What is hypermetropia?
Hyperopia (farsightedness) is the most common vision problem in the world. In this, you can see distant objects clearly, but the surrounding things may appear blurred. Problems such as far-sightedness are often referred to as refractive errors. Farsightedness is also known by the names of hypermetropia, farsightedness, etc.
Many children have mild vision problems, which gradually get better. Adults with distant vision defects find it difficult to focus on nearby objects, such as focusing on a book. As they mature, they may also find it difficult to focus on distant objects.
The degree of hyperopia is determined by the strength of the lens that must be placed in front of the eye to precisely focus the light beams on the retina. Farsightedness is often accompanied by astigmatism. The greatest degree of hyperopia occurs in people with aphakia.
Causes of hyperopia
The cause of hyperopia can be both a relatively flat curvature of the cornea, and its combination with an insufficient refractive power of the lens, increased density of the lens, a short anteroposterior axis of the eyeball, or a deviation from the average values of the optical parameters of the eye.
Presbyopia is often confused with hyperopia – a natural condition for every person that occurs after 40 years, in which the accommodative abilities of the eye decrease. This process leads to a decrease in near visual acuity and can contribute to the manifestation of previously unrevealed hyperopia. In connection with the development of presbyopia by the age of 40-45, there is an increase in the number of patients with hyperopic refraction due to the manifestation of latent hyperopia.
Positive hypermetropia: Positional hypermetropia results from the crystalline lens in the posterior of the eye.
Index Hypermetropia: Index hypermetropia occurs due to changes in the refractive index of crystalline lenses with age.
Currently, there is no data on the effect of gender on the predisposition to hyperopia. However, it is noted that it is more widespread among African Americans, residents of the Pacific region, and North American Indians.
Depending on the mechanism of development of hyperopia, axial or axial hyperopia is distinguished, associated with a shortened PZO of the eyeball, and refractive, due to a decrease in the refractive power of the optical apparatus.
In the event that the existing refractive error is compensated by the tension of accommodation, they speak of latent hyperopia; if self-correction is impossible and it is necessary to use convex lenses, hyperopia is regarded as obvious. With age, latent hyperopia, as a rule, turns overt.
Depending on age, natural physiological hyperopia in children, congenital hyperopia (with congenital weakness of refraction), and age-related hyperopia (presbyopia) are distinguished.
According to the degree of required correction in diopters and on the basis of refractometry data, hyperopia is divided into three degrees:
- weak – up to +2 diopters
- medium – up to +5 diopters
- high – over +5 diopters
Weak degrees of hyperopia at a young age occur without any symptoms: due to the tension of accommodation, good vision is preserved both near and far. With moderate farsightedness, distant vision is practically not impaired, however, when working at a close distance, there is rapid eye fatigue, pain in the eyeballs, in the area of the brow, forehead, nose bridge, visual discomfort, a feeling of fuzziness or fusion of lines and letters, the need to distance the considered object from eyes and brighter lighting of the workplace. High degrees of farsightedness is accompanied by a pronounced decrease in vision near and far, and asthenopic symptoms (a feeling of bloating and “sand” in the eyes, headache, rapid visual fatigue). With the farsightedness of medium and high degrees, changes in the fundus are revealed – hyperemia and indistinct boundaries of the optic disc.
Children with congenital uncorrected hyperopia over +3 diopters are more likely to develop friendly (convergent) strabismus. This is facilitated by the need for constant tension of the oculomotor muscles and bringing the eyes to the nose in order to achieve greater clarity of vision. As farsightedness and strabismus progress, amblyopia may develop.
Farsightedness, recurrent blepharitis, conjunctivitis, barley, and chalazion often occur, since patients involuntarily rub their eyes, thereby introducing an infection. In older people, hyperopia is one of the factors contributing to the development of glaucoma.
Farsightedness is usually diagnosed by an ophthalmologist during a visual acuity test. Viscometry for hyperopia is performed without correction and using trial plus lenses (refraction test).
Diagnosis of hyperopia involves a mandatory study of refraction (skiascopy, computer refractometry). To identify latent hyperopia in children and young patients, refractometry is recommended under conditions of induced cycloplegia and mydriasis (after installation of atropine sulfate into the eyes).
In order to determine the anteroposterior axis of the eyeball, ultrasound of the eye and echobiometry are performed. To identify concomitant hyperopia of pathology, perimetry, ophthalmoscopy, biomicroscopy with a Goldman lens, gonioscopy, tonometry, etc. are performed. In the case of strabismus, biometric examinations of the eye are performed.
Farsightedness treatment methods are combined into conservative (eyeglass or contact correction), laser (LASIK, SUPER LASIK, LASEK, EPI-LASIK, Femto LASIK), and surgical (lensectomy, hyperfakia, hyperartifakia, thermokeratoplasty, etc.). Timeliness and adequacy are the main conditions for correcting hyperopia.
In the absence of asthenopic complaints, visual acuity of both eyes is not less than 1.0, and stable binocular vision, correction is not indicated.
The main way to correct children’s hyperopia is the selection of glasses. Preschool children with hyperopia of more than +3 diopters need glasses for constant wearing. In the absence of a tendency to develop strabismus and amblyopia by 6-7 years, spectacle correction is canceled. For asthenopia, “plus” glasses or corrective contact lenses are selected, taking into account individual data and concomitant diseases. In some cases, with hyperopia up to +3 diopters, night orthokeratological lenses are used. With high degrees of hyperopia, complex glasses or two pairs of glasses (for working at close and long distances) may be prescribed.
In case of hyperopia, it is recommended to use course apparatus treatment (Ambliokor, Ambliotrener, Synoptophore, software and computer treatment, etc.) physiotherapy (massage of the neck-collar zone, laser therapy, magnetotherapy, etc.), courses of vitamin therapy, and dietary supplements. When watching TV, it is advisable to use perforated glasses, which reduce the stress of accommodation.
From the age of 18, it is possible to carry out laser correction of hyperopia up to +6 diopters. The most popular laser techniques are LASIK, LASEK, IntraLASIK, Super LASIK, EPI-LASIK, and photorefractive keratectomy (PRK). Each of the methods of laser correction of hyperopia has its own indications, but their essence is the same – the formation of the corneal surface with individual parameters. Excimer laser correction of hyperopia is non-traumatic, which excludes complications from the cornea and minimizes the likelihood of developing astigmatism.
In hyperopia surgery, the method of refractive lens replacement is used: in this case, the eye’s own lens is removed (lensectomy) and replaced with an intraocular lens of the required optical power (hyperartifakia). Refractive lens replacement is used, including age-related hyperopia.
Surgical treatment of hyperopia can also include hyperphagia (implantation of a positive phakic lens), thermokeratocoagulation, laser thermokeratoplasty, keratoplasty (corneal plastics).
Prevention of hyperopia
Complications of uncorrected hyperopia can be strabismus, amblyopia, recurrent inflammatory eye diseases (conjunctivitis, blepharitis, keratitis), or glaucoma. Patients with hyperopia are recommended to visit an ophthalmologist at least 2 times a year.
When farsightedness is detected, strict adherence to the prescribed recommendations, and adherence to the correct visual regime (use of sufficient lighting, gymnastics for the eyes, alternation of visual work with active rest) is necessary. The same recommendations can be applied to the prevention of hyperopia. In order to prevent the development of strabismus, ophthalmological examinations of children from 1-2 months, 1 year, 3 years, and 6-7 years are carried out.