What Is Hypermetropia?

Hyperopia refers to a state of refraction that is imaged on the retina after the parallel beam is adjusted to relax the refraction of the eyeball. Hyperopia occurs when the refractive power of the eyeball is insufficient or the length of the axial axis is insufficient. The optical focus of this eye is behind the retina, so the image formed on the retina is blurred. In order to see the nearby objects, the focus behind the retina must be moved to the retina by using the adjustment power. Generally, convex lenses are used for correction. Therefore, hyperopic eyes are often in an adjusted state and prone to eye fatigue.

Basic Information

English name: hyperopia
Visiting department: Ophthalmology
Common causes: Physiological or pathological ocular anterior-posterior axis becomes shorter, the surface curvature of any refractive body in the eyeball refractive system is smaller, the refractive power of the lens is weakened, etc.

Common symptoms: Reduced vision and visual fatigue

Causes of hyperopia

Axial hyperopia

The most common hyperopic eye is axial hyperopia, that is, the anterior-posterior axis of the eye is shorter than that of the emmetropic eye, which is a more common type of abnormal refractive power in the eye. The anterior and posterior axis of the eye becomes shorter, which can be a physiological change and can also be seen in pathological conditions. An eye tumor or an inflammatory mass in the orbit can invade and flatten the posterior pole of the eye; furthermore, new creatures and the wall behind the ball Tissue edema can move the macular area of the retina forward.

2. curvature hyperopia

The other cause of hyperopia is curvature hyperopia, which is caused by the small curvature of the surface of any refractive body in the eyeball refractive system. It is called curvature hyperopia, and the cornea is a part that is prone to such changes. It may be It is a congenital flat cornea, and can also be caused by trauma or corneal disease. According to optical theoretical calculations, every 1 mm increase in the corneal bending radius can produce 600 degrees of hyperopia. In this type of curvature hyperopia, there are very few corneas Can maintain perfect sphere, almost all have astigmatism with different degrees.

3. Exponential hyperopia

The third type of hyperopia is called exponential hyperopia, which is caused by the diminished refractive power of the lens. This type of hyperopia is caused by physiological changes in old age and pathological changes caused by diabetes in treatment; Posterior dislocation of the lens can also cause hyperopia, which may be caused by congenital abnormalities, eye trauma or eye disease; in addition, the lack of lens can also cause hyperopia.

Hyperopia clinical manifestations

Visual fatigue and visual impairment

Often cause varying degrees of vision loss and visual fatigue. As far-sighted eyes have to adjust their function regardless of whether they are far-sighted or near-sighted, except for those who have far-sightedness and are young, they are prone to visual fatigue when reading, writing, or other near-sighted work. , The vision is blurred, the eyeballs are heavy, the sense of pressure, soreness, deep pain in the eyeballs, or headaches of varying degrees. Eyes are prone to conjunctival hyperemia and tearing. Headaches are mostly in the forehead or upper orbit, sometimes causing scapular discomfort, migraine, or even nausea and vomiting. These symptoms are all caused by the action of regulation, so they are called regulatory asthenopia.

2. Systemic symptoms

In addition to hyperopic eyes, which can easily cause accommodative asthenopia, they also sometimes cause systemic symptoms, especially changes in the nervous system.

3. Regulation and aggregation linkage disorders

When a hyperopia patient looks at a distant target, the eyes must be parallel, that is, they do not need to be gathered, but must be adjusted; when the two eyes are fixed at the near target, the adjustment is often greater than the set, resulting in the imbalance between the adjustment and the set linkage relationship. Become esotropia, the person with esotropia appears.

4. Eye changes

Higher degrees of hyperopia can see changes in the front and fundus of the eye. The common eyeballs are relatively small, the appearance of the eyeballs is slightly concave, the anterior chamber is shallow, and the pupils are small. Due to frequent adjustment of tension, conjunctival congestion may be accompanied by chronic conjunctivitis, blebitis, and blepharitis. Because of the large Alpha angle and the visual axis is often on the nasal side of the optical axis, the appearance of hyperopia is pseudo exotropia.

Moderate and highly hyperopic eyes often have varying degrees of fundus changes. The more common is pseudo-optic neuritis. A few severe cases can present with pseudo-optic disc edema.

Hyperopia

Ultrasound examination

A-ultrasonography was used to measure the axial length, anterior chamber depth, and lens thickness.

2. Computer Optometry and Examining Microscope Inspection

It needs to be done in a fully ciliary muscle paralysis, especially for adolescents.

Hyperopia diagnosis

According to the naked eye's far and near vision and detection results, there is no difficulty in detecting hyperopia.

Hyperopia treatment

Frame glasses correction

For most patients, it is difficult to adjust to corrective lenses, because the improvement in vision is not considered significant. In the uncorrected state, hyperopia patients can completely improve the contrast with too much adjustment. When this improvement in contrast is achieved through lens correction, patients may feel "blurred", although there may be no difference in vision. This "fuzzy" feeling is mild in some patients, but some patients respond strongly. In order to reduce the problem of adaptation, the positive power of the positive lens obtained by the examination needs to be adjusted to keep the patient with some additional adjustments.

2. Contact lens correction

In hyperopia patients, contact lenses are not widely used due to: hyperopia patients whose symptoms need to be corrected are usually elderly, do not require beauty, and have poor adherence to contact lenses; young patients have Regulating ability, even if symptoms need to be corrected, it does not need to be worn all day, and it is not necessary to use a contact lens.

3. Refractive surgery

With the development of science and technology in recent years, refractive surgical instruments have been continuously updated, and surgical techniques have become more and more mature. Patients who meet the indications and require surgery can be considered. Specific surgical methods are: surface corneal lens laser, refractive keratotomy (PRK), excimer laser keratomileusis (LASIK) and so on.