S Galgauskas

Age-related changes in corneal thickness and endothelial characteristics

Purpose To determine the influence of age on central corneal thickness (CCT), endothelial cell density (ECD), average cell size, coefficient of variation in cell size, and percentage of regular hexagonal cells; and to estimate the average ECD and CCT in seven age groups. Materials and methods After obtaining informed consent, 211 Caucasian patients (358 eyes) were examined using a noncontact specular microscope at the Center of Eye Diseases in Vilnius University Hospital Santariskiu Clinic. The main corneal parameters were: ECD, average cell size, coefficient of variation in cell size, percentage of regular hexagonal cells, and CCT. Subjects (20–89 years) were stratified by age into seven groups. Correlations between CCT, endothelial parameters (ECD, percentage of regular hexagonal cells, average, coefficient of variation), and age were found. Student’s t-test and Pearson’s correlation coefficient (r) values were calculated. Results A total of 114 (54.03%) women and 97 (45.97%) men participated in the study. Average ECD (cell/mm2) ranged from 2,931 (±371) in 20–29 year olds to 2,222 (±182) in 80–89 year olds; CCT (μm) ranged from 563 (±44) in 20–29 year olds to 540 (±35) in 80–89 year olds. A strong inverse correlation was observed between age and corneal ECD (r=−0.650, P<0.01) and a weak inverse correlation was observed between age and CCT (r=−0.156, P<0.01). ECD and CCT correlated directly (r=0.232, P<0.01). The average size of corneal endothelial cells directly correlated with age (r=0.586, P<0.01). There was no correlation between age and the coefficient of variation in cell size nor the percentage of regular hexagonal cells (P>0.05). Conclusion Young people have higher ECD. CCT also decreases, but its dependence on age is weaker. A lower cell density indicates a thinner cornea. The variation in cell size and percentage of regular hexagonal cells are not dependent on age.

Central corneal thickness and corneal endothelial characteristics in healthy, cataract, and glaucoma patients

Purpose The aim of this study was to describe and compare endothelial cell parameters and central corneal thickness (CCT) in four different groups of patients (patients with cataract, patients with glaucoma, elderly healthy subjects, and young healthy subjects) and identify correlations between these characteristics, patient age, and sex. Methods Before conducting invasive procedures, 104 patients were examined using a non-contact specular microscope. Parameters examined included endothelial cell density (ECD), percentage of regular hexagonal cells (6A), average size of endothelial cells (Ave), and CCT. Patients’ ages and sexes were also noted. Results A total of 47 (45%) patients were men and 57 (55%) were women. CCT, ECD, 6A, and Ave in cataract group were 540 (±64) μm, 2633 (±430) cells/mm2, 60 (±10)%, and 390 (±66) μm, respectively; these values in the glaucoma group were 553 (±32) μm, 2484 (±82) cells/mm2, 60 (±10)%, and 397 (±58) μm. In the elderly group these figures were 545 (± 39) μm, 2394 (±416) cells/mm2, 64 (±10)%, and 386 (±43) μm; and in young healthy subjects the values were 555 (±43) μm, 2940 (±345) cells/mm2, 66 (±10)%, and 345 (±42) μm. A weak inverse correlation was observed between ECD and subject age (r = −0.459; P < 0.05) and between ECD and CCT (r = 0.232; P < 0.05). CCT was inversely correlated with patient age (r = −0.13; P = 0.189), but statistically significant data was observed only for the glaucoma group (r = −0.572; P < 0.05). Conclusion ECD in young subjects was higher than in elderly subjects in all groups; these patients have more endothelial cells and smaller, thicker corneas. The corneal endothelium cells in males have more regular hexagonal cells than do females. No difference in CCT and the ECD was observed between sexes. CCT and average size of endothelial cells do not differ between groups.

Changes in choroidal thickness and corneal parameters in diabetic eyes.

Purpose To evaluate the effect of diabetes mellitus (DM) on central corneal thickness (CCT), corneal endothelial parameters (endothelial cell density [ECD], average size [AVE], hexagonality [A6], polymegathism [SD]), and subfoveal choroidal thickness (SFCT), and to determine whether these parameters depend on the duration of DM and hemoglobin A1c (HbA1c) level. Methods A total of 62 patients with type 2 DM and 65 healthy subjects were examined using a noncontact specular microscope, A-scan ultrasound, and spectral-domain optical coherence tomography. The study parameters included medical history, age, eye axial length, CCT, ECD, AVE, A6, SD, and SFCT. The duration of DM and HbA1c level of the 2 latest tests were noted. Results The SFCT (258.0 ± 74.4 µm) and ECD (2721.8 ± 264.1 cells/mm2) were significantly lower, and the CCT (566.7 ± 35.7 µm) higher, in diabetic patients than in the control group (313.1 ± 88.5 µm, 2967.3 ± 220.6 cells/mm2, 550.0 ± 56.4 µm, respectively) (p<0.05). There were no differences in age, sex, or axial length between the diabetic and control groups (p>0.05). Diabetic retinopathy and macular edema did not influence SFCT significantly (p>0.05). No differences in endothelial parameters between groups and no correlations among HbA1c, duration of DM, and any of the examined parameters were found (p>0.05). Conclusions Diabetic patients have thicker corneas, lower ECD, and thinner subfoveal choroid than healthy subjects.

Age-related changes in central corneal thickness in normal eyes among the adult Lithuanian population

Background The purpose of this study was to estimate mean central corneal thickness (CCT) and determine whether there are any correlations between CCT, age, and sex in the adult Lithuanian population. Methods A total of 1,650 Caucasians of Lithuanian origin (aged 18–89 years) comprising 688 (41.7%) men and 962 (58.3%) women were examined. Subjects were stratified by age into seven groups. CCT was measured using ultrasonic pachymetry. Correlations between CCT, age, and sex were sought. Results Mean (± standard deviation) CCT for both eyes was 544.6±30.5 μm. Mean CCT was 545.2±30.5 μm in the left eye and 544.6±30.5 μm in the right eye, and was 545.0±25.6 μm in men and 544.4±33.5 μm in women. Mean CCT was 550.8±35.7 μm in subjects aged 18–29 years, 557.5±27.6 μm in those aged 30–39 years, 551.3±31.4 μm in those aged 50–59 years, 544.0±31.4 μm in those aged 50–59 years, 544.2±31.6 μm in those aged 60–79 years, 535.1±27.8 μm in those aged 70–79 years, and 530.1±16.8 μm in those aged 80–89 years. No statistically significant difference in CCT was found between the sexes (P>0.05). However, there was a significant difference in subjects aged 18–29 years; men had higher CCT than women (P<0.05). A statistically significant negative correlation was found between CCT and age (r=-0.263, P<0.05) that was stronger in men (r=-0.406, P<0.05) than in women (r=-0.118, P<0.05). Conclusion The mean CCT in adult Lithuanians was 544.6±30.5 μm, of the left eye 545.2±30.5 μm and of the right – 544.6±30.5 μm. CCT of the right eye was equal to the CCT of both eyes. Mean CCT was 545.0±25.6 μm in men and 544.4±33.5 μm in women. Young men tended to have higher CCT than women. CCT decreases over the lifetime, meaning that older people have thinner corneas. CCT’s dependence on age is stronger in men.

Comparison of intraocular pressure measurements with different contact tonometers in young healthy persons.

AIM To analyze the correlation of Goldmann applanation tonometer (GAT), I-Care tonometer and Tono-Pen tonometer results in young healthy persons, and to investigate the influence of central corneal thickness (CCT) on intraocular pressure (IOP) measurements recorded with these tonometers. METHODS We conducted a pilot clinical study in 78 eyes of 78 subjects aged 22-28 years old (44 women and 34 men; mean age 23.8±1.19y). IOP was measured using GAT, I-Care and Tono-Pen tonometers, followed by measurements of CCT. Statistical analysis was performed using SPSS 20.0. RESULTS The mean IOPs and standard deviation (±SD) for GAT, I-Care and Tono-Pen were 15.62±2.281 mm Hg, 16.29±2.726 mm Hg and 16.32±2.393 mm Hg, respectively. The mean CCT was 555.15±29.648 µm. Clear positive correlations between GAT and I-Care, GAT and Tono-Pen, and I-Care and Tono-Pen tonometers were found (r=0.867, P<0.001; r=0.861, P<0.001; r=0.915, P<0.001, respectively). In comparison between devices, Bland-Altman analysis showed a significant mean difference (MD) in the measurements by GAT and I-Care of -0.679 mm Hg and by GAT and Tono-Pen of -0.705 mm Hg ( P<0.001), but there was no significant difference between I-Care and Tono-Pen ( P>0.05). Both non-gold standard tonometers were affected by CCT; that is, both I-Care and Tono-Pen tonometer values were significantly higher with higher CCT means (>555 µm; MD=-1.282, P<0.001; MD=-0.949, P<0.001, respectively) compared with GAT. CONCLUSION Both I-Care and Tono-Pen tonometers overestimated IOP compared with the GAT values. Either the I-Care or Tono-Pen tonometer could be used instead of GAT because there was no significant difference between their results. Higher CCT values (>555 µm) were associated with overestimated IOP values.