Background: Keratoconus is the most common corneal ectasia. It usually appears in the second decade of the life and affects both genders and all ethnicities. Tomographic-based data have added significantly more information to the screening of corneal ectasia. In addition to anterior corneal analysis, tomography also provides information about the posterior cornea and the pachymetric distribution, which can increase our ability to identify early and subtle corneal changes.
Aim of the Work: The main aim is to determine how the corneal volume measurement changes in different diameters of corneal tissue, in the central 3 mm and 5 mm in mild and severe cases of keratoconus; in an attempt to quantify the loss of corneal tissue in keratoconus.
Patients and methods: This cross-sectional study included 20 eyes of keratoconic patients, from 15 to 36 years old. They were divided into 2 groups, each group included 10 eyes: Group A: mild keratoconic cases with steepest keratometry reading lower than 45 D. Group B: severe cases with steepest keratometry greater than 52 D, All cases were diagnosed as keratoconus using pentacam parameters.
Results: Corneal volume at 3 and 5 mm diameter was significantly lower in the severe keratoconic cases than in mild cases (P<0.01).
Conclusion: based on the data in our study, we think the effect of keratoconus is not limited to corneal thickness. Rather, it affects all anterior segment parameters of the eye and results in significant alternations with the progression of the disease. There is a clear reduction of corneal volume in early keratoconus, and such reduction increases significantly with the severity of the disease. Measurement of corneal volume could prove to be a useful tool to monitor the progression of the disease and in other applications, such as assessing the effect of treatments including corneal collagen crosslinking and implatation of Intacs.