocal microscope(TSCM), the slit scanning confocal microscope (SSCM), andthe laser scanning confocal microscope (LSCM) [11, 12]. Atpresent, IVCM has been widely applied to the studies ofcorneal tissues and keratonosus. *e scope of studies nowcovers the studies on normal human cornea, contact lenswear, keratoconus, dry eye disease, neurotrophic keratop-athy and infectious keratitis, corneal dystrophies, epithelial

Table 3: Comparison of the density of corneal cells between the central corneal zone and marginal corneal zone in Terrien’s marginaldegeneration patients (M±Q).

Group CaseDensity of corneal cells

Epithelium Anterior stroma Medium stroma Deep stroma EndotheliumCentral cornea 10 5068.0± 1185.3 477.5± 744.0 250.0± 510.0 250.0± 529.0 2708.0± 319.0Marginal cornea 10 4679.0± 2001.5 0.0± 0.0 0.0± 0.0 0.0± 0.0 2655.5± 362.3z value — −3.672 −10.991 −7.407 −9.681 −0.289p value —

and subepithelial corneal dystrophy, stromal dystrophies,endothelial dystrophies, other ocular diseases, neuropathiccorneal pain, penetrating keratoplasty, phototherapeutickeratectomy, photorefractive keratectomy, laser-assisted insitu keratomileusis, laser-assisted subepithelial keratectomy,autoimmune diseases, peripheral neuropathies, diabetesmellitus, and other systemic diseases [13–26]. IVCM hasbeen widely used in the study of keratoconjunctivitis, but sofar, there are only few reports on the study of using IVCM toobserve the characteristic corneal lesions of TMD patients,and there is still no comparative analysis study on marginaland central corneal lesions in TMD patients.

Ferrari’s IVCM examination of a patient with early TMDshowed the highly reflective substances in the lesion of thepatient, the activated anterior stroma for honeycombchanges, the decreased density of subepithelial nerve plexus,and the abnormality of the epithelial basement membraneand Bowman membrane. Meanwhile, Ferrari et al. alsofound the abnormality of the subepithelial nerve plexus andthe activated anterior stromal cells and dendritic cells in thecontralateral eye of the patient [3]. *e above findings werealso reported later by Ceresara et al., MD, in their obser-vation of right-eye TMD patient by IVCM. Ceresara et al.,MD, noted the infiltration of inflammatory cells, absence ofthe epithelial basement membrane, and neovascularizationin the lesion zone of the right-eye TMD patient under IVCM[4]. In the current study, the density of corneal epithelialcells in the TMD patients was also found to be reduced,which was correlated with the severity of the disease.Moreover, the boundary of corneal epithelial cells wasblurred, accompanied by dot-like, massive, and cord-likehighly reflective substance deposition, and the corneal de-generation of the marginal zone wasmore severe than that ofthe central zone.

In this study, we also found a decreased density ofmarginal and central corneal epithelial nerve fibers in botheyes of all TMD patents, the broken subepithelial nervefibers, the absence of subepithelial nerve fibers for severepatients, the bent nerve trend, the thinned nerve fibers,activated dendritic cells in nerve fiber layers of some pa-tients, the increased density, and dot-like, massive, and cord-like highly reflective substances. Moreover, the density re-duction of subepithelial nerve fiber layer was positivelycorrected with the severity of TMD. And the corneal de-generation of the marginal zone wasmore severe than that ofthe central zone in all patients. *e decrease in the density ofthe subepithelial nerve fiber plexus is found in many dis-eases, and our study has further demonstrated that TMD canalso be involved in the corneal subepithelial nerve fibers.

TMD is a corneal stromal atrophy disease. Our studyfurther confirmed the gradual decrease of corneal stromalcells of TMD patients and the loss of normal stromalstructure with the development of the disease.We also foundthat the anterior stromal cells in TMD patients were notnecessarily in an activated state, while they were associatedwith the severity and location of the disease. *e central andcorneal anterior stromal cells in TMD patients at Stages Iand II could be activated, and the activated anterior stromalcells were mainly located in the central cornea. However, the

central and marginal anterior stromal cells in TMD patientsat Stages III and IV mainly showed a blurred or fuzzystructure of stromal cells, and even the dot-like, needle-like,and uneven reflections without cell structures were pre-sented. We speculated that the anterior stromal cells in theearly TMD period showed an activated state, while, with thedevelopment of the disease, the density of stromal cellsgradually decreased and disappeared eventually, showing thedot-like, needle-like, and flaky uneven reflections withoutcell structures. Meanwhile, the similar changes were foundin the medium and deep stromal cells.

Our studies showed the dot-like reflections in the cornealendothelium layer, blurred boundary of corneal endothelialcells, and uneven highly reflective deposition in 11 eyesamong all 20 eyes. We infer that the corneal degeneration ofthe TMD patients can also be involved in the corneal en-dothelium. In previous IVCM studies, the abnormality of thecorneal endothelium was not found in TMD patients. *is ismaybe because there is no comparative analysis of cornealendothelial cells in TMD patients with different pathologicalchanges due to a small number of study cases.

Previous studies showed that TMD was an immune-related disease, and the activated anterior stromal cells anddendritic cells were found in the IVCM examination ofTMD patients [3]. Our study also found a large number ofactivated Langerhans cells in the Bowman membrane andsubepithelial nerve plexus of two TMD patients (4 eyes),accounting for 20% of all cases; and a large number ofunactivated Langerhans cells in the Bowman membrane andsubepithelial nerve plexus of one TMD patient (1 eye),accounting for 5% of all cases. Langerhans cells are immunecells, and a large number of activated Langerhans cells arefound in rodent corneal ulcer and other immune-relatedcorneal diseases. However, in this study, they were foundonly in the Bowman membrane and subepithelial nerveplexus of two TMD patients, suggesting that TMD may beassociated with the immunity. However, further studies areneeded to observe the existence of other pathogenesis forTMD.

We hypothesized that TMD was a degenerative diseaseinvolving all the layers of cornea and the pathogenesis maybe associated with the immunity, but there may be otherpathogenesis mechanisms which need to be further studied.*e degeneration was the first to be involved in the cornealstroma; TMD was a commonly degenerative disease for themarginal and peripheral cornea, and the degeneration of themarginal cornea was earlier and more severe than that of thecentral cornea. Apart from the corneal endothelial cells inTMD patients, the decrease in the density of corneal stromalcells and the density of subepithelial nerve fibers was neg-atively corrected with the severity of the disease. As anoninvasive examination tool to observe characteristics ofcorneal degeneration, IVCM will be of great significance forthe diagnosis and follow-up of the TMD patients.

Data Availability

*e data are available from Ting Chen to researchers whomeet the criteria for access to the confidential data.

6 Journal of Ophthalmology

Conflicts of Interest

*e authors declare that they have no conflicts of interest.

Authors’ Contributions

Ting Chen and Min Liao curated the data; Hua Wang wereinvolved in formal analysis; Qiangxiang Li and Hua Wangwere responsible for funding acquisition; Xiangbo Tang andHua Wang were responsible for methodology; QiangxiangLi was involved in collection of resources; Ting Chen andXiangbo Tang analyzed the data using software; and TingChen wrote the original draft.

Acknowledgments

*is work was supported financially by the grants from theNational Natural Science Foundation of China (81170823),Science and Technology Program Project of Hunan Pro-vincial Science & Technology Department (nos. 2015JC3011and 2015JC3118), Science and Technology Plan Project ofHunan Provincial Administration of Traditional ChineseMedicine (201855), Science and Technology Plan Project ofChangsha Municipal Science and Technology Bureau(kq1701054), Scientific research project of Hunan ProvinceEducation Department (16 C0965), and Project of HunanTraditional Chinese Medicine Administration (201856).

References

[1] A. T. Chan, R. Ulate, Y. Goldich, D. S. Rootman, andC. C. Chan, “Terrien marginal degeneration: clinical char-acteristics and outcomes,” American Journal of Ophthal-mology, vol. 160, no. 5, pp. 867–872, 2015.

[2] A. T. Chan, R. Ulate, Y. Goldich, D. S. Rootman, andC. C. Chan, “Reply,” American Journal of Ophthalmology,vol. 164, no. 5, p. 152, 2016.

[3] G. Ferrari, S. Tedesco, E. Delfini, and C. Macaluso, “Laserscanning in vivo confocal microscopy in a case of terrienmarginal degeneration,” Cornea, vol. 29, no. 4, pp. 471–475,2010.

[4] G. Ceresara, L. Migliavacca, N. Orzalesi, and L. Rossetti, “Invivo confocal microscopy in terrien marginal corneal de-generation: a case report,” Cornea, vol. 30, no. 7, pp. 820–824,2011.

[5] Y. B. Zhang and H. Jia, “Terrien’s marginal degenerationaccompanied by latticed stromal opacities,” Optometry andVision Science, vol. 91, no. 5, pp. 110–116, 2014.

[6] N. Wang, C.-X. Wang, X.-F. Lian, S.-J. Duan, D. Huang, andS.-Y. Zhou, “Staging of development in Terrien’s degenerationbased on corneal curvatures detected by optical coherencetomography,” Graefe’s Archive for Clinical and ExperimentalOphthalmology, vol. 253, no. 10, pp. 1757–1764, 2015.

[7] M. Zhang, J. Chen, L. Luo, Q. Xiao, M. Sun, and Z. Liu,“Altered corneal nerves in aqueous tear deficiency viewed byin vivo confocal microscopy,” Cornea, vol. 24, no. 7,pp. 818–824, 2005.

[8] M. Fernandes, “Scanning slit topography: diagnostic boon inpresumed unilateral terrien’s marginal degeneration,”ContactLens and Anterior Eye, vol. 34, no. 6, pp. 282–286, 2011.

[9] E. Meijering, M. Jacob, J.-C. F. Sarria, P. Steiner, H. Hirling,and M. Unser, “Design and validation of a tool for neurite

tracing and analysis in fluorescence microscopy images,”Cytometry, vol. 58A, no. 2, pp. 167–176, 2004.

[10] M. Tavakoli, P. Hossain, and R. A. Malik, “Clinical applica-tions of corneal confocal microscopy,” Clinical Ophthalmol-ogy, vol. 2, no. 2, pp. 435–445, 2008.

[11] C. A. Girkin, “Principles of confocal scanning laser oph-thalmoscopy for the clinician,” in

between LASIK and laser epithelial keratomileusis (LASEK),”American Journal of Ophthalmology, vol. 141, no. 6,pp. 1009–1015, 2006.

[26] C. Zhao, S. Lu, A. Truffert et al., “Corneal nerves alterations invarious types of systemic polyneuropathy, identified by in vivoconfocal microscopy,” Klinische Monatsblätter für Augen-heilkunde, vol. 225, no. 5, pp. 413–417, 2008.

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