Effectiveness of Glaucoma Diagnostic Parameters from Spectral Domain-Optical Coherence Tomography of Myopic Patients / 中华医学杂志(英文版)

Background@#Currently, spectral-domain optical coherence tomography (SD-OCT) appears to be a new type of glaucoma diagnostic tool. Thus, this study aimed to evaluate the effectiveness of glaucoma diagnostic parameters from SD-OCT of patients with different severities of myopia.@*Methods@#This was a cross-sectional study. A total of 248 participants (248 eyes) were enrolled, including 51 cases in the early primary open-angle glaucoma group, 79 cases in the control group (0.50 D to -0.50 D, excluding -0.50 D), 47 cases in the low-myopic group (-0.50 to -3.00 D, excluding -3.00 D), 43 cases in the moderate-myopic group (-3.00 to -6.00 D, excluding -6.00 D), and 28 cases in the high-myopic group (≤-6.00 D). All participants were examined using the Humphrey visual field test and SD-OCT. The SD-OCT parameters of the retinal nerve fiber layer (RNFL) and ganglion cell complex were analyzed statistically using the receiver operating characteristic curve and area under the curve (AUC).@*Results@#The AUC showed that the best parameters for the control and low-myopic groups were the inferior and inferior temporal RNFL thicknesses (AUC >0.94), respectively; for the moderate- and high-myopic groups, the best parameter was the temporal low RNFL thickness (AUC, 0.926 and 0.896, respectively). The AUC of the inferior parameters of the moderate-myopic group (0.864) was lower, ranked 15 among all RNFL parameters. When the sensitivity was fixed at 85%, the specificity of the inferior, superior, inferior temporal, and superior temporal quadrants was higher (>80%) in the control and low-myopic groups, while they were lower (20-60%) for the moderate- and high-myopia groups. The green color based on the OCT database was also less for the high-myopic group compared with that of other groups (P < 0.05).@*Conclusions@#Glaucoma diagnostic parameters from SD-OCT were not clinically effective for the moderate- and high-myopic groups. The specificities were low. The moderate- and high-myopic groups require comprehensive analyses for the diagnoses of glaucoma. The SD-OCT database should be improved to better indicate the level of myopia based on the corresponding diopter readings.

Corneal Biomechanical Parameters and Asymmetric Visual Field Damage in Patients with Untreated Normal Tension Glaucoma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>High intraocular pressure (IOP) and low central corneal thickness (CCT) are important validated risk factors for glaucoma, and some studies also have suggested that eyes with more deformable corneas may be in higher risk of the development and worsening of glaucoma. In the present study, we aimed to evaluate the association between corneal biomechanical parameters and asymmetric visual field (VF) damage using a Corvis-ST device in patients with untreated normal tension glaucoma (NTG).</p><p><b>METHODS</b>In this observational, cross-sectional study, 44 newly diagnosed NTG patients were enrolled. Of these, 31 had asymmetric VF damage, which was defined as a 5-point difference between the eyes according to the Advanced Glaucoma Intervention Study scoring system. Corneal biomechanical parameters were obtained using a Corvis-ST device, such as time from start until the first and second applanation is reached (time A1 and time A2, respectively), cord length of the first and second applanation (length A1 and length A2, respectively), corneal speed during the first and second applanation (velocity A1 and velocity A2, respectively), time from start until highest concavity is reached (time HC), maximum amplitude at the apex of highest concavity (def ampl HC), distance between the two peaks at highest concavity (peak dist HC), and central concave curvature at its highest concavity (radius HC).</p><p><b>RESULTS</b>Time A1 (7.19 ± 0.28 vs. 7.37 ± 0.41 ms, P = 0.010), length A1 (1.73 [1.70-1.76] vs. 1.78 [1.76-1.79] mm, P = 0.007), length A2 (1.58 [1.46-1.70] vs. 1.84 [1.76-1.92] mm, P< 0.001), peak dist HC (3.53 [3.08-4.00] vs. 4.33 [3.92-4.74] mm, P = 0.010), and radius HC (6.20 ± 0.69 vs. 6.59 ± 1.18 mm, P = 0.032) were significantly lower in the worse eyes than in the better eyes, whereas velocity A1 and def ampl HC were significantly higher (0.156 [0.149-0.163] vs. 0.145 [0.138-0.152] m/s, P = 0.002 and 1.19 ± 0.13 vs. 1.15 ± 0.13 mm, P = 0.005, respectively). There was no significant difference in time A2, velocity A2, and time HC between the two groups. In addition, no difference was observed in IOP, CCT, and axial length. In the univariate and multivariate analyses, some of the Corvis-ST parameters, including time A1 and def ampl HC, were correlated with known risk factors for glaucoma, and there was also a significant positive correlation between def ampl HC and age.</p><p><b>CONCLUSIONS</b>There were differences in dynamic corneal response parameters but not IOP or CCT between the paired eyes of NTG patients with asymmetric VF damage. We suggest that the shape of the cornea is more easily altered in the worse eyes of asymmetric NTG patients.</p>

The study of anterior sclera thickness and associated ocular parameters / 中华实验眼科杂志

Background The condition of the sclera is associated with many ocular diseases.The measurement of human scleral thickness in vivo is helpful for us to understand the features of the sclera and related diseases.Objective The present study was to measure the anterior sclera thickness(AST) in patients with senile cataract and to analyze the relationship among AST and other associated ocular parameters.Methods This study was approved by the Ethic Commission of First Hospital of Peking University.Written informed consent was obtained from each individual prior to examination.One hundred and five senile cataract patients were recruited in this study.Central corneal thickness (CCT),corneal curvature (CCV) and axial length were measured using ultrasonic pachymeter,keratometer,and A-scan unit,respectively.The AST was measured at 2 mm posterior to the scleral spur in the temporal meridian using ultrasound biomicroscope (UBM).The differences of CCT,CCV,ocular axial length and AST between bilateral eyes and the different sexes were compared by the Paired test and independent sample t test.The correlations among various parameters were assessed by the Pearson linear correlation analysis.The differences of CCT and AST among different axial length groups were evaluated by one-way ANOVA.Results No significant differences were found in the CCT,CCV,axial length and AST between bilateral eyes (t =0.584,P =0.561 ; t =1.161,P =0.248 ; t =0.140,P =0.889 ; t =0.342,P =0.773).Temporal AST at 2 mm posterior to the sclera spur was (0.589 ±0.051)mm in the right eyes.An insignificant decline in CCT was found in the male group compared with the female group (right eyes:t =0.469,P =0.641 ; left eyes:t =0.465,P =0.643).However,compared with the female group,the increase of axial length,reduction of the mean CCV value and enhancement of the mean AST were observed(right eyes:all P＜0.01 ;left eyes:all P＜0.01).CCV showed a negative correlation with ocular axial length (r =-0.50,P＜0.01),but no significant correlation was found among age,CCT,ocular axial length and AST(P＞0.05).No remarkable differences were found in CCT and AST among the various axial length groups (CCT:F =0.998,P=0.372;AST:F=1.919,P=0.383).Conclusions In senile cataract patients,correlation is not found between AST and CCT;the increase of axial length is not associated with the thinning of the eyeball wall to a certain extent.Differences exist in some ocular parameters between different sexes.

Measurement of anterior scleral thickness and its correlation with central corneal thickness and axial length in different types of glaucoma patients / 中华实验眼科杂志

Background A close relation between sclera thickness and glaucoma has been determined.Clinical features vary in different types of glaucoma patients,which hints that the scleral thickness might be distinct among these patients.Objective The aim of this study was to investigate the differences of central corneal thickness(CCT),anterior scleral thickness(AST) and axial length in glaucomatous patients.Methods This study was approved by the Ethic Commission of First Hospital of Peking University.Written informed consent was obtained from each individual prior to the examination.A retrospective descriptive study was designed.One hundred and sixty consecutive patients were recruited from March,2009 to November,2010 in First Hospital of Peking University,including 35 eyes with primary angle closure glaucoma(PACG) (35 cases),34 eyes with primary open-angle glaucoma POAG) (34 cases),37 eyes with normal tension glaucoma(NTG) (37 cases)and 17 eyes of ocular hypertension OHT) (17 cases).Thirty-seven eyes of 37 subjects with incipient cataract served as the control group.CCT and ocular axial length were measured with ultrasonic pachymeter and A-scan unit,respectively,and AST at the temporal quadrant 2 mm posterior to the scleral spur was measured by ultrasonic biomicroscopy (UBM).The measuring parameters among different groups were compared by analysis of covariance,and the correlations of AST,CCT with ocular axial length were analyzed using Pearson linear correlation and linear regression.The differences and correlation of CCT,AST and AL among five groups were analyzed.Results The CCT values in PACG group,POAG group,NTG group,OHT group and control group were (535.54 ± 5.20),(550.47 ± 5.28),(521.61 ± 5.07),(575.75 ± 7.76) and (535.06± 5.06) μm,respectively,showing a significant difference among them (F =9.560,P =0.000),and the CCT value of OHT group was increased in comparison with POAG group,PACG group,NTG group and control group(all P =0.000).The CCT of the POAG group was thicker than that in the PACG group,NTG group and control group(P=0.046,0.000,0.040).No significant difference was found in CCT among NTG group,PACG group and control group(P=0.950,0.060).The AST values of PACG group,POAG group,NTG group,OHT group and control group were(0.593±0.050),(0.600±0.050),(0.592-±0.060),(0.610-±0.060) and(0.604±0.060) mm,respectively,showing a insignificant difference among them (F =0.700,P =0.590).The axial length in the patients with PACG was shorter than that of the POAG group,NTG group,OHT group and control group (all P =0.000).The Pearson correlation analysis showed significantly positive correlation between CCT and AST in POAG group and NTG group(r=0.445,P=0.008;r=0.400,P=0.014).Conclusions This study confirms that there is dissimilarity in CCT but not in AST among different types of glaucomatous patients.The changes of CCT and AST are consistent in POAG and NTG patients.

Diagnostic capability of Fourier-Domain optical coherence tomography in early primary open angle glaucoma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Optical coherence tomography (OCT) is a high resolution noncontact imaging modality which can quantitatively detect the optic disc and retinal structure. This study was designed to evaluate the diagnostic capability of parameters of the optic disc, retinal nerve fiber layer thickness, and ganglion cell complex (GCC) using a new technology called Fourier-domain OCT (FD-OCT) for early primary open angle glaucoma (POAG) patients.</p><p><b>METHODS</b>Two groups of patients, early perimetric damage POAG and normal subjects were included in this observational cross-sectional study. All patients underwent FD-OCT and visual field examination in addition to full ophthalmic examinations. Receiver operating characteristic curves (ROC) were studied for all parameters. The sensitivity and specificity for distinguishing between normal and early glaucomatous eyes, the areas under the receiver operating characteristic curves (AROC) and positive, negative likelihood ratios were evaluated for all the single parameters and selected combined parameters using arbitrary cutoffs.</p><p><b>RESULTS</b>Thirty-four eyes of 34 early POAG patients and 42 eyes of 42 normal subjects were analyzed. Cup/disc (C/D) vertical ratio presented the best sensitivity and positive likelihood ratio for selected specificities (95% and 85%) which were 79.4% and 88.2%, 33.4 and 7.4, respectively. Among all single parameters, the C/D vertical ratio demonstrated the highest AROC which was at 0.930. The average thickness of circumpapillary RNFL on 3.45 mm showed the highest AROC among all of the peripapillary RNFL parameters. The sensitivity at selected specificity and AROC of GCC were not as high as C/D vertical ratio and RNFL AT on 3.45 mm. When the C/D vertical ratio, RNFL AT on 3.45 mm, and rim area were combined using a logistical diagnostic model, the AROC was raised to 0.949 but not significantly different from the top single parameter, C/D vertical ratio.</p><p><b>CONCLUSIONS</b>The key parameters obtained by FD-OCT were able to show the significant differences of optic discs, thickness of RNFL and GCC between POAG patients and normal subjects. According to sensitivity, specificity, likelihood ratio and AROC, the top three parameters from FD-OCT for early diagnosis of POAG were C/D vertical ratio, RNFL AT on 3.45 mm, and the rim area.</p>