A corneal epithelial-stromal defect is recognized as a major contributor to corneal scarring.Given the rising prevalence of blindness caused by corneal scarring,increasing attention has been focused on corneal epithel...A corneal epithelial-stromal defect is recognized as a major contributor to corneal scarring.Given the rising prevalence of blindness caused by corneal scarring,increasing attention has been focused on corneal epithelialstromal defects.Currently,the etiology and pathogenesis of these defects remain inadequately understood,necessitating further investigation through experimental research.Various modeling methods exist both domestically and internationally,each with distinct adaptive conditions,advantages,and disadvantages.This review primarily aims to summarize the techniques used to establish optimal animal models of corneal epithelial-stromal injury,including mechanical modeling,chemical alkali burns,post-refractive surgery infections,and genetic engineering.The intention is to provide valuable insights for studying the mechanisms underlying corneal epithelial-stromal injury and the development of corresponding therapeutic interventions.展开更多
Corneal neuromas,also termed microneuromas,refer to microscopic,irregula rly-shaped enlargements of terminal subbasal nerve endings at sites of nerve damage or injury.The formation of corneal neuromas results from dam...Corneal neuromas,also termed microneuromas,refer to microscopic,irregula rly-shaped enlargements of terminal subbasal nerve endings at sites of nerve damage or injury.The formation of corneal neuromas results from damage to corneal nerves,such as following corneal pathology or corneal or intraocular surge ries.Initially,denervated areas of sensory nerve fibers become invaded by sprouts of intact sensory nerve fibers,and later injured axons regenerate and new sprouts called neuromas develop.In recent years,analysis of corneal nerve abnormalities including corneal neuromas which can be identified using in vivo confocal microscopy,a non-invasive imaging technique with microscopic resolution,has been used to evaluate corneal neuropathy and ocular surface dysfunction.Corneal neuromas have been shown to be associated with clinical symptoms of discomfort and dryness of eyes,and are a promising surrogate biomarker for ocular surface diseases,such as neuropathic corneal pain,dry eye disease,diabetic corneal neuropathy,neurotrophic keratopathy,Sjogren's syndrome,bullous keratopathy,post-refra ctive surgery,and others.In this review,we have summarized the current literature on the association between these ocular surface diseases and the presentation of corneal microneuromas,as well as elaborated on their pathogenesis,visualization via in vivo confocal microscopy,and utility in monitoring treatment efficacy.As current quantitative analysis on neuromas mainly relies on manual annotation and quantification,which is user-dependent and labor-intensive,future direction includes the development of artificial intelligence software to identify and quantify these potential imaging biomarkers in a more automated and sensitive manner,allowing it to be applied in clinical settings more efficiently.Combining imaging and molecular biomarkers may also help elucidate the associations between corneal neuromas and ocular surface diseases.展开更多
AIM:To investigate the role of transmembrane protein 206(TMEM206)in corneal edema in mice by knockout the TMEM206 gene using CRISPR/Cas9 editing technology.METHODS:TMEM206-knockout mice were generated using the CRISPR...AIM:To investigate the role of transmembrane protein 206(TMEM206)in corneal edema in mice by knockout the TMEM206 gene using CRISPR/Cas9 editing technology.METHODS:TMEM206-knockout mice were generated using the CRISPR-Cas9 system.Variations in ophthalmic pathology were observed using slit lamp microscope and optical coherence tomography(OCT),intraocular pressure(IOP)was measured using a TonoLab Rebound Tonometer,and the ultrastructure of the corneal was observed using a transmission electron microscope.RESULTS:Corneal opacity was observed in 4/18 homozygous TMEM206^(-/-)mice whereas a similar change was not observed in heterozygous TMEM206^(+/-)mice and wild-type littermates.OCT examination showed that the mean central cornea thickness was 125±5.4μm in 4 homozygous TMEM206^(-/-)mice developed corneal edema and 115±1.2μm in wild-type mice(t=3.468,P<0.05)at 43wk.The mean IOP was 12.08±0.07 mm Hg in four right eyes with corneal edema and 12.03±0.03 mm Hg in three normal left eyes(P>0.05).Transmission electron microscopy revealed a disruption in the organization of the collagen fibrils in the central part of the cornea in homozygous TMEM206^(-/-)mice.CONCLUSION:TMEM206 is associated with corneal edema which caused organizational disruption of collagen fibrils in corneas of mice.展开更多
Diabetic corneal neuropathy and diabetic retinopathy are ocular complications occurring in the context of diabetes mellitus.Diabetic corneal neuropathy refers to the progressive damage of corneal nerves.Diabetic retin...Diabetic corneal neuropathy and diabetic retinopathy are ocular complications occurring in the context of diabetes mellitus.Diabetic corneal neuropathy refers to the progressive damage of corneal nerves.Diabetic retinopathy has traditionally been considered as damage to the retinal microvasculature.However,growing evidence suggests that diabetic retinopathy is a complex neurovascular disorder resulting from dysfunction of the neurovascular unit,which includes both the retinal vascular structures and neural tissues.Diabetic retinopathy is one of the leading causes of blindness and is frequently screened for as part of diabetic ocular screening.However,diabetic corneal neuropathy is commonly overlooked and underdiagnosed,leading to severe ocular surface impairment.Several studies have found that these two conditions tend to occur together,and they share similarities in their pathogenesis pathways,being triggered by a status of chronic hyperglycemia.This review aims to discuss the interconnection between diabetic corneal neuropathy and diabetic retinopathy,whether diabetic corneal neuropathy precedes diabetic retinopathy,as well as the relation between the stage of diabetic retinopathy and the severity of corneal neuropathy.We also endeavor to explore the relevance of a corneal screening in diabetic eyes and the possibility of using corneal nerve measurements to monitor the progression of diabetic retinopathy.展开更多
AIM:To evaluate the clinical outcomes after subsequent implantation of a new intrastromal corneal ring segment(ICRS)model followed by an additional short-arc ICRS implant in keratoconus patients.METHODS:This retrospec...AIM:To evaluate the clinical outcomes after subsequent implantation of a new intrastromal corneal ring segment(ICRS)model followed by an additional short-arc ICRS implant in keratoconus patients.METHODS:This retrospective single-arm cohort study evaluated 25 eyes of 21 keratoconus patients implanted with the new ICRS followed by 140-arch length ICRS(140-ICRS)implantation.Uncorrected distance visual acuity(UDVA,logMAR),corrected distance visual acuity(CDVA,logMAR),sphere,astigmatism,keratometry,spherical equivalent(SE),and asphericity were compared preoperatively and postoperatively after both ICRS implantation.RESULTS:The average follow-up time after 140-ICRS implantation was 6.40±2.20mo.The mean preoperative UDVA improved from 1.27±0.14 preoperative to 0.52±0.26 after both ICRS implantation(P=0.03).The mean sphere value reduced from-5.34±2.74 preoperatively to-2.06±1.84 postoperatively(P<0.001)after the first ICRS implantation and decreased to-0.59±1.54 postoperatively(P<0.001)after 140-ICRS implantation.The mean preoperative astigmatism was-3.72±1.56 and improved to-2.82±1.08 after the first ICRS implantation,and following the 140-ICRS implantation,the mean astigmatism was-1.37±0.67(P=0.001).The SE and asphericity changes were statistically significant(P<0.001).The researchers did not find intraoperative or postoperative complications for both procedures.CONCLUSION:The combination of 2 different ICRSs can efficiently regularize the cornea,reduce the SE,and improve visual acuity in selected keratoconus patients.展开更多
AIM:To assess the corneal high-order aberration(HOA)and its correlation with corneal morphological parameters in patients with bilateral keratoconus(KCN)and unilateral Vogt’s striae.METHODS:A total of 168 eyes of 84 ...AIM:To assess the corneal high-order aberration(HOA)and its correlation with corneal morphological parameters in patients with bilateral keratoconus(KCN)and unilateral Vogt’s striae.METHODS:A total of 168 eyes of 84 patients with KCN,whose corneas had definite signs of unilateral Vogt’s striae,were enrolled.Corneal HOA and morphological parameters were measured using Pentacam HR.RESULTS:The corneal morphological parameters between KCN eyes with and without Vogt’s striae were evidently different(P<0.001).The 3rd coma 90°,4th spherical aberration,5th coma 90°,root-mean-square(RMS)(total),and RMS(HOA)in the front,back surfaces and total cornea in KCN eyes with Vogt’s striae were significantly higher than those in KCN eyes without Vogt’s striae(P<0.001).In KCN eyes with Vogt’s striae,the 3rd coma 90°and 4th spherical aberration in the front surface and total cornea were negatively correlated with flat keratometry value(K1),steep keratometry value(K2),mean keratometry value(Km),maximum keratometry value(Kmax),anterior corneal elevation(ACE),and posterior corneal elevation(PCE;P<0.05).The 3rd coma 90°,4th spherical aberration in back surface and RMS(total),RMS(HOA)in the front,back surfaces,total cornea were positively correlated with K1,K2,Km,Kmax,ACE,and PCE(P<0.05).CONCLUSION:Corneal HOA especially vertical coma and spherical aberration may increase when Vogt’s striae appeared in KCN eyes.The scale of increase is significantly related with changes in corneal shapes.展开更多
In recent years, stem cells have been a focal point in research designed to evaluate the efficacy of ophthalmologic therapies, specifically those for corneal conditions. The corneal epithelium is one of the few region...In recent years, stem cells have been a focal point in research designed to evaluate the efficacy of ophthalmologic therapies, specifically those for corneal conditions. The corneal epithelium is one of the few regions of the body that maintains itself using a residual stem cell population within the adjacent limbus. Stem cell movement has additionally captivated the minds of researchers due to its potential application in different body regions. The cornea is a viable model for varying methods to track stem cell migratory patterns, such as lineage tracing and live imaging from the limbus. These developments have the potential to pave the way for future therapies designed to ensure the continuous regeneration of the corneal epithelium following injury via the limbal stem cell niche. This literature review aims to analyze the various methods of imaging used to understand the limbal stem cell niche and possible future directions that might be useful to consider for the better treatment and prevention of disorders of the cornea and corneal epithelium. .展开更多
Among refractive errors,astigmatism is the most common optical aberration,where refraction changes in different meridians of the eye.It causes blurred vision at any distance and includes corneal,lenticular,and retinal...Among refractive errors,astigmatism is the most common optical aberration,where refraction changes in different meridians of the eye.It causes blurred vision at any distance and includes corneal,lenticular,and retinal astigmatism.Cataract surgery used to cause a progressive increase in the pre-exisiting corneal astigmatism because of creating a surgically induced astigmatism,for example,a large size surgery incision.The development of surgical techniques during last decades has made cataract surgery interchange to treat preoperative corneal astigmatism at time of surgery.Nowadays,three surgical approaches can be used.By placing a sutureless clear corneal incision on the steep meridian of the cornea,a preoperative corneal astigmatism less than 1.0 D can be corrected.Single or paired peripheral corneal relaxing incisions(PCRIs)provide 1.0-3.0 D corneal astigmatism correction.PCRIs are typically used for treating 1.0-1.5 D of regular corneal astigmatism,if more than 2.0 D,the risk of overcorrection and irregular astigmatism is increased.When toric intraocular lenses(IOLs)are unavailable in markets,PCRIs are still a reasonable option for patients with up to 3.0 D of pre-existing corneal astigmatism.Toric IOLs implantation can correct 1.0-4.5 D of corneal astigmatism.Several IOLs are approved to correct a high degree of corneal astigmatism with cylinder power up to 12.0 D.These approaches can be used alone or in combination.展开更多
Background: This case report presents a case of bilateral Thiel-Behnke corneal dystrophy in Denmark. Thiel-Behnke is an autosomal dominant inherited epithelial-stromal TGFBI dystrophy causing visual impairment. Method...Background: This case report presents a case of bilateral Thiel-Behnke corneal dystrophy in Denmark. Thiel-Behnke is an autosomal dominant inherited epithelial-stromal TGFBI dystrophy causing visual impairment. Methods and Results: This case study presents a 24-year-old Lithuanian man, with no previous ocular history, who had experienced slowly progressive visual impairment since his childhood. He was examined at the Department of Ophthalmology at Vejle Hospital and Aarhus University Hospital, where he was diagnosed with bilateral Thiel-Behnke corneal dystrophy. Histology confirmed the diagnosis. A lamellar corneal transplantation was performed in the right eye;however, due to epithelial growth under the corneal graft, it was later decided to redo the operation. Following the operations, the patient experienced a visual improvement in best corrected visual acuity (BCVA) from 0.1 (20/25 Snellen equivalent) to 0.3 (20/40 Snellen equivalent) in his right eye. Conclusions: This case of Thiel-Behnke corneal dystrophy is to our knowledge the first reported case in Denmark.展开更多
The expression of VEGF-C and molecular mechanisms of lymphangiogenesis in rat cornea after alkali injury was studied. The rat alkali injured corneal models were made. Under electron microscopy, the lymphatic vessels i...The expression of VEGF-C and molecular mechanisms of lymphangiogenesis in rat cornea after alkali injury was studied. The rat alkali injured corneal models were made. Under electron microscopy, the lymphatic vessels in the rat injured corneas were examined. The expression of VEGF-C proteins was detected by using immunohistochemical assay at day 1, 3, 5, 7, 9 after injury. The expression levels of VEGF-C mRNA were quantified with reverse transcription polymerase chain reaction (RT-PCR). The results showed that the lymphatic vessels were found in the injured rat corneas 14 days after the injury. The VEGF-C protein was detectable 3 days after injury, reached the peak 5 days after injury, and gradually decreased. In the control group, no VEGF-C proteins were detected. The VEGF-C mRNA was minimally detected in the normal rat corneas, but it was highly expressed 5 days after the injury. The difference was statistically significant. It was concluded that VEGF-C might be one of the most important relevant factors in corneal lymphangiogenesis after alkali injury.展开更多
BACKGROUND An in vitro injury model mimicking a corneal surface injury was optimised using human corneal epithelial cells(hCEC).AIM To investigate whether corneal-stroma derived stem cells(CSSC) seeded on an amniotic ...BACKGROUND An in vitro injury model mimicking a corneal surface injury was optimised using human corneal epithelial cells(hCEC).AIM To investigate whether corneal-stroma derived stem cells(CSSC) seeded on an amniotic membrane(AM) construct manifests an anti-inflammatory, healing response.METHODS Treatment of hCEC with ethanol and pro-inflammatory cytokines were compared in terms of viability loss, cytotoxicity, and pro-inflammatory cytokine release, in order to generate the in vitro injury. This resulted in an optimal injury of 20%(v/v) ethanol for 30 s with 1 ng/mL interleukin-1(IL-1) beta. Co-culture experiments were performed with CSSC alone and with CSSC-AM constructs.The effect of injury and co-culture on viability, cytotoxicity, IL-6 and IL-8 production, and IL1 B, TNF, IL6, and CXCL8 mRNA expression were assessed.RESULTS Co-culture with CSSC inhibited loss of hCEC viability caused by injury. Enzyme linked immunosorbent assay and polymerase chain reaction showed a significant reduction in the production of IL-6 and IL-8 pro-inflammatory cytokines, and reduction in pro-inflammatory cytokine mRNA expression during co-culture with CSSC alone and with the AM construct. These results confirmed the therapeutic potential of the CSSC and the possible use of AM as a cell carrier for application to the ocular surface.CONCLUSION CSSC were shown to have a potentially therapeutic anti-inflammatory effectwhen treating injured hCEC, demonstrating an important role in corneal regeneration and wound healing, leading to an improved knowledge of their potential use for research and therapeutic purposes.展开更多
Objective: To observe the changes in corneal tissue after explosive corneal injury and the effect of seawater soaking on the healing of cornea after explosive injury with the help ofoptical microscope. Methods: Make 1...Objective: To observe the changes in corneal tissue after explosive corneal injury and the effect of seawater soaking on the healing of cornea after explosive injury with the help ofoptical microscope. Methods: Make 10 similar explosive injury models of rabbit′s eyeball using 10 adult greyrabbits. For each rabbit, both eyes are artificially injured through explosion; its right eye is the comparison eye and after the injury the left eye is soaked in seawater for 30 minutes.Conduct slit lamp examinations, fluorescein dyeing, and ultrasonic cornea thickness metering on the corneas at intervals, that is, before the injury, 1 , 2, 3, 4, 5, 7, 9, 12, 15days after the injury respectively. Examine the corneas under the optical microscope andmake comparisons.Results: The corneal thickness of the experiment eye becomes apparently thicker than thatof the comparison eye after the injury. The corneal clouding of the former apparentlyaggravates compared with the latter. The healing of corneal epithelium in the injured eye isslower compared with that in the comparison eye. Comparative examination under the opticalmicroscope shows: after the injury, the corneal tissue of the experiment eye changesdistinctly, its healing is delayed and the vascularization degree becomes high in cornealstroma.Conclusion: Scars and vascularization of various degrees will appear in corneal stroma afterexplosive injuries. Seawater soaking will have bad effects on the healing of the corneainjured in explosions.展开更多
Phacoemulsification is the main gold standard for cataract operation in the developed world together with foldable intraocular lens(IOL) implantation by injection,allowing for stable wound construction and less postop...Phacoemulsification is the main gold standard for cataract operation in the developed world together with foldable intraocular lens(IOL) implantation by injection,allowing for stable wound construction and less postoperative astigmatism. It is a safe procedure with high success rate with the advancement in machines,improvement of IOL injection systems and further maturation of surgeons’ techniques. Despite the large number of operations performed every day, foldable IOL injection leading to an intra-stromal corneal track is a very rare complication. We report a case of this unusual finding in a 70-year-old gentleman who has undergone cataract operation in November 2011 in our hospital and will review on the complications related to foldable IOL injection.展开更多
AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zeala...AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions(BSS)were injected into the anterior chamber(10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5mm in diameter from each group were dissected at 30 min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography(HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24 h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for30 min on the corneal surface(8 without epithelium and 8with intact epithelium).RESULTS: The mean riboflavin concentrations were11.19, 18.97, 25.08, 20.18, and 1.13 μg/g for 0.5%, 1%, 2%,de-epithelialzed samples, and the transepithelial groups,respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking(CXL) could be achieved by intracameral 1%riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30 min.CONCLUSION: Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL.展开更多
The corneal epithelium is composed of stratified squamous epithelial cells on the outer surface of the eye,which acts as a protective barrier and is critical for clear and stable vision.Its continuous renewal or wound...The corneal epithelium is composed of stratified squamous epithelial cells on the outer surface of the eye,which acts as a protective barrier and is critical for clear and stable vision.Its continuous renewal or wound healing depends on the proliferation and differentiation of limbal stem cells(LSCs),a cell population that resides at the limbus in a highly regulated niche.Dysfunction of LSCs or their niche can cause limbal stem cell deficiency,a disease that is manifested by failed epithelial wound healing or even blindness.Nevertheless,compared to stem cells in other tissues,little is known about the LSCs and their niche.With the advent of single-cell RNA sequencing,our understanding of LSC characteristics and their microenvironment has grown considerably.In this review,we summarized the current findings from single-cell studies in the field of cornea research and focused on important advancements driven by this technology,including the heterogeneity of the LSC population,novel LSC markers and regulation of the LSC niche,which will provide a reference for clinical issues such as corneal epithelial wound healing,ocular surface reconstruction and interventions for related diseases.展开更多
Introduction: Corneal opacities in children are relatively common. In children, it is urgent because of the risk of irreversible amblyopia. The causes of these blindnesses vary considerably according to the regions of...Introduction: Corneal opacities in children are relatively common. In children, it is urgent because of the risk of irreversible amblyopia. The causes of these blindnesses vary considerably according to the regions of the world. Chlorhexidine digluconate is a broad-spectrum antiseptic directed against gram-positive and gram-negative bacteria. It has been used as an antiseptic for more than 50 years, both in humans and in animals. However, despite these benefits, it can cause serious damage if applied to the eyes. Incidents of eye damage with 7.1% chlorhexidine have been reported to WHO across Africa. Observation: We report and write two cases of bilateral corneal blindness caused by accidental ocular use of chlorhexidine (HEXZ) GEL 7.1% in two newborns in the health district of Kati in MALI. The ophthalmological examination had revealed corneal opacity, conjunctival hyperaemia and limbic ischemia greater than 50% in 1 eye out of 4, corresponding to stage IV of the ROPPER HALL classification;2 eyes out of 4 were at stage III and 1 eye out of 4 was at stage I of the same classification. Conclusion: It is essential to ensure correct use of chlorhexidine digluconate gel 7%. It is an antiseptic which should not be used on the ocular and auditory mucous membranes, at the risk of most often permanent burns.展开更多
Background: The mean central corneal thickness (CCT) values are known to have an influence on intraocular pressure measurement and vary widely with age, sex and ethnicity. Little is known about the pattern of CCT in c...Background: The mean central corneal thickness (CCT) values are known to have an influence on intraocular pressure measurement and vary widely with age, sex and ethnicity. Little is known about the pattern of CCT in central Uganda. Aim: To determine the mean central corneal thickness and its associated factors among adult patients attending Mulago Hospital eye clinic, Kampala Uganda. Design and Method: A cross sectional study was done from August to October 2016 on 270 adult patients selected by systemic random sampling. The study included all adult patients who attended the eye clinic during the study period and consented to the study excluding those who had conditions causing abnormal thinning, thickening or irregularity of the cornea. The participants were evaluated by history taking and ocular examination including visual acuity assessment, slit lamp examination, central cornea thickness measurement, intraocular pressure measurement and funduscopy. Data were collected using a pretested questionnaire, entered using Epidata and analyzed by STATA11.0. Results: Of the 270 patients examined, 61% were female, 39% male, the mean age being 42 years ranging from 18 to 96 years. The mean central corneal thickness for both eyes was 539.3 (SD ± 41.65 μm) ranging from 332 μm to 701 μm and mean intraocular pressure was 15 (SD ± 5.34) mmHg. Gender, ethnicity, IOP, glaucoma, hypertension, diabetes, refractive error, were not statistically significantly associated with central cornea thickness. However central cornea thickness was statistically significantly associated with systolic blood pressure (r = -0.24, p = 0.025) and age (p = 0.002). A one-year increase in age reduced the mean central cornea thickness by 0.54 μm. Conclusion: The average CCT of Ugandan adult population was 539.3 ± 41.65 μm which falls in the category of normal central cornea thickness. Central corneal thickness reduced with increasing age and increasing systolic blood pressure.展开更多
Background: To compare central corneal thickness (CCT) values measured in diabetic eyes and compare the CCT values in normal patients without diabetes. Methods: A total of 83 diabetic patients and 83 non-diabetic pati...Background: To compare central corneal thickness (CCT) values measured in diabetic eyes and compare the CCT values in normal patients without diabetes. Methods: A total of 83 diabetic patients and 83 non-diabetic patients were prospectively enrolled in this comparative case series. CCT was measured using a Topcon CT-1P non-contact automated pachymeter, and values were compared. Results: Mean age was 57 ± 11 years, with a range of 23 and 80 years. The mean CCT was 508.87 ± 35.83 μm for diabetic patients and 513.41 ± 37.22 μm for non-diabetic patients. There was no statistically significant difference between the CCT of diabetic patients compared to non-diabetic patients (p = 0.260). We did not find a significant correlation between the CCT of diabetic patients and clinical characteristics of diabetes. However, there was a positive and statistically significant linear correlation between the CCT of diabetic patients and intra ocular pressure (IOP). Conclusion: The mean CCT in diabetic patients was lower than in non-diabetic control patients, although there was no statistically significant difference.展开更多
Background and Objective:Corneal neurotization is a novel surgical technique used to restore corneal sensation in patients with neurotrophic keratopathy.Neurotrophic keratopathy is a disorder characterized by dysfunct...Background and Objective:Corneal neurotization is a novel surgical technique used to restore corneal sensation in patients with neurotrophic keratopathy.Neurotrophic keratopathy is a disorder characterized by dysfunction of the ophthalmic division of the trigeminal nerve,which provides sensory innervation to the cornea.Without sensation,the cornea is at risk of infection,ulceration,perforation,and ultimately,vision loss.Corneal neurotization has emerged as an innovative technique to reinnervate anesthetized corneas by transferring a healthy donor nerve to the affected eye around the corneoscleral limbus.As the field of corneal neurotization rapidly grows,there is a need to synthesize the existing body of literature on corneal neurotization and identify important areas for further research.In this review,we will discuss neurotrophic keratopathy and its current management strategies,followed by an overview of corneal neurotization techniques,outcomes,surgical considerations,and future directions.Methods:PubMed and Google Scholar searches were conducted to retrieve and analyze relevant original papers and reviews on neurotrophic keratopathy and corneal neurotization up until April 2022.Key Content and Findings:Currently,numerous techniques for corneal neurotization exist,including direct nerve transfers,as well as indirect neurotization via interposition nerve grafts.So far,corneal neurotization has been shown to be highly successful in restoring corneal sensation,improving visual acuity,and improving corneal epithelial health.To date,there have been no significant differences in outcomes between direct versus indirect neurotization techniques,different donor nerves,or autologous versus allogeneic interposition grafts.However,there is some evidence that corneal neurotization procedures may be more successful in pediatric patients.Conclusions:Corneal neurotization shows great promise in treating neurotrophic corneas and represents the first management option to date that addresses the underlying pathophysiological mechanism of neurotrophic keratopathy by restoring corneal sensation.As the use of corneal neurotization continues to broaden,additional studies will become important to compare techniques in a systematic manner,with larger sample sizes,as well as standardized outcome measures and follow-up time.展开更多
基金Supported by the National Key Research and Development Program of China(No.2020YFE0204400)the National Natural Science Foundation of China(No.82271042)the Zhejiang Province Key Research and Development Program(No.2023C03090).
文摘A corneal epithelial-stromal defect is recognized as a major contributor to corneal scarring.Given the rising prevalence of blindness caused by corneal scarring,increasing attention has been focused on corneal epithelialstromal defects.Currently,the etiology and pathogenesis of these defects remain inadequately understood,necessitating further investigation through experimental research.Various modeling methods exist both domestically and internationally,each with distinct adaptive conditions,advantages,and disadvantages.This review primarily aims to summarize the techniques used to establish optimal animal models of corneal epithelial-stromal injury,including mechanical modeling,chemical alkali burns,post-refractive surgery infections,and genetic engineering.The intention is to provide valuable insights for studying the mechanisms underlying corneal epithelial-stromal injury and the development of corresponding therapeutic interventions.
文摘Corneal neuromas,also termed microneuromas,refer to microscopic,irregula rly-shaped enlargements of terminal subbasal nerve endings at sites of nerve damage or injury.The formation of corneal neuromas results from damage to corneal nerves,such as following corneal pathology or corneal or intraocular surge ries.Initially,denervated areas of sensory nerve fibers become invaded by sprouts of intact sensory nerve fibers,and later injured axons regenerate and new sprouts called neuromas develop.In recent years,analysis of corneal nerve abnormalities including corneal neuromas which can be identified using in vivo confocal microscopy,a non-invasive imaging technique with microscopic resolution,has been used to evaluate corneal neuropathy and ocular surface dysfunction.Corneal neuromas have been shown to be associated with clinical symptoms of discomfort and dryness of eyes,and are a promising surrogate biomarker for ocular surface diseases,such as neuropathic corneal pain,dry eye disease,diabetic corneal neuropathy,neurotrophic keratopathy,Sjogren's syndrome,bullous keratopathy,post-refra ctive surgery,and others.In this review,we have summarized the current literature on the association between these ocular surface diseases and the presentation of corneal microneuromas,as well as elaborated on their pathogenesis,visualization via in vivo confocal microscopy,and utility in monitoring treatment efficacy.As current quantitative analysis on neuromas mainly relies on manual annotation and quantification,which is user-dependent and labor-intensive,future direction includes the development of artificial intelligence software to identify and quantify these potential imaging biomarkers in a more automated and sensitive manner,allowing it to be applied in clinical settings more efficiently.Combining imaging and molecular biomarkers may also help elucidate the associations between corneal neuromas and ocular surface diseases.
基金Supported by National Natural Science Foundation of China(No.31571294).
文摘AIM:To investigate the role of transmembrane protein 206(TMEM206)in corneal edema in mice by knockout the TMEM206 gene using CRISPR/Cas9 editing technology.METHODS:TMEM206-knockout mice were generated using the CRISPR-Cas9 system.Variations in ophthalmic pathology were observed using slit lamp microscope and optical coherence tomography(OCT),intraocular pressure(IOP)was measured using a TonoLab Rebound Tonometer,and the ultrastructure of the corneal was observed using a transmission electron microscope.RESULTS:Corneal opacity was observed in 4/18 homozygous TMEM206^(-/-)mice whereas a similar change was not observed in heterozygous TMEM206^(+/-)mice and wild-type littermates.OCT examination showed that the mean central cornea thickness was 125±5.4μm in 4 homozygous TMEM206^(-/-)mice developed corneal edema and 115±1.2μm in wild-type mice(t=3.468,P<0.05)at 43wk.The mean IOP was 12.08±0.07 mm Hg in four right eyes with corneal edema and 12.03±0.03 mm Hg in three normal left eyes(P>0.05).Transmission electron microscopy revealed a disruption in the organization of the collagen fibrils in the central part of the cornea in homozygous TMEM206^(-/-)mice.CONCLUSION:TMEM206 is associated with corneal edema which caused organizational disruption of collagen fibrils in corneas of mice.
文摘Diabetic corneal neuropathy and diabetic retinopathy are ocular complications occurring in the context of diabetes mellitus.Diabetic corneal neuropathy refers to the progressive damage of corneal nerves.Diabetic retinopathy has traditionally been considered as damage to the retinal microvasculature.However,growing evidence suggests that diabetic retinopathy is a complex neurovascular disorder resulting from dysfunction of the neurovascular unit,which includes both the retinal vascular structures and neural tissues.Diabetic retinopathy is one of the leading causes of blindness and is frequently screened for as part of diabetic ocular screening.However,diabetic corneal neuropathy is commonly overlooked and underdiagnosed,leading to severe ocular surface impairment.Several studies have found that these two conditions tend to occur together,and they share similarities in their pathogenesis pathways,being triggered by a status of chronic hyperglycemia.This review aims to discuss the interconnection between diabetic corneal neuropathy and diabetic retinopathy,whether diabetic corneal neuropathy precedes diabetic retinopathy,as well as the relation between the stage of diabetic retinopathy and the severity of corneal neuropathy.We also endeavor to explore the relevance of a corneal screening in diabetic eyes and the possibility of using corneal nerve measurements to monitor the progression of diabetic retinopathy.
文摘AIM:To evaluate the clinical outcomes after subsequent implantation of a new intrastromal corneal ring segment(ICRS)model followed by an additional short-arc ICRS implant in keratoconus patients.METHODS:This retrospective single-arm cohort study evaluated 25 eyes of 21 keratoconus patients implanted with the new ICRS followed by 140-arch length ICRS(140-ICRS)implantation.Uncorrected distance visual acuity(UDVA,logMAR),corrected distance visual acuity(CDVA,logMAR),sphere,astigmatism,keratometry,spherical equivalent(SE),and asphericity were compared preoperatively and postoperatively after both ICRS implantation.RESULTS:The average follow-up time after 140-ICRS implantation was 6.40±2.20mo.The mean preoperative UDVA improved from 1.27±0.14 preoperative to 0.52±0.26 after both ICRS implantation(P=0.03).The mean sphere value reduced from-5.34±2.74 preoperatively to-2.06±1.84 postoperatively(P<0.001)after the first ICRS implantation and decreased to-0.59±1.54 postoperatively(P<0.001)after 140-ICRS implantation.The mean preoperative astigmatism was-3.72±1.56 and improved to-2.82±1.08 after the first ICRS implantation,and following the 140-ICRS implantation,the mean astigmatism was-1.37±0.67(P=0.001).The SE and asphericity changes were statistically significant(P<0.001).The researchers did not find intraoperative or postoperative complications for both procedures.CONCLUSION:The combination of 2 different ICRSs can efficiently regularize the cornea,reduce the SE,and improve visual acuity in selected keratoconus patients.
基金Supported by Xi’an Health Committee Research Projects(No.2023yb14)Shaanxi Province Natural Science Basic Research Project(No.2024JC-YBMS-623)Shaanxi Province Science and Technology Plan Project(No.2024SFYBXM-331).
文摘AIM:To assess the corneal high-order aberration(HOA)and its correlation with corneal morphological parameters in patients with bilateral keratoconus(KCN)and unilateral Vogt’s striae.METHODS:A total of 168 eyes of 84 patients with KCN,whose corneas had definite signs of unilateral Vogt’s striae,were enrolled.Corneal HOA and morphological parameters were measured using Pentacam HR.RESULTS:The corneal morphological parameters between KCN eyes with and without Vogt’s striae were evidently different(P<0.001).The 3rd coma 90°,4th spherical aberration,5th coma 90°,root-mean-square(RMS)(total),and RMS(HOA)in the front,back surfaces and total cornea in KCN eyes with Vogt’s striae were significantly higher than those in KCN eyes without Vogt’s striae(P<0.001).In KCN eyes with Vogt’s striae,the 3rd coma 90°and 4th spherical aberration in the front surface and total cornea were negatively correlated with flat keratometry value(K1),steep keratometry value(K2),mean keratometry value(Km),maximum keratometry value(Kmax),anterior corneal elevation(ACE),and posterior corneal elevation(PCE;P<0.05).The 3rd coma 90°,4th spherical aberration in back surface and RMS(total),RMS(HOA)in the front,back surfaces,total cornea were positively correlated with K1,K2,Km,Kmax,ACE,and PCE(P<0.05).CONCLUSION:Corneal HOA especially vertical coma and spherical aberration may increase when Vogt’s striae appeared in KCN eyes.The scale of increase is significantly related with changes in corneal shapes.
文摘In recent years, stem cells have been a focal point in research designed to evaluate the efficacy of ophthalmologic therapies, specifically those for corneal conditions. The corneal epithelium is one of the few regions of the body that maintains itself using a residual stem cell population within the adjacent limbus. Stem cell movement has additionally captivated the minds of researchers due to its potential application in different body regions. The cornea is a viable model for varying methods to track stem cell migratory patterns, such as lineage tracing and live imaging from the limbus. These developments have the potential to pave the way for future therapies designed to ensure the continuous regeneration of the corneal epithelium following injury via the limbal stem cell niche. This literature review aims to analyze the various methods of imaging used to understand the limbal stem cell niche and possible future directions that might be useful to consider for the better treatment and prevention of disorders of the cornea and corneal epithelium. .
基金Supported by Independent Research Foundation of the 305 Hospital of PLA(No.24ZZJJLW-010).
文摘Among refractive errors,astigmatism is the most common optical aberration,where refraction changes in different meridians of the eye.It causes blurred vision at any distance and includes corneal,lenticular,and retinal astigmatism.Cataract surgery used to cause a progressive increase in the pre-exisiting corneal astigmatism because of creating a surgically induced astigmatism,for example,a large size surgery incision.The development of surgical techniques during last decades has made cataract surgery interchange to treat preoperative corneal astigmatism at time of surgery.Nowadays,three surgical approaches can be used.By placing a sutureless clear corneal incision on the steep meridian of the cornea,a preoperative corneal astigmatism less than 1.0 D can be corrected.Single or paired peripheral corneal relaxing incisions(PCRIs)provide 1.0-3.0 D corneal astigmatism correction.PCRIs are typically used for treating 1.0-1.5 D of regular corneal astigmatism,if more than 2.0 D,the risk of overcorrection and irregular astigmatism is increased.When toric intraocular lenses(IOLs)are unavailable in markets,PCRIs are still a reasonable option for patients with up to 3.0 D of pre-existing corneal astigmatism.Toric IOLs implantation can correct 1.0-4.5 D of corneal astigmatism.Several IOLs are approved to correct a high degree of corneal astigmatism with cylinder power up to 12.0 D.These approaches can be used alone or in combination.
文摘Background: This case report presents a case of bilateral Thiel-Behnke corneal dystrophy in Denmark. Thiel-Behnke is an autosomal dominant inherited epithelial-stromal TGFBI dystrophy causing visual impairment. Methods and Results: This case study presents a 24-year-old Lithuanian man, with no previous ocular history, who had experienced slowly progressive visual impairment since his childhood. He was examined at the Department of Ophthalmology at Vejle Hospital and Aarhus University Hospital, where he was diagnosed with bilateral Thiel-Behnke corneal dystrophy. Histology confirmed the diagnosis. A lamellar corneal transplantation was performed in the right eye;however, due to epithelial growth under the corneal graft, it was later decided to redo the operation. Following the operations, the patient experienced a visual improvement in best corrected visual acuity (BCVA) from 0.1 (20/25 Snellen equivalent) to 0.3 (20/40 Snellen equivalent) in his right eye. Conclusions: This case of Thiel-Behnke corneal dystrophy is to our knowledge the first reported case in Denmark.
文摘The expression of VEGF-C and molecular mechanisms of lymphangiogenesis in rat cornea after alkali injury was studied. The rat alkali injured corneal models were made. Under electron microscopy, the lymphatic vessels in the rat injured corneas were examined. The expression of VEGF-C proteins was detected by using immunohistochemical assay at day 1, 3, 5, 7, 9 after injury. The expression levels of VEGF-C mRNA were quantified with reverse transcription polymerase chain reaction (RT-PCR). The results showed that the lymphatic vessels were found in the injured rat corneas 14 days after the injury. The VEGF-C protein was detectable 3 days after injury, reached the peak 5 days after injury, and gradually decreased. In the control group, no VEGF-C proteins were detected. The VEGF-C mRNA was minimally detected in the normal rat corneas, but it was highly expressed 5 days after the injury. The difference was statistically significant. It was concluded that VEGF-C might be one of the most important relevant factors in corneal lymphangiogenesis after alkali injury.
文摘BACKGROUND An in vitro injury model mimicking a corneal surface injury was optimised using human corneal epithelial cells(hCEC).AIM To investigate whether corneal-stroma derived stem cells(CSSC) seeded on an amniotic membrane(AM) construct manifests an anti-inflammatory, healing response.METHODS Treatment of hCEC with ethanol and pro-inflammatory cytokines were compared in terms of viability loss, cytotoxicity, and pro-inflammatory cytokine release, in order to generate the in vitro injury. This resulted in an optimal injury of 20%(v/v) ethanol for 30 s with 1 ng/mL interleukin-1(IL-1) beta. Co-culture experiments were performed with CSSC alone and with CSSC-AM constructs.The effect of injury and co-culture on viability, cytotoxicity, IL-6 and IL-8 production, and IL1 B, TNF, IL6, and CXCL8 mRNA expression were assessed.RESULTS Co-culture with CSSC inhibited loss of hCEC viability caused by injury. Enzyme linked immunosorbent assay and polymerase chain reaction showed a significant reduction in the production of IL-6 and IL-8 pro-inflammatory cytokines, and reduction in pro-inflammatory cytokine mRNA expression during co-culture with CSSC alone and with the AM construct. These results confirmed the therapeutic potential of the CSSC and the possible use of AM as a cell carrier for application to the ocular surface.CONCLUSION CSSC were shown to have a potentially therapeutic anti-inflammatory effectwhen treating injured hCEC, demonstrating an important role in corneal regeneration and wound healing, leading to an improved knowledge of their potential use for research and therapeutic purposes.
文摘Objective: To observe the changes in corneal tissue after explosive corneal injury and the effect of seawater soaking on the healing of cornea after explosive injury with the help ofoptical microscope. Methods: Make 10 similar explosive injury models of rabbit′s eyeball using 10 adult greyrabbits. For each rabbit, both eyes are artificially injured through explosion; its right eye is the comparison eye and after the injury the left eye is soaked in seawater for 30 minutes.Conduct slit lamp examinations, fluorescein dyeing, and ultrasonic cornea thickness metering on the corneas at intervals, that is, before the injury, 1 , 2, 3, 4, 5, 7, 9, 12, 15days after the injury respectively. Examine the corneas under the optical microscope andmake comparisons.Results: The corneal thickness of the experiment eye becomes apparently thicker than thatof the comparison eye after the injury. The corneal clouding of the former apparentlyaggravates compared with the latter. The healing of corneal epithelium in the injured eye isslower compared with that in the comparison eye. Comparative examination under the opticalmicroscope shows: after the injury, the corneal tissue of the experiment eye changesdistinctly, its healing is delayed and the vascularization degree becomes high in cornealstroma.Conclusion: Scars and vascularization of various degrees will appear in corneal stroma afterexplosive injuries. Seawater soaking will have bad effects on the healing of the corneainjured in explosions.
文摘Phacoemulsification is the main gold standard for cataract operation in the developed world together with foldable intraocular lens(IOL) implantation by injection,allowing for stable wound construction and less postoperative astigmatism. It is a safe procedure with high success rate with the advancement in machines,improvement of IOL injection systems and further maturation of surgeons’ techniques. Despite the large number of operations performed every day, foldable IOL injection leading to an intra-stromal corneal track is a very rare complication. We report a case of this unusual finding in a 70-year-old gentleman who has undergone cataract operation in November 2011 in our hospital and will review on the complications related to foldable IOL injection.
文摘AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions(BSS)were injected into the anterior chamber(10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5mm in diameter from each group were dissected at 30 min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography(HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24 h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for30 min on the corneal surface(8 without epithelium and 8with intact epithelium).RESULTS: The mean riboflavin concentrations were11.19, 18.97, 25.08, 20.18, and 1.13 μg/g for 0.5%, 1%, 2%,de-epithelialzed samples, and the transepithelial groups,respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking(CXL) could be achieved by intracameral 1%riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30 min.CONCLUSION: Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL.
文摘The corneal epithelium is composed of stratified squamous epithelial cells on the outer surface of the eye,which acts as a protective barrier and is critical for clear and stable vision.Its continuous renewal or wound healing depends on the proliferation and differentiation of limbal stem cells(LSCs),a cell population that resides at the limbus in a highly regulated niche.Dysfunction of LSCs or their niche can cause limbal stem cell deficiency,a disease that is manifested by failed epithelial wound healing or even blindness.Nevertheless,compared to stem cells in other tissues,little is known about the LSCs and their niche.With the advent of single-cell RNA sequencing,our understanding of LSC characteristics and their microenvironment has grown considerably.In this review,we summarized the current findings from single-cell studies in the field of cornea research and focused on important advancements driven by this technology,including the heterogeneity of the LSC population,novel LSC markers and regulation of the LSC niche,which will provide a reference for clinical issues such as corneal epithelial wound healing,ocular surface reconstruction and interventions for related diseases.
文摘Introduction: Corneal opacities in children are relatively common. In children, it is urgent because of the risk of irreversible amblyopia. The causes of these blindnesses vary considerably according to the regions of the world. Chlorhexidine digluconate is a broad-spectrum antiseptic directed against gram-positive and gram-negative bacteria. It has been used as an antiseptic for more than 50 years, both in humans and in animals. However, despite these benefits, it can cause serious damage if applied to the eyes. Incidents of eye damage with 7.1% chlorhexidine have been reported to WHO across Africa. Observation: We report and write two cases of bilateral corneal blindness caused by accidental ocular use of chlorhexidine (HEXZ) GEL 7.1% in two newborns in the health district of Kati in MALI. The ophthalmological examination had revealed corneal opacity, conjunctival hyperaemia and limbic ischemia greater than 50% in 1 eye out of 4, corresponding to stage IV of the ROPPER HALL classification;2 eyes out of 4 were at stage III and 1 eye out of 4 was at stage I of the same classification. Conclusion: It is essential to ensure correct use of chlorhexidine digluconate gel 7%. It is an antiseptic which should not be used on the ocular and auditory mucous membranes, at the risk of most often permanent burns.
文摘Background: The mean central corneal thickness (CCT) values are known to have an influence on intraocular pressure measurement and vary widely with age, sex and ethnicity. Little is known about the pattern of CCT in central Uganda. Aim: To determine the mean central corneal thickness and its associated factors among adult patients attending Mulago Hospital eye clinic, Kampala Uganda. Design and Method: A cross sectional study was done from August to October 2016 on 270 adult patients selected by systemic random sampling. The study included all adult patients who attended the eye clinic during the study period and consented to the study excluding those who had conditions causing abnormal thinning, thickening or irregularity of the cornea. The participants were evaluated by history taking and ocular examination including visual acuity assessment, slit lamp examination, central cornea thickness measurement, intraocular pressure measurement and funduscopy. Data were collected using a pretested questionnaire, entered using Epidata and analyzed by STATA11.0. Results: Of the 270 patients examined, 61% were female, 39% male, the mean age being 42 years ranging from 18 to 96 years. The mean central corneal thickness for both eyes was 539.3 (SD ± 41.65 μm) ranging from 332 μm to 701 μm and mean intraocular pressure was 15 (SD ± 5.34) mmHg. Gender, ethnicity, IOP, glaucoma, hypertension, diabetes, refractive error, were not statistically significantly associated with central cornea thickness. However central cornea thickness was statistically significantly associated with systolic blood pressure (r = -0.24, p = 0.025) and age (p = 0.002). A one-year increase in age reduced the mean central cornea thickness by 0.54 μm. Conclusion: The average CCT of Ugandan adult population was 539.3 ± 41.65 μm which falls in the category of normal central cornea thickness. Central corneal thickness reduced with increasing age and increasing systolic blood pressure.
文摘Background: To compare central corneal thickness (CCT) values measured in diabetic eyes and compare the CCT values in normal patients without diabetes. Methods: A total of 83 diabetic patients and 83 non-diabetic patients were prospectively enrolled in this comparative case series. CCT was measured using a Topcon CT-1P non-contact automated pachymeter, and values were compared. Results: Mean age was 57 ± 11 years, with a range of 23 and 80 years. The mean CCT was 508.87 ± 35.83 μm for diabetic patients and 513.41 ± 37.22 μm for non-diabetic patients. There was no statistically significant difference between the CCT of diabetic patients compared to non-diabetic patients (p = 0.260). We did not find a significant correlation between the CCT of diabetic patients and clinical characteristics of diabetes. However, there was a positive and statistically significant linear correlation between the CCT of diabetic patients and intra ocular pressure (IOP). Conclusion: The mean CCT in diabetic patients was lower than in non-diabetic control patients, although there was no statistically significant difference.
文摘Background and Objective:Corneal neurotization is a novel surgical technique used to restore corneal sensation in patients with neurotrophic keratopathy.Neurotrophic keratopathy is a disorder characterized by dysfunction of the ophthalmic division of the trigeminal nerve,which provides sensory innervation to the cornea.Without sensation,the cornea is at risk of infection,ulceration,perforation,and ultimately,vision loss.Corneal neurotization has emerged as an innovative technique to reinnervate anesthetized corneas by transferring a healthy donor nerve to the affected eye around the corneoscleral limbus.As the field of corneal neurotization rapidly grows,there is a need to synthesize the existing body of literature on corneal neurotization and identify important areas for further research.In this review,we will discuss neurotrophic keratopathy and its current management strategies,followed by an overview of corneal neurotization techniques,outcomes,surgical considerations,and future directions.Methods:PubMed and Google Scholar searches were conducted to retrieve and analyze relevant original papers and reviews on neurotrophic keratopathy and corneal neurotization up until April 2022.Key Content and Findings:Currently,numerous techniques for corneal neurotization exist,including direct nerve transfers,as well as indirect neurotization via interposition nerve grafts.So far,corneal neurotization has been shown to be highly successful in restoring corneal sensation,improving visual acuity,and improving corneal epithelial health.To date,there have been no significant differences in outcomes between direct versus indirect neurotization techniques,different donor nerves,or autologous versus allogeneic interposition grafts.However,there is some evidence that corneal neurotization procedures may be more successful in pediatric patients.Conclusions:Corneal neurotization shows great promise in treating neurotrophic corneas and represents the first management option to date that addresses the underlying pathophysiological mechanism of neurotrophic keratopathy by restoring corneal sensation.As the use of corneal neurotization continues to broaden,additional studies will become important to compare techniques in a systematic manner,with larger sample sizes,as well as standardized outcome measures and follow-up time.