Corneal thickness and volume in subclinical and clinical keratoconus

Abstract

To evaluate corneal thickness and volume in subclinical and clinical keratoconus in Asian population with the aim of discriminating between normal and ectatic cornea. Eyes were placed into one of the following three groups: normal, subclinical, and mild-moderate keratoconus. Pentacam Scheimpflug imaging (Oculus Inc., Wetzlar, Germany) was performed for each participant to record thinnest corneal thickness, central corneal thickness, corneal volume (CV), peripheral corneal thickness (PCT) and percentage thickness increase (PTI) at 2, 4, 6, and 8 mm. The data were exported to SPSS for statistical analysis. Subjects comprised 52 normal, 15 subclinical keratoconus, and 32 mild-moderate clinical keratoconus eyes. Our results indicated that corneal thickness (CT) distribution, PTI, and CV in normal eyes were significantly different compared with subclinical and clinical keratoconus (P < .05). Overall, subclinical group exhibited lower CT distribution and volume, and higher PTI in comparison with normal eyes. However, they showed higher CT distribution and volume, and lower PTI compared with keratoconus group. In addition, there was a smaller change in PCT and PTI from the thinnest point of the cornea to the periphery. The results of the present study indicate that CT parameters and CV were significantly different in normal versus subclinical group and in normal versus keratoconus group. These findings could help clinicians to better discriminate between normal and ectatic cornea.

Characteristics of keratoconic patients attending a specialist contact lens clinic in Kenya

“…[61425] Contrary to this observation, a lack of correlation between severity and age of onset was reported in one study. [9] Early onset may reflect the variability of the disease process and genetic differences between the various ethnic groups for which some evidence has been reported. [926] The high proportion of bilateral cases in the current study concurs with other studies, where only 0.5% of patients had unilateral KC which was documented using the same procedure.…”

“…[9] Early onset may reflect the variability of the disease process and genetic differences between the various ethnic groups for which some evidence has been reported. [926] The high proportion of bilateral cases in the current study concurs with other studies, where only 0.5% of patients had unilateral KC which was documented using the same procedure. [2728] In contrast, 14.2% of bilateral cases were reported in a study of 600 eyes conducted before the development of corneal topography.…”

“…However, recent studies report lower percentages of referral to keratoplasty likely due to the well-documented success of corneal collagen cross-linking. [913] For example, a study from Malaysia reported 52% of patients were prescribed contact lenses, 24% had cross-linking, and only 2.5% had a corneal graft procedure. [9]…”

“…Characteristics such as age, gender, visual acuity, severity, associated factors, and management have been reported in studies conducted in Australia,[1] England,[2] India,[345] Iran,[6] Israel,[7] Jordan,[8] Malaysia,[9] New Zealand,[10] Scotland,[11] Singapore,[12] Turkey,[13] and United States. [14151617]…”

Oxidative Stress in the Pathogenesis of Keratoconus and Fuchs Endothelial Corneal Dystrophy

“…KC is a bilateral disorder in which alternations in structure and function of the cornea depend on its progression [24]. It is characterized by central thinning of the corneal stroma, leading to deformation of the normal shape of the cornea (Figure 2) [25,26]. The disease is associated with breaks in Bowman’s layer and Fleischer’s ring–iron deposits in the basal layer of the epithelium [27].…”