scholarly journals Central Corneal Thickness of Syrian Population in Relation to Different Parameters: ثخانة القرنية المركزية لِعيّنة من المواطنين السورييّن وعلاقتها مع المتغيّرات المختلفة

2021 ◽  
Vol 5 (3) ◽  
pp. 27-19
Author(s):  
Noura Jamal Nasser Alloush, Yusuf Suleiman, Kahtan Jalloul Noura Jamal Nasser Alloush, Yusuf Suleiman, Kahtan Jalloul
Keyword(s):  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Corneal Topography ◽  
University Hospital ◽  
Syrian Population ◽  
The Mean ◽  
Age Range

Objectives: The aim of this study is to determine the mean Central Corneal Thickness (CCT) among a normal Syrian population and to correlate between Central Corneal Thickness and age, gender and axial length. Methods: This study was carried out at Tishreen University Hospital in Latakia. A total of 516 eyes from 258 individuals with an age range from 18 to 56 years were studied. Central Corneal Thickness was measured using corneal topography (SIRIUS). Axial length was measured using contact ultrasound A-scan (AVISO). Results: The mean CCT was 546.7±31.2 µm with a range from 456 to 643 µm. CCT was not affected by gender. CCT significantly negatively correlated with age (p=0.001). There was no statistically significant correlation between CCT and axial length (p=0.6). Conclusions: CCT varies according to race. Among a Syrian population, CCT significantly decreased with age.

scholarly journals Effects of SMILE Surgery on Intraocular Pressure, Central Corneal Thickness, Axial Length, Peripapillary Retinal Nerve Fiber Layer, and Macular Ganglion Cell Complex Thickness

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Zhanlin Zhao ◽  
Sylvain Michée ◽  
Jean-François Faure ◽  
Christophe Baudouin ◽  
Antoine Labbé
Keyword(s):  
Intraocular Pressure ◽  
Ganglion Cell ◽  
Nerve Fiber ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Ganglion Cell Complex ◽  
Fiber Layer ◽  
Rnfl Thickness ◽  
The Mean

Purpose. To evaluate the change in intraocular pressure (IOP), central corneal thickness (CCT), axial length, peripapillary retinal nerve fiber layer (RNFL) thickness, and macular ganglion cell complex (GCC) thickness after small incision lenticule extraction (SMILE) surgery. Methods. This prospective observational study was conducted in Espace Nouvelle Vision, Ophthalmological Clinic, Paris, France. Fifty eyes of 25 patients were enrolled in this study and underwent SMILE surgeries. IOP, central corneal thickness (CCT), axial length (AL), peripapillary RNFL thickness, and macular GCC thickness were measured before and at 3 months after SMILE. Results. The mean preoperative spherical equivalent was −3.15 ± 1.50 diopters (D), and the mean postoperative value was 0.15 ± 0.28 D. After SMILE surgery, IOP decreased from 15.03 ± 2.79 mmHg to 11.02 ± 2.73 mmHg and 10.02 ± 2.21 mmHg at 1 and 3 months, respectively ( P < 0.01 for both comparisons). The mean decrease in measured IOP as a function of ablation depth was 0.065 ± 0.031 mmHg/μm. CCT decreased from 545.98 ± 26.61 μm to 478.40 ± 30.26 μm after SMILE surgery ( P < 0.01 ). AL decreased from 24.80 ± 0.84 mm to 24.70 ± 0.83 mm ( P < 0.01 ). There was no statistically significant change in mean peripapillary RNFL or mean GCC thickness after SMILE surgery. Conclusions. SMILE surgery modified IOP measurement, CCT, and AL but did not change peripapillary RNFL and macular GCC thicknesses. The postoperative drop in measured IOP might be explained by the decreased CCT. An accurate re-evaluation of AL should be performed before cataract surgery among post-SMILE patients.

Evaluation of biometric parameters in phacomorphic glaucoma and mature cataracts

2020 ◽  
pp. 112067212091453
Author(s):  
Ali Keleş ◽  
Emine Şen ◽  
Ufuk Elgin
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Odds Ratio ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Mature Cataract ◽  
Biometric Parameters ◽  
Significant Difference ◽  
The Mean

Purpose: The aims of this study were to compare the biometric parameters and axial lengths of eyes with phacomorphic glaucoma and mature cataract and to identify differences that might predispose to development of phacomorphic glaucoma. Methods: Three hundred forty-two patients were enrolled in this retrospective study. The eyes were divided into four groups—Group (G)1: phacomorphic glaucoma ( n = 29), G2: mature cataract ( n = 313), G3: contralateral phacomorphic glaucoma ( n = 29), and G4: contralateral mature cataract ( n = 313). Central corneal thickness and anterior chamber depth were assessed by optical low-coherence reflectometry (Lenstar LS 900®; Haag-Streit AG, Switzerland), while axial length was determined by A-scan ultrasound biometry. Results: The mean central corneal thickness of G1 was significantly higher than in other groups ( p < 0.001) and the mean anterior chamber depth of G1 was the lowest among the groups ( p < 0.001). Also, G2 had lower mean anterior chamber depth than G4 ( p < 0.001) and G3 had lower mean anterior chamber depth than G4 ( p = 0.007). Anterior chamber depth less than 3.27 mm had the higher odds ratio for distinguishing G3 versus G4 (odds ratio = 10.79, p < 0.001). Furthermore, patients aged ⩾68.9 years had the higher odds ratio for distinguishing G1 versus G2 (odds ratio = 2.82, p = 0.019). There was no significant difference in the presence of pseudoexfoliation material between G1 and G2 ( p = 0.057). There were no significant differences in axial length values among the four groups ( p = 0.097). Conclusion: Advanced age and shallow anterior chamber depth were found to be risk factors for developing phacomorphic glaucoma, but the presence of pseudoexfoliation material was not found to play a role as a risk factor in phacomorphic glaucoma development.

Inter-Observer Reproducibility of Axial Ocular Measurements with Non-contact HAAG-STRAIT Biometer

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
Muhammad Suhail Sarwar ◽  
Sehrish Shahid ◽  
Muhammad Arslan Ashraf ◽  
Shaista Kanwal
Keyword(s):  
Data Analysis ◽  
Anterior Chamber ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Excellent Correlation ◽  
Interclass Correlation ◽  
The Mean

Purpose:  To check inter observer reproducibility of axial ocular measurements i.e. central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AD), lens thickness (LT), anterior segment lens (ASL), vitreous length (VL) and axial length (AL) with non-contact HAAG-STRAIT biometer. Study Design:  Comparative Reproducibility Analysis. Place and Duration of Study:  College of ophthalmology and allied vision sciences (COAVS), Mayo Hospital, Lahore. Methods:  This study included 66 healthy students (132 eyes). Data was collected through self-designed proforma by 2 operators independently. SPSS 21 was used for data analysis. Interclass correlation was applied for agreement between the two readings. Interclass coefficient (ICC) value greater than 0.7 was considered as excellent correlation. Results:  The mean CCT, AD, ACD, LT, ASL, VL, and AL were 526.47 ± 35.72 µm and 526.47 ± 36.06 µm (ICC = 0.92); 2.93 ± 0.29 mm and 2.93 ± 0.29 mm (ICC = 0.81); 3.45 ± 0.30 mm and 3.46 ± 0.30 mm (ICC = 0.79); 3.58 ± 0.28 mm and 3.56 ± 0.22 mm (ICC = 0.76); 7.03 ± 0.30 mm and 7.02 ± 0.27 mm (ICC = 0.80); 16.56 ± 0.85 mm and 16.62 ± 0.81 mm (ICC = 0.72); and 23.59 ± 0.85 mm and 23.64 ± 0.87 mm (ICC: 0.76) of observer 1 and 2, respectively. Conclusion:  Non-contact Biometer (HAAG-STRAIT) has high inter-observer reproducibility with strong interclass coefficient of greater than 0.72. Key Words:  Biometry, Axial Length, Central Corneal Thickness, Anterior Chamber Depth.

scholarly journals Presbyopia and its anatomical and physiological variants

1970 ◽  
Vol 3 (2) ◽  
pp. 155-158
Author(s):  
M Gupta ◽  
RR Sukul ◽  
Y Gupta ◽  
M Dey ◽  
A Phougat ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Physiological Parameters ◽  
Corneal Curvature ◽  
Lens Thickness ◽  
Significant Difference ◽  
The Mean

Aim: To study the various ocular anatomical and physiological parameters in presbyopia. Materials and methods: We studied the various ocular anatomical and physiological parameters like corneal curvature (keratometry readings: K1 and K2), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL) in 100 presbyopic patients between 35 - 55 years of age. The patients were divided into two age groups: I (35 – 44 years) and II (45-55 yrs). ACD, AL and LT were measured using an Ascan. CCT was measured with ultrasonic pachymetry. Results: The CCT decreased (BE), LT increased and ACD decreased (RE) significantly with increasing age (p < 0.05). There was no significant difference in males and females. Nearly 3/4th of the total increase in lens thickness was responsible for the decrease in the anterior chamber depth and the rest, 1/4th , goes posteriorly. Corneal curvature and AL showed no significant change with age. Conclusions: The mean of CCT decreased significantly with advancing age. As age increased, the mean value of lens thickness increased and anterior chamber depth decreased. Nearly 3/ 4th of total increase in LT was anteriorly, decreasing the ACD. Corneal curvature and AL has no relation with age. Key words: Presbyopia, central corneal thickness, anterior chamber depth, lens thickness, axial length DOI: http://dx.doi.org/10.3126/nepjoph.v3i2.5269 Nepal J Ophthalmol 2011; 3(2): 155-158

scholarly journals The Effects of Soft Contact Lens Wear on Corneal Thickness, Curvature, and Surface Regularity

2014 ◽  
Vol 4 (2) ◽  
pp. 35-39
Author(s):  
RP Sah ◽  
N Paudel ◽  
M Chaudhary ◽  
P Adhikari ◽  
SK Mishra
Keyword(s):  
Contact Lens ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Corneal Topography ◽  
Control Group ◽  
Soft Contact ◽  
Contact Lens Wear ◽  
Soft Contact Lens ◽  
The Mean ◽  
Lens Wear

Contact lenses have various cosmetic and optical advantages over spectacles. However, long term lens use might affect the normal corneal anatomy and physiology in a variety of ways. The aim of this study was to determine the effect of soft contact lens wear on corneal thickness, curvature, and surface regularity.A total of 138 eyes of 69 subjects wearing contact lenses for more than 1 year were evaluated. One eye of each case was randomly selected for the analysis. Nidek Magellan Mapper corneal topography system was used to evaluate the anterior corneal topography. Central corneal thickness (CCT) was measured using Quantel Medical Axis II PR. Corneal topography and CCT measurements on 138 eyes of 69 subjects were performed. The mean age of the cases and controls was 24.76 ± 5.52 25.13±5.49 years respectively. The mean dura­tion of contact lens wear was 4.83±4.19 years. The mean CCT in case and control group was 527.56±37.40 microns and 544.60±26.10 microns respectively. The mean central corneal thickness in the cases was significantly less by about 16.31 μm in comparison to controls (P <0.05, 95% CI of the difference: 9 μm - 24μm). The SRI and SAI indices were significantly greater in contact lens wearers than in the control group (P = 0.00 for both SRI and SAI).Regular corneal pachymetry and topography assessments are mandatory in soft contact lens users as long term lens wear appears to reduce the central corneal thickness and increase the corneal surface irregularity. DOI: http://dx.doi.org/10.3126/jcmc.v4i2.10861 Journal of Chitwan Medical College 2014; 4(2): 35-39

scholarly journals Relationship between axial length, keratometry and central corneal thickness in patients with refractive errors at a teaching hospital in Southwest, Nigeria

2021 ◽  
Vol 8 (11) ◽  
pp. 1657
Author(s):  
Anthony O. Betiku ◽  
Adeola O. Onakoya ◽  
Olufisayo T. Aribaba ◽  
Omodele O. Jagun
Keyword(s):  
Teaching Hospital ◽  
Refractive Error ◽  
Axial Length ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
University Teaching ◽  
Refractive Errors ◽  
Cross Sectional ◽  
The Mean

Background: Aim of the study was to determine the relationship between axial length (AL), keratometry and central corneal thickness (CCT), and refractive errors in adult patients attending the Guinness eye centre (GEC), Lagos university teaching hospital (LUTH) Idi-Araba, Lagos.Methods: A descriptive cross-sectional study conducted among consecutive patients aged 16 years and above with refractive errors attending the GEC, LUTH. Ocular parameters measured included AL, anterior corneal curvature, CCT and refractive errors. AL and keratometry were measured with IOL master and CCT with ultrasonic A scan pachymeter. Refraction was done with auto-refractor-keratometer. Data analysis was done with statistical package for social science (SPSS) 20. Results: A total of 394 patients were studied, 157 males and 237 females. The age range was 16-65 years, mean -37.9±13.3 years and median -36.5 years. There were more myopic patients 215 (54.6%) than hyper-metropes 179 (45.4%). The mean AL was 23.9±1.1 mm and eyes with longer AL were more likely to be myopic (r=-0.676, p<0.001); to have flatter cornea (r=0.519, p<0.001) and thicker cornea (r=0.149, p=0.003). The mean CCT was 520.3±31.0 µm. There was a weak negative correlation between CCT and refractive error (r=-0.111, p=0.027).Conclusions: The mean CCT was lower than the mean CCT of other Nigerian studies. Hypermetropic patients were more likely to have thinner corneas. This may lead to underestimation of intraocular pressure (IOP) in these patients. Significant correlation was seen between AL and refractive error, CCT and keratometry. AL correlated with less spherical equivalent refractive error, flatter and thicker cornea. It is therefore important to measure the CCT of all patients going for refractive surgery to detect those at risk of developing corneal ectasia following refractive surgery.

Long term results of accelerated corneal collagen cross-linking in pediatric keratoconus

2021 ◽  
pp. 112067212110183
Author(s):  
Yasin Cinar ◽  
Cagla Cilem Han ◽  
Alparslan Sahin ◽  
Zeba A Syed
Keyword(s):  
Visual Acuity ◽  
Corneal Thickness ◽  
University Hospital ◽  
Long Term Results ◽  
Cross Linking ◽  
Distance Visual Acuity ◽  
The Mean ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Purpose: To evaluate the long term visual, refractive, and corneal tomographic outcomes of epithelium-off accelerated corneal collagen cross-linking (ACXL) in the management of pediatric keratoconus (KC). Methods: This retrospective study included patients under 18 years old with progressive KC who underwent ACXL between 2012 and 2019 at Dicle University Hospital. Complete ophthalmic examination was performed including uncorrected distance visual acuity (UDVA), best spectacle-corrected distance visual acuity (CDVA), manifest refraction, and corneal tomography. Evaluations were performed preoperatively and at 6 months intervals postoperatively. Results: Forty-nine eyes of 49 patients were included in the study. The mean age of patients at the time of ACXL was 14.2 ± 1.8 (range: 9.5–17.3) years. Mean follow up was 4.61 ± 1.90 (range: 2.0–8.1) years. The mean LogMAR UDVA improved from 0.94 ± 0.41 to 0.81 ± 0.43, 0.69 ± 0.41, and 0.67 ± 0.33 after 1, 3, and 5 years respectively ( p = 0.001). The mean LogMAR CDVA improved from 0.58 ± 0.36 to 0.46 ± 0.31, 0.34 ± 0.23, and 0.39 ± 0.27 after 1, 3, and 5 years respectively ( p = 0.015). The mean refractive cylinder improved significantly from 6.01 ± 2.07 diopters (D) to 5.46 ± 1.87, 5.38 ± 2.18, and 5.02 ± 2.31 D after 1, 3, and 5 years respectively ( p = 0.005). As compared to preoperative values, steep keratometry and maximum keratometry were not significantly different ( p = 0.805 and 0.448, respectively) following ACXL, while flat keratometry significantly improved after ACXL ( p = 0.012). Although central corneal thicknesses decreased significantly ( p = 0.029), the decrease in thinnest corneal thickness was not statistically significant ( p = 0.205). Conclusion: Epithelium-off ACXL seems to be effective for halting KC progression with long term clinical benefits in pediatric patients.

scholarly journals Corneal Biomechanical Parameters and Central Corneal Thickness in Glaucoma Patients, Glaucoma Suspects, and a Healthy Population

2021 ◽  
Vol 10 (12) ◽  
pp. 2637
Author(s):  
Mª. Ángeles del Buey-Sayas ◽  
Elena Lanchares-Sancho ◽  
Pilar Campins-Falcó ◽  
María Dolores Pinazo-Durán ◽  
Cristina Peris-Martínez
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Mean Difference ◽  
The Other ◽  
Control Group ◽  
Healthy Population ◽  
Diagnostic Categories ◽  
Significant Difference ◽  
Biomechanical Parameters ◽  
The Mean

Purpose: To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. Methods: In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. Results: The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). Conclusion: This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group.

Detecting subclinical keratoconus by biomechanical analysis in tomographically regular keratoconus fellow eyes

2021 ◽  
pp. 112067212110637
Author(s):  
Victor A Augustin ◽  
Hyeck-Soo Son ◽  
Isabella Baur ◽  
Ling Zhao ◽  
Gerd U Auffarth ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Case Series ◽  
Biomechanical Analysis ◽  
Corvis St ◽  
Corrected Visual Acuity ◽  
The Mean ◽  
Best Corrected Visual Acuity ◽  
Fellow Eyes

Purpose To analyze the tomographically non-affected second eyes of keratoconus patients using the Corvis ST to detect any biomechanical abnormalities or subclinical keratoconus. Methods In this retrospective, single-center, consecutive case series 244 eyes of 122 keratoconus patients were analyzed between November 2020 and February 2021. Fourteen fellow eyes fulfilled the inclusion criteria and showed no clinical or tomographic signs of keratoconus. Main outcome measures included best-corrected visual acuity, tomographic and biomechanical analyses using Scheimpflug imaging: Pentacam and Corvis ST (Oculus, Wetzlar, Germany). Tomographic analyses included anterior and posterior simulated keratometry, K-Max, central corneal thickness, thinnest corneal thickness, Belin/Ambrosio Ectasia Display, and the ABCD grading system. For biomechanical analyses, the corneal biomechanical index (CBI) and tomographic biomechanical index were used. Results The mean best-corrected visual acuity was 0.01 ± 0.10 logMAR. Mean K-Max was 43.79 ± 1.12 D, mean central corneal thickness 529 ± 25 µm, mean thinnest corneal thickness 524 ± 23 µm, and mean Belin/Ambrosio Ectasia Display 1.0 ± 0.32. The mean CBI was 0.30 ± 0.21. Regular CBI values were found in six of 14 patients. The mean tomographic biomechanical index was 0.47 ± 0.22 with regular values observed in only two of 14 patients. No signs of tomographic or biomechanical abnormalities were shown in only one of 14 keratoconus fellow eyes, with regular ABCD, Belin/Ambrosio Ectasia Display, CBI and tomographic biomechanical index values. Conclusions Tomographically normal fellow eyes of keratoconus patients are rare. In these cases, a biomechanical analysis of the cornea may help detect a subclinical keratoconus. The tomographic biomechanical index was the most sensitive index to verify a mild ectasia.

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