Topical ketotifen treatment for allergic conjunctivitis:a systematic review and Meta-analysis

AIM:To assess the efficacy of ketotifen in treating allergic conjunctivitis.METHODS:A systematic search of systematic reviews and Meta-analyses was conducted on the Pub Med and Web Science of Science until October 2021 to address this knowledge gap.Mean difference with 95%CI and P values were used to assess the efficacy of ketotifen.The heterogeneity(I^(2))was used to evaluate the impact of heterogeneity.RESULTS:Eight randomized controlled trials(RCTs)involving 1589 patients were included in this Meta-analysis.The results revealed that after treating with ketotifen,itching(MD=-0.91,95%CI:-1.63 to-0.20,I^(2)=94%,P=0.01),tearing(MD=-0.40,95%CI:-0.61 to-0.18,I^(2)=75%,P=0.0003)and total signs and symptoms(MD=-0.85,95%CI:-1.12 to-0.58,I2=0,P<0.00001)showed better benefit effect compared to the placebo group.CONCLUSION:Topical ketotifen is an effective treatment for patients with allergic conjunctivitis.

Pseudomembranous conjunctivitis in a patient with DRESS syndrome

Dear Editor,Drug rash with eosinophilia and systemic symptoms(DRESS)syndrome is a drug reaction featuring high fever,eosinophilia,skin rashes,and multi-organ involvement that may be fatal.Ocular manifestations,including cicatrizing conjunctivitis,corneal infiltration,and anterior uveitis,are rarely reported[1-6]but may cause serious complications if untreated.Therefore,it is important to diagnose DRESS syndrome in patients with ocular features promptly with appropriate treatment.This article reports a case diagnosed with DRESS syndrome associated with pseudomembranous conjunctivitis secondary to carfilzomib.

A Case of Serratia marcescens Conjunctivitis in a Young Male after Exposure to Contaminated Shampoo in a Fitness Club

The contamination of shampoo with bacteria is not very common but can happen and can be a potential cause of conjunctivitis. This case report describes a 24-year-old male who developed conjunctivitis after using a Serratia marcescens contaminated shampoo in a fitness club. The patient had redness, swelling, and discharge in both eyes. Cultures of the shampoo and eye swabs were positive for S. marcescens with indistinguishable DNA fingerprints. The patient was treated with an eye drop antibiotic and his symptoms resolved within a week. This case highlights the possibility of exposure in places where shampoos containers are refilled or shared. The avoidance of refilling them and using replaceable cartridges, single-sealed refill bags, or bringing personal shampoo is highly recommended to prevent such incidents.

Effects of vernal and allergic conjunctivitis on severity of keratoconus

AIM: To demonstrate the effects of two different types of allergic conjunctivitis on severity of keratoconus (KC). ·METHODS: We retrospectively reviewed the medical records of 171 KC patients referred between June 2010 and June 2011. The KC patients were divided into 3 groups as KC (group A), KC with vernal keratoconjunctivitis (VKC) (group B) and KC with allergic conjunctivitis (AC) (group C). Main outcome measures were demographic and ocular clinical features including age at presentation, gender, spherical equivalent (SE), best spectacle corrected visual acuity (BCVA), mean keratometric measurement (Km), central corneal thickness (CCT), and intraocular pressure (IOP). Groups were compared in term of study variables. · RESULTS: The median age at presentation was significantly lower in group B (P 【0.001). According to the median SE (P =0.003), BCVA(P =0.022), Km(P 【0.001), CCT (P =0.015) and Amsler-Krumeich classification (P 【 0.001), KC was more severe in group B. There was no significant difference in terms of IOP and corrected IOP among the groups (P =0.44), however there were 4 patients who had increased corrected IOP developed after topical corticosteroid use in group B. The differences among the groups persisted even after controlling for age and gender. · CONCLUSION: Our findings demonstrated a more severe KC in VKC patients despite their younger age which suggests evaluation of VKC patients as a separate group in keratoconus disease.

Effect of diluted povidone iodine in adenoviral keratoconjunctivitis on the rate of subepithelial corneal infiltrates

AIM: To evaluate the clinical characteristics of adenoviral keratoconjunctivitis, the management modalities, as well as the incidence of subepithelial corneal infiltrates(SEI).METHODS: Patients with characteristic clinical symptoms and signs, who presented to our clinic within the first week of symptoms and received the diagnosis of adenoviral keratoconjunctivitis between January 2013 and April 2016, were included in the study. A total of 211 patients were included in the study. Patients were evaluated for the incidence of clinical signs, late complications, management preferences, and the effect of diluted povidone-iodine(d-PVP-I) 2%. RESULTS: Patients’ mean age was 33.03±14.76 y. We observed an increase in the number of cases according to the years. At presentation and/or early follow-up, the clinical signs were conjunctival hyperemia(100%), conjunctival follicules(79.1%), edema of the eyelids(39.3%), chemosis(16.1%), pseudomembrane formation(16.6%), and corneal epitheliopathy(29.9%). During late follow-up 13.3% patients developed conjunctival subepithelial fibrosis, and 39.8% developed SEI. A significant decrease in the incidence of SEI development was observed in patients who used d-PVP-I 2%(P=0.032;33.3% vs 45.9%, respectively in patients who received d-PVP-I 2% and who did not).CONCLUSION: Adenoviral keratoconjunctivitis has a tremendous effect on patient’s comfort and abilities in short-term. Additionally, almost half of the patients develop visual problems related to SEI. According to our clinical experience, using d-PVP-I 2% in the first days of adenoviral keratoconjunctivitis might be helpful in reducing the risk of SEI as a complication.

The Effect of BCG-PSN on T-cell Subsets and Cytokines in Vernal Conjunctivitis

The effects of BCG PSN on T cell subsets and cytokines in vernal conjunctivitis were observed. The level of total IgE was quantitatively determined before and after treatment with BCG PSN by allergen diagnostic instrument in vitro . The content of T cell subsets of peripheral blood and cytokine were determined by using indirect immune fluorescence method, and IL 4 and INF γ were quantified by ELISA. The results showed that the level of total IgE was substantially reduced ( P <0.01) after treatment in the BCG PSN group. Meanwhile, CD + 8 was decreased, CD + 4 and CD + 4/CD + 8 ratio elevated with significant differences ( P <0.05) as compared with pre treatment results. The changes in total IgE, CD + 8 ,CD + 4 and CD + 4/CD + 8 ratio after treatment also presented significant differences ( P <0.05) between BCG PSN group and routine treatment group. The level of IL 4 in serum declined ( P <0.05) after treatment in the BCG PSN group, and INF γ went up ( P <0 05). IL 4 and INF γ in serum showed significant differences ( P <0.05) between two groups after treatment. It is concluded that BCG PSN has a bi directional immunoregulating effect. It can bring CD + 4 and CD + 8 into homeostasis, thereby preventing the occurrence of anaphylaxis. At the same time, BCG PSN can restrain Th 2, decrease the synthesis of IL 4, switch the balance of Th l/Th 2 to Th 1 side, boost up the predominance of Th 1 relatively, which is propitious to perennial stabilization and recovery of vernal conjunctivitis.

Semaphorin 3A controls allergic and inflammatory responses in experimental allergic conjunctivitis

AIM: To assess the efficacy of topical Semaphorin 3A(SEMA3A) in the treatment of allergic conjunctivitis.METHODS: Experimental allergic conjunctivitis(EAC)mice model induced by short ragweed pollen(SRW) in 4-week-old of BALB/c mice, mice were evaluated using haematoxylin and eosin(H&E) staining, immunofluor-escence and light microscope photographs. Early phase took the samples in 24 h after instillation and late phase took the samples between 4 to 14 d after the start of treatment. The study use of topical SEMA3A(10 U, 100 U,1000 U) eye drops and subconjunctival injection of SEMA3 A with same concentration. For comparison, five types of allergy eyedrops were quantified using clinical characteristics.· RESULTS: Clinical score of composite ocular symptoms of the mice treated with SEMA3 A were significantly decreased both in the immediate phase and the late phase compared to those treated with commercial ophthalmic formulations and non-treatment mice. SEMA3 A treatment attenuates infiltration of eosinophils entering into conjunctiva in EAC mice. The score of eosinophil infiltration in the conjunctiva of SEMA3 A 1000 U-treated group were significantly lower than low-concentration of SEMA3 A treated groups and non-treated group. SEMA3 A treatment also suppressed T-cell proliferation in vitro and decreased serum total Ig E levels in EAC mice. Moreover, treatment of SEMA3 A suppressed Th2-related cytokines(IL-5, IL-13 and IL-4)and pro-inflammatory cytokines(IFN-γ, IL-17 and TNF-α)release, but increased regulatory cytokine IL-10 concentration in the conjunctiva of EAC mice.CONCLUSION: SEMA3 A as a biological agent, showed the beneficial activity in ocular allergic processes with the less damage to the intraocular tissue. It is expected that SEMA3 A may be contributed in patients with a more severe spectrum of refractory ocular allergic diseases including allergic conjunctivitis in the near future.

The efficacy and safety of besifloxacin for acute bacterial conjunctivitis: a Meta-analysis

AIM: To evaluate the relative efficacy and safety of besifloxacin for treatment of acute bacterial conjunctivitis.METHODS: A comprehensive search in PubMed, EMBASE Web of Science, Cochrane Central Database and CNKI was undertaken for randomized controlled trials(RCTs) comparing besifloxacin with other treatments or placebo. The primary outcome measures were clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, and bacterial eradication rates of different kinds of pathogens. Safety outcomes were the number of adverse effects(AEs). The final search was performed on August 2018.RESULTS: Eight RCTs were included. Five studies compared the efficacy and safety of besifloxacin with placebo, 2 studies compared besifloxacin with moxifloxacin, and 1 study compared besifloxacin with gatifloxacin. A total of 3105 patients met the inclusion criteria. Besifloxacin presented higher efficacy and safety than did placebo in clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, bacterial eradication rates of different kinds of pathogens and the number of AEs. There was no significant difference between besifloxacin and moxifloxacin or gatifloxacin in the comparison items mentioned above.CONCLUSION: Besifloxacin is highly effective and safe for treatment of acute bacterial conjunctivitis. Further comparative trials regarding the effect of besifloxacin for treatment of acute bacterial conjunctivitis will aid in treatment decisions.

Ragweed pollen induces allergic conjunctivitis immune tolerance in mice via regulation of the NF-κB signal pathway

AIM:To investigate the feasibility and mechanism of immune tolerance in allergic conjunctivitis.METHODS:The allergic conjunctivitis immune tolerance mice model was established by ragweed pollen(RW)and the related cytokines were detected.The mice were divided into 9 groups and the maslinic acid(MA)or PBS were given for different group after modeling.The expression levels of chemokine ligand 5(CCL5)and P-65 in the conjunctival tissue were analyzed by immunohistochemistry,quantitative reverse transcription polymerase chain reaction(q RT-PCR)and Western blot.The percentage of interleukin-17(IL-17)and CD4+CD25+in the splenocyte supernatant was analyzed by flow cytometry.Fur thermore,the serum and splenocyte supernatant concentration of total-IgE,interleukin-10(IL-10),and IL-17 was analyzed by enzyme linked immune response(ELISA).RESULTS:After the model was established,symptoms of conjunctivitis were alleviated,the level of P-65,CCL5,IL-17,and total-IgE was raised,while the expression of IL-10,CD4+CD25+was decreased.This result fully demonstrated that a typical IL-17/regulatory-T-cells(Treg cells)imbalance and NF-κB activation.When the NF-κB signal pathway was suppressed,it showed that there was a further relief of conjunctivitis in mice.At the same time,the expression of total-IgE,IL-17,and CCL5 was decreased and the expression of anti-inflammatory factor(IL-10,CD4+CD25+)was increased.CONCLUSION:In the state of immune tolerance,symptoms of conjunctivitis in mice are alleviated,the Th-17 cells of allergic conjunctivitis mice are inhibited,and Treg cells activity is enhanced.

Expression levels of pro-inflammatory interleukin-8 and certain antimicrobial peptides in concurrent with bacterial conjunctivitis

AIM:To detect the quantitative expression levels of the pro-inflammatory interleukin-8(IL8),antimicrobial peptides human beta defense-2(HBD2),and human beta defense-3(HBD3)genes in bacterial conjunctivitis.METHODS:The human conjunctival epithelial cells were obtained using the impression cytology technique from healthy controls and patients.The genes expression levels were determined utilizing a reverse transcription quantitative polymerase chain reaction(RT-q PCR).The contribution of causative agent type,the number of isolates and severity of clinical features,in the increase of genes expression was also determined.RESULTS:The RT-q PCR showed that IL8,HBD2,and HBD3 expression increased in bacterial conjunctivitis as compared to healthy control(P<0.001).In gram-negative bacterial conjunctivitis,HBD2 was highly up-regulated(P<0.001)compared to other types of bacterial conjunctivitis.In mixed bacterial conjunctivitis,a direct correlation between HBD2 up-regulation and HBD3 up-regulation was observed(P<0.05).The severity of clinical features was related to the up-regulation of IL8 and HBD2(P<0.05).CONCLUSION:IL8,HBD2,and HBD3 are immuneeffectors in infectious conjunctivitis.HBD2 is active during different bacterial conjunctivitis but is more released with gram-negative bacteria compared to gram-positive bacteria.HBD3 is an obvious defender in different bacterial conjunctivitis.

Pediatric allergic conjunctivitis and allergic rhinitis

Objective： To assess the relationship between allergic conjunctivitis（AC） and allergic rhinitis（AR） in pediatric ophthalmology and E.N.T outpatient clinic. Methods：Eight hundred and ninety two patients were enrolled in survey during Mar. 2005-Jan. 2007, 407 allergic conjunctivitis cases were placed in the ophthalmology clinic group and 485 allergic rhinitis cases were from the E.N.T clinic. The comorbid disorders, histories, symptoms, signs of patients were recorded. Type 1 allergy was tested in 479 cases by a specific IgE antibody blood test. Eosinophils were detected in superficial conjunctival scrapings of the superior tarsal conjunctiva and mucosa surface scrapings of middle nasal meatus in 88 cases with both diseases. Results：302（74%）, 374（92%）, 116（29%） in 407 cases with allergic conjunctivitis had concomitant eczema, rhinitis and asthma, respectively; 334（69%）, 430（89%）, 145（30%） in 485 cases with allergic rhinitis had concomitant eczema, allergic conjunctivitis and asthma, respectively. The prevalence of allergic conjunctivitis concomitant allergic rhinitis and allergic rhinitis concomitant allergic conjunctivitis had no significant difference（x2=2,6, P 〉 0.05）. The prevalence of allergic conjunctivitis and allergic rhinitis concomitant eczema and asthma also had no significant difference （x2=3.08; x2=0.21, P 〉 0.05）. The degree of severity of two kinds of disease symptoms is not parallel, in the patients with seasonal allergic conjuctivitis（SAC） and perennial allergic conjunctivitis（PAC）, the clinical signs of AR were always severer（x2=258.2, P 〈 0.05） than those of AC. However, the results coincided with the cases with vernal keratoconjuctivitis（VKC）（x2=66.5, P 〈 0.05）; Eosinophils were revealed in 50（57%） conjunctival scrapings and nasal mucosa scrapings（x2=1.5, P〉 0.05）, 47（53%） cases had positive results in both scrapings. The main aeroallergens were house dust mites, house dust and fungi, and the main food-allergens were fish, crab and shrimp. Conclusion：The two disorders were shown to share more similarities than differences, as suggested that allergic conjunctivitis should be considered in future guidelines on preventing the development of rhinitis and asthma in children.

Treating with besifloxacin for acute bacterial conjunctivitis: a Meta-analysis

AIM: To evaluate the relative efficacy and safety of besifloxacin for treatment of acute bacterial conjunctivitis. METHODS: A comprehensive search in PubM ed, EMBASE Web of Science, Cochrane Central Database and CNKI was undertaken for randomized controlled trials(RCTs) comparing besifloxacin with other treatments or placebo. The primary outcome measures were clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, and bacterial eradication rates of different kinds of pathogens. Safety outcomes were the number of adverse effects(AEs). The final search was performed on August 2018. RESULTS: Six RCTs were included. Four studies compared the efficacy and safety of besifloxacin with placebo, 1 study compared besifloxacin with moxifloxacin, and 1 study compared besifloxacin with gatifloxacin. A total of 2780 patients met the inclusion criteria. Besifloxacin presented higher efficacy and safety than did placebo in clinical resolution, rates of bacterial eradication, individual clinical outcomes, cure rates, bacterial eradication rates of different kinds of pathogens and the number of AEs. There was no significant difference between besifloxacin and moxifloxacin or gatifloxacin in the comparison items mentioned above. CONCLUSION: Besifloxacin is highly effective and safe for treatment of acute bacterial conjunctivitis. Further comparative trials regarding the effect of besifloxacin for treatment of acute bacterial conjunctivitis will aid in treatment decisions.

Investigation of possible risk factors in the development of seasonal allergic conjunctivitis

AIM： To analyze the possible risk factors in the development of seasonal allergic conjunctivitis（SAC） through an evaluation of skin allergy tests and data obtained from questionnaires.METHODS： The study included a total of 75 SAC patients and 71 control subjects without SAC diagnosis who were admitted to the Abant Izzet Baysal University Medical Faculty Ophthalmology Clinic between March 2016 and December 2016. Skin prick tests were performed for all participants. Serum levels of total IgE and 25-OH vitamin D were also measured. In the tear, total IgE levels were measured. Moreover, possible risk factors for the onset of SAC（smoking, paracetamol exposure, vitamin D supplementation and environmental factors etc.） were examined for all patients by both prenatal and postnatal aspects.RESULTS： The patients with SAC were found to have a history of maternal paracetamol exposure during the prenatal period. Likewise, in the same patient group, the duration of postnatal vitamin D supplementation was shorter（P〈0.001）. However, no significant correlation was found between SAC and maternal antibiotic exposure, maternal smoking, the mode of delivery and birth weight, as well as presence of pets. Moreover, patients with SAC were more likely to have asthma, allergic rhinitis and oral allergy syndrome. We have also found that SAC patients＇ mothers and siblings were more likely to have allergic conjunctivitis. Likewise, their fathers were more likely to have allergic rhinitis. CONCLUSION： Prenatal maternal paracetamol exposure and shorter duration of vitamin D supplementation in the postnatal period may play a role in development of SAC. Therefore prevention of unnecessary gestational paracetamol intake and vitamin D supplementation during infancy could potentially reduce the onset and development of SAC.

CLINICAL REPORT ON 142 CASES (278 EYES) OF AFRICAN EPIDEMIC HEMORRHAGIC CONJUNCTIVITIS TREATED WITH ACUPUNCTURE

This paper introduces the curative effects on 142 cases (278 eyes) of African epi-demic hemorrhagic conjunctivitis treated by acupuncture, and 128 (90. 1%) cases (250 eyes) of allpatients have been improved. Three groups were clinically observed in the present report. There were55 cases (104 eyes) in the first group for body acupuncture, of which 46 (83. 6%) cases were effec-tively treated; In the second group for auricular acupuncture, 34 (91. 6% ) cases (68 eyes) out of 37cases (74 eyes) were improved; There were 50 cases (100 eyes) in the third group for boyauricular-acupuncture, among which 48 (96. 0%) cases (96 eyes) were improved. The curative effects of thethird group were better than those of the other two groups.

Neuronal FceRI mediates acute and chronic conjunctivitis itch

Although ocular itch in allergic conjunctivitis(ACJ)is conventionally thought to result from proinflammation mediators,especially released by mast cells,the unsatisfying effect of anti-histamine strategy indicates that ocular itch and conjunctival inflammation are at least partially uncoupled.Here we showed that FceRI,an immune receptor for IgE immune complex(IgE-IC),was expressed in a subpopulation of conjunctivitis sensory neurons and IgG-IC directly activated these neurons to evoke acute ocular itch without obvious concurrent inflammation and mast cells activation for naive mice.These effects were diminished in both global and MrgprA3+neuron-specific Fcer1-knockout mice,but not in mast cell deficient mice.

Coagulase-negative Staphylococci in Conjunctivitis and Blepharitis

Coagulase-negative staphylococcus(C-NS)are regarded as normal flora of the lids and conjunctiva.The ability of these organisms to cause conjunctivitis and blepharitis can be overlooked or disregarded.To elucidate the role of individual C-NS species in these eye diseases we compared Staphylococcus sp.isolated from the conjunctiva and lids of 50 healthy volunteers with 248 strains of Staphylococcus isolated from patients with staphylococcal conjunctivitis or blepharitis.S.epidermidis was the most frequent species isolated from the conjunctiva and lids of both groups.S.aureus was isolated only from infected patients.No individual C-NS species was found to be significantly associated with eye disease,but the colony count of C-NS after isolation was a useful indicator of conjunctivitis and blepharitis.The ability of Staphylococcus to ferment mannitol or mannose was associated with isolates only from infected patients.

Can omalizumab be used effectively to treat severe conjunctivitis in children with asthma?A case example and review of the literature

A 14-year-old girl with poorly controlled asthma attended the difficult-to-treat asthma clinic for review.Although she has eosinophilia and significantly raised immunoglobulin E levels,she is not currently a candidate for omalizumab(Xolair).She also suffers from chronic urticaria,eosinophilic eosophagitis and severe conjunctivitis.You wonder if omalizumab would be effective in treating her multiple atopic conditions,in particular her troublesome conjunctivitis.PubMed was searched using the following search terms:(Omalizumab)or(Xolair)and(conjunctivitis).Searches were conducted in November 2020.Abstracts were selected for full text review if the study population identified asthma as a comorbidity.Non-paediatric studies and those that were not written in English were excluded.The use of omalizumab has the potential to be effective in the treatment of conjunctivitis associated with asthma and other atopic conditions.However,research is needed to address the question,in the form of multicenter,double-blind randomized control trials.

Effects of olopatadine combined with pranoprofen eye drops on serum immunoglobulin, HA and ECP in patients with allergic conjunctivitis

Objective: To observe the clinical application of olopatadine eye drops alone or combination with pranoprofen eye drops in the treatment of allergic conjunctivitis (AC). The levels of serum immunoglobulin, histamine (HA) and eosinophil cationic protein (ECP) were analyzed. Methods: A total of 90 AC patients were randomly divided into control group (n=45) and observation group (n=45) according to the lottery method. The control group was treated with olopatadine hydrochloride eye drops. On the basis of the control group, the observation group was treated with pranoprofen eye drops. The levels of serum immunoglobulin, HA and ECP were measured in all subjects. Results: There was no significant difference in serum immunoglobulin level between the observation group and the control group before treatment. After treatment, the levels of serum IgG, IgA and IgE in the observation group and the control group were significantly lower than those before treatment. And the observation group was significantly lower than the control group after treatment. There were no significant differences in serum HA and ECP levels between the observation group and the control group before treatment. After treatment, the levels of serum HA and ECP in the observation group and the control group were significantly lower than those before treatment. And the observation group was significantly lower than the control group after treatment. Conclusion: Compared with olopatadine eye drops, olopatadine eye drops combined with pranoprofen eye drops in the treatment of AC patients, can effectively reduce the serum immunoglobulin, HA and ECP levels, which may be the clinical treatment of AC patients Of the effective reference program.

Effect of olopatadine on the serum and tear related indicators in patients with allergic conjunctivitis

Objective: To explore the efficacy of olopatadine in the treatment of allergic conjunctivitis and the changes of ECP and IgE levels in the serum and tear before and after treatment. Methods:A total of 94 patients with allergic conjunctivitis were included in the study and randomized into the treatment group and the control group with 47 cases in each group. The patients in the control group were given sodium cromoglycate eye drops, while the patients in the treatment group were given olopatadine eye drops. After 2-week treatment, the clinical efficacy in the two groups was evaluated. The improvement of symptoms before and after treatment in the two groups was recorded and compared. The levels of serm and tear related indicators in the two groups were detected and compared. Results: When compared with before treatment, HA, ECP, and IgE levels in the serum and tear 1 and 2 weeks after treatment in the two groups were significantly reduced, and the reduced degree in the treatment group was significantly superior to that in the control group. Conclusions: Olopatadine in the treatment of allergic conjunctivitis can effectively reduce the serum and tear ECP and IgE levels, and rapidly alleviate the clinical symptoms of affected eye, with the clinical efficacy significantly superior to that by sodium cromoglycate eye drops.

Corneal biomechanical changes in allergic conjunctivitis

Background:To explore corneal biomechanical changes,identify related factors and determine early indicators of keratoconus(KC)development risk in allergic conjunctivitis(AC)patients.Methods:A total of 50 patients,including 20 eyes without AC and 30 eyes with AC were enrolled in this study.All patients underwent a complete ocular examination,including evaluations of clinical manifestations of AC,corneal tomography and densitometry by Pentacam,corneal biomechanics by Corvis ST,and corneal and epithelial thickness mapping by RTvue optical coherence tomography(OCT).Results:The index of surface variance(ISV),index of vertical asymmetry(IVA),keratoconus index(KI),index of height decentration(IHD)and Belin/Ambrosio enhanced ectasia total deviation index(BAD-D)were significantly higher in the AC group than in the non-allergic conjunctivitis(NAC)group(P<0.05).The tomography and biomechanical index(TBl)was also significantly higher in the AC group(P=0.04).The average epithelial thickness in the 2-7 mm annulus was significantly thinner in the AC group than in the NAC group(P<0.05).The average densitometry of the total cornea and the anterior layer were higher in the AC group than in the NAC group(P<0.001).The ISV,IVA,KI,IHD and BAD-D were significantly correlated with the TBI and changes in corneal epithelial thickness in AC patients(P<0.05).The changes in epithelial thickness were closely related to the eye rubbing frequency and allergic sign scores(P<0.05).Conclusions:AC patients should be advised to routinely undergo corneal tomographic and biomechanical measurements,and the TBl could be used as an indicator of KC development risk in AC patients.Trial registration:Corneal Biomechanical Changes of Allergic Conjunctivitis,NCT04299399.Registered March 3,2020-Retrospectively registered.