Corneal Research Articles

Distinct Inflammatory and Oxidative Effects of Diabetes Mellitus and Hypothyroidism in the Lacrimal Functional Unit.

Diabetes mellitus (DM) and hypothyroidism (HT) are prevalent diseases associated with dry eye (DE). Their impact on the lacrimal functional unit (LFU) is poorly known. This work evaluates the changes in the LFU in DM and HT. Adult male Wistar rats had the disease induced as follows: (a) DM: streptozotocin and (b) HT: methimazole. The tear film (TF) and blood osmolarity were measured. Cytokine mRNA was compared in the lacrimal gland (LG), trigeminal ganglion (TG), and cornea (CO). Oxidative enzymes were evaluated in the LG. The DM group showed lower tear secretion (p = 0.02) and higher blood osmolarity (p < 0.001). The DM group presented lower mRNA expression of TRPV1 in the cornea (p = 0.03), higher Il1b mRNA expression (p = 0.03), and higher catalase activity in the LG (p < 0.001). The DM group presented higher Il6 mRNA expression in the TG (p = 0.02). The HT group showed higher TF osmolarity (p < 0.001), lower expression of Mmp9 mRNA in the CO (p < 0.001), higher catalase activity in the LG (p = 0.002), and higher expression of Il1b mRNA in the TG (p = 0.004). The findings revealed that DM and HT induce distinct compromises to the LG and the entire LFU.

Differential compensatory role of internal astigmatism in school children and adults: The Hong Kong Children Eye Study.

To compare the prevalence of refractive (RA), corneal (CA), and internal astigmatism (IA) in Hong Kong children and adults and evaluate the role of IA in compensating for total astigmatism and its relations to myopic traits. The Hong Kong Children Eye Study is a population-based cross-sectional study. Totally 3704 school children (mean age 7.5 ± 1.0 years) and 5577 adults (mean age 41.1 ± 7.5 years), who were their parents, were recruited. Cycloplegic and non-cycloplegic refractive cylinders were obtained from children and adults, respectively. Spearman correlation was applied to detect associations between astigmatism, ocular biometrics, refraction, and lens power. Astigmatism compensation factor (CF) was derived from the power vector analysis J0 and J45. The prevalence of RA (≤-1.0 D), CA (≥+1.0 D) and IA (≥+1.0 D) was 21.9%, 63.9%, and 9.9% in children, and 30.9%, 39.5%, and 23.7% in adults respectively. The mean RA, CA and IA values in children and adults were -0.69 ± 0.66 D, +1.14 ± 0.61 D, +0.62 ± 0.32 D, and -0.80 ± 0.74 D, +0.97 ± 0.69 D, and +0.76 ± 0.43 D, respectively. In adults and children, IA was negatively correlated with axial length (p < 0.0001), but positively correlated with spherical values and equivalent (p < 0.0001), suggesting an association of astigmatism with myopic traits. A greater proportion of children exhibited compensation by IA than adults in J0 (86.6% vs. 66.0%, p < 0.0001) and J45 components (55.5% vs. 41.7%, p < 0.0001). Chinese children in Hong Kong exhibit a higher prevalence of RA and CA than in other cities. Children displayed a greater compensation by IA than adults, suggesting an age-related attenuation of IA compensation. IA is associated with myopic traits.

Subjective and objective clinical outcomes of a new trifocal toric intraocular lens and effect of femtosecond laser cataract surgery.

To evaluate the clinical outcomes and quality of life following implantation of PanOptix toric intraocular lens (IOL) and to compare the outcomes following femtosecond laser assisted cataract surgery (FLACS) and standard cataract surgery (SCS). This comparative retrospective study included 79 eyes of 55 patients underwent cataract or refractive lens exchange surgery between April 2017 and January 2020 in Bayindir Hospital and Kaskaloglu Eye Hospital. Corneal (CA) and refractive astigmatism (RA), uncorrected visual acuities for distant, intermediate, and near (UDVA, UIVA, and UNVA), low contrast distance visual acuity, rotational stability, defocus curves, photopic and mesopic contrast sensitivity (CS), visual function-14 (VF-14) test, presence of dysphotopsia, and need for spectacles were evaluated at postoperative third month. Outcomes were compared between FLACS and SCS group. The mean UDVA, UIVA, and UNVA were 0.05 ± 0.07, 0.08 ± 0.08, and 0.06 ± 0.07 logMAR, respectively. All patients achieved ⩾0.3 logMAR uncorrected visual acuity for all distances. UDVA was found significantly better in FLACS group (p = 0.03). All eyes had ⩽1 D of subjective postoperative RA. Defocus curve had two peaks at 0 and -1.50 D. Spectacle independence was achieved in 88.7% of patients. Photopic and mesopic CS was within normal range in all patients. The mean VF-14 score was 98 ± 2. The mean IOL axis rotation was 2.1° ± 2.3°. Only one patient reported seeing disturbing halos. This trifocal toric IOL effectively reduced refractive astigmatism and provided excellent visual outcomes with high spectacle independence, patients' satisfaction, and good rotational stability. FLACS might have an impact on optimal postoperative results.

Analysis of the Refractive Profile of Children with Oculocutaneous Albinism versus an Age-Matched Non-Albino Group.

PurposeTo find out and analyze the points of difference in the refractive profile between children with complete oculocutaneous albinism (OCA) and an age-matched, non-albino group seeking paediatric ophthalmic examination.MethodsA cross-sectional study was conducted on 164 infants and young children in Paediatric Ophthalmology Center, Sohag City, Egypt. Informed consent was obtained from the participants’ guardians. The study divided the population into 2 equal groups: albino group = 82 eyes, non-albino group = 82 eyes. Cycloplegic refraction and average keratometric measurements using the hand-held autokeratometer were taken for the study groups.ResultsIn the albino group, astigmatism and hypermetropia were the most common refractive errors, 100% and 62% respectively, with significant difference between both groups. Mean total (TA), corneal (CA) and lenticular astigmatism (LA) were significantly higher in albino group (P<0.05). All albino eyes were high astigmats (≥1.25 D).ConclusionThis study is novel in being comparative and includes the largest sample size ever reported for albino eyes of infants and children. High WTR astigmatism is the most prevalent refractive error in albinos with an overall bias toward hyperopia, but extreme errors (>−11.00D myopia or >+10.00D hyperopia) are not common. Albino eyes have a significantly higher degree of LA which compensates for the high CA to decrease the amount of TA. The study emphasizes the importance of refraction examination and visual rehabilitation for OCA children as early as possible to reduce eye morbidity-associated low vision.

Diagnosis of surra in buffalo based on Clinical Symptoms

Blood samples were collected to diagnose the surra disease from 92 buffaloes showing clinical symptoms from January 2015 to December 2015 and prevalence was 22.83 per cent (21). In high frequency group (>60 per cent), the clinical signs reduced milk yield (100.00 per cent), anorexia (95.24 per cent), anaemia (90.48 per cent), excitement (85.71 per cent), respiratory distress (71.43 per cent) and fever (61.90 per cent) were recorded. Clinical signs like exophthalmia (52.38 per cent), edema of dependent parts (52.38 per cent), emaciation (42.86 per cent), and salivation (33.33 per cent) had moderate frequency (30-60 per cent) whereas clinical signs including nasal discharge (23.81 per cent), circling (19.05 per cent), depression (14.29 per cent), corneal opacity (14.29 per cent), head pressing (9.52 per cent) and lacrimation (4.76 per cent) had low frequency of occurrence (<30 per cent). Therefore if buffalo is showing combination of above mentioned clinical symptoms, then he or she should be suspected for trypanosomosis and after examination of blood smear, immediate treatment should be recommended.

Tetracaine for Corneal Abrasions in the Emergency Department

The use of topical anesthetics such as tetracaine in patients with corneal abrasions is controversial, largely due to concerns about delayed healing.

How the life support system can affect pinniped eye health: a case study with long-nosed fur seal (Arctocephalus forsteri)

Eye health issues have commonly been reported in captive pinnipeds. Excessive exposure to UV light, poor enclosure design features and suboptimal water quality have all been associated with eye pathology in pinnipeds. A long-nosed fur seal Arctocephalus forsteri developed corneal disease shortly after introduction into a new facility. Medical therapies provided some alleviation of symptoms, but long-term sustained improvements in eye health were only achieved after life support system modifications. These modifications centred on lowering the production of disinfection by-products by removing most of the organic matter before applying ozone to the system. The reduction in eye pain following improvements in water quality were also critical for the keepers to be able to train the fur seal to receive eye drops voluntarily.

Quantitative Measurement of Vascular Density and Flow Using Optical Coherence Tomography Angiography in Patients with Vasculitis; Can OCTA detect the vasculitis?

Methods: Patients with uveitis and vasculitis in at least one eye were included and compared with 50 eyes from healthy individuals. The OCTA was done for each patient and control subject. The images were analysed at three capillary plexuses layers (superficial and deep retinal capillary layers and choriocapillaris layer). contact lens was placed on the corneal surface. Corneal edema decreased gradually in one month post-operatively. Results: Fifty-five eyes from 28 patients were enrolled in the study. Studied eyes were categorized into 4 groups: 1-eyes with posterior vasculitis (38 eyes), 2-eyes with peripheral vasculitis without posterior vasculitis (7 eyes), 3-fellow uninvolved eyes of patients with unilateral vasculitis (10 eyes), and 4-eyes of healthy controls (50 eyes). The whole vascular density and parafoveal vascular density in both superficial and deep retinal capillary plexuses were reduced significantly from group 4 to group1. A decreasing trend in macular blood flow was also observed from group 4 followed by group 3, group 2 and group 1 in all three capillary layers including superficial retinal capillary plexus, deep retinal capillary plexus and choriocapillaris. By choosing the threshold of 26.2, the formula (-0.447×F1ch+75.82×VDdp) was the best model to differentiate the vasculitis group from the control group with an area under the curve (AUC) of 0.979, the sensitivity of 98% and specificity of 92.3%. (F1ch: flow in the central 1mm-radius-circle of the choriocapillaris, and VDdp: vascular density of parafoveal in the deep capillary network). Conclusion: In patients with vasculitis, especially in the cases with posterior pole involvement, OCTA showed reduced vascular density and flow in all three capillary layers. OCTA might be a helpful tool to give us additional information about the macular microvasculature changes under inflammatory conditions.

Advance in research of beta coronavirus receptors on ocular surface

2019-Novel coronavirus (2019-nCoV) caused an outbreak of corona virus disease 2019 (COVID-19) from December 2019 in China.2019-nCoV which was identified as a kind of beta coronavirus belongs to one of four coronavirus genera.Except 2019-nCoV, two other beta coronavirus, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) are also quite harmful to human beings.2019-nCoV uses the same cell entry receptor, angiotensin-converting enzyme 2 (ACE2), as SARS-CoV.And dipeptidyl peptidase 4 (DPP4) or CD26 is the cell receptor for MERS-CoV.The expression of ACE2 was found to have obvious positive expression in human corneal and conjunctival epithelium, and corneal endothelium.DPP4 activity was presented in normal animal conjunctival epithelium and fibroblasts of the subjacent connective tissue.It was also presented in the whole corneal epithelium and tear fluid of animal with severe injured corneas.The two receptors, ACE2 and DPP4, are involved in many cellular signaling pathways and pathophysiological processes.Their expression in the cells of ocular surface may be an access route of corona virus in eye, which provides clues to elucidating the pathogenesis of corona virus in the eyeballs. Key words: Coronavirus; Receptor; Angiotensin-converting enzyme 2; Dipeptidyl peptidase 4; Ocular surface

The Value of Conjunctival Immunohistochemistry Analysis for the Diagnosis of Ocular Mucous Membrane Pemphigoid

Ocular Mucous Membrane Pemphigoid (OMMP), a subset of Mucous Membrane Pemphigoid (MMP) is an autoimmunemediated progressive cicatrizing conjunctivitis with the potential for corneal blindness. Direct Immunofluorescence (DIF) is considered the gold standard for the diagnostic confirmation of this condition; nevertheless, in many cases, this immunopathological technique is inconclusive. A 54 years old female presented to our service complaining of progressive diminished visual acuity, foreign body sensation, and photophobia in both eyes. The slit-lamp examination showed bulbar and palpebral conjunctival hyperaemia, as well as bilateral corneal scarring. During clinical follow-up, progressive conjunctival scarring with inferior fornix foreshortening, symblepharon formation, and significant corneal opacity dramatically diminished her visual acuity. A conjunctival biopsy was negative for DIF; therefore, Immunohistochemical analysis (IHCA) for IgG, IgA, and C3 immune reactants linear deposition on the conjunctival Basement-membrane zone (BMZ) was necessary for diagnosis confirmation. The present clinical case highlights the utility of paraffin-embedded conjunctival IHCA as an alternative immunohistopathology tool for the diagnosis of OMMP when DIF is non-conclusive.

Clinically Diagnosed Homozygous Familial Hypercholesterolemia-rare entity

Familial Hypercholesterolemia (FH) is a rare autosomal dominant genetic disorder characterized by raised levels of Low-Density Lipoprotein Cholesterol (LDL-C). Homozygous type of familial hypercholesterolemia is very rare entity with incidence of one in a million. They are very few case reports of this entity reported in India. We present a 7-year-old male child presenting to the department of cardiology with clinical features of homozygous type of FH such as corneal arcus ,multiple xanthomas and laboratory features suggestive of hypercholesterolemia. His father had similar features of hypercholesterolemia. The patient was started on statins. The patient was lost to follow up.

The effect of intracameral ketorolac in cataract surgery for diabetic patients

Aim: This study aims to assess the effect of intracameral ketorolac interaoperatively in cataract surgery for diabetic patients. Purpose: This study aims to assess the effect of intracameral ketorolac in cataract surgery for diabetic patients. Methods: This study was conducted on cataract patients who need phacoemulsification subjected to ophthalmology department of Menoufia university careful history and ophthalmological examination was done including best corrected visual acuity, slit-lamp examination, fundus examination. All patients were dilated preoperatively by topical tropicamid 1% as mydriatc, and were operated under local peribulbar anesthesia and measurement of pupil diameter by squint caliper at the beginning and at the end of surgery and for standerization systemic and topical NSAIDS were prohibited preoperative. We assed the pupil diameter and surgical time intraoperative Results: The mean pupillary diameter at the end of the operation in first group (non-ketorolac) was 7.18 ± 1.09 mm while in the second (ketorolac) group was 7.98 ± 1.34 mm with p value <0.05 which is statistically significant. On measuring the change that occur to the pupil diameter during surgery in group I it was 1.48 ± 0.77 mean while in group II it was 1.11 ± 0.66 with p value <0.01 which is highly significant also there was significant effect of interacameral ketorolac in decreasing corneal edema. As regard surgical time: In group I the mean surgical time in minutes was 24.73 ± 9.72 while in group II it was 22.77 ± 7.10 which shows that there is decrease in surgical time in ketorolac group but not significant. Conclusion: Intracameral ketorolac is safe in maintaining pupil dilated especially in poorly dilated pupil.

The Boston keratoprosthesis

The Boston Keratoprosthesis (KPro) is one of several types of artificial cornea manufactured worldwide that are being implanted in increasing numbers in patients with severe corneal diseases and graft failures. To summerize the advances in design of the Boston type I keratoprosthesis and in the treatment strategies to conquer the post operative complications have expanded the indications and application of this technology. Many modifications to the design of the Boston type I keratoprosthesis and treatment of the patient in the post operative period have occurred. Also, the technology has been more widely accepted as a primary surgical option for patients with a poor preoperative prognosis for traditional penetrating keratoplasty. The outcomes of visual acuity, retention, and post-operative infection rates have all significantly improved since the technology has been modified and offers patients an alternative for visual rehabilitation. This is implanted into a carrier corneal graft or into the patient's own cornea. The allograft cornea can be the carrier, which may solve the shortage of donor cornea in China.

Tear film stability assessment by corneal reflex image degradation: publisher's note.

This publisher's note corrects the funding in J. Opt. Soc. Am. A36, B110 (2019).JOAOD60740-323210.1364/JOSAA.36.00B110.

Ocular Findings in HIV-Positive Children in Two Hospital Facilities in Yaoundé, Cameroon

Background: HIV infection in children as well as adults remain a disease with potential multisystemic disorders despite the increased use of Highly Active Antiretroviral Therapy (HAART). The aim of this work was to determine the profile of eye diseases among HIV-positive children aged 5 to 15 years in the Mother and Child Centre of the Chantal Biya Foundation and the University Hospital Centre (UHC) in Yaounde. Materials and Methods: an analytical study was conducted from June 1, to July 31, 2019. Our sample consisted of all children aged 5 - 18 years who were HIV positive and whose parent or legal guardian gave his or her consent. A complete clinical examination was performed. The following variables were collected: socio-demographic data, Immunological data. A comprehensive eye exam was also performed. Data were analysed by the Epi info 3.5.4 software. Results: A total of 53 children were retained for the study. The population consisted of 28 boys (52.3%), for a sex ratio of 1.12. The mean age was 12.7 ± 4.2 years [5 - 18 years]. And 84.9% of children had normal immune status. The average duration of HAART was 8.3 ± 3.9 years [0 to 16 years] with more than half (50.9%) of the children on treatment for more than 8 years. The main eye complaints were pruritus (11.32%), eye pain (11.32%) and tingling (9.43%). The frequency of ophthalmological manifestations was 52.8% with adnexal involvement the most frequent (34%), followed by anterior (7.5%) and posterior segment involvement (1.9%). Anterior segment involvement was marked by granulomatous anterior uveitis, keratouveitis and corneal ulcer. A cytomegalovirus retinitis and a macular scar of a unilateral retinitis were found in 2 patients. In a multivariate analysis, elevated CD4 count (>500) was associated with ocular manifestations. Conclusion: In the HAART era, an ocular examination is mandatory to prevent harmful eye diseases among children because ophthalmological diseases remain frequent. Although they are most often lesions of the annexes, corneal and chorioretinal involvement can be detrimental for the vision.

Distribution and significance of angiotensin-converting enzyme 2, a key receptor of 2019-nCoV, in ocular tissues

Corona virus disease-19 (COVID-19) outbroke in the end of 2019 in Wuhan and is spreading worldwide, and its pathogeny is 2019 novel corona virus (2019-nCoV). 2019-nCoV mainly causes human respiratory infection and pulmonary inflammation, however, some COVID-19 patients are found to present viral conjunctivitis. Bilateral viral conjunctivitis is an initial symptom in some other cases. It is vital for us to know whether the eye can be directly infected by the virus and the consequence of the viral infection in ocular tissue. 2019-nCoV invades human cells primarily through binding to the angiotensin-converting enzyme 2 (ACE2) receptors. ACE2 expresses not only in lung, kidney, and cardiovascular system, but also in human cornea, conjunctiva, aqueous humor and retina. Therefore, it is crucial to expand our understanding of the infection mechanism and pathogenesis of COVID-19 comprehensively by clarifying the distribution of ACE2 in the eye. ACE2 is not only the receptor of 2019-nCoV, but also a key enzyme in renin-angiotensin system (RAS). RAS, which appears relatively independent in the eye, plays a modulate role in the eye and is associated with many common eye diseases. This article reviews the distribution and clinical significance of ACE2 in ocular tissues. Key words: Angiotensin-converting enzyme 2; Eye; Novel corona virus; Infection; Renin-angiotensin system

Analysis of the diagnosis and missed diagnosis of intrauterine adhesions by three-dimensional transvaginal sonography Render and tomographic ultrasound imaging

Objective To investigate the value of three-dimensional transvaginal sonography(3D-TVS) in the diagnosis of intrauterine adhesions(IUA) and to analyze the causes of the missed diagnosis. Methods Forty-seven patients with IUA were examined by three-dimensional transvaginal sonography(3D-TVS), 3D volume imaging (Render imaging) and tomographic ultrasound imaging(TUI imaging) in the Union Hospital of Fujian Medical University from January 2017 to July 2019. The abnormal echo data of the endometrium were recorded and analyzed, and the ultrasound diagnosis and hysteroscopic diagnosis were compared. Results 3D-TVS correctly diagnosed IUA was accurate in the 39 cases whose ultrasound imaging showed an uneven thickness of endometrial echo with the uterine cavity line having different degrees of echo continuity interruption. The diagnostic accuracy rate was 83.0%(39/47). In the Render imaging, 7 cases showed endometrial echo with honeycomb change, 28 cases showed partial echo loss with irregular low echo zone or low echo, and 4 cases showed corneal disappearance of one side. In TUI imaging, the endometrium was partly thinned in varying degrees where echo continuity was interrupted with hypoechoic band-like changes in all 39 cases. Three of the 8 missed IUA cases showed slender endometrium with filiform or membranous adhesions, and the other 5 were patients with uterine endometrial polyps. Conclusions 3D-TVS, Render imaging and TUI imaging technology can display stereo images, which contributes to the better preoperative diagnosis and postoperative follow-up. Care should be taken to avoid missed diagnosis and to improve the diagnostic accuracy for IUA by the techniques. Key words: Ultrasonography, transvaginal, three-dimensional; Intrauterine adhesions

Nursing safety management of cataract surgery in Caribbean

Objective To summarize the nursing safety management measures of cataract surgery in the Caribbean in order to provide experience for medical assistance in the future. Methods A retrospective study was conducted to analyze the safety factors of 344 patients (355 eyes) undergoing cataract surgery in the Caribbean. The safety management measures included: pre-investigation preparation, perfect preoperative examination, perioperative systemic disease nursing and health education, strict safety verification and operating room management. Results On the day of operation, 2 patients were changed due to high blood pressure and blood glucose, 1 patient was rescheduled due to deviation in the understanding of surgical eyes, the completion rate of operation was 99.13% (341/344) , and 2 eyes of traumatic cataract were not implanted with intraocular lens (IOL). The success rate of operation was 99.44% (353/355) . One day after operation, corneal edema occurred in 63 eyes (17.75%) and intraocular lens shifted in 1 eye. During the follow-up period, all patients had no infective endophthalmitis, and there was no significant progress in patients with systemic disease. Conclusions The working conditions of health care are difficult, the population of the Caribbean is aging, most of them are accompanied by serious systemic diseases, and the condition of patients is complex. Through a series of safety management measures, the operation can be carried out safely and successfully and good results can be achieved. Key words: Safety management; Phacoemulsification; Caribbean region

Role of the nuclear factor kappa B signaling pathway in the pathogenesis and development of diabetic keratopathy

In recent years, with the increasing incidence of diabetes, diabetic keratopathy has gradually attracted more attention from clinicians.Diabetic keratopathy is mainly manifested as delayed corneal epithelial healing, corneal edema, decreased corneal sensitivity, and neurotrophic corneal ulcer.There are many mechanisms of diabetic keratopathy, including the abnormal accumulation of metabolites, an inflammatory reaction, oxidative stress, the lack of neurotrophic factors, corneal limbal stem cell abnormalities, etc.At present, most of the research on diabetic keratopathy at home and abroad has mainly focused on epithelial damage repair and changes in nerve function, and the pathological mechanism is mainly inflammatory response and apoptosis.Nuclear factor kappa B(NF-κB) is an important transcription regulatory factor, and is involved in regulating the expression of inflammatory factors, chemokines, cell adhesion molecules, apoptosis-related genes, growth factors, and other target genes.Studies have reported that chronic inflammation and epithelial cell apoptosis of the diabetic corneal epithelium are involved in the regulation of the NF-κB signaling pathway, which is also involved in the regulation of diabetic peripheral neuropathy, and diabetic corneal neuropathy belongs to the category of diabetic peripheral neuropathy.The NF-κB signaling pathway is closely related to the occurrence and development of diabetic keratopathy, and this article summarizes its mechanism. Key words: Diabetes mellitus/complications; Diabetic keratopathy; Nuclear factor-κB; Mechanism; Singnal pathway

Association between neurosensory abnormalities and dry eye

Dry eye affects a large number of people worldwide.A vicious cycle involving multiple factors tends to be implicated in its pathophysiology.Tear secretion is regulated by the sympathetic and parasympathetic nervous systems.Corneal nerve fibers secrete neurotransmitters and neuropeptides, which together participate in the maintenance of ocular surface homeostasis.Abnormal neuromodulation can cause abnormal tear secretion and a disruption of ocular surface homeostasis, leading to dry eye.The persistent abnormal tear film in dry eye can damage the normal repair system of ocular surface and leave the ocular surface and the lacrimal gland in a chronic inflammatory state.The cornea in dry eye patients is more sensitive to temperature change and mechanical stimulation than in healthy individuals.Symptomatic eye pain may be related to the effect of chronic inflammation on the corneal pain signal pathway.In vivo confocal microscopy and corneal esthesiometry can be used to evaluate the corneal nerve morphology and function in dry eye patients.This may ead to a more comprehensive treatment of dry eyes through the use of nerve related factors to nourish the cornea and the stimulation of neural pathways or related neural receptors to increase tear secretion.This study reviewed the relationship between neurosensory abnormalities and dry eye. Key words: Dry eye; Tear film; Ocular surface; Corneal nerves; Corneal sensitivity; In vivo confocal microscope