Lastigmatismo

Lastigmatismo, more commonly referred to as astigmatism, is a common refractive error of the eye caused by an irregular curvature of the cornea or lens. This irregular shape prevents light from focusing evenly on the retina, leading to blurred or distorted vision at all distances.

There are several forms of astigmatism. Regular astigmatism occurs when the cornea or lens has two principal meridians with different curvatures, aligning at one axis. Irregular astigmatism results from an irregular corneal surface or lens, often due to injury, disease, or surgery. Astigmatism can be categorized as myopic, hyperopic, simple, compound, or mixed, depending on whether the eye is nearsighted, farsighted, or both in different meridians. Lenticular astigmatism refers to curvature irregularities of the lens itself.

Causes and risk factors include genetic predisposition and developmental factors. It can be present at birth or develop later. Conditions such as keratoconus, corneal scarring, or previous eye surgery can contribute to irregular astigmatism.

Symptoms typically involve blurred or distorted vision, eyestrain, headaches, and difficulty with night driving or reading. Diagnosis is made through a comprehensive eye exam, including refraction tests, keratometry, corneal topography, and sometimes wavefront analysis.

Treatment aims to provide a clear image. Corrective lenses with cylindrical power in glasses or toric contact lenses are common options. Orthokeratology may be used in some children. Refractive surgery, such as LASIK, PRK, or SMILE, can reduce dependence on lenses for eligible individuals. Irregular astigmatism may require specialized contact lenses, such as scleral lenses, for better visual quality. Regular eye exams help monitor progression and management.