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AIM:To investigate the effect of wearing corneoscleral contact lens on visual acuity, and corneal parameters in keratoconus patients.METHODS:In this prospective study, 43 cases(83 eyes)with keratoconus were included and examined. A corneoscleral contact lens was fitted, and thorough exams were carried out at baseline, 3 and 6 mo after wearing lenses, including slit lamp examination, objective and subjective refraction, uncorrected visual acuity(UCVA), and best-corrected visual acuity(BCVA), keratometry(Kmax, K1 and K2), central corneal thickness and endothelial cells count.RESULTS: Mean BCVA(LogMAR)improved from 0.34±0.23 with the spectacles to 0.03±0.05 with the corneoscleral contact lenses in 6 mo(P<0.001). Kmax changed from 52.80±5.93 D to 51.51±5.64 D in 6 mo(P<0.001), central corneal thickness changed from 483.84±34.69 μm to 476.28±35.38 μm(P<0.001), and endothelial cell count changed from 2559.18±275.7 cells/mm2 to 2572.73±274.3 cells/mm2 after wearing corneoscleral contact lens for 6 mo(P<0.001).CONCLUSION: Corneoscleral lenses could significantly increase visual acuity, since there were no clinical noticeable changes in the corneal parameters, this lenses can be used safely in patients with keratoconus.
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ABSTRACT Purpose: To determine the absorbance coefficient of the thin porcine cornea to ultraviolet-A radiation (365 nm) submitted for crosslinking. Methods: This in vitro, benchtop experiment using cadaver tissue study analyzed 12 porcine corneal lamellas, which were obtained using a microkeratome after mechanical de-epithelization and separated into three thickness groups: 180, 300, and 360 μm. The corneal thickness values were measured by anterior-segment optical coherence tomography. All lamellas had ultraviolet-A (365 nm) absorbance measured with a 96-well plate spectrophotometer using an ultraviolet transparent microplate before riboflavin instillation and preand post-crosslinking according to the Dresden protocol. Results: The ultraviolet absorbance profiles of the 180, 300, and 360 μm groups were obtained as α-coefficients of 12.85, 76.55, and 120.27, respectively. A theoretical formula was calculated though a statistical analysis that demonstrated the correlation between stromal lamellar thickness and ultraviolet absorbance. Conclusions: Corneal thickness and ultraviolet-A spectral absorbance of corneal lamellas showed linear correlation. These findings can potentially contribute to the optimization of ultraviolet-A application during crosslinking, making the treatment of corneas with thickness <400 μm safe and personalized energy delivery for each corneal thickness.
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Purpose: To compare readings of intraocular pressure (IOP) taken with the Goldmann applanation tonometer (GAT), the non?contact tonometer (NCT), and the rebound tonometer (RBT), and to compare their correlation with central corneal thickness (CCT). Methods: This was a prospective, cross?sectional, observational study to which patients above 18 years of age were enrolled. A total of 400 eyes of 200 non?glaucomatous patients underwent IOP recordings using the GAT, NCT, and RBT, and CCT was also noted. Informed consent of the patients was taken. The IOP readings taken via the three methods were compared and correlated with CCT. Paired t test was used to compare the two devices. Simple and multivariate linear regression analyses were used to study the relationship between factors. A P value less than 0.05 was considered significant. Correlation was determined using the Pearson correlation coefficient, and a Bland–Altman graph was plotted. Results: Mean IOP measured by the NCT was 15.65 ± 2.80 mmHg, by the RBT was 14.23 ± 3.05 mmHg, and by the GAT was 14.69 ± 2.97 mmHg. The mean CCT was 510.61 ± 33.83 microns. The difference between mean IOP recorded by the NCT and that by the RBT was 1.41 ± 2.39 mmHg, between the NCT and GAT was 0.95 ± 2.03 mmHg, and between the GAT and RBT was 0.45 ± 2.22 mmHg. The difference between the IOP values was statistically significant (P < 0.005). All tonometers showed a statistically significant correlation with CCT, but it was observed that the NCT had a stronger correlation (0.4037). Conclusion: The IOP readings taken by all the three methods were comparable; however, RBT values were closer to GAT values. CCT did influence the IOP values, and this should be kept in mind while evaluating.
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@#Introduction: Glaucoma causes a reduction of contrast sensitivity (CS) while thinner central corneal thickness is (CCT) associated with the risk of glaucoma. Thus, in glaucoma suspect patients, CS and CCT measurements may better evaluate and monitor the disease. The purpose of this study was to compare CS and CCT between a Primary Open Angle Glaucoma (POAG) suspect group and a normal group of similar age. Methods: CS was measured with the Pelli-Robson CS chart, while CCT was measured with a hand-held pachymeter. In total, 115 glaucoma suspects and 102 normal participants were included. Results: There was a significant effect of the clinical condition on CS [F(1,209)=5.409, p=0.02]. The effect of age on CS was also significant [F(3,209)=20.419, p<0.001]. The interaction between age and clinical condition was not statistically significant [F(3,209)=0.815, p=0.49]. CS of POAG suspects was significantly lower than that of the normal group for the younger age groups (40 to 59 years old) but not for the older age groups (50 to 80 years old). There was no significant effect of clinical condition on CCT [F(3,209)=0.754, p=0.39]. However, there was a significant effect of age on CCT [F(3,209)=3.789, p=0.01]. Conclusion: Contrast sensitivity measurement is potentially useful to be integrated with routine investigations for POAG suspect patients, especially those who are younger than 60 years old. Measurements of central corneal thickness alone may not be able to differentiate between POAG suspects and visually normal individuals.
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Objective:To investigate the distribution of intraocular pressure (IOP) in high-altitude population aged 18 years and over in Xining, Qinghai and establish the reference interval (RI) of IOP.Methods:A cross-sectional study was conducted in Xining, Qinghai Province at 2.271 km above sea level from September 2019 to May 2020.Ophthalmic examinations and IOP measurement were conducted among subjects from Physical Examination Center of Qinghai Provincial People's Hospital.The subjects who had been living in Xining without leaving for three months were enrolled.Ophthalmic examinations included vision examination, IOP measurement, slit-lamp microscopy, fundus photography, anterior and posterior segment optical coherence tomography.IOP was measured using Goldmann applanation tonometry under local anesthesia.Subjects with factors that could cause significant changes in IOP and affect the accuracy of IOP measurement, and those who were unable to receive IOP measurement were excluded.Subjects were grouped according to sex, age and ethnicity, and the distribution and RI of IOP were compared among all groups.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (No.TRECKY2017-024). Written informed consent was obtained from each subject.Results:A total of 6 120 subjects (6 120 eyes) aged 18-90 years old were enrolled, including 2 850 males and 3 270 females with average age of (45.54±13.85) years.The average IOP of high-altitude population in Xining, Qinghai Province was (14.32±1.93) mmHg (1 mmHg=0.133 kPa), with the RI of 10.54-18.10 mmHg.The average IOP was (14.42±1.98) mmHg in male with the RI of 10.54-18.30 mmHg, (14.23±1.88) mmHg in female with the RI of 10.55-17.91 mmHg.The IOP of male was higher than that of female ( t=3.71, P<0.001). The IOP of Han, Tibetan, Hui and other nationalities were (14.38±1.91), (13.93±2.06), (14.21±1.87), (13.94±1.95) mmHg, respectively, with a statistically significant overall difference ( F=6.73, P<0.001). The IOP of Han nationality was significantly higher than that of Tibetan, Hui and other nationalities, and the differences were statistically significant (all at P<0.05). Conclusions:RI of IOP in high-altitude population from Xining, Qinghai is lower compared with normal altitude area.
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AIM: To investigate the difference, correlation, and consistency of corneal thickness and the thinnest point position detected by Pentacam HR corneal topography map and RTVue optical coherence tomography(OCT)in patients with keratoconus.METHODS: Cross-sectional comparative study. The corneal curvature map, corneal thickness map, thinnest point position, and thinnest point thickness were detected by Pentacam HR and RTVue OCT. Paired sample t-test was used for data consistent with normal distribution, and paired sample rank sum test was used for data inconsistent with normal distribution. Spearman correlation analysis and Bland-Altman analysis were used for the correlation and consistency of the two measurement methods.RESULTS: A total of 63 patients(105 eyes)with keratoconus were included in this study, including 49 males(77.8%)and 14 females(22.2%), aged 22.24±6.19 years; among them, relevant data of Pentacam HR topographic map: Km was 47.85±4.73D and Kmax was 55.43±8.72D. In measuring central corneal thickness and the thinnest point thickness of keratoconus, the Pentacam HR was 4.70μm and 19.46μm thicker than the mean value measured by RTVue OCT(P<0.05). There was no significant difference between the horizontal and vertical coordinates of the thinnest points measured by the two devices(P>0.05). The central corneal thickness and the thinnest point thickness measured by the two devices were highly correlated, the horizontal coordinate of the thinnest point was moderately correlated, and the vertical coordinate of the thinnest point was weakly correlated. Bland-Altman analysis showed that the central corneal thickness, the thinnest point thickness, the horizontal coordinate of the thinnest point, and the vertical coordinate of the thinnest point were 95.2%(100/105)and 93.3%(98/105), 95.2%(100/105), 95.2%(100/105)respectively, which were within the 95% consistency limit, while the consistency ranges were -36.00～+26.62μm, -42.27～+3.36μm, -0.80～+0.84mm, and -1.95～+1.06mm, respectively.CONCLUSION: In keratoconus, the central corneal thickness and the thinnest point thickness measured by Pentacam HR were higher than those measured by RTVue OCT. It is not recommended that the central corneal thickness and the thinnest point thickness measured by the two instruments be interchangeable in clinical use because of the wide range of consistency between the two instruments' results. The position of the thinnest corneal point measured by the two instruments is similar and consistent, so it could be considered to replace the measured values of the two instruments in clinical use.
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Purpose: To evaluate and compare endothelial cell changes in phacoemulsification and manual small- incision cataract surgery (MSICS) in patients with uncomplicated senile cataracts. Methods: This was a prospective, tertiary care hospital-based, randomized, double-blinded interventional study. In total, 152 patients with an uncomplicated senile cataract of nuclear grade III and above were recruited. Exclusion criteria included patients with preoperative endothelial cell density (ECD) less than 1500 cells/mm3, a history of previous ocular surgery, any other coexisting ocular disease, and intraoperative or postoperative surgical complications. Preoperative and postoperative values of ECD and central corneal thickness (CCT) were measured, analyzed, and correlated with various factors. Results: Patients were randomized into two interventional groups-MSICS and phacoemulsification. Factors associated with significant drop in postoperative ECD following phacoemulsification were patients with advanced age (P = 0.01), higher grades of cataract (P = 0.01), and longer effective phacoemulsification time (P = 0.007). Shallow anterior chamber depth (ACD) was strongly associated with greater ECD loss in both groups (P < 0.0001). A threshold value of 2.86 mm of ACD was defined for minimal endothelial cell loss following phacoemulsification. CCT was observed to slightly increase postoperatively in both groups but was insignificant (P > 0.05). Conclusion: Both MSICS and phacoemulsification have similar postoperative visual outcomes. An increase in postoperative CCT is insignificant following surgery. Greater postoperative ECD loss is associated with phacoemulsification with advanced age, hard nuclear cataracts, and longer effective phacoemulsification time. ACD can be used as an essential parameter preoperatively to determine the choice of surgical technique between MSICS and phacoemulsification
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Purpose: To determine the pattern of corneal thickness and epithelial thickness distribution in healthy North Indian eyes by using spectral domain optical coherence tomography (SD?OCT). Methods: The observational study measured total corneal and epithelial thickness in the central 2 mm zone and eight sectors each in paracentral 2�mm (ring 1) and midperipheral 5�mm (ring 2) zones on SD?OCT. Results: The study included 67 eyes of 67 subjects with a male:female ratio of 32:35 and mean age of 25.04 � 4.54 years. The mean central corneal and epithelial thicknesses were 505.97 � 30.12 ?m and 60.48 � 8.37 ?m, respectively. The epithelium of inferior and infero?nasal sectors in ring 1 and inferior sector in ring 2 was significantly thicker than the radially opposite sectors of the respective rings (P = 0.001; P = 0.01 and P = 0.02, respectively). Sector?wise analysis did not reveal any significant correlation between the total corneal thickness and epithelial thickness (all P > 0.05) except in the outer superior sector where there was a weak positive correlation (r = 0.28, P = 0.02). Central epithelial thickness in males (60.59 � 9.28 ?m) and females (60.37 � 7.58 ?m) was comparable (P = 0.91). Pachymetry was thinnest in the inferior, inferonasal, and inferotemporal sectors in 44.79% of eyes (n = 30), while thinnest epithelium was seen in the superior, superonasal, and superotemporal quadrants in 50.75% of eyes (n = 34). Conclusion: The epithelial thickness distribution in this sample of topographically normal healthy North Indian eyes was nonuniform and independent of the underlying corneal thickness. Epithelium was thinner in the superior cornea, whereas total corneal thickness was minimum in the inferior part
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Purpose: To study corneal endothelial changes post phacoemulsification in diabetic and non?diabetic patients. Methods: A comparative, prospective, observational study was conducted on 100 diabetic and 100 non?diabetics who underwent phacoemulsification. All patients were operated by the same surgeon by using the phaco chop technique to exclude any surgeon?related bias. Endothelial cell count, CCT, and coefficient of variance (CV) were measured with a specular microscope along with BCVA preoperatively and at 1 week, 4 weeks, and 3 months postoperatively. For statistical analysis, data were analyzed by using SPSS (version 27.0; SPSS Inc., Chicago, IL, USA). Data were summarized as mean and standard deviation for numerical variables and count and percentages for categorical variables. Chi square test, independent sample T test, and paired T test were used to compare the data. P ? 0.05 was considered statistically significant. Results: Postoperatively at 1 week, 4?week, and 3 months follow?up intervals, the mean endothelial cell count and coefficient of variance were significantly higher, and the mean percentage of hexagonal cells was significantly lower in non diabetic as compared to the diabetic group. A significant difference in mean central corneal thickness of the two groups was observed at 1?week and 4?weeks postoperative intervals; at both these intervals, the mean value was significantly higher in non diabetic as compared to the non?diabetic group. However, at 3?months post?operative interval, the difference between the two groups was not significant statistically. Mean BCVA values were significantly higher in diabetic as compared to the diabetic group at all three follow?up intervals. Conclusion: The findings of the present study show that endothelial cell characteristics are adversely affected in diabetic eyes as compared to non?diabetic patients undergoing phacoemulsification; this might also have an effect on the visual outcomes.
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Background:Corneal endothelial cells are susceptible to mechanical trauma from ultrasound energy during phacoemulsification. Several studies have reported various results of phacoemulsification effect on corneal endothelial cells between diabetic and non-diabetic patients due to stressful events. Present study was aimed to evaluate corneal endothelial density, hexagonality and Central Corneal Thickness (CCT) changes between diabetic and non-diabetic patients at early postoperative period and 1 month after phacoemulsification.Material And Methods:Specular microscopy examinations prior to phacoemulsification and at early postoperative period and 1 months after phacoemulsification were performed on diabetic and non-diabetic groups in grade 2 and grade 3 nuclear sclerosis. Laterthe changes in endothelial density, the percentage of hexagonality, and Central corneal thickness were evaluated.Result:Mean age of 120 study sample was 58.45 years (standard deviation –8.498 years), with the highest 74 years and lowest 43 years. Therewere 53 (44%) females and 67 (56%) males in the study. 42 (35%) samples were from 51-60 years age group followed by 37 (30.83%) subjects in 61-70 years age group. Mean corneal endothelial cell density decreases after cataract surgery in comparison with pre-operative density among study samples. Mean pre-operative corneal endothelial cell density was lower in diabetics in comparison with non-diabetics, and the difference was statistically significant. Cell density count decreases after cataract surgery inboth groups with significant difference between two groups. Mean corneal endothelial cell morphology (hexagonal cell percentage) decreases after cataract surgery in comparison with pre-operative density among study sample s. Central corneal thickness increases in early postoperative period followed by normalisation at day 30.Conclusion:Diabetic group showed greater hexagonality decrease compared to non-diabetic group at 1 month after phacoemulsification. It is suggested that diabetic corneal endothelium requires additional care and protective measures during cataract surgery to minimize surgical trauma. There were no statistically significant differences in the endothelial loss and Central corneal thickness changes between the diabetic and non-diabetic group at 1 month follow up after phacoemulsification.
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It is essential to assess the corneal thickness in diabetes patient.Introduction: diabetes mellitus is a major cause of blindness throughout the worldDiabetic retinopathy is the most importance given on day to day basics studies especially for ophthalmologist studied indicators in eye. However, functional oddities have been recognised in cornea too like changes in central corneal thickness.Objectives: 1. To estimate the central corneal thickness (CCT) of type 2 diabetes mellitus patients without diabetic retinopathy age/sex matched normal people. 2. To measure central corneal thickness (CCT) of type 2 diabetes mellitus patient with diabetic retinopathy with age/ sex matched normal person.Methods: This is a hospital based case control study.Expected Results: The central corneal thickness is more in type 2 diabetes patients than non-diabetic individual.
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@#AIM: To explore the value of corneal epithelial thickness parameters in the diagnosis of early keratoconus by Fourier domain optical coherence tomography(FD-OCT).<p>METHODS: Retrospective control study. Patients with early keratoconus who were admitted to the Department of Ophthalmology of the First Affiliated Hospital of Soochow University from January 2015 to October 2020 and patients who received laser refractive surgery for myopia during the same period were included in this study. Using FD-OCT to measure the cornea in circle centralized by the pupil and with diameter of 9mm in the early-keratoconus group and the control group. This was to obtain the thickness parameter of corneal epithelium with diameter of 7mm, the respective averaged thickness value of corneal epithelium and the respective averaged thickness value of the full corneal layer on each of the 25 divisions. The parameter value differences between the early-keratoconus group and the control group were compared, and the diagnosis value of parameters that hold difference was analyzed. <p>RESULTS: The Min-e value in early-keratoconus group was significantly lower than that of the control group. On contrary, the value of Std.Dev, Max-Min-e, and Max-e were significantly higher in early-keratoconus group than that in latter one(all <i>P</i><0.001). The value of Std.Dev and Max-Min-e hold a greater diagnostic efficiency on diagnosis of early keratoconus(AUC=0.937, 0.928), while Max -e value and Min-e value performed a medium diagnostic efficiency(AUC=0.871, 0.797). Analysis on thickness of corneal epithelium on the 25 divisions found that the thickness of corneal epithelium at infratemporal region of inner ring(EIT1)became thinner most obviously in early-keratoconus group, with greatest diagnostic efficiency(AUC=0.827). The average corneal thickness of the 25 zones of the early keratoconus group was significantly thinner than that in the normal control group. Averaged corneal thickness at infratemporal region of inner ring(CIT1)hold a relatively high diagnostic efficiency among the 25 divisions(AUC=0.903).<p>CONCLUSION: The parameter values of corneal epithelium thickness including Std.Dev, Max-Min-e, Max-e, Min-e, the averaged thickness value of corneal epithelium at infratemporal region of inner ring, and the thickness value of full corneal layer at infratemporal region of inner ring can all be used for diagnosis of early keratoconus.
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AIM: To construct and validate a diagnostic model for early detection of keratoconus based on parameters in Sirius.METHODS: The study comprised of 46 early keratoconus eyes(including 20 right eyes and 26 left eyes in 34 patients)and 46 age- and gender-matched normal eyes(including the right eyes of 46 patients)in the prediction group. The predictive index was constructed using LASSO and Logistic regression analyses based on the topographic, pachymetric and aberrometry variables of Sirius. There were 23 early keratoconus eyes categorized as suspected keratoconus cases by Sirius(including 12 right eyes and 11 left eyes in 23 patients)and 23 age- and gender-matched normal eyes(including the right eyes of 23 patients)included in the application cohort. External validation of predictors was performed for the application cohort.RESULTS: Sirius Keratoconus Index(SKI)was calculated based on the minimum corneal thickness and symmetry index back of Sirius. Highest AUC values were obtained in the prediction group(AUC=0.932)after Logistic regression analysis. The cut-off value of SKI was set at 0.44. Then, the receiver operating characteristic(ROC)curve, calibration plot and nomogram of the diagnostic formula were analyzed for the prediction cohort in detail. Finally, the accuracy of the SKI was evaluated in the application cohort; the sensitivity was 91% and the specificity was 96%.CONCLUSION: SKI based on minimum corneal thickness and symmetry index back of Sirius is a simple and effective method for early detection of keratoconus in the preoperative screening for refractive surgery.
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Introducción: La longitud axial ocular, la profundidad de la cámara anterior y el grosor corneal central, son tres índices biométricos oculares importantes. Estas medidas son útiles para mostrar los cambios en la población vietnamita con presbicia. Objetivos: Determinar los índices biométricos oculares, longitud axial ocular, profundidad de la cámara anterior y espesor corneal central, en población vietnamita y evaluar la correlación entre ellos y con la edad y el sexo. Métodos: Se realizó un estudio transversal en población vietnamita, con edad de 46 a 65 años. Se recogieron los datos de longitud axial ocular, profundidad de la cámara anterior y grosor corneal central. Se utilizaron la prueba t de Student y ANOVA para comparar las medias de los índices, agrupados por edad y sexo. La relación entre los índices biométricos oculares fue probada mediante la correlación de Pearson, con un nivel de significación de p < 0,05. Resultados: Se analizaron 390 ojos de 195 personas. La longitud media del eje ocular fue 23,13 ± 0,66 mm, la profundidad de la cámara anterior, 3,15 ± 0,36 mm, el grosor corneal central, 529,15 ± 30,57 µm. Los tres índices biométricos disminuyeron con la edad y fueron mayores en los hombres (p < 0,05). La longitud del eje ocular tuvo relación positiva con la profundidad de la cámara anterior (r = 0,411 y p < 0,001) y el espesor corneal central (r = 0,141 y p < 0,001). No hubo relación entre la profundidad de la cámara anterior y el grosor corneal central (r = 0,039 y p = 0,44). Conclusión: Los tres índices biométricos oculares disminuyeron con la edad y fueron mayores en los hombres. La longitud del eje ocular se relacionó con la profundidad de la cámara anterior y el grosor de la córnea central(AU)
Introduction: Ocular axial length, anterior chamber depth and central corneal thickness are three important ocular biometric indices. These measurements are useful to show changes in the Vietnamese population with presbyopia. Objectives: To determine the ocular biometric indices, ocular axial length, anterior chamber depth and central corneal thickness, in Vietnamese population and evaluate the correlation between these indices. Methods: A cross-sectional study was carried out in a Vietnamese population, aged 46 to 65 years. Data on ocular axial length, anterior chamber depth and central corneal thickness were collected. The Student's t test and ANOVA were used to compare the means of the indices, grouped by age and sex. The relationship between the ocular biometric indices was tested using Pearson's correlation, with a significance level of p <0.05. Results: 390 eyes of 195 people were analyzed. The mean length of the ocular axis was 23.13 ± 0.66 mm, the depth of the anterior chamber, 3.15 ± 0.36 mm, and the central corneal thickness, 529.15 ± 30.57 µm. The three biometric indices decreased with age and were higher in men (p <0.05). The length of the ocular axis had a positive relationship with the depth of the anterior chamber (r = 0.411 and p <0.001) and the central corneal thickness (r = 0.141 and p <0.001). There was no relationship between anterior chamber depth and central corneal thickness (r = 0.039 and p = 0.44). Conclusion: Three ocular biometric indices decreased with age and were higher in men. The length of the ocular axis was related to the depth of the anterior chamber and the thickness of the central cornea(AU)
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Humans , Middle Aged , Axial Length, Eye/physiology , Anterior Chamber/physiology , Cross-Sectional Studies , Biometry/methodsABSTRACT
@#The thickness of the central cornea has an important influence on various eye diseases and operations such as keratoconus and other corneal diseases, glaucoma, and corneal refractive surgery. Obtaining accurate central corneal thickness is a topic that clinicians have been paying close attention to. It decides the operation method and operation parameters(cutting depth, cutting optical area size, <i>etc.</i>)of refractive surgery. Accurate measurement of central corneal thickness is a great concern to clinicians. At present, there are two kinds of measurement of corneal thickness: the first is ultrasonic measurement, such as traditional Type A ultrasonic corneal thickness meter and ultrasonic biological microscope; the second is optical measurement, including Pentacam, corneal endokeratoscope, optical coherence tomography, <i>etc</i>. Different measuring methods and instruments have their own advantages and disadvantages. However, the ultimate goal of developing corneal thickness measurement is easy operation and good repeatability. Therefore, based on the summarization of current clinically-used corneal thickness measurement instruments and of research progress of corneal thickness measurement, this paper aims at providing theoretical guide for clinical oculists.
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Objective:To explore the differences of anterior segment parameters in Uyghur patients with pseudoexfoliation syndrome (PEX), pseudoexfoliation glaucoma (PEXG), primary open-angle glaucoma (POAG) and age-related cataracts in Xinjiang.Methods:A retrospective study was conducted, Uyghur patients included 114 eyes of 84 cases with PEX, 96 eyes of 70 cases with PEXG, 88 eyes of 72 cases with POAG and 80 eyes of 80 cases with age-related cataracts (control, CON) who had received treatment in Ophthalmology Center of Xinjiang Military Region General Hospital of Chinese People's Liberation Army from April 2019 to July 2020 were selected to obtained central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), axial length (AL) and corneal curvature (horizontal curvature K1 and vertical curvature K2).Results:There was no significant difference in gender ratio and age of patients between CON, PEX, PEXG and POAG groups ( P > 0.05). The CCT of patients in CON, PEX, PEXG and POAG groups were (545.52 ± 34.22), (536.81 ± 42.64), (516.74 ± 32.39) and (530.38 ± 28.72) μm, respectively, the CCT in CON, PEX and POAG groups were all higher than those in PEXG group ( P < 0.05), and the CCT in PEXG group became thinner. The ACD of patients in CON, PEX, PEXG and POAG groups were (3.05 ± 0.38), (2.87 ± 0.36), (2.77 ± 0.41), (2.81 ± 0.32) mm, respectively, compared with CON group, the ACD in PEX, PEXG and POAG groups were all lower ( P < 0.05). There was no significant difference in LT, AL, K1 and K2 of patients between each group ( P > 0.05). Conclusion:This study has showed that the ACD of Uyghur patients with PEX in Xinjiang is shallower than that of CON group, but the CCT of PEXG patients is thinner than that of PEX patients.
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@#AIM: To investigate the changes of corneal endothelial cells and ocular surface after phacoemulsification for age-related cataract(ARC)patients with diabetes mellitus. <p>METHODS: Retrospective case study. A total of 190 cataract patients with diabetes mellitus who received phacoemulsification combined with IOL implantation in 190 eyes admitted to our hospital from January 2017 to January 2019 were selected. In addition, 230 ARC patients without diabetes who underwent phacoemulsification and intraocular lens implantation at the same time were selected as the control group. Ocular surface disease index(OSDI)score, tear film rupture time(BUT), basal tear secretion test(S I t), corneal endothelial cell density and coefficient of variation were compared between the two groups.<p>RESULTS: There was no significant difference in preoperative OSDI score, BUT, S I t, corneal endothelial cell density and coefficient of variation between the two groups(<i>P</i>>0.05). In the observation group, OSDI scores were significantly increased 1wk, 1mo and 3mo after surgery compared with those before surgery, with statistically significant differences(all <i>P</i><0.01). The OSDI scores of patients in the control group increased significantly one week and one month after the operation compared with those before the operation, with statistically significant differences(all <i>P</i><0.01). The OSDI scores in the observation group at each time point after the operation were higher than those in the control group, with statistically significant differences(all <i>P</i><0.05). One week after surgery, 1mo after surgery, BUT and S I t in the two groups decreased significantly compared with that before surgery(<i>P</i><0.05), and the difference was not statistically significant compared with that before surgery 3mo after surgery. In addition, compared with BUT between the two groups, the observation group had a lower tear film stabilization time and a more significant decrease(<i>P</i><0.05). The corneal endothelial cell density in the two groups decreased significantly 1wk, 1mo and 3mo after surgery compared with that before surgery(<i>P</i><0.05). The variation coefficient of corneal endothelial cells in the two groups was statistically significant 1wk after the operation and 1mo after the operation compared with that before the treatment(<i>P</i><0.05). The variation coefficient of corneal endothelial cells in the observation group was more significant than that in the control group(<i>P</i><0.05).<p>CONCLUSION: Cataract patients with diabetes surgery tolerance is low, the corneal endothelial cell density and the central corneal thickness and corneal appears before tear secretion with stability and foundation treatment have significant changes, and its characteristic is cataract patients without diabetes more apparent, clinical intraoperative and postoperative corneal endothelial protection should be strengthened, and the surface of the eye protection ability of the organization.
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@#AIM: To determine the ocular biometric measurements and central corneal thickness(CCT)in Nigerian children so as to have a reference database.<p>METHODS:A hospital-based observational study of a cross-section of children seen consecutively between November 2017 and January 2018. The socio-demographic data of patients, visual acuity(VA)was assessed with LogMAR charts and Lea charts according to age group. Examination under anesthesia(EUA)was carried out for children eight years and below. Anterior and posterior segments examination through dilated pupil were done. Corneal diameters(CD)were assessed using calipers. Intraocular pressures(IOP)were examined using hand held tonometer, CCT and axial length(AL)were measured using the ultrasonic pachymeter. Cycloplegic refraction was carried out after clinical examination. Data were entered into and analysed using SPSS version 17 to generate results through descriptive statistics. Frequencies and cross tabulations of variables were done(<i>P</i><0.05).<p>RESULTS:Sixty-six children with 132 eyes, of ages between 3-16(mean: 9.13±3.70)years were studied. Male with female ratio was 1:1.7. The modal age group range was 6-10 years(42.4%). Most of them were primary school students 36(54.5%). The predominant parents' occupation was traders/unskilled workers(51.6%)and the professionals/civil servants(30.3%). The mean right and left VA were 0.45±0.46 and 0.45±0.44(LogMAR)respectively. The mean right and left horizontal corneal diameters(HCD)were 10.5±1.6 mm and 10.37±1.45 mm respectively. The mean right and left vertical corneal diameters(VCD)were 9.7±1.2 mm and 9.7±1.3 mm respectively. The mean right and left CCT were 556.71±2.61 μm and 556.47±45.53 μm respectively. Myopia 23(34.8%), myopic astigmatism 18(27.3%)and simple astigmatism 16(24.2%)were the commonest types refractive error. No significant associations were observed between CCT and HCD(<i>P</i>=0.739), VA(<i>P</i>=0.058)and refractive error(<i>P</i>=0.199). However, CCT slightly significantly correlated with the age groups(<i>P</i>=0.055).<p>CONCLUSION: Mean values for CCT, IOP and CD are known for the first time in Nigerian children. No significant association was seen between CCT and VA, CD and refractive errors. Further studies are required to ascertain findings.
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The main attributes of cornea which makes it optically important is its ability to maintain its dehydrated state. This corneal dehydration can be achieved and maintained by various factors among which corneal endothelial cell count and morphology play a significant role. Corneal attributes considered in this study i.e. the corneal endothelial cell count and central corneal thickness are extremely variable, and changes are seen even with smaller changes in anterior segment or overall structural changes in eyes. We wanted to compare central corneal thickness in emmetropia and axial myopia and compare corneal endothelial cell count in emmetropia and axial myopia. METHODSThe sample size was decided taking into consideration various prevalence studies. The patients were consecutively recruited for the study considering the inclusion and exclusion criteria. The subjects were divided into two groups emmetropia and axial myopia and were differentiated on the basis of the axial lengths. Specular microscopy was performed for the subjects and corneal endothelial cell count, morphology and central corneal thickness were measured, and comparative study was performed. RESULTSThis study of 80 eyes shows us that the difference between mean the corneal endothelial cell count between emmetrope (2812.80 cells / mm2) and axial myopes (2653 cells / mm2) is statistically significant where p was < 0.05 while the mean central corneal thickness measurements didn’t show statistically significant change between emmetrope (490.05 microns) and axial myope. (489.37 microns). CONCLUSIONSAxial length has an indirect correlation with the corneal endothelial cell count which is statistically significant. While significant correlation between the central corneal thickness and axial length cannot be established in this study.
ABSTRACT
Background and Objectives: The normal Central corneal thickness (CCT) ranges about 510-520 microns. It is normally seen in clinical practice that corneas which are thicker are linked with greater intraocular pressures (IOPs). The purpose of the study was to determine the central corneal thickness and establish its relationship with age and serum electrolytes in hypertensive and non-hypertensive patients. Methodology: A total of 108 subjects were included in our cross-sectional comparative study (54 hypertensive and 54 non-hypertensive). Written informed consent was taken. We measured blood pressure with mercuric sphygmomanometer. Ultrasound pachymeter was used to measure central corneal thickness while we drew 5 ml of blood for estimation of the serum electrolytes. Data was entered and evaluated using IBM SPSS 17. Quantitative variables were presented as Mean ± SD. Pearson correlation was used to find correlation of normally distributed variables p-value ≤ 0.05 was considered to be statistically significant. Results: Central corneal thickness was statistically same in hypertensive and non-hypertensive subjects. Serum Na+ was significantly increased in hypertensive subjects while serum K+ and Cl- were significantly decreased in hypertensive subjects. No significant correlation was seen in hypertensive while weak negative correlation was observed between CCT and age in non-hypertensive patients. Weak positive correlation was observed between CCT and Na+ both in hypertensive and non-hypertensive. Significant correlation was observed in CCT and K+ in hypertensive while negative correlation was seen in non-hypertensive. Weak correlation was observed in CCT and Cl- both in hypertensive and non-hypertensive. Conclusion: Mean CCT was significantly lower in hypertension. CCT and age showed weak and positive correlation in hypertensive while weak and negative correlation in non-hypertensive. Serum electrolytes and CCT showed no significant correlation.