Posters

Visual, refractive, topographic, aberrometric and biomechanical characterization of mild forms of keratoconus

Poster Details

First Author: P.Sanz-Diez SPAIN

Co Author(s):    A. Vega Estrada   J. Alio   M. Maldonado   R. Barraquer   R. Gutierrez   L. Sadaba Echarri     

Abstract Details

Purpose:

To characterize the clinical features of mild forms of keratoconus taking into consideration visual, refractive, anterior corneal aberrometric, and corneal biomechanical properties and to find new clinical aspects of the incipient keratoconus.

Setting:

Cooperative Health Research Thematic Network "Prevention, Early Detection and Treatment of Prevalent, Degenerative and Chronic Eye Diseases”, sub-programme “Ocular Structures and Common Pathologies” (RD12/0034).

Methods:

Multicentric, restrospective study including mild forms of keratoconus defined as those cases with a corrected distance visual acuity (CDVA) > 0.9. A comprehensive ophthalmologic examination was performed in all cases including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction (sphere and cylinder), slit lamp biomicroscopy, Goldmann tonometry, fundus evaluation and corneal topographic analysis. Corneal aberrometry was recorded and analyzed with the CSO topography system. Corneal biomechanics: corneal hysteresis (CH) and corneal resistant factor (CRF) were characterized with the Ocular Response Analyzer.

Results:

This study comprised 625 eyes (316 right [50.6%]; 384 left [49.5%]) of 448 patients with a mean age of 36.07±10.54 years. Three hundred seventy-nine patients (60.6%) were men and two hundred forty-three (38.9%) women. The mean refractive spherical equivalent was -2.45±2.81 diopters. Mean keratometric values were 44.9±2.08 diopters. The intraocular pressure values were 12.61±2.75 mmHg. Analysis of corneal coma-like showed 1.43±1.15 µm. Mean asphericity in a 4.5 mm diameter corneal area was -0.27±0.82, and mean asphericity in an 8.0 mm was -0.29±0.82. In biomechanical data we observed CH = 8.94±1.36 and CRF = 7.95±1.75 mmHg.

Conclusions:

Mild forms of keratoconus, graded by the limitation of the visual acuity, are characterized by a low refractive error, an increased in the corneal asphericity and coma aberration, and also, by a reduction of the corneal biomechanics.

Financial Disclosure:

NONE