Automatic analysis of corneal nerves imaged using in vivo confocal microscopy

REFERENCES

• Oliveira‐soto L, Efron N. Morphology of corneal nerves using confocal microscopy. Cornea 2001; 20: 374–384.
   PubMed Web of Science ®Google Scholar
• Kowtharapu BS, Winter K, Marfurt C et al. Comparative quantitative assessment of the human corneal sub‐basal nerve plexus by in vivo confocal microscopy and histological staining. Eye (Lond) 2017; 31: 481–490.
   Web of Science ®Google Scholar
• Parissi M, Karanis G, Randjelovic S et al. Standardized baseline human corneal subbasal nerve density for clinical investigations with laser‐scanning in vivo confocal microscopy. Invest Ophthalmol Vis Sci 2013; 54: 7091–7102.
   PubMed Web of Science ®Google Scholar
• Al rashah K, Pritchard N, Dehghani C et al. Repeatability of measuring corneal nerve migration rate in individuals with and without diabetes. Cornea 2016; 35: 1355–1361.
   Web of Science ®Google Scholar
• Efron N, Edwards K, Roper N et al. Repeatability of measuring corneal subbasal nerve fiber length in individuals with type 2 diabetes. Eye Contact Lens 2010; 36: 245–248.
   Web of Science ®Google Scholar
• Chen Y, Le Q, Hong J et al. In vivo confocal microscopy of toxic keratopathy. Eye (Lond) 2017; 31: 140–147.
   Web of Science ®Google Scholar
• Alzahrani Y, Colorado LH, Pritchard N et al. Longitudinal changes in Langerhans cell density of the cornea and conjunctiva in contact lens‐induced dry eye. Clin Exp Optom 2017; 100: 33–40.
   Web of Science ®Google Scholar
• Alzahrani Y, Pritchard N, Efron N. Changes in corneal Langerhans cell density during the first few hours of contact lens wear. Cont Lens Anterior Eye 2016; 39: 307–310.
   Web of Science ®Google Scholar
• Hazlett LD, Mcclellan SM, Hume EB et al. Extended wear contact lens usage induces Langerhans cell migration into cornea. Exp Eye Res 1999; 69: 575–577.
   Web of Science ®Google Scholar
• Zhivov A, Stave J, Vollmar B et al. In vivo confocal microscopic evaluation of langerhans cell density and distribution in the corneal epithelium of healthy volunteers and contact lens wearers. Cornea 2007; 26: 47–54.
   PubMed Web of Science ®Google Scholar
• Shiraishi A, Uno T, Oka N et al. In vivo and in vitro laser confocal microscopy to diagnose acanthamoeba keratitis. Cornea 2010; 29: 861–865.
   Web of Science ®Google Scholar
• Scarpa F, Ruggeri A. Automated morphometric description of human corneal endothelium from in‐vivo specular and confocal microscopy. Conf Proc IEEE Eng Med Biol Soc 2016; 2016: 1296–1299.
   Google Scholar
• Efron N, Al‐dossari M, Pritchard N. In vivo confocal microscopy of the bulbar conjunctiva. Clin Exp Ophthalmol 2009; 37: 335–344.
   PubMed Web of Science ®Google Scholar
• Efron N, Al‐dossari M, Pritchard N. Confocal microscopy of the bulbar conjunctiva in contact lens wear. Cornea 2010; 29: 43–52.
   PubMed Web of Science ®Google Scholar
• Efron N, Al‐dossari M, Pritchard N. In vivo confocal microscopy of the palpebral conjunctiva and tarsal plate. Optom Vis Sci 2009; 86: E1303–E1308.
   PubMed Web of Science ®Google Scholar
• Matsumoto Y, Sato EA, Ibrahim OM et al. The application of in vivo laser confocal microscopy to the diagnosis and evaluation of meibomian gland dysfunction. Mol Vis 2008; 14: 1263–1271.
   PubMed Web of Science ®Google Scholar
• Randon M, Liang H, El hamdaoui M et al. In vivo confocal microscopy as a novel and reliable tool for the diagnosis of Demodex eyelid infestation. Br J Ophthalmol 2015; 99: 336–341.
   PubMed Web of Science ®Google Scholar
• Dehghani C, Pritchard N, Edwards K et al. Morphometric stability of the corneal subbasal nerve plexus in healthy individuals: a 3‐year longitudinal study using corneal confocal microscopy. Invest Ophthalmol Vis Sci 2014; 55: 3195–3199.
   PubMed Web of Science ®Google Scholar
• Hamrah P, Cruzat A, Dastjerdi MH et al. Corneal sensation and subbasal nerve alterations in patients with herpes simplex keratitis: an in vivo confocal microscopy study. Ophthalmology 2010; 117: 1930–1936.
   PubMed Web of Science ®Google Scholar
• Villani E, Viola F, Sala R et al. Corneal involvement in Graves' orbitopathy: an in vivo confocal study. Invest Ophthalmol Vis Sci 2010; 51: 4574–4578.
   PubMed Web of Science ®Google Scholar
• Wei YH, Chen WL, Hu FR et al. In vivo confocal microscopy of bulbar conjunctiva in patients with Graves' ophthalmopathy. J Formos Med Assoc 2015; 114: 965–972.
   PubMed Web of Science ®Google Scholar
• Labbe A, Liang Q, Wang Z et al. Corneal nerve structure and function in patients with non‐sjogren dry eye: clinical correlations. Invest Ophthalmol Vis Sci 2013; 54: 5144–5150.
   PubMed Web of Science ®Google Scholar
• Villani E, Galimberti D, Viola F et al. The cornea in Sjogren's syndrome: an in vivo confocal study. Invest Ophthalmol Vis Sci 2007; 48: 2017–2022.
   PubMed Web of Science ®Google Scholar
• Erdelyi B, Kraak R, Zhivov A et al. In vivo confocal laser scanning microscopy of the cornea in dry eye. Graefes Arch Clin Exp Ophthalmol 2007; 245: 39–44.
   PubMed Web of Science ®Google Scholar
• Benitez del castillo JM, Wasfy MA, Fernandez C et al. An in vivo confocal masked study on corneal epithelium and subbasal nerves in patients with dry eye. Invest Ophthalmol Vis Sci 2004; 45: 3030–3035.
   PubMed Web of Science ®Google Scholar
• Lum E, Golebiowski B, Swarbrick HA. Mapping the corneal sub‐basal nerve plexus in orthokeratology lens wear using in vivo laser scanning confocal microscopy. Invest Ophthalmol Vis Sci 2012; 53: 1803–1809.
   Web of Science ®Google Scholar
• Wang Y, Kornberg DL, St clair RM et al. Corneal nerve structure and function after long‐term wear of fluid‐filled scleral lens. Cornea 2015; 34: 427–432.
   Web of Science ®Google Scholar
• Chao C, Golebiowski B, Stapleton F. The role of corneal innervation in LASIK‐induced neuropathic dry eye. Ocul Surf 2014; 12: 32–45.
   Web of Science ®Google Scholar
• Chao C, Golebiowski B, Zhao X et al. Long‐term effects of LASIK on corneal innervation and tear neuropeptides and the associations with dry eye. J Refract Surg 2016; 32: 518–524.
   Web of Science ®Google Scholar
• Misra S, Ahn HN, Craig JP et al. Effect of panretinal photocoagulation on corneal sensation and the corneal subbasal nerve plexus in diabetes mellitus. Invest Ophthalmol Vis Sci 2013; 54: 4485–4490.
   Web of Science ®Google Scholar
• Iaccheri B, Torroni G, Cagini C et al. Corneal confocal scanning laser microscopy in patients with dry eye disease treated with topical cyclosporine. Eye (Lond) 2017; 31: 788–794.
   PubMed Web of Science ®Google Scholar
• Fea AM, Aragno V, Testa V et al. The effect of autologous platelet lysate eye drops: an in vivo confocal microscopy study. Biomed Res Int 2016; 2016: 8406832.
   Web of Science ®Google Scholar
• Chinnery HR, Naranjo golborne C, Downie LE. Omega‐3 supplementation is neuroprotective to corneal nerves in dry eye disease: a pilot study. Ophthalmic Physiol Opt 2017; 37: 473–481.
   PubMed Web of Science ®Google Scholar
• Mastropasqua L, Agnifili L, Fasanella V et al. Conjunctival goblet cells density and preservative‐free tafluprost therapy for glaucoma: an in vivo confocal microscopy and impression cytology study. Acta Ophthalmol 2013; 91: e397–e405.
   PubMed Web of Science ®Google Scholar
• Misra SL, Craig JP, Patel DV et al. In vivo confocal microscopy of corneal nerves: an ocular biomarker for peripheral and cardiac autonomic neuropathy in type 1 diabetes mellitus. Invest Ophthalmol Vis Sci 2015; 56: 5060–5065.
   PubMed Web of Science ®Google Scholar
• Misra SL, Patel DV, Mcghee CN et al. Peripheral neuropathy and tear film dysfunction in type 1 diabetes mellitus. J Diabetes Res 2014; 2014: 848659.
   PubMed Web of Science ®Google Scholar
• Edwards K, Pritchard N, Vagenas D et al. Utility of corneal confocal microscopy for assessing mild diabetic neuropathy: baseline findings of the LANDMark study. Clin Exp Optom 2012; 95: 348–354.
   PubMed Web of Science ®Google Scholar
• Dehghani C, Pritchard N, Edwards K et al. Natural history of corneal nerve morphology in mild neuropathy associated with type 1 diabetes: development of a potential measure of diabetic peripheral neuropathy. Invest Ophthalmol Vis Sci 2014; 55: 7982–7990.
   PubMed Web of Science ®Google Scholar
• Ziegler D, Papanas N, Zhivov A et al. Early detection of nerve fiber loss by corneal confocal microscopy and skin biopsy in recently diagnosed type 2 diabetes. Diabetes 2014; 63: 2454–2463.
   PubMed Web of Science ®Google Scholar
• Edwards K, Pritchard N, Poole C et al. Development of a novel technique to measure corneal nerve migration rate. Cornea 2016; 35: 700–705.
   Web of Science ®Google Scholar
• Kobayashi A, Yokogawa H, Sugiyama K. In vivo laser confocal microscopy of Bowman's layer of the cornea. Ophthalmology 2006; 113: 2203–2208.
   PubMed Web of Science ®Google Scholar
• Kim J, Tan K, Chowdhury NS. Image statistics and the fine lines of material perception. Iperception 2016; 7: 2041669516658047.
   Web of Science ®Google Scholar
• Patel DV, Tavakoli M, Craig JP et al. Corneal sensitivity and slit scanning in vivo confocal microscopy of the subbasal nerve plexus of the normal central and peripheral human cornea. Cornea 2009; 28: 735–740.
   PubMed Web of Science ®Google Scholar
• Niederer RL, Perumal D, Sherwin T et al. Age‐related differences in the normal human cornea: a laser scanning in vivo confocal microscopy study. Br J Ophthalmol 2007; 91: 1165–1169.
   PubMed Web of Science ®Google Scholar
• Erie JC, Mclaren JW, Hodge DO et al. The effect of age on the corneal subbasal nerve plexus. Cornea 2005; 24: 705–709.
   PubMed Web of Science ®Google Scholar
• Pritchard N, Edwards K, Russell AW et al. Corneal confocal microscopy predicts 4‐year incident peripheral neuropathy in type 1 diabetes. Diabetes Care 2015; 38: 671–675.
   PubMed Web of Science ®Google Scholar
• Mehra S, Tavakoli M, Kallinikos PA et al. Corneal confocal microscopy detects early nerve regeneration after pancreas transplantation in patients with type 1 diabetes. Diabetes Care 2007; 30: 2608–2612.
   PubMed Web of Science ®Google Scholar
• Tavakoli M, Mitu‐pretorian M, Petropoulos IN et al. Corneal confocal microscopy detects early nerve regeneration in diabetic neuropathy after simultaneous pancreas and kidney transplantation. Diabetes 2013; 62: 254–260.
   PubMed Web of Science ®Google Scholar
• Pritchard N, Edwards K, Shahidi AM et al. Corneal markers of diabetic neuropathy. Ocul Surf 2011; 9: 17–28.
   PubMed Web of Science ®Google Scholar
• Vagenas D, Pritchard N, Edwards K et al. Optimal image sample size for corneal nerve morphometry. Optom Vis Sci 2012; 89: 812–817.
   PubMed Web of Science ®Google Scholar
• Foracchia M, Grisan E, Ruggeri A. Luminosity and contrast normalization in retinal images. Med Image Anal 2005; 9: 179–190.
   Web of Science ®Google Scholar
• Ruggeri A, Scarpa F, Grisan E. Analysis of corneal images for the recognition of nerve structures. In: Engineering in Medicine and Biology Society, 2006 EMBS'06 28th Annual International Conference of the IEEE: IEEE, 2006. p 4739–4742.
   Google Scholar
• Scarpa F, Grisan E, Ruggeri A. Automatic recognition of corneal nerve structures in images from confocal microscopy. Invest Ophthalmol Vis Sci 2008; 49: 4801–4807.
   PubMed Web of Science ®Google Scholar
• Freeman WT, Adelson EH. The design and use of steerable filters. IEEE Trans Pattern Anal Mach Intell 1991; 13: 891–906.
   Web of Science ®Google Scholar
• Gonzalez RC, Woods RE. Thresholding. In: McDonald M and Dworkin A (eds). Digital Image Processing. Upper Saddle River, New Jersey: Pearson Prentice Hall, 2002. pp. 595–611.
   Google Scholar
• Dabbah M, Graham J, Tavakoli M et al. Nerve fibre extraction in confocal corneal microscopy images for human diabetic neuropathy detection using gabor filters. In: Medical Image Understanding and Analysis (MIUA), 2009. pp. 254–258.
   Google Scholar
• Dixon R, Taylor C. Automated asbestos fibre counting. Inst Phys Conf Ser 1979; 44: 178–185.
   Google Scholar
• Dabbah M, Graham J, Petropoulos I et al. Dual‐model automatic detection of nerve‐fibres in corneal confocal microscopy images. In: Jiang T, Navab N, Pluim JPW, Viergever M (eds). Medical Image Computing and Computer‐Assisted Intervention–MICCAI 2010. Berlin: Springer Verlag, 2010. pp. 300–307.
   Google Scholar
• Frangi AF, Niessen WJ, Vincken KL et al. Multiscale vessel enhancement filtering. In: Wells WM, Colchester A and Delp SL (eds). International Conference on Medical Image Computing and Computer‐Assisted Intervention. Berlin: Springer Verlag, 1998. pp. 130–137.
   Google Scholar
• Selesnick IW, Baraniuk RG, Kingsbury NC. The dual‐tree complex wavelet transform. IEEE Sig Process Mag 2005; 22: 123–151.
   Web of Science ®Google Scholar
• Felsberg M, Sommer G. The monogenic signal. IEEE Trans Sig Process 2001; 49: 3136–3144.
   Web of Science ®Google Scholar
• Dabbah MA, Graham J, Petropoulos IN et al. Automatic analysis of diabetic peripheral neuropathy using multi‐scale quantitative morphology of nerve fibres in corneal confocal microscopy imaging. Med Image Anal 2011; 15: 738–747.
   PubMed Web of Science ®Google Scholar
• Tavakoli M, Ferdousi M, Petropoulos IN et al. Normative values for corneal nerve morphology assessed using corneal confocal microscopy: a multinational normative data set. Diabetes Care 2015; 38: 838–843.
   PubMed Web of Science ®Google Scholar
• Ferreira A, Morgado AM, Silva JS. A method for corneal nerves automatic segmentation and morphometric analysis. Comput Methods Programs Biomed 2012; 107: 53–60.
   Web of Science ®Google Scholar
• Kovesi P. Symmetry and asymmetry from local phase. In: Tenth Australian Joint Conference on Artificial Intelligence. Citeseer, 1997. p 2–4.
   Google Scholar
• Poletti E, Ruggeri A. Automatic nerve tracking in confocal images of corneal subbasal epithelium. In: Computer‐based medical systems (CBMS). IEEE, 2013. p 119–124.
   Google Scholar
• Dijkstra EW. A note on two problems in connexion with graphs. Numer Math 1959; 1: 269–271.
   Web of Science ®Google Scholar
• Guimarães P, Wigdahl J, Ruggeri A. A fast and efficient technique for the automatic tracing of corneal nerves in confocal microscopy. Transl Vis Sci Technol 2016; 5: 7.
   Web of Science ®Google Scholar
• Pridmore TP. Thresholding images of line drawings with hysteresis. In: Blostein D and Kwon YB (eds). Graphics Recognition Algorithms and Applications. Berlin: Springer, 2002. pp. 310–319.
   Google Scholar
• Batawi H, Shalabi N, Joag M et al. Sub‐basal corneal nerve plexus analysis using a new software technology. Eye Contact Lens 2017. https://doi.org/10.1097/ICL.0000000000000375.
   Web of Science ®Google Scholar
• Kim J, Markoulli M. Psychophysically‐based enhancement of features in medical images. In: 13th Asia Pacific Conference on Vision APCV. Tainan, Taiwan, 2017.
   Google Scholar
• Kim J, Marlow PJ, Anderson BL. Texture‐shading flow interactions and perceived reflectance. J Vis 2014; 14: 1–1.
   Web of Science ®Google Scholar
• Dehghani C, Pritchard N, Edwards K et al. Fully automated, semiautomated, and manual morphometric analysis of corneal subbasal nerve plexus in individuals with and without diabetes. Cornea 2014; 33: 696–702.
   PubMed Web of Science ®Google Scholar
• Bracher D. Changes in peripapillary tortuosity of the central retinal arteries in newborns. Graefes Arch Clin Exp Ophthalmol 1982; 218: 211–217.
   Web of Science ®Google Scholar
• Capowski JJ, Kylstra JA, Freedman SF. A numeric index based on spatial frequency for the tortuosity of retinal vessels and its application to plus disease in retinopathy of prematurity. Retina 1995; 15: 490–500.
   PubMed Web of Science ®Google Scholar
• Dougherty G, Varro J. A quantitative index for the measurement of the tortuosity of blood vessels. Med Eng Phys 2000; 22: 567–574.
   PubMed Web of Science ®Google Scholar
• Kallinikos P, Berhanu M, O'donnell C et al. Corneal nerve tortuosity in diabetic patients with neuropathy. Invest Ophthalmol Vis Sci 2004; 45: 418–422.
   PubMed Web of Science ®Google Scholar
• Hart WE, Goldbaum M, Côté B et al. Measurement and classification of retinal vascular tortuosity. Int J Med Inform 1999; 53: 239–252.
   PubMed Web of Science ®Google Scholar
• Holmes TJ, Pellegrini M, Miller C et al. Automated software analysis of corneal micrographs for peripheral neuropathy. Invest Ophthalmol Vis Sci 2010; 51: 4480–4491.
   PubMed Web of Science ®Google Scholar
• Krippendorff K. Bivariate agreement coefficients for reliability of data. Sociol Methodol 1970; 2: 139–150.
   Google Scholar
• Annunziata R, Kheirkhah A, Aggarwal S et al. Two‐dimensional plane for multi‐scale quantification of corneal subbasal nerve tortuosity. Invest Ophthalmol Vis Sci 2016; 57: 1132–1139.
   Web of Science ®Google Scholar
• Scarpa F, Zheng X, Ohashi Y et al. Automatic evaluation of corneal nerve tortuosity in images from in vivo confocal microscopy. Invest Ophthalmol Vis Sci 2011; 52: 6404–6408.
   Web of Science ®Google Scholar
• Lagali N, Poletti E, Patel DV et al. Focused tortuosity definitions based on expert clinical assessment of corneal subbasal nervesexpert assessment of corneal nerve tortuosity. Invest Ophthalmol Vis Sci 2015; 56: 5102–5109.
   Web of Science ®Google Scholar
• Hosal BM, Ornek N, Zilelioglu G et al. Morphology of corneal nerves and corneal sensation in dry eye: a preliminary study. Eye (Lond) 2005; 19: 1276–1279.
   PubMed Web of Science ®Google Scholar
• Maciver M, Tanelian D. Structural and functional specialization of A delta and C fiber free nerve endings innervating rabbit corneal epithelium. J Neurosci 1993; 13: 4511–4524.
   PubMed Web of Science ®Google Scholar
• Mocan MC, Durukan I, Irkec M et al. Morphologic alterations of both the stromal and subbasal nerves in the corneas of patients with diabetes. Cornea 2006; 25: 769–773.
   PubMed Web of Science ®Google Scholar
• He J, Bazan HE. Mapping the nerve architecture of diabetic human corneas. Ophthalmology 2012; 119: 956–964.
   PubMed Web of Science ®Google Scholar
• Tuominen IS, Konttinen YT, Vesaluoma MH et al. Corneal innervation and morphology in primary Sjogren's syndrome. Invest Ophthalmol Vis Sci 2003; 44: 2545–2549.
   PubMed Web of Science ®Google Scholar
• Tuisku IS, Konttinen YT, Konttinen LM et al. Alterations in corneal sensitivity and nerve morphology in patients with primary Sjogren's syndrome. Exp Eye Res 2008; 86: 879–885.
   PubMed Web of Science ®Google Scholar
• Niissalo S, Hukkanen M, Imai S et al. Neuropeptides in experimental and degenerative arthritis. Ann N Y Acad Sci 2002; 966: 384–399.
   PubMed Web of Science ®Google Scholar
• Grupcheva CN, Wong T, Riley AF et al. Assessing the sub‐basal nerve plexus of the living healthy human cornea by in vivo confocal microscopy. Clin Exp Ophthalmol 2002; 30: 187–190.
   PubMed Web of Science ®Google Scholar
• Patel DV, Mcghee CN. Quantitative analysis of in vivo confocal microscopy images: a review. Surv Ophthalmol 2013; 58: 466–475.
   PubMed Web of Science ®Google Scholar
• Allgeier S, Zhivov A, Eberle F et al. Image reconstruction of the subbasal nerve plexus with in vivo confocal microscopy. Invest Ophthalmol Vis Sci 2011; 52: 5022–5028.
   PubMed Web of Science ®Google Scholar
• Patel DV, Mcghee CN. Mapping of the normal human corneal sub‐Basal nerve plexus by in vivo laser scanning confocal microscopy. Invest Ophthalmol Vis Sci 2005; 46: 4485–4488.
   PubMed Web of Science ®Google Scholar
• Auran JD, Koester CJ, Kleiman NJ et al. Scanning slit confocal microscopic observation of cell morphology and movement within the normal human anterior cornea. Ophthalmology 1995; 102: 33–41.
   PubMed Web of Science ®Google Scholar
• Patel DV, Mcghee CN. In vivo laser scanning confocal microscopy confirms that the human corneal sub‐basal nerve plexus is a highly dynamic structure. Invest Ophthalmol Vis Sci 2008; 49: 3409–3412.
   PubMed Web of Science ®Google Scholar
• Turuwhenua JT, Patel DV, Mcghee CN. Fully automated montaging of laser scanning in vivo confocal microscopy images of the human corneal subbasal nerve plexus montaging of laser scanning IVCM images. Invest Ophthalmol Vis Sci 2012; 53: 2235–2242.
   PubMed Web of Science ®Google Scholar
• Szeliski R. Image alignment and stitching: a tutorial. Found Trends Comput Graph Vis 2006; 2: 1–104.
   Google Scholar
• Zhivov A, Blum M, Guthoff R et al. Real‐time mapping of the subepithelial nerve plexus by in vivo confocal laser scanning microscopy. Br J Ophthalmol 2010; 94: 1133–1135.
   PubMed Web of Science ®Google Scholar
• Efron N. The Glenn A. Fry award lecture 2010: ophthalmic markers of diabetic neuropathy. Optom Vis Sci 2011; 88: 661–683.
   PubMed Web of Science ®Google Scholar
• Edwards K, Pritchard N, Gosschalk K et al. Wide‐field assessment of the human corneal subbasal nerve plexus in diabetic neuropathy using a novel mapping technique. Cornea 2012; 31: 1078–1082.
   PubMed Web of Science ®Google Scholar
• Poletti E, Wigdahl J, Guimarães P et al. Automatic montaging of corneal sub‐basal nerve images for the composition of a wide‐range mosaic. In: Engineering in Medicine and Biology Society (EMBC), 2014 36th Annual International Conference of the IEEE: IEEE, 2014. p 5426–5429.
   Google Scholar
• Al‐fahdawi S, Qahwaji R, Al‐waisy AS et al. A fully automatic nerve segmentation and morphometric parameter quantification system for early diagnosis of diabetic neuropathy in corneal images. Comput Methods Programs Biomed 2016; 135: 151–166.
   Web of Science ®Google Scholar
• Patel DV, Mcghee CN. Contemporary in vivo confocal microscopy of the living human cornea using white light and laser scanning techniques: a major review. Clin Experiment Ophthalmol 2007; 35: 71–88.
   PubMed Web of Science ®Google Scholar
• Patel DV, Mcghee CN. In vivo confocal microscopy of human corneal nerves in health, in ocular and systemic disease, and following corneal surgery: a review. Br J Ophthalmol 2009; 93: 853–886.
   PubMed Web of Science ®Google Scholar
• Hertz P, Bril V, Orszag A et al. Reproducibility of in vivo corneal confocal microscopy as a novel screening test for early diabetic sensorimotor polyneuropathy. Diabet Med 2011; 28: 1253–1260.
   PubMed Web of Science ®Google Scholar
• Villani E, Beretta S, De capitani M et al. In vivo confocal microscopy of meibomian glands in Sjogren's syndrome. Invest Ophthalmol Vis Sci 2011; 52: 933–939.
   PubMed Web of Science ®Google Scholar
• Markoulli M, You J, Kim J et al. Corneal nerve morphology and tear film substance P in diabetes. Optom Vis Sci 2017; 94: 726–731.
   Web of Science ®Google Scholar