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Publicación cuatrimestral editada por la Secretaría de Salud Jalisco

2023, Number 1

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Sal Jal 2023; 10 (1)

Astigmatism analysis of keratoconus with Scheimpflug corneal tomography

Rodríguez-López CE, Mora-González GF, Rendón-Félix J, Jáuregui-García GD, Mora-Jáuregui MF, García-Castro A, Ibáñez-Hernández MÁ

Language: Spanish
References: 16
Page: 31-39
PDF size: 258.17 Kb.


ABSTRACT

Introduction: keratoconus (KC) is multifactorial and progressive corneal affection with changing anatomic structures, and it is associated with anomalies in the corneal collagen. The corneal stroma is thinnest, resulting in a conic protuberance named KC. This modification of the corneal structure conditions myopia and irregular astigmatism, conducting to visual impairment. Objective: compare corneal astigmatism using different measures of corneal refractive power obtained with Pentacam Scheimpflug corneal tomography (Oculus®, Wetzlar, Germany) of eyes with keratoconus (KC), possible keratoconus (possible KC) and control group of eyes with regular corneal astigmatism. Material and methods: this is a descriptive, observational and retrospective study. The sample was collected for convenience and corresponds to 149 eyes of 80 Mexican patients of both sexes, which underwent the Pentacam scan during 2020 in private ophthalmic consultation at Puerta de Hierro Medical in Zapopan, Jalisco, Mexico. Results: our study showed that anterior corneal astigmatism (ACA) was higher in the keratoconus group than in the control group or possible KC. However there were no differences in astigmatism calculated with total corneal refractive power (TCRP) and Holladay report at 3 mm (HR 3 mm). Magnitude of astigmatism shows a direct linear correlation with topographic keratoconus classification (TKC) in all investigated corneal power measurement methods. With all the methods the steepest, the flattest and the mean keratometries in the KC group were significantly higher than those of the other groups. Based on the normal distribution we determined possible cut-off point to differentiate keratoconus from regular astigmatism. Conclusions: taking into account the characteristics of KC in the Mexican population improves the precision of multiple clinical procedures performed in this population and sets a precedent for future prospective research.


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