Central Corneal Thickness In Patients Research Articles

Overview of Central Corneal Thickness in Patients with Glaucoma: A Single Center Observational Study at Dr. M. Djamil General Hospital, Padang, Indonesia

Background: Central corneal thickness (CCT) is an important risk factor in the diagnosis and management of glaucoma. This study aims to determine the CCT picture of various types of glaucoma at Dr. M. Djamil General Hospital Padang. Methods: This descriptive retrospective study involved data from glaucoma patients at Dr. M. Djamil General Hospital Padang for the period January 2019 - December 2020. CCT data was obtained from medical records and OCT computer data. Descriptive analysis was carried out to see the distribution of CCT in ocular hypertension (OHT), glaucoma suspect (GS), normal tension glaucoma (NTG), primary open-angle glaucoma (POAG), and juvenile open-angle glaucoma (JOAG) groups. Results: A total of 123 glaucoma patients were analyzed. The overall mean CCT was 535.50 ± 43.82 µm. The highest mean CCT was in the OHT group (566.30 ± 32.07 µm) and the lowest in POAG (523.39 ± 39.43 µm). The mean age of patients was 35.19 ± 16.20 years. The POAG group had the highest mean age (52.52 ± 9.54 years), while the JOAG group had the lowest (22.00 ± 5.84 years). Conclusion: There are variations in CCT in various types of glaucoma, with OHT having the highest CCT and POAG the lowest. This data can be a basis for consideration in the diagnosis and management of glaucoma in Indonesia.

Anterior scleral thickness in Marfan syndrome: A quantitative analysis.

To investigate the anterior scleral thickness (AST) in patients with Marfan syndrome (MFS). A prospective, cross-sectional study was conducted at the Department of Ophthalmology, Ghent University Hospital, Ghent, including patients with a genetically confirmed clinical diagnosis of MFS and age-, gender- and axial length-matched controls. Subjects with known corneal, conjunctival or scleral pathology and a history of ocular surgery, including pars plana vitrectomy, recent contact lens use or high-grade astigmatism were excluded. Subjects underwent non-cycloplegic autorefraction, Scheimpflug-based corneal tomography, axial length measurement and spectral-domain optical coherence tomography (OCT). AST was manually measured at 1 mm (AST1), 2 mm (AST2) and 3 mm (AST3) from the scleral spur, temporally and nasally. A total of 56 subjects (28 subjects in the MFS group and 28 matched subjects in the control group) were included in this study. In patients with MFS, AST was significantly reduced compared to matched controls, both overall and at every analysed measuring point in the nasal and temporal areas (p < 0.001). Central corneal thickness (CCT) and mean keratometry (Kmean) values were significantly lower in patients with MFS (p < 0.05). A positive correlation was found between nasal AST and CCT in patients with MFS. No correlation was found between AST and Kmean or between AST and axial length. In patients with MFS with ectopia lentis, compared to those without, temporal AST3 was significantly lower (p < 0.05). AST was significantly lower in patients with MFS harbouring a variant predicted to cause haploinsufficiency compared to those with a variant expected to lead to a dominant negative effect for both nasal and temporal measurements. Based on anterior segment OCT measurements, AST of patients with MFS is significantly lower compared to matched controls.

Comparing intraocular pressures with different types of tonometers and its correlation with central corneal thickness in patients presenting in a tertiary care centre

Comparing intraocular pressures with different types of tonometers and its correlation with central corneal thickness in patients presenting in a tertiary care centre

A comparative study of central corneal thickness in patients with diabetes and without diabetes mellitus

Diabetes mellitus (DM) is becoming increasingly and seriously prevalent lifestyle health problem worldwide. Up to 70% of diabetic patients can develop corneal changes and are also difficult to manage. Several studies were done to find out the morphological changes in cornea in type 2 DM, but the results are highly variable. Central corneal thickness (CCT) is widely considered as a constant parameter, so are measured only once during follow up in our daily clinical practice. Here we study the effect of diabetes over CCT, for a better understanding of the impact of diabetes over CCT.A comparative observational study of one and half years done among 106 diabetes and 106 non diabetic patients between 35 to 75 years old, attending ophthalmology OPD. CCT of both eyes was measured and mean CCT and was compared between diabetic and non-diabetic groups, among different subgroups of diabetic subjects and other parameters.CCT was thicker among diabetic groups (553.4434um) than non-diabetic groups (549.8491) but was not statistically significant according to our study. But there was statistically significant (p value 0.000165) thickening with increasing grades of diabetic retinopathy (DR) (mild DR (535.4524), moderate DR (543) and PDR (591.5)). Our study concludes that DM is associated with thicker cornea; hence CCT values can vary with time in DM. So repeated CCT measurements for corrected IOP values is advised and warranted in DM patients for proper management of IOP.

Quantitative changes in the corneal endothelium and central corneal thickness during anterior chamber inflammation: A systematic review and meta-analysis.

To establish the effects of anterior chamber inflammation (ACI) on the corneal endothelium parameters and central corneal thickness (CCT). We conducted a comprehensive literature review using medical databases (PubMed, EMBASE, VHL, and medRxiv) on March 8, 2023, for studies that included patients with ACI who had undergone specular microscopy or pachymetry. Case series with >10 patients, cross-sectional, case-control, and cohort studies were included. The risk of bias was assessed using CLARITY tools and validated scales such as those by Hassan Murad et al. and Hoy et al. A narrative synthesis and a quantitative standardized mean difference meta-analysis, I2 heterogeneity assessment, and publication bias tests were conducted. The study was registered in PROSPERO (CRD42023420148) and approved by the Universidad del Rosario ethical committee (DVO005 2277- CV1712). Thirty-four studies, encompassing 1,388 eyes with ACI, were included. Compared with healthy controls, overall, ACI eyes show significant mean differences in endothelial parameters (endothelial cell density (ECD), coefficient of variation (CV), and hexagonality (HEX)) (P < 0.05). In the subgroup analysis compared with healthy controls, both active and chronic-recurrent ACI demonstrated a reduced ECD. An increased CV was observed in active, inactive, and chronic-recurrent ACI. Lower HEX was evident in inactive, acute, and chronic-recurrent ACI, while both active and acute ACI exhibited high CCT. ACI leads to significant alterations in endothelial parameters and CCT. The primary contributors to these changes are increased IOP, uveitis duration, and intraocular surgeries. Further studies are needed to explore the impact of ACI etiology on the endothelium, potential biases in IOP measurements during acute ACI episodes, and the potential necessity for monitoring the endothelial parameters and CCT in patients with chronic ACI.

Central Corneal Thickness in Patients with Dry Eye Disease

Background: Dry eye or Keratoconjunctivitis sicca is mainly due to decreased tears which causes eye visual disturbance and discomfort. Dry eye affects corneal thickness. Aims and Objectives: Aim of the study is to evaluate the effect of dry eye disease on CCT with age and gender match controls. Materials and Methods: Two Hundred and twenty subjects , 110 Patients are cases and 110 are controls. Subjects are from the Department of Ophthalmology Narayana Medical college and Hospital Out patient Department are included in the the study. Dry eye disease diagnosed with questionnaire , Tear film Break up test , Schirmer’s test and slit lap examination . CCT is measures with Optical Pachymetry. T test was used to determine the significane of difference between two means. Results: In our study, there were 140 female patients and 80 male patients. The CCT among cases was very low (534.19 ?m±30.05) compared to controls (562.7 ?m±45.56) and this difference was statistically significant (P&lt;0.05. The difference in CCT among males between the two groups was statistically significant and it was highly significant among females. Conclusion: There is a significant decrease in CCT due to Dry eye Disease. Pachymetry for CCT estimation shall be included in the routine management of dry eye patients so that corneal thinning could be easy to identify earlier and treated earlier

The Effect of Artificial Tear Treatment on Central Corneal Thickness in Dry Eyes

Objective: To evaluate the role of artificial tear treatment on central corneal thickness in patients with dry eyes coming to a tertiary care eye hospital. Study Design: Quasi-experimental study. Place and Duration of Study: Tertiary Care Eye Center, Armed Forces Institute of Ophthalmology, Rawalpindi Pakistan, from May to Nov 2022. Methodology: The study included central corneal thickness of 210 eyes (n=210) of 110 patients with dry eye disease measured before and after treatment with continuous use of artificial tear drops one month apart, patients were diagnosed on the presence of symptoms such as burning, dryness, pain, irritation, grittiness followed by slit lamp examination for marginal tear meniscus(&lt;0.25mm) or absent, tear film BUT of &lt;10 seconds , Schrimer test 2 of &lt;6mm after 5 minutes and ocular surface staining score of &gt;1 with fluorescein. Central corneal thickness was measured using corneal topography (Galleli G6 Ziemer). Results: A total of two hundred and twenty eyes of 110 individuals having dry eyes were included in our study. Median CCT before treatment with artificial tears was 522(75)µm while median CCT after 1 month treatment with artificial tears was 547(22.25)µm this showed a percentage increase of 3.79% in central corneal thickness after one month treatment with artificial tears (p-value &lt;0.001) therefore treatment with artificial tears was significantly associated with an increase in central corneal thickness in dry eye disease. Conclusion: Central corneal thickness is substantially related to dry eyes.

Assessment of the effects of intrastromal injection of adipose-derived stem cells in keratoconus patients.

To evaluate the efficacy and safety of intrastromal transplantation of adipose-derived stem cells (ASCs) in keratoconus patients. This study was conducted on 8 eyes of 8 patients with moderate to severe keratoconus. In the patients, ophthalmic assessments including visual acuity, refraction, slit lamp examination, fundoscopy, corneal topography, and confocal microscopy were performed. Autologous stem cells were used. The isolated stem cells were injected into the corneal stroma by using femtosecond laser. Surgical procedure was similar to intracorneal ring implantation. All patients were re-assessed 1, 3, and 6mo after surgery. The baseline mean visual acuity was 0.48±0.18 and improved to 0.66±0.17 after surgery and final acuity increased by 1.85±0.80 lines (P=0.001). The mean spherical refraction of patients improved 0.34±0.35 D (P=0.039), and the mean cylindrical refraction of patients improved 0.84±0.23 D (P=0.016). The mean flat keratometry decreased 0.78±0.71 D (P=0.017), and the mean steep keratometry decreased 0.59±0.68 D (P=0.023). The mean central corneal thickness of patients improved of 6.29±4.47 µm (P=0.03). The mean keratocyte density at the anterior and middle stroma of cornea increased (P<0.05) but remained stable at the posterior stroma after 6mo. All patients had no complications and their corneas remained transparent. Intrastromal transplantation of ASCs has positive effects on vision and refractive parameters in most patients with keratoconus. After six months, visual acuity improved moderately, corneal parameters reduced slightly, and stromal keratocytes density increased. This modality is safe, and patients do not have any complications.

Correlation between retinal nerve fiber layer thickness and anterior segment parameters in patients with pseudoexfoliation: A cross-sectional comparative study.

The purpose of this study was to assess the retinal nerve fiber layer (RNFL) thickness in patients with pseudoexfoliation (PXF) and to correlate it with anterior segment parameters such as intraocular pressure (IOP), central corneal thickness (CCT), pigments in angle structures, and grades of PXF. This was a cross-sectional comparative study in a tertiary care center. Patients having unilateral PXF were categorized as group 1. Age- and sex-matched healthy controls were categorized as group 2. All subjects underwent IOP measurement, CCT measurement, and retinal nerve fiber thickness measurement. Subjects in group 1 also underwent gonioscopy and perimetry. Data were entered and analyzed using the IBM-SPSS program (version 20.0); Chicago, IL. Mean RNFL thickness in group 1 was 85.91 ± 22.237 μ and in group 2 was 106.65 ± 6.1 μ. The mean RNFL thickness in patients with PXF syndrome was 103.38 ± 5.815 μ and in patients with PXF glaucoma was 67.82 ± 17.984 μ. The mean CCT in patients with PXF syndrome was 516.41 ± 23.03 μ and in patients with PXF glaucoma was 507 ± 33.05 μ and control group was 526.6 m. The mean IOP in patients with PXF syndrome was 8 ± 6.01 mmHg; in patients with PXF glaucoma was 17.21 ± 7.33 mmHg; and in the control group was 14.12 ± 2.693 mmHg. There was a negative correlation between IOP and RNFL thickness, and a positive correlation between CCT and RNFL thickness, but it was not statistically significant. A statistically significant correlation was found between grades of PXF and RNFL thinning with a correlation coefficient of 0.437 (P = 0.001). Patients with PXF have a lower CCT, higher mean IOP, and RNFL thinning compared to normal subjects. The presence of grade 3 PXF (on the lens surface edge) showed a statistically significant correlation with RNFL thinning.

Evaluation of the corneal biomechanical properties and corneal thickness in patients with Graves' orbitopathy.

To evaluate the corneal biomechanical properties and central corneal thickness in patients with Graves' orbitopathy (GO). A total of 132 eyes of 66 patients with GO and 108 eyes of 54 healthy subjects were enrolled. Eyes with GO were classified as high score clinical activity score (CAS, ≥ 3) (Group 1, n = 64) and low CAS score (< 3) (Group 2, n = 68). Corneal biomechanical parameters [corneal hysteresis (CH), corneal resistance factor (CRF)], Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated IOP (IOPcc) levels were measured with Ocular Response Analyzer (ORA, Reichert Ophthalmic Instruments, Buffalo, NY) and compared between the groups. The mean CH values were found as 9.6 ± 1mmHg in Group 1, 10.2 ± 0.9mmHg in Group 2, and 11.4 ± 1.7mmHg in the Control Group (p < 0.001). In post hoc analysis the mean CH was significantly lower in Group 1 than Group 2 and Control Group (Group 1-Group 2, p < 0.001; Group 1-Control Group, p < 0.001). The mean CRF was found as 10.5 ± 2.1 in Group 1, 10.4 ± 2.2 in Group 2, and 10.43 ± 2.0 in the Control group. There was no statistically significant difference between the groups in CRF measurements (p = 0.959). The mean IOPcc values were found as 17.1 ± 3.6mmHg in Group 1, 15.8 ± 4.0mmHg in Group 2 and 15.2 ± 4.1mmHg in the Control Group. The IOPcc and IOPg measurements between all groups were statistically significant (p = 0.009, p = 0.027, respectively). Corneal biomechanical measurements were different in the GO patients with varying CAS scores compared to healthy individuals.

The Effect of Prostaglandin Analogs on Central Corneal Thickness of Patients with Glaucoma or Ocular Hypertension: A Systematic Review

Background: Prostaglandin analogs (PGAs) are first-line antiglaucoma agents that appear to either decrease or increase central cornea thickness (CCT), creating controversy regarding the benefits of PGAs in treating CCT. Purpose: We performed the first meta-analysis of observational studies to evaluate the effects of PGAs on CCT in patients with glaucoma or ocular hypertension (OHT). Methods: This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. A literature search was performed of the PubMed, Embase, Cochrane Library, System for Information on Grey Literature in Europe (Open Grey), and ClinicalTrials.gov databases and the references of retrieved studies. Only observational studies were included in the meta-analysis. The final CCT of patients and 95% confidence interval (CI) of each study were extracted. Study quality was assessed using the Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ). A fixed-effects model was used to calculate the weighted mean difference (WMD) and 95% CI. Subgroup analyses based on several stratified factors such as public bias (Begg’s test) and sensitivity analyses were performed. Results: Five cohort, 5 case-control, and three cross-sectional studies including 2,722 subjects were included. The pooled effect of all thirteen studies showed that PGAs reduced the CCT of patients with glaucoma or OHT slightly but significantly (WMD = −9.37; 95% CI [−12.18, −6.57]; p = 0.00; I2 = 45.5%). Significant effects were also observed in all three study designs: cohort (WMD = −5.17; 95% CI [−9.52, −0.82]), case-control (WMD = -15.31; 95% CI [−22.66, −7.97]), and cross-sectional (WMD = −8.65; 95% CI [−17.30, −0.01]). In addition, subgroup analysis of exposure time showed the effect of PGAs to be more obvious in the first (WMD = −5.81; 95% CI [−9.49, −2.14]) and second (WMD = −13.73; 95% CI [−20.19, −7.28]) years. Conclusions: The pooled effects of previously reported studies suggest that PGA use can reduce the CCT of patients with glaucoma or OHT slightly but significantly, with this effect more pronounced in the first 2 years. These findings suggest that clinicians must closely monitor changes in CCT in the first 2 years of PGA use to identify cases of intraocular pressure misestimation and the efficacy of PGAs.

Central Corneal Thickness of a Saudi Population in Relation to Age, Gender, Refractive Errors, and Corneal Curvature.

Background In this study, we aimed to investigate the relationship between central corneal thickness (CCT) and age, gender, refractive errors, and corneal curvature in a Saudi population. Methodology In this randomized, hospital-based, retrospective study, data were collected from Dr. Sulaiman Al Habib Hospital and Imam Medical Center, Riyadh. A total of 1,005 eyes were included and recruited from patients referred to the refractive surgery clinic for Lasik assessment. The study included patients aged between 17 and 57 years with no history of any ocular pathology, eye surgeries, and systemic disease, as well as all groups with stable refractions. The identifying data were the age and gender of the patients, as well as their CCT, refraction, and corneal curvature. CCT and corneal curvature were measured by ultrasound pachymeter Pentacam. Results The distribution of CCT was 543.81 ± 34.47 μm. A significant difference in the mean CCT was observed across different refractive errors (p = 0.004). Patients with astigmatism had the lowest CCT, followed by myopic and hyperopic patients. An association between the spherical equivalent of patients with myopia and CCT (p = 0.001) was noted. Conclusions In the Saudi population, we found no significant association between mean corneal curvature and CCT in all three groups. Spherical equivalent in myopic patients was significantly associated with CCT. A significant difference in the mean CCT was observed across different refractive errors. There was a significant negative and weak correlation between age in myopic and astigmatism patients and CCT. Gender was significantly associated with CCT in patients with astigmatism.

Evaluation of central corneal thickness in patients with dry eye disease in a tertiary eye hospital in Kancheepuram

Background: Dry eye disorder is a disease mainly due to the tear insufficiency which results in eye discomfort and disturbances in vision. Dry eye also affects the ocular dimensions, especially corneal thickness. Central corneal thickness (CCT) assessment plays an important role in refractive surgeries and in the pre-operative assessment of other ocular surgeries. Aims and Objectives: This study aims to assess the effect of dry eye disease (DED) on CCT with age- and gender-matched controls. Materials and Methods: One hundred and four subjects (52 cases and 52 controls) who attended SRM Medical College and Hospital ophthalmology outpatient department were included in the study. DED was diagnosed with DEQS questionnaire, slit-lamp examination, TFBUT, and Schirmer’s test. Pachymetry was used for measuring the CCT of all subjects. Student “t”-test was used to determine the significance of difference between two means. P&lt;0.05 was considered statistically significant. Results: In our study, there were 60 female patients and 44 male patients. The ratio of male-to-female was 1:1.3. The CCT among cases was very low (533.19 μm±30.05) compared to controls (569.27 μm±45.56) and this difference was statistically significant (P&lt;0.05). When subgrouped under gender, the difference in CCT among males between the two groups was statistically significant and it was highly significant among females. When the reduction in CCT among the cases was studied under different age groups, the subjects in the 41–60 years age group had a statistically highly significant difference in CCT between the two groups while it was also significant in other age groups. Conclusion: There is a significant decrease in CCT due to DED. Pachymetry for central corneal estimation shall be included in the routine management of dry eye patients so that corneal thinning could be identified earlier and treated with artificial tears or other substitutes.

Erythrocyte Distribution Width and Central Corneal Thickness in Patients with Obstructive Sleep Apnea Syndrome

Erythrocyte Distribution Width and Central Corneal Thickness in Patients with Obstructive Sleep Apnea Syndrome

Effect of prostaglandin analogues on central corneal thickness in patients with glaucoma: A systematic review and meta-analysis with trial sequential analysis.

The objective of this meta-analysis was to evaluate the effect of prostaglandin analogues (PGA) on central corneal thickness (CCT) in patients with glaucoma. Key electronic databases were searched for randomized controlled trials (RCTs) involving the CCT effects of prostaglandin use for glaucoma. Primary outcome measures were the mean difference in the CCT measurement from baseline to the last available assessment. Intraocular pressure and other corneal changes were recorded as secondary. Efficacy estimates were measured by their weighted mean difference (WMD) with 95% confidence intervals (CI’s) by using the random-effects model for primary and secondary outcomes Trial sequential analysis was used to determine if the current evidence was sufficient and conclusive. Eight RCTs met our inclusion criteria. A total of 879 patients were included. The overall effect showed that PGA’s had a significant CCT lowering effect (WMD = −7.04, 95%CI: −10.07 to −4.00, P < 0.00001). We pooled results of 5 RCT’s on Travoprost (WMD = −10.44, 95%CI: −16.80 to −4.08, P = 0.001), seven trials on Latanoprost (WMD = −4.73, 95% CI: −9.70 to 0.25, P = 0.06), and three trials on Bimatoprost (WMD = −11.88, 95%CI: −21.03 to −2.73, P = 0.01). The WMD across groups in >6 months of PGA use was −11.37 (95%CI: −17.17 to −5.58, P = 0.0001), and in <6 months of PGAs group was −8.35 (95% CI: −12.01 to −4.69, P < 0.00001), suggesting a longitudinal effect of PGAs on CCT. In conclusion, Bimatoprost and Travoprost caused a statistically significant reduction in the thickness of central cornea. Though only a few studies were included, the narrow confidence intervals and adequate sample size suggest that these findings are valid.

Comparison of Central Corneal Thickness in patients with Pseudoexfoliation Syndrome v/s Controls

Introduction: Pseudoexfoliation in the eye is diagnosed by the presence of white, flaky, dandruff-like fibrillo granular material on the pupillary margin or the anterior capsule of the lens. A characteristic “three-ring sign” is noted on the anterior lens capsule after pupillary dilatation. The presence of pseudoexfoliation (PEX) material in the anterior stromal layers of the cornea and a decrease in the stromal cell densities have been suggested to be the cause of thinner CCT in eyes with PEX. The thinning is presumed to be due to apoptosis of the keratocytes. Aim: To evaluate Central Corneal Thickness in patients with pseudo-exfoliation syndrome and compare them with normal healthy controls. Material & Methods: The proposed case-control hospital-based study comprised 100 participants divided into two groups: Group I: Patients above 40 years of age diagnosed with pseudoexfoliation syndrome on Slit lamp examination. Group II: Healthy individuals above 40 years of age without pseudoexfoliation syndrome. Informed written consent was taken from all participants. Other ophthalmic or systemic conditions which influence the corneal thickness measurement like Corneal dystrophies, degenerations, scars and post corneal refractive surgery, previous ocular surgery or ocular trauma, Glaucoma, Ocular hypertension, Uveitis, Systemic diseases like diabetes, or with ocular manifestations (collagen, skin, mucous membrane diseases), usage of topical medications which might affect the corneal conditions (esp. medications with preservatives), were excluded from the study. After a comprehensive ophthalmic examination, specular microscopy was performed on all study participants using TOPCON SP-1P Specular microscope to record central corneal thickness. Results: The mean Central Corneal Thickness (µm) obtained from specular microscopy in the PEX group was 487.34±27.16, while in controls, the mean Central Corneal Thickness (µm) recorded using specular microscopy was 505.09±26.36. The comparison of CCT (µm) between the PEX group and the Control group was statistically significant (p-value

A study to correlate the central corneal thickness to the severity of diabetic retinopathy and HbA1c levels in type 2 diabetes mellitus

Background: Diabetic retinopathy (DR) is one of the most common causes of preventable blindness. Patients with Diabetes Mellitus (DM) develop not only DR but also corneal endothelial damage leading to anatomical and physiological changes in cornea. Central corneal thickness (CCT) is a key parameter of refractive surgery and Intraocular pressure (IOP) estimation. The role of CCT and higher glycemic index in DR needs to be researched upon. Objectives: To identify the corneal endothelial morphology in patients with type 2 DM, to measure the Central Corneal thickness (CCT) in patients with type 2 Diabetes Mellitus, to assess the relationship of CCT with HbA1C levels in the study group and to correlate the CCT with the severity of Diabetic retinopathy in the study group. Methods: A cross-sectional observational study was conducted between January 2018 and June 2019 in Vydehi Institute of Medical Sciences and Research Centre, Bangalore. The study included 100 subjects with type 2 DM for 5 years or more. Patients with comorbidities that may affect the severity of DR or alter CCT and other corneal endothelial parameters such as glaucoma, previous ocular surgery or trauma, corneal degenerations and dystrophies, chronic kidney disease and Hypertension were excluded. DR was assessed by dilated fundoscopy, fundus photography and optical coherence imaging of the macula and graded as per the Early Treatment of Diabetic Retinopathy Study (ETDRS) classification. CCT and other corneal endothelial parameters were measured through specular microscopy. Relevant blood investigations including blood sugar levels were done for all patients. Statistical analysis: Relationship between CCT and grades of DR and HbA1c levels were established using the Chi-Square test. The level of significance was set at p &lt; 0.05. Results: The mean CCT in patients with no diabetic retinopathy, very mild and mild non-proliferative diabetic retinopathy (NPDR), moderate NPDR, severe and very severe NPDR and PDR was 526.62 ± 8.084 μm, 542.07 ± 8.713 μm, 562.16 ± 8.255 μm, 582.79 ± 7.368 μm and 610.43 ± 18.256 μm respectively. Analysis of the relationship between CCT and severity of DR showed a statistically significant positive correlation between the two parameters (Pearson r = 0.933, P=0.001). Beyond this, a correlation was found between all the corneal endothelial parameters and severity of DR. Multivariate analysis showed that advanced DR was positively correlated with CV (r = 0.917) and CCT (r = 0.933); while it was negatively correlated with ECD (r = -0.872) and Hex (r = -0.811). A statistically significant correlation was also found between CCT and HbA1c. Also increasing age, duration of DM and higher glycemic index were positively correlated with severity of DR. Conclusion: This study, by demonstrating a strong correlation between the central corneal thickness to the severity of DR and HbA1c levels emphasizes the importance of evaluation of corneal endothelial morphology in the early screening and diagnosis of microvascular complications of DM.

Evaluation of the relation between myopia and central corneal thickness in patients admitted to vali-e-asr hospital in birjand, iran

Introduction: Considering the increasing prevalence of myopia and the subsequent complications, and due to the dearth of studies on the correlation between myopia and gender with corneal thickness in Iran, this study aimed to determine this relationship in patients admitted to the ophthalmic clinic of Vali-e-Asr Hospital, Birjand, Iran. Methods: This descriptive-analytic epidemiologic study was conducted on 100 patients admitted to Vali-e-Asr ophthalmic clinic in Birjand, Iran, for one year since January 2017. According to the degree of myopia, the patients were divided into three groups of low (0-3 D), moderate (3-6 D), and high myopia (6≤D). Corneal thickness was measured using Orbscan and Pentacam. The data were analyzed in SPSS software (Version 19) through ANOVA and T-test to determine the possible relationship between myopia and central corneal thickness. A p-value equal to and less than (P≤0.05) was considered statistically significant. Results: Overall, 100 patients (49 males and 51 females) were enrolled in this study. Moderate myopia had the highest frequency in both eyes. The results of the T-test revealed that no significant difference was observed in the mean corneal thickness measured by Pentacam between the two genders (P=0.18 in the right eye and P=0.32 in the left eye). Based on the ANOVA findings, the mean corneal thickness measured by Pentacam was not significantly different among the myopia categories (P=0.05 in the right eye and P=0.51 in the left eye) Conclusions: The study results revealed that there was no significant relationship between myopia and gender with corneal thickness.

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

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&lt;0.001); to have flatter cornea (r=0.519, p&lt;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.

Do topical antiglaucoma drugs affect the cornea?

To investigate effects of beta blocker (BB; timolol or betaxolol), latanoprost, and latanoprost-timolol combination (LTC) drugs on corneal endothelial cell density (ECD) and central corneal thickness (CCT) in primary open-angle glaucoma (POAG) patients. Sixty-one patients in BB group, 64 patients in latanoprost group, 59 patients in LTC group, and 58 healthy cases in control group were included. Intraocular pressures (IOP), ECDs, and CCTs of groups were recorded at initial (pre-treatment) period, first and third years after treatment, and comparisons were done. In groups, changes of ECDs according to time were not significant (p > 0.05). In BB and control groups, changes of CCTs according to time were not significant (p > 0.05). In latanoprost and LTC groups, CCTs in both first and third years were significantly thinner than initial CCTs (p = 0.039 for latanoprost, p = 0.041 for LTC at first year; p = 0.018 for latanoprost, p = 0.032 for LTC at third year). In latanoprost and LTC groups, CCTs of patients using drugs for 1 year were similar to those of patients using drugs for 3 years (p > 0.05). In our study, uses of BB, latanoprost or LTC did not affect ECD. BB drugs had no effect on CCT. Although latanoprost and LTC appeared to reduce CCT at 3-year follow-up from the statistical point of view, this 8-10 μm difference in CCT was not clinically significant.