Central and Peripheral Corneal Endothelial Cell Analysis With Slit-Scanning Wide-Field Contact Specular Microscopy: Agreement With Noncontact Specular Microscopy

Applications of Imaging Technologies in Fuchs Endothelial Corneal Dystrophy: A Narrative Literature Review

Fuchs endothelial corneal dystrophy (FECD) is a complex genetic disorder characterized by the slow and progressive degeneration of corneal endothelial cells. Thus, it may result in corneal endothelial decompensation and irreversible corneal edema. Moreover, FECD is associated with alterations in all corneal layers, such as thickening of the Descemet membrane, stromal scarring, subepithelial fibrosis, and the formation of epithelial bullae. Hence, anterior segment imaging devices that enable precise measurement of functional and anatomical changes in the cornea are essential for the management of FECD. In this review, the authors will introduce studies on the application of various imaging modalities, such as anterior segment optical coherence tomography, Scheimpflug corneal tomography, specular microscopy, in vitro confocal microscopy, and retroillumination photography, in the diagnosis and monitoring of FECD and discuss the results of these studies. The application of novel technologies, including image processing technology and artificial intelligence, that are expected to further enhance the accuracy, precision, and speed of the imaging technologies will also be discussed.

Investigation of the Sectorized Corneal Thickness of Eyes With Corneal Endothelial Dysfunction Using Anterior-Segment Optical Coherence Tomography

PURPOSE

The aim of this study was to investigate the sectorized corneal thickness of eyes with corneal endothelial dysfunction using anterior-segment optical coherence tomography.

METHODS

We retrospectively collected anterior-segment optical coherence tomography data conducted before endothelial keratoplasty on 53 eyes of 53 patients with corneal endothelial dysfunctions including Fuchs endothelial corneal dystrophy, bullous keratopathy (BK) after trabeculectomy, and BK after laser iridotomy and from 18 normal eyes of 18 subjects. The imaging points were divided into 17 sectors. The mean for each sector was calculated and compared with the corresponding superior/inferior and temporal/nasal sectors.

RESULTS

In the normal eyes, the superior sectors were thicker than the inferior and the temporal sectors thinner than the nasal. In the diseased eyes, the superior sectors were thicker than the inferior in all subgroups; however, this tendency was no longer observed after the values were divided by the mean for the normal eyes. No significant differences were found on horizontal comparisons; however, after the values were divided by the mean for the normal eyes, the temporal sectors were thicker than the nasal. When comparing the values between the with-hole and the without-hole sides in the BK after laser iridotomy eyes, the sectors on the with-hole side were thicker than the other side.

CONCLUSIONS

Corneal thickness of endothelial dysfunction was thicker in the superior sectors than the inferior but at a similar level to normal eyes. No significant differences were found for horizontal comparisons but, based on comparison with the normal eyes, the temporal sectors were thicker than the nasal.

Corneal endothelial cell density and morphology in ophthalmologically healthy young individuals in Japan: An observational study of 16842 eyes

We aimed to investigate the cell density and morphology of the corneal endothelium in ophthalmologically healthy young Japanese, given the lack of normative data in literature. This observational study included eyes without ophthalmologic diseases, besides refractive errors, examined between 1996 and 2015 at Miyata Eye Hospital. Eyes with a history of ophthalmologic diseases or contact lens usage were excluded. Correlation of corneal endothelial cell density (ECD), coefficient of variation (CV), appearance rate of hexagonal cells (6A), and cell area with age were examined. Multivariate linear regression analysis was performed to determine the predictors of corneal parameters. We included 16842 eyes of 8421 individuals (19.6 ± 8.7 years). ECD was 3109.0 ± 303.7 cells/mm² and significantly reduced with age (p < 0.001). The ECD reduction rate was 0.42%/year in the total population. On multivariate analysis, age and sex were significantly correlated with ECD, CV, 6A, and cell area (all p < 0.001). ECD, 6A, CV, and cell area are significantly associated with age in healthy young Japanese individuals. Monitoring their corneal endothelium is essential to assess the risk of endothelial damage.