A Population Study of the Normal Cornea using an in Vivo, Slit-Scanning Confocal Microscope (original) (raw)

Clinical Interventions in Aging, 2013

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/mm 2 ) 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.

The purpose of our experimental research was to assess the effects of aging on the main corneal structures in healthy corneas. Small, human cornea samples were collected from 20 Caucasian subjects during surgery for traumatic lesions to the eye. Ten subjects were adults (mean age 28 years) and 10 were elderly (mean age 76 years). Morphological analysis was carried out using light microscopy and electron microscopy. Another 40 patients (20 young: mean age < 30 years; 20 elderly: mean age > 70 years) were studied in vivo by confocal microscopy. The resulting images were analyzed qualitatively, quantitatively, and statistically. The basic light microscope revealed a decrease in endothelial cell density with age accompanied by an increase in endothelial cell size. Transmission electron microscopy revealed a corneal thinning and a decrease in the number of corneal stromal cells. A marked decrease in stromal nerve fibers was observed in the older subjects compared to the younger ones. Variable pressure scanning electron microscopy (VP-SEM) was used to make surface morphological observations and to determine the chemical composition of in vivo hydrated human corneas. Our results showed the effects of aging on normal corneal morphology highlighting the structural diversity of the cor-neal layers and revealing an age-related reduction in nerve fibers, thus explaining the decreased corneal sensitivity that may be observed in the elderly. Clin. Anat. 00:000-000, 2019.

Corneal confocal microscopy in a healthy Brazilian sample

Arquivos de Neuro-Psiquiatria, 2016

Objective This study aims to evaluate the characteristics of the corneal sub-basal plexus by performing in vivo confocal microscopy of healthy Brazilians to provide reference values for the Brazilian population. Method This study is an observational, cross-sectional, descriptive study comparing corneas from 55 healthy Brazilian individuals across the age span of 20-70 years. Results The average number of fibers was 5.35 ± 1.36, fiber density was 33.4 ± 8.5 fibers per field, and the mean number of Langerhans cells was 5.13 ± 8.10. A correlation between the average number of fibers and age showed an inverse relationship between the number and density of fibers and age for women (p < 0.05). In the multivariate analysis, each annual increase of age showed an average increase of 1.017 (95%CI: 1.008 to 1.026) in the number of Langerhans cells, adjusting for sex and thickness. Conclusion Compared to other samples, this Brazilian population showed a higher average number of fibers, thoug...

Corneal endothelial cell density in healthy Caucasian population

Saudi Journal of Ophthalmology, 2016

Aim: To reveal the changes of corneal endothelial characteristics with aging among Caucasian population. Methods: Non-contact specular microscopy was performed in 564 eyes of 282 healthy Caucasian Turkish patients. Endothelial cell density (MCD), mean cell area (MCA), coefficient of variation (CV) in cell size, percentage of hexagonal cells, and central corneal thickness (CCT) were measured. Results: The mean age was 42 ± 17.1 (6-85) years. The MCD of the population was 2732 ± 305 cell/mm 2 (range, 1904-3802 cell/ mm 2). The MCA was 368 ± 41 m 2 (range, 263-522 m 2). The mean CV in cell size was 34 ± 7 (range, 25-68), the mean percentage of hexagonal cells was 46 ± 8% (range, 25-76%), and CCT was 513 ± 39 (range, 407-623). There was statistically significantly negative correlation (p < 0.05) between age and cell density, hexagonality, and pachymetry. There was statistically significant correlation (p < 0.05) between age and MCA. Conclusion: We report the normal values of corneal endothelial characteristics in Caucasian Turkish eyes. Over the age of 20, the MCD of Caucasian eyes is more than the Indian and Iranian eyes and less than the Chinese eyes. Caucasian population's cell density in under the age of 20 is 3101 ± 268 cell/mm 2 .

Effects of aging on corneal parameters measured with Pentacam in healthy subjects

Scientific Reports, 2019

Our purpose was to prospectively analyze the age-related changes of corneal Scheimpflug parameters in healthy subjects. Thirty-five eyes of 35 volunteers (age 14-67 years) were investigated with an average interval of 3.6 years. Changes of corneal parameters (flattest keratometric reading at anterior (K1F) and posterior surface (K1B), steepest keratometric reading at anterior (K2F) and posterior surface, anterior astigmatism, posterior astigmatism (AstigB), flat axis of anterior and posterior astigmatism (AxisB), thinnest pachymetric value (PachyMin), corneal volume (CV10-mm)) were analyzed. K1F and K2F decreased significantly during observation and showed stronger decrease in younger than in older individuals. Higher values proved to be more stable. K1B decreased significantly and the degree of decrease was dependent on its baseline value and age: in young subjects low values increased, high values decreased. AstigB decreased significantly and showed a baseline-dependent significant increase from lower and a significant decrease from higher initial values. Over time, the mean AxisB shifted significantly. PachyMin and CV decreased significantly with age, especially from higher baseline values in younger subjects. The results of this longitudinal study suggest that both corneal surfaces change significantly with age. We demonstrate for the first time that age and baseline values influence agerelated changes of corneal parameters. Aging is a physiological process and occasionally it is hard to differentiate between time dependent biological changes and damages from environmental insults 1. Age-related changes occur in all structures of the eye, with various consequences 2. Age has been identified as an important individual variable affecting the outcome after keratorefractive surgery 3. Corneal aging generates structural and functional changes including steepening of keratometry indices, and a rotation of the axis of astigmatism resulting in a shift from with-the-rule to against-the-rule astigmatism 1,4-11. Alterations of higher-order aberrations of the cornea are also well known 9. The level of astigmatism decreased significantly with age both of the anterior and posterior corneal surfaces in a study by Nemeth et al. 9 , although age as a primary factor was not analyzed in this report. To differentiate between physiological and pathological changes of the aging cornea, it is indispensable to know what the physiological changes are. There are clinical situations where it is important to distinguish between pathological and normal age-related changes. The assessment of the progression of ectatic corneal disorders in young patients determines the optimal treatment and the glaucoma management in the elderly can only be personalized if we take account the changes of corneal thickness. A complete and precise evaluation of the cornea must take keratometric, astigmatic vectorial as well as pachymetric characteristics into account. Age-dependent change of corneal thickness has been studied extensively. Corneal thickness decreases throughout infancy; during babyhood (around 3 years of age) it reaches adult thickness and, from that point on, central corneal thickness (CCT) appears to be stable over time 12. However, age-related change in corneal thickness appears to be rather controversial in other studies 13-18. CCT has been extensively investigated in glaucoma

The effects of corneal parameters on the assessment of endothelial cell density in the elderly eye

British Journal of Ophthalmology, 2004

Background: The possible impact of corneal thickness, curvature, and size on the measurement of endothelial cell density (ECD) has largely been ignored in the normal eye. The aim of this study was to investigate the possible impact of the main corneal parameters on the analysis of ECD values at the central, superior, and temporal parts of the corneal surface. Methods: All 75 participants (52 females, 23 males) were assessed as part of a pre-cataract surgery investigation. The mean age was 75.7 (SD 10.9) years. Confocal microscopy was used to measure ECD and the percentage of six sided cells at the central, superior, and temporal parts of the cornea. The Orbscan II topography system was used to measure corneal thickness, topography, and horizontal corneal diameter. Results: The mean central ECD measured was 2488 (SD 301) cells/mm 2 , compared with 2525 (SD 505) cells/mm 2 in the temporal cornea and 2639 (SD 398) cells/mm 2 in the superior cornea. The regional differences in ECD were not significant (p.0.14). The central ECD was significantly correlated to the central (mean 0.593 (SD 0.039) mm, p = 0.021) as well as the temporal (0.628 (SD 0.039) mm, p,0.001) and the superior corneal thickness (SD 0.644 (SD 0.048) mm, p = 0.018). The mean corneal curvature at the centre (7.7 (SD 0.34) mm, p = 0.002) as well as 3 and 5 mm from the apex was significantly related to ECD (p = 0.008 and p = 0.009, respectively). Conclusions: The study suggests that in an older population, lower ECD values would be expected in thinner and/or steeper corneas.

Research Square (Research Square), 2020

Purpose: To assess the corneal endothelial morphometry in healthy elderly Hispanic eyes. Methods: A retrospective, cross-sectional, observational, descriptive, and analytical study was designed to assess by specular microscopy the central region of the corneal endothelium. In a 4-year period, a total of 75 eyes from 42 patients were studied. All eyes included were from patients 65 or older (mean: 73.87±6.86), without ocular disease or surgeries. Results: The mean cell density (MCD) was 2268±597.0 cells/mm 2. 44% of patients had polymegethism, with an average coe cient of variation (CV) of 42.04 ± 10.1%. 76% of patients had low pleomorphism, with an average of 42.3 ± 8.9% hexagonal cells. The mean corneal thickness was 537±38.2 μm. There was no statistically signi cant difference between age groups for MCD, CV, hexagonality and pachymetry (p=>.05). 27% of patients had corneal guttata. Conclusion: This study suggests that the elderly Hispanic population has a high prevalence of polymegethism, pleomorphism and guttata. Surprisingly, the oldest age group (>85) had an above average MCD, low polymegethism and good pleomorphism.

The Open Ophthalmology Journal, 2022

To assess the corneal endothelial morphometry in healthy elderly Hispanic eyes. Methods: A retrospective, cross-sectional, observational, descriptive, and analytical study was designed to assess the central region of the corneal endothelium by specular microscopy. A total of 241 eyes from 125 patients were studied. All eyes included were from healthy patients 65 or older (mean: 74.56± 6.74), without ocular disease or surgeries. Results: The mean cell density (MCD) was 2198.92±493.43 cells/mm 2. 125 (51.87%) eyes had polymegethism, with a mean coefficient of variation (CV) of 42.89 ± 9.16%. 148 (61.41%) eyes presented pleomorphism, with an average of 46.25 ± 7.13% hexagonal cells. The mean corneal thickness was 527.55±28.37 μm. A statistically significant difference between age groups was found for MCD and pachymetry (P<0.05). 41 eyes (17.01%) had cornea guttata. Conclusion: This study suggests that the elderly Hispanic population has a high prevalence of polymegethism, pleomorphism, and guttata. Surprisingly, the oldest age group (>85) had an above-average MCD, with lower rates of polymegethism and pleomorphism.

Specular Microscopic Evaluation of Corneal Endothelium in Normal Egyptian Eyes and Its Relation to Age, Gender, and Refraction

Egyptian Journal of Clinical Ophthalmology, 2023

Aim: Describe the parameters of corneal endothelial cell of normal Egyptians and to determine its correlation with sex, age, and refractive eye state. Methods: Non-contact specular microscopy was performed in 390 eyes of healthy Egyptian. Age, sex, refractive state, Endothelial cell density (ECD), the standard deviation of hexagonal cells HEX, coefficient of variation (CV) were analyzed. The system recorded the mean cell density MCD (cell/mm2), mean cell area MCA (μm2), central corneal thickness CCT, and HEX percentage.

A Population Study of the Normal Cornea using an in Vivo, Slit-Scanning Confocal Microscope (original) (raw)

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