scholarly journals Alteration of corneal biomechanical properties in patients with dry eye disease

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254442
Author(s):  
Vannarut Satitpitakul ◽  
Parichart Taweekitikul ◽  
Vilavun Puangsricharern ◽  
Ngamjit Kasetsuwan ◽  
Usanee Reinprayoon ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Dry Eye ◽  
Linear Regression Analysis ◽  
Corneal Thickness ◽  
Schirmer Test ◽  
Corvis St ◽  
Tear Production ◽  
Biomechanical Parameters ◽  
Corneal Staining ◽  
Symptoms And Signs

Purpose To evaluate the association between symptoms and signs of dry eye diseases (DED) with corneal biomechanical parameters. Methods This cross-sectional study enrolled 81 participants without history of ocular hypertension, glaucoma, keratoconus, corneal edema, contact lens use, diabetes, and ocular surgery. All participants were evaluated for symptoms and signs of DED using OSDI questionnaire, tear film break-up time (TBUT), conjunctival and corneal staining (NEI grading) and Schirmer test. Corneal biomechanical parameters were obtained using Corvis ST. Mixed-effects linear regression analysis was used to determine the association between symptoms and signs of DED with corneal biomechanical parameters. Difference in corneal biomechanical parameter between participants with low (Schirmer value ≤10 mm; LT group) and normal (Schirmer value >10mm; NT group) tear production was analyzed using ANCOVA test. Results The median OSDI scores, TBUT, conjunctival and corneal staining scores as well as Schirmer test were 13±16.5 (range; 0–77), 5.3±4.2 seconds (range; 1.3–11), 0±1 (range; 0–4), 0±2 (ranges; 0–9) and 16±14 mm (range; 0–45) respectively. Regression analysis adjusted with participants’ refraction, intraocular pressure, and central corneal thickness showed that OSDI had a negative association with highest concavity radius (P = 0.02). The association between DED signs and corneal biomechanical parameters were found between conjunctival staining scores with second applanation velocity (A2V, P = 0.04), corneal staining scores with second applanation length (A2L, P = 0.01), Schirmer test with first applanation time (A1T, P = 0.04) and first applanation velocity (P = 0.01). In subgroup analysis, there was no difference in corneal biomechanical parameters between participants with low and normal tear production (P>0.05). The associations were found between OSDI with time to highest concavity (P<0.01) and highest displacement of corneal apex (HC-DA, P = 0.04), conjunctival staining scores with A2L (P = 0.01) and A2V (P<0.01) in LT group, and Schirmer test with A1T (P = 0.02) and HC-DA (P = 0.03), corneal staining scores with A2L (P<0.01) in NT group. Conclusions According to in vivo observation with Corvis ST, patients with DED showed more compliant corneas. The increase in dry eye severity was associated with the worsening of corneal biomechanics in both patients with low and normal tear production.

scholarly journals Dry eye disease among Glaucoma patients on topical hypotensive medications, in a tertiary hospital, Ethiopia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Miraf Sahlu ◽  
Abeba T. Giorgis
Keyword(s):  
Dry Eye ◽  
Ocular Surface ◽  
Signs And Symptoms ◽  
Dry Eye Disease ◽  
Eye Disease ◽  
Eye Drops ◽  
Schirmer Test ◽  
Ocular Surface Disease Index ◽  
Cross Sectional ◽  
Corneal Staining

Abstract Background Dry eye disease is a multifactorial disease; causing various ocular symptoms with potential damage to the ocular surface. Applying hypotensive eye drops are presumed to initiate or exacerbate existing dry eye disease. The purpose of this study was to determine the frequency of signs and symptoms and severity of dry eye disease among glaucoma patients on topical hypotensive medications and controls. Methods A cross-sectional comparative study, involving 320 glaucoma patients and controls. Ocular Surface Disease Index (OSDI) symptoms score and Schirmer, tear breakup time and corneal staining tests were used to assess dry eye disease. Data was analyzed using SPSS version 24 software; p-value less than 0.05 was considered as statistically significant. Results Among the 160 study glaucoma patients, the mean duration of topical hypotensive medication use was 5.2 ± 5.21 years (range, 4 months - 32 years). Mild to severe level of OSDI score was found in 122 (76%) glaucoma patients and in 137 (86%) controls (p = 0.033). Mild to sever abnormal clinical tests in the glaucoma patients and control, respectively, were 106 (66%) vs 80 (50%) corneal staining (p = 0.045), 79 (49%) vs 72 (45%) TBUT (p = 0.021), and 91 (57%) vs 83 (52%) Schirmer test (p = 0.242). Test results at the level of sever: 2 (1%) vs 0 (0%) corneal staining, 50 (31%) vs 39 (24%) TBUT and 65 (41%) vs 60 (38%) Schirmer test in the glaucoma patents and controls, respectively. Corneal staining and TBUT had correlation with the number of drugs (p = 0.004 and 0.031, respectively), and more relationship of the two tests with total number of drops applied per day (p = 0.01 and p <  0.001, respectively). Patients on pilocarpine and timolol had more corneal staining and lower TBUT [(p = 0.011 and p <  0.001) and (p = 0.04 and 0.012), respectively]. Conclusions The study has identified glaucoma patients to be more affected by dry eye disease than non-glaucoma patients, and presence of significantly lower TBUT and higher corneal staining in the glaucoma patients on multidrops and multidose per day. We recommend consideration of evaluation and management of DED for glaucoma patients on multidrops and multidose hypotensive medications.

scholarly journals Corneal Biomechanical Properties in Varying Severities of Myopia

2021 ◽  
Vol 8 ◽  
Author(s):  
Mohammad-Reza Sedaghat ◽  
Hamed Momeni-Moghaddam ◽  
Abbas Azimi ◽  
Zohreh Fakhimi ◽  
Mohammed Ziaei ◽  
...  
Keyword(s):  
Axial Length ◽  
Corneal Thickness ◽  
Biomechanical Properties ◽  
Cross Sectional Study ◽  
Geometrical Parameters ◽  
Cross Sectional ◽  
Corvis St ◽  
Multiple Parameters ◽  
Inverse Radius ◽  
Biomechanical Parameters

Purpose: To investigate corneal biomechanical response parameters in varying degrees of myopia and their correlation with corneal geometrical parameters and axial length.Methods: In this prospective cross-sectional study, 172 eyes of 172 subjects, the severity degree of myopia was categorized into mild, moderate, severe, and extreme myopia. Cycloplegic refraction, corneal tomography using Pentacam HR, corneal biomechanical assessment using Corvis ST and Ocular Response Analyser (ORA), and ocular biometry using IOLMaster 700 were performed for all subjects. A general linear model was used to compare biomechanical parameters in various degrees of myopia, while central corneal thickness (CCT) and biomechanically corrected intraocular pressure (bIOP) were considered as covariates. Multiple linear regression was used to investigate the relationship between corneal biomechanical parameters with spherical equivalent (SE), axial length (AXL), bIOP, mean keratometry (Mean KR), and CCT.Results: Corneal biomechanical parameters assessed by Corvis ST that showed significant differences among the groups were second applanation length (AL2, p = 0.035), highest concavity radius (HCR, p &lt; 0.001), deformation amplitude (DA, p &lt; 0.001), peak distance (PD, p = 0.022), integrated inverse radius (IR, p &lt; 0.001) and DA ratio (DAR, p = 0.004), while there were no significant differences in the means of pressure-derived parameters of ORA between groups. Multiple regression analysis showed all parameters of Corvis ST have significant relationships with level of myopia (SE, AXL, Mean KR), except AL1 and AL2. Significant biomechanical parameters showed progressive reduction in corneal stiffness with increasing myopia (either with greater negative SE or greater AXL), independent of IOP and CCT. Also, corneal hysteresis (CH) or ability to dissipate energy from the ORA decreased with increasing level of myopia.Conclusions: Dynamic corneal response assessed by Corvis ST shows evidence of biomechanical changes consistent with decreasing stiffness with increasing levels of myopia in multiple parameters. The strongest correlations were with highest concavity parameters where the sclera influence is maximal.

Relationship between novel intraocular pressure measurement from Corvis ST and central corneal thickness and corneal hysteresis

2019 ◽  
Vol 104 (4) ◽  
pp. 563-568 ◽  
Author(s):  
Masato Matsuura ◽  
Hiroshi Murata ◽  
Yuri Fujino ◽  
Mieko Yanagisawa ◽  
Yoshitaka Nakao ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Central Corneal Thickness ◽  
Linear Regression Analysis ◽  
Corneal Thickness ◽  
Biomechanical Properties ◽  
Applanation Tonometry ◽  
Corneal Hysteresis ◽  
Corneal Resistance Factor ◽  
Corvis St ◽  
The Relationship

AimsCorvis ST (CST) yields biomechanical corrected IOP (bIOP) which is purported to be less dependent on biomechanical properties. In our accompanied paper, it was suggested that the repeatability of bIOP is high. The purpose of the current study was to assess the relationship between intraocular pressure (IOP) measured with CST and central corneal thickness (CCT) and corneal hysteresis (CH), in comparison with IOP measured with Goldmann applanation tonometry (GAT) and the ocular response analyzer (ORA).MethodsA total of 141 eyes from 141 subjects (35 healthy eyes and 106 glaucomatous eyes) underwent IOP measurements with GAT, CST and ORA. The relationships between IOP measurements (ORA-IOPg, ORA-IOPcc, CST-bIOP and GAT IOP) and biomechanical properties (CCT, CH and corneal resistance factor (CRF)) were analysed using the linear regression analysis.ResultsIOPg, IOPcc and GAT IOP were significantly associated with CCT (p<0.001), whereas bIOP was not significantly associated with CCT (p=0.19). IOPg, bIOP and GAT IOP were significantly associated with CH (IOPg: p<0.001; bIOP: p<0.001; GAT IOP: p=0.0054), whereas IOPcc was not significantly associated with CH (p=0.18). All of IOP records were associated with CRF (p<0.001).ConclusionThe bIOP measurement from CST is independent from CCT, but dependent on CH and CRF.

scholarly journals Corneal Biomechanical Assessment Using Corneal Visualization Scheimpflug Technology in Keratoconic and Normal Eyes

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lei Tian ◽  
Yi-Fei Huang ◽  
Li-Qiang Wang ◽  
Hua Bai ◽  
Qun Wang ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Corneal Thickness ◽  
Area Under The Curve ◽  
Biomechanical Properties ◽  
Corvis St ◽  
Biomechanical Assessment ◽  
Deformation Amplitude ◽  
Biomechanical Parameters ◽  
And Control ◽  
Corneal Biomechanical Properties

Purpose. To compare the corneal biomechanical properties of keratoconic patients and age-matched controls using corneal visualization Scheimpflug technology (Corvis ST).Methods. Sixty keratoconic eyes from 47 keratoconus patients and 60 normal eyes from 60 controls were enrolled in this prospective study. Tomography and biomechanical parameters of all eyes were obtained with the Pentacam and Corvis ST, respectively. Intraocular pressure was measured using a Goldmann applanation tonometer.Results.The tomography and biomechanical parameters of the keratoconic corneas were significantly different from those of the normal corneas except for the anterior chamber angle, first applanation length, the highest concavity time, and peak distance. The deformation amplitude was the best predictive parameter (area under the curve: 0.882), with a sensitivity of 81.7%, although there was a significant overlap between keratoconic and normal corneas that ranged from 1.0 to 1.4 mm. In both the keratoconus and control groups, the deformation amplitude was negatively correlated with intraocular pressure, central corneal thickness, and corneal volume at 3 and 5 mm.Conclusions. Corvis ST offers an alternative method for measuring corneal biomechanical properties. The possibility of classifying keratoconus based on deformation amplitude deserves clinical attention.

scholarly journals Effects of menopause on corneal topography and dry eye

2017 ◽  
Vol 6 (2) ◽  
pp. 461
Author(s):  
Fethiye Gulden Turgut ◽  
Abdulkadir Turgut ◽  
Zehra Nihal Dolgun ◽  
Nadiye Köroğlu
Keyword(s):  
Postmenopausal Women ◽  
Dry Eye ◽  
Test Scores ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Schirmer Test ◽  
Positive Correlation ◽  
Eye Symptoms ◽  
Estradiol Levels ◽  
Dry Eye Symptoms

Background: The aim of this study was to investigate the effect of estrogen and progesterone on central corneal thickness, corneal curvature, and the development of dry eye in postmenopausal women.Methods: This is a case-control study including 54 premenopausal and 54 postmenopausal women. The two groups were compared in terms of follicle stimulating hormone, estradiol, progesterone, and horizontal and vertical curvatures, astigmatism, central corneal thickness, Schirmer I test scores, and dry eye scores of both eyes.Results: In the postmenopausal women, central corneal thickness was significantly thinner in both eyes (p=0.017) and the Schirmer test scores were significantly lower both for the right (p=0.001) and the left eye (p=0.003). Estradiol levels were positively correlated with central corneal thickness (p=0.003-0.006) and Schirmer test scores (p=0.004-0.002) whereas progesterone levels showed a positive correlation only with Schirmer test scores (p=0.036-0.044). Although a significant positive correlation was found between estradiol levels and dry eye scores (p=0,009), no significant correlation was found between progesterone levels and dry eye scores (p=0,118).Conclusions: Age-related hormonal abnormalities lead to central corneal thinning, increased dry eye symptoms, and decreased tear flow, particularly in the postmenopausal term. Decreased estrogen levels are associated with central corneal thickness and dry-eye symptoms, decreased estrogen and progesterone levels correlates well with diminished tear production but progesterone levels does not effect dry-eye symptoms.

scholarly journals Leptin’s concentration in tears and dry eye: a clinical observational study

2021 ◽  
Vol 14 (1) ◽  
pp. 83-88
Author(s):  
Ran Hao ◽  
◽  
Xue-Min Li ◽  
Keyword(s):  
Dry Eye ◽  
Linear Regression Analysis ◽  
Multivariate Linear Regression Analysis ◽  
Ocular Surface Disease Index ◽  
Fluorescein Staining ◽  
Significant Difference ◽  
Eye Symptoms ◽  
Tear Meniscus Height ◽  
Symptoms And Signs ◽  
Dry Eye Symptoms

AIM: To investigate the concentration of leptin in tears and its correlation with dry eye symptoms and signs. METHODS: The study enrolled individuals (n=39) responding to an advertising or dry eye patients (n=58) from the Ophthalmology Department. Tear samples were collected for leptin concentration measuring. Ocular Surface Disease Index (OSDI), tear meniscus height (TMH), tear break up time (TBUT), cornea fluorescein staining, Schirmer test (ST) and impression cytology (IC) were assessed. Leptin concentration in tears of dry eye patients and healthy controls, and its correlation with clinical features of dry eye disease (DED) were analyzed. RESULTS: Age, body mass index (BMI), OSDI scores and cornea fluorescein staining scores showed a negative correlation with leptin concentration in tears (r=-0.340, P=0.001; r=-0.332, P=0.001; r=-0.258, P=0.011; r=-0.424, P<0.001, respectively). ST showed positive correlation with leptin concentration in tears (r=0.206, P=0.045). No significant difference was observed in leptin concentration between dry eye patients and controls (P=0.682). Multivariate linear regression analysis revealed that dry eye, OSDI, corneal fluorescein staining scores and ST correlated with leptin concentration in tears. CONCLUSION: This is the first study measuring leptin concentration in tears. The correlation between leptin concentration and DED symptoms and signs reveal that leptin level correlated with the dry eye, potentially contributing to repair of ocular damage and dry eye improvement.

scholarly journals Preoperative Anatomy Parameters in Implantable Collamer Lenses

2021 ◽  
Author(s):  
Yanzhen Xue ◽  
Yonghong Guo ◽  
Ruibo Zhao
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Anterior Chamber ◽  
Linear Regression Analysis ◽  
Corneal Thickness ◽  
Intraclass Correlation ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Case Series ◽  
Significant Difference

Abstract Purpose: To determine patient preoperative anatomical features and the parameters of implantable collamer lenses (ICLs) relevant in explaining vault variability.Setting: Ophthalmology Xi’an Aier Gucheng Eye hospital , Xi’an China.Design: Retrospective case series.Methods:This study comprised 88 eyes of 45 patients implanted with myopic or toric ICLs between May 2021 and August 2021.Pentacam imaging was used for assessing white-to-white (WTW) diameter, central keratometry, anterior chamber depth(ACD), central corneal thickness and vault. Anterior-segment optical coherence tomography（AS-OCT） was used to measure the horizontal anterior chamber angle distance (ATA). Ultrasound biomicroscopy (UBM) was used to measure horizontal and vertical sulcus to sulcus(vSTS). According to different ACD,we divide ACD into shallow group(2.8 to 3.2 mm),medium group(3.2 to 3.5 mm),and deep group(＞3.5mm).Results: Linear regression analysis found significant correlation between WTW diameters and ATA diameters( y= 0.9605x+0.1491,R² = 0.9148),with a coefficient of determinant of 0.9148 (P＜0.01). Linear regression analysis found significant correlation between hSTS and vSTS（y=0.9855x-0.0178,R²=0.1979）,with a coefficient of determinant of 0.1979 (P＜0.01). WTW diameters showed statistically significant difference in shallow and medium ACD (t=-3.28,P＜0.01 ), significant difference in shallow and deep ACD (t=-4.69,P＜0.01 ),there was no correlation in medium and deep ACD(t=-1.41,P＞0.05 ). There was a statistically significant correlation between WTW diameters and hSTS diameters when the ACD was less than 3.5 mm (t=-0.451, P=0.000) (t=1.406, P=0.026),but weak correlation when the ACD was bigger than 3.5 mm(t=1.594, P=0.051). ATA and WTW with a mean difference close to zero(-0.66 mm). Despite the relatively high correlation (intraclass correlation co-efficient =0.689), the range of agreement is quite broad (1.33 mm).Conclusions:ATA measured with AS-OCT can not be used interchangeably with WTW obtained with Pentacam. WTW diameters and hSTS diameters have a statistically significant correlation when the ACD was less than 3.5 mm. WTW, ATA, hSTS and vSTS all should be considered during design the size of lens and regulating the vault after surgery.

scholarly journals Corneal Parameters in Healthy Subjects Assessed by Corvis ST

2020 ◽  
Author(s):  
Ramin Salouti ◽  
Mansoureh Bagheri ◽  
Anis Shamsi ◽  
Mohammad Zamani ◽  
Maryam Ghoreyshi ◽  
...  
Keyword(s):  
Linear Regression Analysis ◽  
Corneal Thickness ◽  
Case Series ◽  
Biomechanical Properties ◽  
Radius Of Curvature ◽  
Corvis St ◽  
Deformation Amplitude ◽  
Study Results ◽  
The Mean ◽  
The Right

Purpose: To evaluate corneal biomechanics using Corvis ST in healthy eyes from Iranian keratorefractive surgery candidates. Methods: In this prospective consecutive observational case series, the intraocular pressure (IOP), central corneal thickness (CCT), and biomechanical properties of 1,304 eyes from 652 patients were evaluated using Corvis ST. Keratometric readings and manifest refraction were also recorded. Results: The mean (±SD) age of participants was 28 ± 5 years, and 31.7% were male. The mean spherical equivalent refraction was –3.50 ± 1.57 diopters (D), the mean IOP was 16.8 ± 2.9 mmHg, and the mean CCT was 531 ± 31 μm for the right eye. The respective means (±SD) corneal biomechanical parameters of the right eye were as follows: first applanation time: 7.36 ± 0.39 milliseconds (ms); first applanation length: 1.82 ± 0.22 mm; velocity in: 0.12 ± 0.04 m/s; second applanation time: 20.13 ± 0.48 ms; second applanation length: 1.34 ± 0.55 mm; velocity out: –0.67 ± 0.17 m/s; total time: 16.84 ± 0.64 ms; deformation amplitude: 1.05 ± 0.10 mm; peak distance: 4.60 ± 1.01 mm; and concave radius of curvature: 7.35 ± 1.39 mm. In the linear regression analysis, IOP exhibited a statistically significant association with the first and second applanation times, total time, velocity in, peak distance, deformation amplitude, and concave radius of curvature. Conclusion: Our study results can be used as a reference for the interpretation of Corvis ST parameters in healthy refractive surgery candidates in the Iranian population. Our results confirmed that IOP is a major determinant of Corvis parameters.

scholarly journals Evaluating the Functionality of Conjunctiva Using a Rabbit Dry Eye Model

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yuan Ning ◽  
Dhruva Bhattacharya ◽  
Richard E. Jones ◽  
Fangkun Zhao ◽  
Rongji Chen ◽  
...  
Keyword(s):  
Dry Eye ◽  
Nictitating Membrane ◽  
Impression Cytology ◽  
Schirmer Test ◽  
Eye Model ◽  
Tear Production ◽  
Harderian Glands ◽  
New Zealand White Rabbits ◽  
Necrosis Factor ◽  
Epithelial Sodium Channel Enac

Purpose.To assess the conjunctival functionality in a rabbit dry eye (DE) model.Methods.Nictitating membrane, lacrimal and Harderian glands were surgically excised from male New Zealand white rabbits using minimally invasive surgery. Fluorescein/rose Bengal staining of ocular surface (OS) and Schirmer test were done before (BE) and after excision (AE). The expression of interleukin- (IL-) 1β, tumor necrosis factor- (TNF-)α, and MUC5AC proteins were estimated by immunoblotting from conjunctival impression cytology specimens. MUC5AC mRNA was quantified as well. The effect of epithelial sodium channel (ENaC) blockers on tear production and potential differences (PD) of OS were assessed under anesthesia in rabbits with and without surgery.Results.Increase in corneal and conjunctival staining was observed 1 month AE compared to BE. Schirmer tests failed to show decrease in tear production. Elevated IL-1β, and TNF-α, 1 month AE indicated inflammation. MUC5AC expression was elevated 1 month AE. ENaC blockers did not improve tear production in rabbit eyes AE but characteristic changes in PD were observed in rabbits with surgery.Conclusions.DE biomarkers are important tools for OS assessment and MUC5AC expression is elevated in rabbit DE. PD measurement revealed significant electrophysiological changes in rabbits with surgery.

scholarly journals Comparison between two cyclooxygenase inhibitors in an experimental dry eye model in albino rabbits

2008 ◽  
Vol 58 (2) ◽  
pp. 163-173 ◽  
Author(s):  
Amany EL-Shazly ◽  
Amal EL-Gohary ◽  
Laila EL-Shazly ◽  
Ghada EL-Hossary
Keyword(s):  
Dry Eye ◽  
Cyclooxygenase Inhibitors ◽  
Eye Drops ◽  
Atropine Sulphate ◽  
Schirmer Test ◽  
Eye Model ◽  
Cox Inhibitor ◽  
Systemic Side Effects ◽  
Cox 2 ◽  
Corneal Staining

Comparison between two cyclooxygenase inhibitors in an experimental dry eye model in albino rabbitsThe purpose of this study was to compare the topical anti-inflammatory effects of the nonselective cyclooxygenase (COX) inhibitor, ketorolac, with the selective COX-2 inhibitor, nimesulide, in an animal model of dry eye in albino rabbits. All animals were examined by the Schirmer test, tear break-up time (TBUT) and fluorescein corneal staining test. Dry eye model showed significant reduction in tear volume, TBUT, corneal staining and histopathological signs of dryness and inflammation. On treating dry eye model with nimesulide 0.1% eye drops and ketorolac 0.5% eye drops, there were improvements in Schirmer test values, TBUT and fluorescein corneal staining and histopathologically reduced inflammatory reaction, with signs of healing and regeneration. Both nimesulide and ketorolac ameliorate atropine sulphate induced dry eye in albino rabbits. The use of selective COX-2 inhibitor, nimesulide, is preferred to avoid local and systemic side effects which may occur with the use of the nonselective COX inhibitor, ketorolac.

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