Age-related changes in Scheimpflug corneal densitometry and their correlations with corneal topographic measurements in a healthy Chinese population

Abstract

Background: Objective measurement of corneal densitometry (CD) values can be used to assess corneal transparency and health status, to investigate corneal diseases, and to review anterior segment surgeries.However, literature regarding the association between CD and corneal parameters in healthy adolescent and older individuals is limited. This study investigated age-related changes in Scheimpflug CD values and their correlations with age, sex, and corneal topographic parameters.Methods: This retrospective cross-sectional observational study included 347 eyes from 181 consecutive healthy Chinese participants aged between 5 and 90 years. They were divided into 9 age groups: 5-9, 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-90 years. CD and corneal topographic measurements were measured using the Oculus Pentacam. To evaluate CD, the cornea was divided into 3 layers according to depth (anterior 120 μm, central, and posterior 60 μm), and into 4 annular regions according to diameter (0-2, 2-6, 6-10, and 10-12 mm).Results: CD across different depths and regions was positively correlated with age (all P values <0.001). Of the 3 layers of corneal thickness, CD was highest in the anterior 120 μm and lowest in the posterior 60 μm (all P values <0.05). Among the 4 annular regions spanning the corneal diameter, the lowest CD values were 6-10, 2-6, and 0-2 mm at 5-29, 30-69, and 70-89 years, respectively. The highest CD values were 10-12 mm at 5-79 years, and 6-10 mm at 80-90 years (all P values <0.05). CD values of 10-12 mm in the anterior 120 μm corneal layer were significantly lower in men than in women (Z=−2.353; P=0.019). CD of 0-10 mm in each layer was not significantly different between sexes (all P values >0.05). Corneal topographic measurements, including flat-axis keratometry (K1), steep-axis keratometry (K2), and spherical aberration, were slightly positively correlated with age and CD (all P values <0.05). However, central corneal thickness (CCT) and thinnest corneal thickness (TCT), and age or CD showed no correlation (all P values >0.05).

Ten-year observation of corneal densitometry and associated factors following small incision lenticule extraction

“…We found in our study that there was no correlation between CD of all zones in all layers and central corneal thickness postoperatively. It was indicated by previous studies that CD was positively correlated with central corneal thickness in high myopic and keratoconus eyes [2,16] , but showed no correlation in normal eyes [17] , which is consistent with our findings. Ishikawa et al [18] reported a positive correlation between CD values and postoperative corneal thickness after cataract surgery, indicating that corneal edema undetectable by slit-lamp could be evaluated with CD measurement, which also proved the importance of CD examinations in follow-up visits after corneal surgeries.…”

Corneal warpage caused by cosmetic contact lenses: a case description

“…Scheimpflug corneal densitometry is a quantitative measure of corneal transparency, and its value increases with age ( 20 ). One study ( 21 ) reported that central anterior corneal densitometry values were significantly higher in silicone hydrogel contact lens wearers than in healthy controls.…”

Characterization the corneal transparency profile in SMILE-treated myopic patients with densitometry: A 7-year cohort study

“…[ 20 ] The alterations in CD values after 7 years post SMILE is distinct from the age-related variations observed in healthy corneas. [ 21 22 ] There are two potential reasons for this contrasting pattern. Firstly, it is important to note that our subjects, with an average age of 30.5 ± 8.6 years, were monitored longitudinally for 7 years, which contrasts with the prior research that concentrated on CD value shifts in 10-year intervals related to aging.…”

“…Firstly, it is important to note that our subjects, with an average age of 30.5 ± 8.6 years, were monitored longitudinally for 7 years, which contrasts with the prior research that concentrated on CD value shifts in 10-year intervals related to aging. [ 21 22 ] Furthermore, stromal thinning that occurs from SMILE may lead to a decrease in corneal cell and basal nerve density. [ 23 ] Consequently, a more precise assessment of posterior backscattering could be made, potentially resulting in reduced CD values.…”