Effect of Biomechanical Properties on Myopia: a Study of New Corneal Biomechanical Parameters

doi:10.21203/rs.3.rs-25623/v3

Download PDF

Research article

Effect of Biomechanical Properties on Myopia: a Study of New Corneal Biomechanical Parameters

https://doi.org/10.21203/rs.3.rs-25623/v3

This work is licensed under a CC BY 4.0 License

Journal Publication

published 19 Nov, 2020

Read the published version in BMC Ophthalmology →

You are reading this latest preprint version

Background: To investigate assess the corneal stress-strain index (SSI), which is a marker for material stiffness and corneal biomechanical parameters , in myopic eyes.

Methods: A total of 105 4 6 myopic patients were included in this study. Corneal v isuali s ation Scheimpflug t echnology Corvis ST was used to measure the SSI. Corneal biomechanics w ere as evaluated assessed using the first and second applanation time s (A1- time and A2-time s ), maximum deflection amplitude (DefAmax), deflection area (HCDefArea) , and peak distance at highest concavity peak distance (HC-PD), HC-time, HC-DefA, and HC-PD), integrated radius (IR) , whole eye movement (WEM), stiffness parameter (SP), biomechanically corrected intraocular pressure (BIOP) , and Corvis b iomechanical i ndex (CBI). Scheimpflug tomography was used to obtain the mean keratometery (Km) and central corneal thickness (CCT). All participants were divided into two groups according to the spherical equivalent (SE) (low myopia: SE ≤ 3.00D and high myopia: SE ≥ 6.00D).

Results: The mean SSI value was 0.854±0.004. The SSI ha d a positive correlation with A1-time ((r=0.272), HC-time (r=0.218), WEM (r=0.288), SP (r=0.316) , CBI (r=0.199 ) , CCT (r=0.125), BIOP (r=0.230) , and SE (r=0.313) (all p - values＜0.01) . The SSI had a negative correlation with HCDefA (r=-0.721), HCDefArea (r=-0.665), HC-PD(r=-0.597), IR (r=-0.555), DefAmax (r=-0.564) , and Km (r=-0.103) (all p - values＜0.01). There were significant differences in SSI (t=8.960, p＜0.01) and IR (t=-3.509, p＜0.01) between the low and high myopia groups group and high myopia group .

Conclusions: In different grades of myopia, the SSI values were lower in eyes with higher SE spherical equivalent s . It indicates that the mechanical strength of the cornea may be compromise d in high myopia. The SSI was positively correlated with the spherical equivalent , and it It may provide a new way to study the mechanism of myopia.

Ophthalmology

Corneal stress-strain index

Myopia

Corneal biomechanics

Quantification of corneal biomechanics has helped us to understand the changes in corneal shape and structure after refractive surgery[1, 2].The corneal stiffness is a recently described index with clinical significance for the detection in patients who are at risk of ectasia development [3, 4]. Previous studies have shown that the biomechanical properties of the cornea are correlated with many factors such as central corneal thickness (CCT) and intraocular pressure (IOP) [5, 6]. By using finite element models of wide ranges of geometries of human eyeballs affected by different levels of intraocular pressure, Eliasy et al.[7] studied clinical data obtained from two large datasets of healthy participants. According to their algorithm, the study produced a material stiffness parameter-stress-strain index (SSI)as a new parameter does not show significant correlation with CCT and IOP.

However, the distribution characteristics and influencing factors of SSI in myopic patients have not been reported. In this study, we aimed to determine the normative values in myopic patients and the effect of SSI on myopia and to assess its possible correlation with other corneal biomechanical parameters.

2.1 Subjects

This was a retrospective clinical study of 1054 myopic participants (464 women and 590 men) who were scheduled to undergo corneal refractive surgery at Tianjin Eye Hospital, Tianjin Medical University between March 2019 and November 2019. Data from a single representative eye per participant (right eye) were used for the analysis.

According to the spherical equivalent (SE; low myopia: SE ≥ -3.00 D and high myopia: SE ≤ -6.00 D), suitable patients were divided into two groups. The study protocol followed the tenets of the Declaration of Helsinki and was approved by the ethics committee of Tianjin Eye Hospital. Written informed consent was obtained from all participants before enrolment. Inclusion criteria included: stable refraction for at least 2 years and the absence of ocular inflammation. Patients were asked to refrain from using soft contact lenses for at least 2 weeks and rigid contact lenses for at least 4 weeks. Exclusion criteria included: history of ophthalmic surgery, ocular trauma, keratoconus, glaucoma, diabetes, systemic connective tissue disease and abnormal immune function.

2.2 Methods

All the participants underwent comprehensive eye examinations, including uncorrected visual acuity and best corrected visual acuity measurements, subjective refraction, non-contact tonometry, and slit lamp examinations. Corneal thicknesses and mean curvatures were obtained using Scheimpflug imaging (Pentacam, Oculus, Germany). Corneal biomechanical parameters were obtained using the corneal visualisation Scheimpflug technology (Corvis ST) analyser (Oculus, Germany).

2.3 Corvis ST and SSI

The CorvisST (software version 1.6r2015) is a non-contact and visual dynamic intraocular pressure analyzer, which integrates ultra-high-speed Seheimpflug technology into a non-contact intraocular pressure measuring instrument to study the whole dynamic process of corneal deformation under external force. The parameters of the deformation process are recorded, and the biomechanical properties of the cornea are analyzed. (Figure 1). The new software used in this study measures new corneal biomechanical index SSI, included in the dynamic corneal response (DCR) parameters, which consist of first applanation (A1) parameters (A1-time, A1-length and A1-velocity), second applanation (A2) parameters (A2-time, A2-length and A2-velocity), highest concavity (HC) parameters (HC-time, HC-radius, HC deformation amplitude（DA）, HC peak distance（PD）, maximum deflection amplitude (DefAmax), deflection area (HCDefArea), corneal stiffness parameter (SP-A1), biomechanically corrected intraocular pressure (bIOP), and Corvis biomechanical index (CBI) as well.

The value of SSI was estimated by an in-built software using the least squares method, according to numerical modelling using CCT, bIOP, and SP-HC as input and output parameters [7]. It fits the data with the previous numerical analysis results by the regression equation.

where C1=CCT/545 and C2=bIOP/20. ln(SP-HC) the natural logarithm of the SP at HC, and a1-a9 constants are determined by fitting the equation to the numerical input and output values. The ssi was considered as 1.0 for the average experimental behaviour obtained for corneal tissue with age=50 years[8]. Higher values of SSI are indicative of higher tissue stiffness and vice versa.

2.4 Statistical analyses

The statistical analyses were performed using SPSS version 26.0 software (IBM, Corp, Armonk, NY, USA). Descriptive statistical results included means, standard deviations, and minimum and maximum values of parameters. The 95% confidence interval (CI) of the overall mean of the parameters was calculated. Normality of all data samples was checked using the Kolmogorov-Smirnov test. Pearson bivariate correlation statistical analysis was used to obtain the linear fit of the correlation among variables. Stepwise multivariate linear regression analysis was applied to assess the correlation between SSI and other corneal properties; p＜0.05 was considered to be statistically significant.

3.1 Baseline characteristics

Data were collected from 1054 patients. The right eyes were used for the analysis. The characteristics of the participants are summarised in Table 1. The mean age and SE of the participants were 23.9±5.96 years and -5.03±2.03D, respectively.

Table 1. Characteristics of the participants included in the study

Parameters	Mean ±SD Range
Age (years)	23.9±5.96	17-45
MRSE (D)	-5.36±2.07	-0.5- -14.25
Spherical (D)	-5.03±2.03	-0.5- -13.50
Cylinder (D)	-0.66±0.48	0- -1.75
CCT (microns)	553.4±29.9	482-654
Km (D)	43.14±1.35	39.0-46.75
IOPnct (mmHg)	16.39±2.37	9.5-27.5

CCT, central corneal thickness; Km, mean keratometry; MRSE, manifest refraction spherical equivalent; IOPnct, intraocular pressure with non-contact tonometry; SD: standard deviation

Values are presented as means (standard deviations) or as ranges.

3.2 Biomechanical parameters

The mean values of DCR parameters in eyes with corresponding standard deviations and 95% CIs are shown in Table 2.

Table 2: Distribution of normative values of Corvis ST parameters

Parameters	Mean±SD	95% CI
A1-time (ms)	7.208±0.289	7.194,7.223
A2-time (ms)	21.968±0.373	21.949,21.987
HC-time (ms)	17.032±0.401	17.011,17.052
A1DefA (mm)	0.097±0.006	0.096,0.097
A2DefA (mm)	0.109±0.011	0.108,0.109
HCDefA (mm) HCDefArea (mm²)	0.941±0.096 3.521±0.501	0.936,0.946 3.495,3.547
DefAmax (mm)	0.953±0.095	0.948,0.957
DAmax (mm)	4.349±0.424	4.328,4.372
PD (mm)	5.181±0.251	5.169,5.194
WEM (mm)	0.201±0.065	0.258,0.265
SP-A1	107.866±14.927	107.091,108.640
ARTh	581.715±112.10	575.918,587.512
IR	7.902±0.977	7.852,7.951
CBI	0.221±0.187	0.212,0.230
SSI	0.854±0.133	0.847,0.860
CCT (μm)	554±32.75	576,587
bIOP (mmHg)	16±2.06	15.9,16.1

Corvis ST: corneal visualisation Scheimpflug technology; SD: standard deviation; CI: confidence interval; A1-and A2-times: time reaching the first and second applanation; HC-time: highest concavity-time; A1 and A2DefA: displacement of corneal apex at the first or second applanation or at the moment of highest concavity after whole eye motion is removed; HCDefA: amplitude at the highest concavity; HCDefArea: deflection area at the highest concavity; DefAmax: maximum deflection amplitude; DAmax: maximum deformation amplitude; PD: peak distance; WEM: whole eye movement; SP-A1: stiffness parameter; IR: integrated radius; ARTh: ambrosio relational thickness horizontal; CBI: Corvis biomechanical index; SSI: stress-strain index; CCT: central corneal thickness; bIOP: biomechanically corrected intraocular pressure

Values are presented as means (standard deviations) with 95% confidence intervals.

3.3 Correlations of SSI with other biomechanical parameters

3.3.1 Correlation between baseline characteristics and SSI

No statistically significant correlations were observed between SSI and sex (p＞0.05). The SSI was negatively correlated with mean keratometry (Km) (r=-0.103, p＜0.01) and positively correlated with SE (r=0.313, p＜0.01) (Figure 2), CCT (r=0.125, p＜0.01), age (r=0.198, p＜0.01), and bIOP (r=0.23, p＜0.01) (Table 3).

Table 3: Correlations between SSI and characteristics of the participants

Parameters	SSI
	r	p
Age (years)	0.198	＜0.01
MRSE (D)	0.313	＜0.01
CCT (microns)	0.125	＜0.01
Km (D)	-0.103	＜0.01
bIOP (mmHg)	0.230	＜0.01

SSI: stress-strain index; MRSE: manifest refraction spherical equivalent; CCT: central corneal thickness; Km: mean keratometry; BIOP: biomechanically corrected intraocular pressure

Statistical significance has been defined as p < 0.05.

3.3.2 Comparison of parameters in low and high myopia

There were no significant differences in age, CCT, BIOP, SP, ambrosio relational thickness horizontal (ARTh), and CBI between the low and high myopia groups. There was a significant difference in SSI （t=8.960, p＜0.01) and integrated radius (IR)（t=-3.509, p＜0.01) (Figure 3,Table 4).

Table 4: Comparison of the parameters in low and high myopia

Group	Number	Age (years)	CCT (microns)	bIOP	SP-A1	DAmax (mm)	IR (mm)	ARTh	CBI	SSI
Low myopia	161	23.2±6.12	553± 32.9	16±2.07	108.520±15.699	4.272± 0.448	7.663± 1.071	589.402± 114.500	0.214± 0.184	0.920±0.138
High myopia	506	24.0±5.56	551± 29.3	16±1.98	107.787±14.884	4.360± 0.413	7.953± 0.991	577.718± 106.814	0.224± 0.183	0.813±0.129
t		-1.616	0.770	-1.354	0.538	-2.328	-3.509	1.190	-0.609	8.960
p		0.107	0.441	0.176	0.590	0.020	＜0.01	0.234	0.543	＜0.01

CCT: central corneal thickness; bIOP: biomechanically corrected intraocular pressure; SP-A1: stiffness parameter; DAmax: maximum deformation amplitude; IR: integrated radius; ARTh: ambrosio relational thickness horizontal; CBI: Corvis biomechanical index; SSI: stress-strain index

Statistical significance has been defined as p < 0.05.

3.3.3 Regression analysis of SSI and baseline characteristics

Multiple linear stepwise regression analysis was performed with SSI as the dependent variable and SE, Km, CCT, bIOP, and age as independent variables (Table 5). The following regression equation was obtained:

SSI=0.768+0.021SE+0.02bIOP+0.006AGE-0.013KM+0.001CCT

Table 5: Multiple linear stepwise regression analysis with SSI as the dependent variable

	β	t	P	95% CI
Constant	0.768	6.429	＜0.01	0.534,1.002
MRSE (D)	0.021	14.114	＜0.01	0.018,0.024
bIOP	0.020	12.752	＜0.01	0.017,0.023
Age (year)	0.006	11.352	＜0.01	0.005,0.007
Km (D)	-0.013	-5.680	＜0.01	-0.018, -0.009
CCT (μm)	0.001	5.558	＜0.01	0.000,0.001

CI: confidence interval; MRSE: manifest refraction spherical equivalent; bIOP: biomechanically corrected intraocular pressure; Km: mean keratometry CCT: central corneal thickness; SSI: stress-strain index

Values are presented 95% confidence intervals, and statistical significance has been defined as p < 0.05.

3.3.4 Correlation between corneal biomechanical parameters and SSI

A1-time, HC-time, A2DefA, WEM, SP-A1, ARTh, CBI, IR, and bIOP were weak positively correlated with SSI. DAmax, A2-time, and A2DefA were weakly negatively correlated with SSI. HCDefA, HCDefArea, PD, IR, and DefAmax were strongly negatively correlated with SSI. No significant correlation was found between A1DefA and SSI (Table 6, Figure 4).

Table 6: Correlations between SSI and Corvis ST parameters

Parameters	SSI
	R	p
A1-time (ms)	0.272	＜0.01
A2-time (ms)	-0.323	＜0.01
HC-time (ms)	0.218	＜0.01
A1DefA (mm)	-0.007	0.798
A2DefA (mm)	0.081	＜0.01
HCDefA (mm)	-0.721	＜0.01
HCDefArea (mm²)	-0.665	＜0.01
DefAmax (mm)	-0.564	＜0.01
DAmax (mm)	-0.388	＜0.01
PD (mm)	-0.597	＜0.01
WEM (mm)	0.288	＜0.01
SP-A1	0.316	＜0.01
ARTh	0.113	＜0.01
IR	-0.555	＜0.01
CBI	0.199	＜0.01
bIOP	0.230	＜0.01

SSI: stress-strain index; Corvis ST: corneal visualiation Scheimpflug technology; A1-and A2-times: time reaching the first and second applanation; HC-time: highest concavity-time; A1 and A2DefA: displacement of corneal apex at the first or second applanation or at the moment of highest concavity after whole eye motion is removed; HCDefA: amplitude at the highest concavity; HCDefArea: deflection area at the highest concavity; DefAmax: maximum deflection amplitude; DAmax: maximum deformation amplitude; PD: peak distance; WEM: whole eye movement; SP-A1: stiffness parameter; IR: integrated radius; ARTh: ambrosio relational thickness horizontal; CBI: Corvis biomechanical index; bIOP: biomechanically corrected intraocular pressure

Statistical significance has been defined as p < 0.05.

Myopia is a public health problem [9] with a high prevalence, especially in the Far East[10]. The onset and progression of myopia has been associated with genetic and environmental factors [11, 12]. Previous studies have noted that myopia is correlated with an increase in corneal curvature and a decrease in corneal thickness[13]. Animal studies have shown a change in the length of the eye and shape of the anterior cornea during the process of myopia modelling [14, 15]. It is also known that high myopes have lower corneal hysteresis than emmetropes [16]. However, it is difficult to detect the ocular biomechanical properties in vivo [17]. The Corvis ST provides information on corneal deformation parameters by visualising the dynamic reaction of the cornea to a single puff of air [18].

In our study, one of the new Corvis ST parameters—SSI, was evaluated in myopic eyes. We demonstrated that the SSI was positively correlated with SE (r=0.313, p＜0.01) (Figure 1). When comparing eyes with low and high myopia, there were no significant differences in CCT, bIOP, SP, ARTh, and CBI, although there was a significant difference in SSI（t=8.960, p＜0.01）and IR（t=-3.509, p＜0.01 (Figure 2, Table 4) values. The results showed that the SSI of high myopia was lower than that of low myopia, suggesting that the biomechanical properties of the cornea changed and corneal hardness decreased with an increase in the SE.

Inmaculada Bueno-Gimeno et al used ocular response analyser and suggested that corneal biomechanical properties appear to be compromised in myopia from an early age, especially in high myopia [19]. Another study showed a weak although significant correlation between corneal hysteresis (CH) and refractive error, with CH being lower in both moderate and high myopia than in emmetropia and low myopia [20]. Wu et al. [21] reported a difference in corneal biomechanical properties between 835 low myopic eyes and 1027 high myopic eyes. Low CH and corneal resistance factor and high cornea-compensated and Goldmann-correlated IOPs were suggested to be associated with high myopia. However, the correlation of the biomechanics of myopia is controversial. Some studies reported no significant correlation between myopia and CH [22, 23]. The results of our study showed a strong negative correlation of SSI with HCDefA（r=-0.721, p＜0.01）, HCDefArea（r=-0.665, p＜0.01）,PD（r=-0.597, p＜0.01）, IR（r=-0.555, p＜0.01）, and DefAmax（r=-0.564, p＜0.01） (Table 6, Figure 3). Wang et al. [24] found that eyes with high myopia had a larger corneal DA than eyes with mild-to-moderate myopia, and A2-time and HC-radius were positively correlated with SE. Eyes with high myopia also showed longer DA and smaller HC-radius. Similar results were reported by Miaohe et al. [5].These findings are consistent with our results.

Previous studies have shown that the biomechanical properties of the cornea are correlated with CCT. Eyes with thick CCT exhibited strong corneal resistance to external force and are less prone to deformation [25]. Higher intraocular pressure may mask abnormal corneal biomechanical properties, resulting in apparently normal HCDA measurements [26]. The introduction of SSI resolved this issue because it estimates the material stiffness [27]. Eliasy et al. [7] used a numerical model in the study of SSI parameter, which not only covered a wide range of changes in IOP, CCT, geometry and material parameters, but also covered even slightly extended beyond the scope reported in clinical studies. Through the consideration of a Corvis parameter—SP-HC, it is more strongly correlated with corneal stiffness than IOP. As a new index independent of IOP and corneal geometry, SSI could specifically detect high-risk or susceptible patients with ectasia after refractive surgery, remind physicians of the possible risks caused by the decrease of corneal biomechanical properties and could aid in surgery planning.

In this study, we observed a weak correlation among BIOP (r=0.23, p＜0.01), CCT (r=0.125, p＜0.01), and SSI (Table 3). It indicated that despite correction, the effect of corneal biomechanics cannot be completely independent of IOP and thickness, which is consistent with our clinical experience and previous studies. Effects of IOP and corneal biomechanics on eye behaviour are difficult to separate; IOP also affects the immediate corneal stiffness. It is generally believed that sex has no significant effect on corneal biomechanics [28].Our study also suggested that the corneal biomechanical properties of myopia may have nothing to do with sex. Correlation between stress-strain behaviour and age was reported [8, 29], although this study found that there was no strong significant correlation between age (r =0.198, p＜0.01) and SSI, which may be correlated with the concentration of the individual age included.

It is noteworthy that the mean CCT value measured by Corvis ST (553±29.96 um) was slightly lower than that measured by Pentacam corneal topography (554±31.04 um) (t=4.970 p＜0.01）. However, it has been shown that Corvis-ST CCT measurements have good repeatability [30].

The main limitation of the current study is lack of eye axis parameters and a control group with emmetropia, despite a large sample size with myopic participants, which will be improved and supplemented in future studies.

In conclusion, our study showed that there was a positive correlation between SSI and SE. It may provide a new way to study the mechanism of myopia. In different grades of myopia, the SSI values were lower in eyes with higher SE. This indicates that the mechanical strength of the cornea may by compromised in high myopia. Future studies can corroborate the findings of our study. A longitudinal study in progressive and stable myopic participants is warranted.

A1-time: the first and applanation time; A2-time: the second applanation time; ARTh: ambrosio relational thickness horizontal; bIOP: biomechanically corrected intraocular pressure; CBI: Corvis biomechanical index; CH; corneal hysteresis; Corvis ST: corneal visualisation Scheimpflug technology; CCT: central corneal thickness; CI: confidence interval; DA: deformation amplitude; DCR: dynamic corneal response; DefAmax: maximum deflection amplitude: HCDefArea: deflection area; IR: integrated radius; Km: mean keratometery; IOP: intraocular pressure; PD: peak distance; SE: spherical equivalent; SP-A1: stiffness parameter; SP-HC: stiffness parameter at highest concavity; SSI: stress-strain index; WEM: whole eye movement

7.1 Ethics approval and consent to participate

The study adhered to the tenets of the Declaration of Helsinki and was approved by the ethics committee at Tianjin Eye Hospital. Additionally, written informed consent was obtained from each participant.

7.2 Consent for publication

Not applicable.

7.3 Availability of data and materials

The datasets during and/or analysed during the current study are available from the corresponding author on reasonable request.

7.4 Competing interests

The authors declare that they have no competing interests.

7.5 Funding

This work was supported by National Natural Science Foundation of China (No. 81670884, No. 81873684), Yunnan Provincial Science and Technology Bureau (No. 2017FE468 [-115], and the Science and Technology Plan sponsored by Yunnan Provincial Health Commission (No. 2018NS0274).

The funding bodies played no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.

7.6 Authors' contributions

FH and YW contributed to the conception of the work. FH, PHW and MD.L performed data acquisition and analysis, as well as drafting of the manuscript. JN.M was also involved in data analysis. YW and Vishal Jhanji revised the manuscript and produced the final version. All authors reviewed and approved the final manuscript.

7.7 Acknowledgements

Not applicable.

Oner V, Tas M, Ozkaya E, Oruc Y: Effect of pathological myopia on biomechanical properties: a study by ocular response analyzer. Int J Ophthalmol 2015, 8(2):365-368.
M B, K T, C G, W S, KS K: Five-year results of Small Incision Lenticule Extraction (ReLEx SMILE). The British journal of ophthalmology 2016, 100(9):1192-1195.
Tian L, Ko MW, Wang LK, Zhang JY, Li TJ, Huang YF, Zheng YP: Assessment of ocular biomechanics using dynamic ultra high-speed Scheimpflug imaging in keratoconic and normal eyes. J Refract Surg 2014, 30(11):785-791.
Qiu K, Zhang R, Wang G, Zhang M: Relationship of corneal hysteresis and optic nerve parameters in healthy myopic subjects. Scientific Reports 2017, 7(1):17538-17537.
He M, Wang W, Ding H, Zhong X: Corneal Biomechanical Properties in High Myopia Measured by Dynamic Scheimpflug Imaging Technology. Optom Vis Sci 2017, 94(12):1074-1080.
X J, J Y, SH L, XC D: Biomechanics of the sclera and effects on intraocular pressure. International journal of ophthalmology 2016, 9(12):1824-1831.
Xu H, Zong Y, Zhai R, Kong X, Jiang C, Sun X: Intereye and intraeye asymmetry analysis of retinal microvascular and neural structure parameters for diagnosis of primary open-angle glaucoma. Eye (Lond) 2019.
A E, B G, P R, M C, KM M: Characterization of age-related variation in corneal biomechanical properties. Journal of the Royal Society, Interface 2010, 7(51):1475-1485.
Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, Wong TY, Naduvilath TJ, Resnikoff S: Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology 2016, 123(5):1036-1042.
Wei S, Sun Y, Li S, Hu J, Yang X, Lin C, Cao K, J D, Guo J, Li H et al: Refractive Errors in University Students in Central China: The Anyang University Students Eye Study. Invest Ophthalmol Vis Sci 2018, 59(11):4691-4700.
Hung GK, Mahadas K, Mohammad F: Eye growth and myopia development: Unifying theory and Matlab model. Comput Biol Med 2016, 70:106-118.
Lee MW, Kim JM, Shin YI, Jo YJ, Kim JY: Longitudinal Changes in Peripapillary Retinal Nerve Fiber Layer Thickness in High Myopia: A Prospective, Observational Study. Ophthalmology 2019, 126(4):522-528.
TW L, AK L, CS K: Corneal shapes of Chinese emmetropes and myopic astigmats aged 10 to 45 years. Optometry and vision science : official publication of the American Academy of Optometry 2013, 90(11):1259-1266.
Cohen Y, Belkin M, Yehezkel O, Avni I, Polat U: Light intensity modulates corneal power and refraction in the chick eye exposed to continuous light. Vision Res 2008, 48(21):2329-2335.
Rucker F, Britton S, Spatcher M, Hanowsky S: Blue Light Protects Against Temporal Frequency Sensitive Refractive Changes. Invest Ophthalmol Vis Sci 2015, 56(10):6121-6131.
Wong YZ, Lam AK: The roles of cornea and axial length in corneal hysteresis among emmetropes and high myopes: a pilot study. Curr Eye Res 2015, 40(3):282-289.
A E, KJ C, R V, O M, P V, R A, CJ R, A E: Ex-vivo experimental validation of biomechanically-corrected intraocular pressure measurements on human eyes using the CorVis ST. Experimental eye research 2018, 175:98-102.
Roberts CJ: Concepts and misconceptions in corneal biomechanics. J Cataract Refract Surg 2014, 40(6):862-869.
Bueno-Gimeno I, España-Gregori E, Gene-Sampedro A, Lanzagorta-Aresti A, Piñero-Llorens DP: Relationship among Corneal Biomechanics, Refractive Error, and Axial Length. Optometry and Vision Science 2014, 91(5):507 -513.
Shen M, Fan F, Xue A, Wang J, Zhou X, Lu F: Biomechanical properties of the cornea in high myopia. Vision Res 2008, 48(21):2167-2171.
Ha A, Kim YK, Baek SU, Park KH, Jeoung JW: Optic Disc Microhemorrhage in Primary Open-Angle Glaucoma: Clinical Implications for Visual Field Progression. Invest Ophthalmol Vis Sci 2019, 60(6):1824-1832.
L L, G G, YH C, A F, A K, EL S, D T, L T, SM S: Cornea biomechanical characteristics and their correlates with refractive error in Singaporean children. Investigative ophthalmology & visual science 2008, 49(9):3852-3857.
K K, M H, F F, K S: Factors affecting corneal hysteresis in normal eyes. Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie 2008, 246(10):1491-1494.
Wang J, Li Y, Jin Y, Yang X, Zhao C, Long Q: Corneal Biomechanical Properties in Myopic Eyes Measured by a Dynamic Scheimpflug Analyzer. J Ophthalmol 2015, 2015:161869.
SG Ç, SA K, B A-B, M T-Ç: Relationship among Corneal Biomechanics, Anterior Segment Parameters, and Geometric Corneal Parameters. Journal of ophthalmology 2016, 2016:8418613.
Ma J, Wang Y, Hao W, Jhanji V: Comparative analysis of biomechanically corrected intraocular pressure with corneal visualization Scheimpflug technology versus conventional noncontact intraocular pressure. International ophthalmology 2020, 40(1):117-124.
Vinciguerra R, Ambrosio RJ, Elsheikh A, Roberts CJ, Lopes B, Morenghi E, Azzolini C, Vinciguerra P: Detection of Keratoconus With a New Biomechanical Index. J Refract Surg 2016, 32(12):803-810.
Shah S, Laiquzzaman M, Yeung I, Pan X, Roberts C: The use of the Ocular Response Analyser to determine corneal hysteresis in eyes before and after excimer laser refractive surgery. Cont Lens Anterior Eye 2009, 32(3):123-128.
B G, SW J, P R, R A, A E: Age-related variations in the biomechanical properties of human sclera. Journal of the mechanical behavior of biomedical materials 2012, 16:181-191.
Ali NQ, Patel DV, McGhee CN: Biomechanical responses of healthy and keratoconic corneas measured using a noncontact scheimpflug-based tonometer. Invest Ophthalmol Vis Sci 2014, 55(6):3651-3659.

Download PDF

Journal Publication

published 19 Nov, 2020

Read the published version in BMC Ophthalmology →

Submission checks completed at journal
10 Nov, 2020
Editorial decision: Accept
09 Nov, 2020
Editor assigned by journal
08 Nov, 2020
Editor invited by journal
08 Nov, 2020

You are reading this latest preprint version

Effect of Biomechanical Properties on Myopia: a Study of New Corneal Biomechanical Parameters

Status:

Journal Publication

Version 3

Abstract

Figures

1 Background

2 Methods

3 Results

4 Discussion

5 Conclusions

6 Abbreviations

7 Declarations

8 References

Status:

Journal Publication

Version 3