Hypermetropia is a very common disease. Over 25% of people suffer from varying degrees of farsightedness. There is an erroneous opinion that patients always have excellent vision in the distance, but most often the range of the object does not affect the clarity of vision.
Hypermetropia can develop at any age, even in young children. One of the main causes of hyperopia is considered to be a decrease in the eyeball. It is noteworthy that almost all babies have a distorted vision. This is due to the fact that they have small eyes. The growth of the eyeball eliminates this defect, however, some babies are born with a high degree of farsightedness, which does not go away on its own.
In an adult, the size of the eyeball is 24 mm. The difference may include only a few fractions of a millimeter, no more. If the eye is less than normal, the risk of developing farsightedness increases.
The size of the inner axis of the eye should also be considered. This axis runs along the inner surface of the cornea from the anterior pole to the point of the posterior pole of the eye on the retina. In a healthy person, the inner axis is 21.5 mm. If the axis is abnormally short, rays of light will fall into the area behind the retina.
Hypermetropia, its causes and degrees
In some cases, hyperopia can be a consequence of the individual characteristics of the formation of the visual system. Sometimes visual defects occur with impaired refraction, an irregular shape of the eyeball, and exposure to hereditary factors.
- Weak hypermetropia (up to 2 diopters). This degree is noted with age in many healthy people, so in most cases it does not require correction. In children, the structure of the eyeball changes during growth: the muscles grow stronger, the eyeballs increase, and the projection of the image onto the retina is leveled. It is necessary to monitor the state of vision in the dynamics, so every six months the child should be shown to an ophthalmologist. If visual impairment does not disappear when the child reaches the age of seven, you can begin full treatment.
- Hypermetropia of moderate degree (2-5 diopters). This degree of hyperopia is corrected by optical systems (glasses, contact lenses). Depending on the situation, they are appointed on an ongoing basis or for work requiring concentration.
- High degree hypermetropia (from 5 diopters). This degree of hyperopia requires constant correction.
In most cases, hyperopia is not accompanied by tangible symptoms. At an early stage of development of refractive pathology, it can be detected only during preventive visometry. Therefore, it is recommended to contact an ophthalmologist twice a year to identify hidden pathologies.
Symptoms of hyperopia:
- Fatigue. If during reading it is noted that it is necessary to take the book away, and when writing, it is difficult to concentrate your eyes, you should consult a doctor. With farsightedness, the eyes quickly tire in situations requiring visual focus.
- Rapid headaches. With hyperopia, eye strain increases. Reading, writing, and working with small details cause overstrain and headaches. Patients also complain of weakness.
- Frequent cases of inflammation of the visual system. If the patient periodically consults a doctor with blepharitis, conjunctivitis and other eye inflammations, an additional examination is necessary. Inflammatory diseases indicate visual impairment and a critical weakening of the immune system.
Spectacle presbyopic correction
Modern medicine offers patients three effective methods for correcting hyperopia in children and adults. The most popular is the spectacle correction method. If adult patients increasingly prefer contact lenses, parents buy glasses for children. This is due to the fact that children get tired of constantly looking after the lenses and taking them off.
With farsightedness, glasses with plus lenses are prescribed, which collect rays of light, but do not scatter them. Due to this property, the cornea draws focus exactly onto the retina.
Spectacular correction of refractive disorders of vision has its drawbacks. Glasses easily get dirty and fog. Active children are not free to play and play sports. When hit, glasses can break and injure the mucous membrane of the eye. Plastic glasses with safety lenses quickly become scratched, so they need to be changed often.
Glasses cannot correct vision by 100%. The distance between the eyes and lenses creates a distortion of the picture, the side vision is significantly limited. Glasses violate the stereoscopic effect (surround perception of the environment). Drivers suffer from a distortion of spatial perception.
Wrongly selected glasses can only aggravate vision: the eyes will overwork and cause the progression of hyperopia. Despite this, spectacle correction is the easiest and most affordable way to improve vision in the presence of refractive errors. At an early age, glasses help to avoid complications.
Contact lenses for hyperopia
Contact lenses are often prescribed for hyperopia, combined with amblyopia (lazy eye syndrome). Correction of vision with lenses in this case is a therapeutic measure that allows you to clearly project the image on the retina. This, in turn, leads to normal activity of the “lazy" eye and its involvement in the visual process.
Today, lenses are prescribed for both adults and children. Their use is also accompanied by some inconvenience, but the tight contact of the lens and the eye allows you to provide a single optical system and get a clear image. The quality of vision when wearing contact lenses is better than when using glasses. To correct astigmatism with hyperopia, toric lenses are prescribed.
Some patients are not able to get used to a foreign object in the eye, so they refuse lenses in favor of glasses. A common complication of vision correction with lenses is an allergic reaction. It is very important to observe the rules of hygiene when using lenses.
During the adaptation period, many patients suffer from infectious diseases of the organs of vision. Without treatment, they can cause complications and even lead to loss of vision. Infections also develop with insufficient lens cleaning before use.
Despite all these shortcomings, contact lenses are considered a more convenient and effective method for correcting farsightedness. Contact lenses are not visible to others. They allow you to avoid psychological discomfort in children. It is noteworthy that after 15-17 years of constant wearing of lenses, the eyes will stop taking them.
Laser vision correction
Adult patients with stable hyperopia can be offered laser vision correction. The operation is possible with farsightedness up to 5 diopters (mild to moderate), as well as with its combination with astigmatism up to ± 3 diopters. This is the most progressive and fastest method of combating refractive errors. The operation takes a few minutes and provides improved vision at once for several diopters.
For hyperopia, LASIK (laser keratomileusis) technology is recommended. This is a combined operation involving an excimer laser and microsurgical methods. Such an intervention guarantees a complete correction of eye defects without any visual impairment.
Sometimes with farsightedness, a photorefractive keratectomy is prescribed. The operation involves the evaporation of the damaged layer of the cornea using an excimer laser. LASIK surgery is considered more benign because it preserves the structure of the cornea.
Super LASIK is considered the best method of laser correction, since it makes it possible to take into account the individual characteristics of each patient. Before surgery, the doctor can calculate each step, taking into account the shape of the cornea, thus ensuring maximum results.
Advantages of the Super LASIK method for correcting farsightedness:
- better quality of vision
- stability of the result.
If there are no contraindications, it is recommended to choose a laser vision correction. The operation helps to restore eyesight safely and quickly, and during correction at a young age, you can achieve a stable result for life.
Contraindications to laser vision correction:
- age up to 18 years (in children the eyeball is constantly growing),
- the period of bearing a child and breastfeeding,
- glaucoma (increased intraocular pressure),
- autoimmune diseases
- the presence of one eye,
- corneal thickness up to 450 microns,
- cataract (clouding of the lens masses),
- psychoses caused by endogenous factors (internal),
- the presence of a pacemaker.
After a successful laser correction, vision is completely restored, ensuring normal working capacity. Laser vision correction is the most effective method to improve vision in patients aged 18-50. The laser creates in the cornea a natural analogue of “plus” glasses, which will improve the refractive power and ensure the correct focusing of the image on the retina. If at high degrees of hyperopia, the glasses distort the image when turning the head, after the operation, the cornea will project a natural-sized image.
Microsurgery for hyperopia
A lens removal surgery helps to improve refraction and restore vision. The main indication for surgery is cataract, but with high degree hyperopia (from 6 diopters), the lens is sometimes replaced by an intraocular lens.
Modern intraocular lenses provide excellent vision at different distances. The operation is prescribed in cases where there are contraindications to laser correction. The artificial lens allows you to adjust any degree of hyperopia. It eliminates the need to use different glasses for reading, watching TV and driving.
Implantation of phakic lenses is recommended for young patients who have maintained normal focus at different distances. The lens is placed behind or in front of the iris; the lens is not affected. The disadvantage of this method is the need to remove the lens during the development of cataracts.
Lazy eye syndrome (amblyopia) is a pathology that is characterized by low vision with the normal structure of the eyeball. Amblyopia often develops in children against the background of other pathologies of vision. If the defect is not eliminated during the development of the visual system, the syndrome will remain for life.
One of the causes of amblyopia is unrecognized hyperopia. When a clear image is not projected onto the retina due to a defect in the optical system, the eye gradually ceases to participate in the visual process. This is due to the fact that the brain, receiving a fuzzy image, tries to get rid of discomfort by "turning off" the sick eye. If amblyopia cannot be cured in childhood, you can suffer from poor vision quality all your life. Often, lazy eye syndrome is complicated by strabismus.
For the implementation of vision near the human eye, they are a little reduced to ensure convergence (intersection of the visual axes). The eye muscles tighten, focusing the vision. With farsightedness, the muscles are constantly tense, even when looking at distant objects. So the brain smooths out the defect, projects a picture on the retina and provides normalization of vision. A constant spasm of the ciliary muscle can lead to the development of convergent strabismus in people with hyperopia at different ages.
Angle-closure glaucoma is very often diagnosed in patients with farsightedness. Glaucoma is a state of increased intraocular pressure when the outflow of moisture from the anterior chamber of the eyeball is blocked. With hyperopia, the eye has a specific structure that increases the risk of glaucoma.
An attack of glaucoma is an extremely serious condition that requires urgent treatment. Often occurs in patients older than 40 years. It is manifested by severe pain: in the eye, head, temple, cheek. Nausea, decreased visual acuity are also noted, iris circles appear. An acute attack of glaucoma is characterized by rapid progression.
The structure of the farsighted eye suggests the development of an attack. Without urgent treatment, glaucoma can lead to complete blindness, so patients are placed in a hospital for constant monitoring. To avoid complications of glaucoma, you can undergo a laser iridectomy.
Moderate activity and walks in the fresh air contribute to the strengthening of the body and the visual system as well. It is very important to eat and consume foods that contain vitamins for the eyes. If we are talking about a child, nutrition should provide the body with all the necessary useful elements for proper growth and development.
Parents should not encourage addiction to a phone, tablet or computer. You need to limit the time you watch TV. The use of equipment should alternate with outdoor activities. Simple exercises will help train your eye muscles. Visual gymnastics can prevent not only refractive pathologies, but also many other visual impairments.
Desktop lighting should be moderately bright. It is recommended to install lighting on the left, although some experts insist on lighting from the side of the working hand. It is not recommended to combine artificial and natural lighting. The same goes for the workplace at school and at work. If the child is at risk of developing farsightedness, you need to inform the school management, put the child at the front desk and limit physical activity.
Visual discomfort cannot be ignored. If there is a burning sensation, pain and foggy need to be examined. Early diagnosis of hyperopia will allow you to start treatment on time and restore vision.
Causes of Hyperopia
The cause of hyperopia can be both the relatively flat curvature of the cornea, and its combination with insufficient refractive power of the lens, increased density of the lens, short anteroposterior axis of the eyeball, or deviation from the average optical values of the eye.
In young children, this type of refraction is physiological. Most full-term newborns have hyperopic refraction of about 2-3 diopters. About 4-9% of infants aged 6-9 months and 3.6% at the age of 1 year have a farsightedness of more than 3.25 diopters. By 5 years, in most children, refraction approaches emmetropic, but nevertheless, hyperopia still prevails. Concomitant high degrees of astigmatism and farsightedness also tend to decrease by this age. Over the next 10-15 years of life, children have a significant decrease in the incidence of hyperopia and an increase in the incidence of myopia.
Heredity plays a role in the occurrence of most cases of refractive errors, including hyperopia. Along with this, environmental factors influence its development and degree, however, in all probability, it is less significant than with myopia.
High degree hypermetropia can occur in combination with certain general disorders, including albinism, Franceschetti syndrome (microphthalmos, macrophakia, tapetoretinal degeneration), Leber congenital amaurosis, autosomal dominant retinitis pigmentosa.
Presbyopia is often confused with hyperopia - a natural condition for every person that occurs after 40 years, in which the accommodation abilities of the eye are reduced. This process leads to a decrease in visual acuity near and can contribute to the manifestation of previously (hidden) farsightedness that has not manifested itself. 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.
There is currently no data on the effect of gender on predisposition to farsightedness. However, its wider prevalence among African-Americans, residents of the Pacific region, North American Indians is noted.
At a young age, the reserve of accommodation often helps to provide a clear image on the retina without the development of asthenopia. However, its insufficiency, which developed as a result of visual fatigue or as a result of age-related changes in the body, with medium and high degrees of hyperopia can provoke the appearance of the following symptoms and conditions: blurred vision, asthenopia, impaired accommodation and binocular vision, amblyopia, strabismus.
More often, these symptoms are manifested in patients with esophoria and insufficient negative fusion reserves.
Presbyopia that develops with age can lead to the transition of latent hyperopia to manifest, which is accompanied by blurry images, especially near.
Visometry. The effect of hyperopia on visual acuity depends on the degree of hyperopia, the age of the patient, the volume of accommodation, and visual loads. At a young age, with mild or moderate degree of optional hyperopia, usually there is no decrease in visual acuity, but with significant visual stress, blurred vision, asthenopia can occur.
When conducting visometry in patients with a high degree of hyperopia, even at a young age, a decrease in visual acuity is often detected, especially with significant visual stress.
Although indicators of visual acuity may change from time to time, especially near, with latent hyperopia they usually remain normal. However, such patients after visual overfatigue often notice a decrease in visual acuity near and sometimes into the distance.
Patients with an average and high degree of hyperopia who do not use optical correction have a high risk of developing amblyopia.
Cycloplegic agents (atropine, tropicamide, cyclopentolate) can be used before the examination for the most accurate assessment of refraction. They allow you to set the overall degree of hyperopia, including latent, which is especially important in childhood.
The most effective of them is atropine, however, its use requires a long, compared with others, instillation (from 3 days or more), and the effect can persist for several days and even weeks after the end of use. A good compromise between the effectiveness and speed of the examination (the maximum effect occurs after 35-40 minutes) in this case is cyclopentolate. Tropicamide is effective in cases of mild hyperopia in school age, but it cannot provide a sufficient cycloplegic effect, especially in patients with a dark color of the iris and a high degree of hyperopia.
The method of subjective refractometry is used to determine the tolerable optical correction necessary to improve vision, especially in older children and adults.
Other examination methods. Along with the assessment of refraction, in patients with hyperopia it is necessary to evaluate the movements of the eyeballs, binocularity of vision and accommodation. For this, methods such as determining the closest convergence point, accommodation volumes, stereopsis, a test with covering the eyes (cover test) and others are used.
Other ophthalmological studies can be used to determine the cause of pathological hyperopia.
The frequency and volume of examinations with hyperopia (as recommended by the American Optometrists Association, 2008). Table - download.
Classification of Hyperopia
Currently, the American Association of Optometrists distinguishes a slight degree of hyperopia (up to 2.0 diopters), medium (from 2.25 to 5.0 diopters), high (more than 5.0 diopters).
Clinically, hyperopia is also divided into:
• simple (physiological) - occurs due to changes in the length and optical power of the refractive media of the eye, provided there is no pathology of the eye structures,
• pathological - with pathology of the organ of vision, including impaired development, trauma,
• functional - with accommodation paralysis.
It is observed when the anteroposterior size of the eye is shorter than necessary to focus the rays on the retina.
The reason is other, not related to normal biological variants of changes in the optical structures of the eye.
Heredity combined with environmental factors.
Relatively flat curvature of the cornea.
Lack of refractive power of the lens.
Increased lens density.
Short anteroposterior size of the eye.
Deviation from the average optical values of the eye.
Underdevelopment of the eye during the prenatal and early postnatal period.
Changes in the cornea or lens.
Chorioretinal, intraorbital inflammation or swelling.
Neurological or drug related causes.
Permanent or transient blurring of vision.
Redness of the eyes, lacrimation.
Increased frequency of blinking eye movements.
Binocular vision impairment.
The presence of congenital or acquired eye or systemic diseases.
Depending on the state of accommodation function, hyperopia is distinguished: optional - can be compensated by accommodation, absolute - not compensated by accommodation. The total degree of hyperopia is the sum of these two values.
In addition, farsightedness is divided by the magnitude of cycloplegic and noncycloplegic refraction into: manifest - determined by the value of non-cycloplegic refraction, may be optional or absolute, latent - equal to cycloplegic refraction, can be compensated by accommodation. The sum of these two quantities is also equivalent to the total force of hyperopia.
The true magnitude of hyperopia can be established only after an adequate cycloplegia. It is called total. or complete hyperopia. Depending on the condition of the accommodation apparatus, it can be compensated to one degree or another.
Because of this, during a subjective assessment, the magnitude of total hyperopia is often not possible to establish. When the maximum corrective lens is attached to the eye, with the help of which the maximum visual acuity is achieved, we will get manifest hyperopia, and minimally corrective lenses - absolute. The difference between manifest and absolute hyperopia reflects the value of facultative hyperopia. In turn, the difference between total and manifest hyperopia reflects the value of latent hyperopia.
There is currently no universal treatment for hyperopia. It should be planned according to the needs of the patient. In this case, the degree of farsightedness, the presence of astigmatism or anisometropia, the age of the patient, the relationship with esotropia and / or amblyopia, the state of accommodation and convergence, planned visual loads and symptoms should be taken into account. Treatment of hyperopia should be aimed at reducing the accommodation load, providing a clear and comfortable vision, creating conditions for binocular vision, alleviating the symptoms of asthenopia, reducing the risk of amblyopia, strabismus.
Optical correction. The main, most widely used, method of treating hyperopia is optical correction with glasses or contact lenses. For this, spherical or spherical cylindrical collecting (“plus”) lenses are used that shift the focus from the space outside the eye to the retina.
Accommodation plays an important role in determining the necessary correction power. At first, some patients cannot tolerate the full correction corresponding to manifest refraction, and patients with latent hyperopia can not tolerate the full correction revealed by cycloplegia. Nevertheless, children with accommodative esotropia and hyperopia require a short period of time to adapt to complete correction.
In patients with latent farsightedness who cannot tolerate full or partial correction, only close glasses can be used at first. Sometimes a short-acting cycloplegic drug (cyclopentolate) is used to facilitate getting used to the prescribed optical correction. For patients with hyperopia, it is better to use the correction that is most appropriate to the full, as this increases their visual acuity.
A good alternative to glasses is contact lenses. They better help correct anisometropia, creating more optimal conditions for binocular vision. In the presence of accommodative esophoria, contact lenses reduce the load on accommodation and convergence, reduce or block esotropia near. Multifocal contact lenses or monofocal selection according to the principle of monovision can be used in patients who require additional correction near, but for some reason they cannot wear multifocal glasses.
Visual exercises are an effective method of treating accommodative dysfunction and binocular vision disorders resulting from hyperopia. Often, the accommodative response in patients with hypermetropia is not restored only by optical correction, and visual exercises can help eliminate accommodation dysfunction. Accommodation esotropia, coupled with moderate and high degree hyperopia, in some cases leads to a violation of binocular vision. It can be improved by using optical correction and performing visual exercises.
Drug treatment. The prescription of myotics can be indicated for patients who are not able to get used to wearing glasses. Their use causes an artificial spasm of accommodation, which helps to temporarily compensate for part of hyperopia. However, potentially serious side effects limit the use of this group of drugs. Drugs such as phospholinium iodide (echothiophate) and diisopropyl fluorophosphate can be used in patients with accommodative esotropia and hyperopia to reduce the high ratio of accommodative convergence to accommodation (AK / A) and to give the correct position for the eyes when viewing objects close. These drugs mimic the effect of plus lenses without wearing optical correction.
Change in patient lifestyle and environmental conditions. Reducing visual loads does not reduce the level of hyperopia, however, it can alleviate symptoms even in patients using optical correction. Improving the illumination and reducing glare, reading printed texts on good quality paper, observing the correct mode of operation and the principles of ergonomics of the workplace can play a role.
Refractive surgery. Currently, the following methods for correcting hyperopia in refractive surgery exist: holmium YAG laser thermokeratoplasty, automated lamellar keratoplasty, helical hexagonal keratotomy, excimer laser correction, and refractive lensectomy.
Studies have shown that refractive surgery of farsightedness of weak degrees (up to 3 diopters) has the greatest effectiveness and safety. However, LASIK excimer laser technology has received FDA approval for use in the United States for hyperopia up to 6.0 diopters, despite the absence of long-term observations at present.
Various tactics of optical correction of hyperopia
Children under 10 years old. At this age, patients with mild to moderate hyperopia without strabismus, amblyopia and other visual impairments do not need treatment. However, even an episodic decrease in visual acuity, a violation of binocular vision, and a deterioration in visual functions can be a signal to start treatment. Since uncorrected hyperopia can manifest with difficulties in reading, perceiving the material during training, it is necessary to approach its treatment individually.
In most children, the process of emmetropization leads to a decrease in the degree of hyperopia or its complete disappearance by 5-10 years of age. In violation of this process, refraction remains farsighted and there remains an increased risk of strabismus and amblyopia. In patients under the age of 5 years, using optical correction with farsightedness of more than 3.25 diopters, there is a decrease in the risk of amblyopia and strabismus.
However, animal studies have shown that the early onset of optical correction, especially at an early age, can disrupt the process of emmetropization. Thus, early treatment can potentially lead to the preservation of the existing degree of farsightedness throughout life. However, it is important to note that according to the results of clinical studies, partial correction of hyperopia does not prevent emmetropization in children under 3 years of age and can reduce the risk of strabismus.
Optical correction is usually prescribed to patients with moderate and high degree hyperopia. The appointment of optical correction may be delayed in some patients with an average degree of hyperopia, but they should be assigned to a risk group and should be examined regularly. At the same time, in the presence of amblyopia or strabismus, other therapeutic measures should be carried out (occlusion or visual exercises, etc.).
The purpose of the correction should be based on the results of measuring refraction to the “narrow” pupil and against the background of cycloplegia, assessing the state of accommodation and binocular vision, and the AK / A ratio. Subsequently, careful monitoring of the patient is necessary, since a change in the optical power of the glasses used may be necessary. After the beginning of the application of correction, a relative increase in the degree of hyperopia due to manifestation of the latent is possible.
Contact lenses are a good alternative for patients in whom ametropia cannot be completely corrected with glasses (e.g. with anisometropia, a high degree of hyperopia with or without nystagmus, hyperopia with accommodative esotropia).
Older children (> 10 years old) and adults under 40 years old. Most patients with a low degree of hyperopia at this age do not need to wear glasses, since they have no complaints about vision. Reserves of accommodation compensate for hyperopia and prevent the occurrence of problems associated with it. However, with an increase in visual stress, some patients may still require the appointment of correction. So, with an average degree of farsightedness, they often need it, at least for close proximity.
In order to improve accommodation function and create conditions for binocular vision with uncorrected low or medium farsightedness, in addition to optical correction, visual exercises can be used. A great influence on the need for treatment and its features is exerted by the lifestyle, nature of work and environmental conditions.
By the age of 30-35, most patients who have not previously experienced any symptoms and have not used correction begin to notice the appearance of blurring of contours of objects near and discomfort during visual stress. Optional hyperopia, mainly due to the decreasing power of accommodation, gradually turns into absolute.
The presence of latent hyperopia is likely if the symptoms occur together with a lower than normal amplitude for accommodation at this age. In this case, the assessment of refraction against the background of cycloplegia can also help. Often at this age, it will be sufficient to prescribe an optical correction according to the results of measuring refraction by a “narrow” pupil to be worn if necessary. With age and with significant loads near, you may need to assign points for close ones. When selecting them, it must be borne in mind that wearing them can adversely affect the visual acuity of the distance. A good alternative to glasses for some patients is contact lenses, which more effectively relax accommodation.
Patients with Presbyopia. With the onset of presbyopic age, changing focus becomes more and more difficult, especially in low light conditions. This condition requires the appointment of points for near, and sometimes for the distance. Hypermetropia of 1.0 or more diopters usually requires constant correction for distance in patients older than 45 years. As optional farsightedness becomes absolute, the power of spectacle lenses that provide the best vision can change. Progressive or bifocal glasses allow you to see well at different distances. For some patients, bifocal, multifocal contact lenses, or monofocal, selected according to the principle of monovision, are acceptable.
Forecast. Physiological hyperopia is not a progressive disease. For this reason, in most cases, the prognosis for vision is good, with the exception of patients with amblyopia and strabismus. In such cases, it depends on many factors. Adequate optical correction almost always makes the vision clearer and creates the conditions for binocular vision. Treatment for children with a high degree of hyperopia, amblyopia, strabismus, or anisometropia should be started as early as possible. Early detection of hyperopia can prevent the development of strabismus and amblyopia in young children. Children with hyperopia more than 3.5 diopters are 13 times more likely to develop strabismus by 4 years of age if optical correction is not used and reduced visual acuity is 6 times more likely than children with mild hyperopia or emmetropia. In older seniors, uncorrected hyperopia can cause reading difficulties, and, as a result, poor academic performance.
Patients with pathological farsightedness require treatment for their underlying disease.
Complications of Hyperopia
In childhood, the main complications of moderate and high degree hyperopia are amblyopia and strabismus. The vast majority of patients with convergent strabismus have farsighted refraction. The presence of anisometropia of more than 1 diopters in this case increases the risk.
Uncorrected hyperopia of more than 3.5 diopters in one of the eye meridians can also contribute to poor motor and cognitive development of a child aged 9 months to 5.5 years and / or learning problems at an older age. The exact mechanism of this relationship has not been established. Nevertheless, this developmental delay can be compensated for several weeks after the start of the use of permanent correction in children aged 3-5 years.
Definition of the disease. Causes of the disease
Hyperopia or Hyperopia - this is the state of the eye in which light is focused behind the retina, and not on it, as is the case with ordinary, emmetropic refraction. With this vision, closely spaced objects look blurry, while objects located far away are clear, although not always.
Contrary to popular belief, farsightedness is not an age-related disease. It is confused with presbyopia (age-related farsightedness) - when the eye is not able to focus on short distances or change the focus distance.
The cause of farsightedness can be the imperfection of the eyes. How to understand this?
The eye is an organ that strictly obeys two sciences: biology and physics. And if biology is a very “creative” science, which allows freedom in the creation of organs and cells (for example, a variety of sizes and locations), then physics, or rather optics, does not approve of this: the slightest deviation from the norm already leads to violations.
Take, for example, a magnifying glass. In order to set fire to something with its help, you need to adjust the focus. This process is similar to focusing the eye, only the magnifier is solid, unlike the lens. To change the focus, you need to move or bring the lens closer to the tree - this changes the focus spot. And when it is possible to find the cherished "middle", a stream of smoke rises, as evidence of an accurate hit in focus.
There is not much distance in the eye to move the "lens", and therefore nature has come up with something like a liquid lens - this is a lens that is in some kind of "bag" - a lens capsule. When trying to change focus, the ciliary muscle tenses or relaxes due to the ligaments that attach the capsule to this muscle. As a result, the shape of the lens changes, which means that the focus changes. This process is called accommodation.
The development of farsightedness is associated with various reasons:
- mismatch of optical systems to each other (most often we are talking about a small eye size),
- hereditary diseases
- side effects of certain medications
- volumetric formation of the orbit and adjacent areas.
Children are mostly susceptible to farsightedness: 8% have it up to 6 years, 1% have it up to 16 years. In premature babies born before 40 weeks, the chances of hypermetropia increase, and in children with retinopathy of premature babies, the risk of developing myopia.
Hyperopia is a refractive error, the so-called ametropia. This means that in the process of "assembling" the eyes of nature were made inaccuracies.
Imagine a microcircuit that consists of various elements such as transistors, capacitors and diodes. They are in strict sequence and have precise characteristics. If these parts are assembled in the wrong order, or instead of the capacitor needed in volume, take another - this whole circuit will not work in the best case, and in the worst case it can be dangerous to use. According to the same principle, the eye is formed.
The focus on the retina is formed by three main organs:
- Cornea has the greatest optical power. In the case of any abnormal values, for example, if it is not as strong as it should be, then its strength is not enough to collect the rays on the retina. Then the focus will be behind her, that is, farsightedness is formed.
- Lens possesses the second largest refractive power. Due to a change in its position or functional state, focus may also change. Here lies some peculiarity of farsightedness. Thanks to the ciliary muscle, some degrees of farsightedness can be overcome due to stress, which causes discomfort and other symptoms. But sometimes, especially in people over 40 years of age, involutional and pathological changes of the lens lead to even greater farsightedness.
- Vitreous body affects refraction last. It has the least refractive power, but along with this, such power is comparable to the size of the eye. If the volume of the eye does not match the combination of the lens and cornea, then the focus will also not be on the retina.
Physiological hyperopia occurs in young children, since at birth not all organs of the eye have an adult size and function. Along with the growth of the child, the need for higher visual functions grows, the eyeball increases. Normally, by the age of 5-6 years, all systems "fit" together, and the focus is at rest on the retina, and not behind it, as it was at birth (with physiological hyperopia).
Classification and stages of development of farsightedness
The American Association of Ophthalmologists distinguishes three degrees of hyperopia:
- mild hyperopia - up to 2 diopters,
- moderate hyperopia - from 2.25 to 5 diopters,
- high degree hyperopia - over 5 diopters.
This association also shares hyperopia in clinical forms:
- Physiological (simple) farsightedness - not associated with pathological mechanisms, most often refers to children under 4-5 years old. It can develop due to the small anteroposterior axis of the eye, the insufficiently steep cornea and the lack of lens power.
- Pathological hyperopia - may be associated with intrauterine and extrauterine complications. Its cause may be the pathological condition of the cornea or lens, inflammation in the orbit and the volumetric formation of the orbit itself, as well as the use of drugs that increase the density of the lens.
- Functional Hyperopia - develops with pathological or drug paralysis of accommodation (turning off the focusing muscle).
They also distinguish between optional (which accommodation compensates for) and absolute hyperopia. You need to understand that not all farsightedness causes problems to its owner. If the degree of the disease is not high, and the strength of the ciliary muscle is sufficient, then, despite the mismatch of the structures to each other, the muscle will help in focusing and the patient will practically have no problems with focusing.
There are two main complications of hyperopia: amblyopia and strabismus. They are very difficult to treat and diagnose.
Amblyopia or "lazy eye" is a disease that occurs during the use of the incomplete power of visual analyzers. By analogy, it can be compared with changes in the body of an astronaut who does not use his body as intensively as on earth. If during the flight he will not train, then dystrophic changes will necessarily occur in the body, and upon arrival to the ground he will not be able to walk and stand on his own.
In the case of the astronaut, we are talking about developed muscles that, due to inaction, have lost their former strength. With amblyopia, problems arise in connection with the initial underdevelopment. The brain, namely the visual centers due to the fuzzy picture, which was obtained due to farsightedness, did not manage to form a good, active and highly functional resource. In other owls, the brain simply did not learn to look sharper, because the "optics" did not require a better picture from it.
Amblyopia most often occurs with farsightedness of more than 3.5 diopters and a difference in eye refraction of more than 1.5 diopters.
Strabismus often "stems" from a previous complication. The process of keeping the eye in the correct position is very complex: the brain has to control the six oculomotor muscles in each eye. When a person with farsightedness watches an object or reads, the brain has to not only synchronize movements and jump to the next line, but also an even more complicated process - focusing. Even now, while reading this text, the gaze can move from the screen to any other surface, and then the brain, focusing arm and oculomotor muscles will have to do a tremendous job and do it in a coordinated, synchronous manner.
Due to problems with focusing with farsightedness, convergent strabismus most often develops. It requires a phased solution: first, the refractive error is eliminated, then amblyopia is treated, since most often it accompanies a violation of the position of the eyes, and only then the squint itself is eliminated.
It is also often heard that patients with hyperopia are more prone to age-related macular degeneration and other retinal diseases than people with normal vision. But, having assessed the influence of risk factors on the development of the disease using Mendeleev randomization, such information was disproved.
Hyperopia is eliminated due to eye growth. Her treatment depends on the age of the patient and the complications that have arisen. The main methods include:
- optical correction
- laser correction.
Optical correction - This is the complete or partial elimination of refractive error with glasses or lenses.
For a child with amblyopia, strabismus and similar complications, glasses or lenses can almost completely, and sometimes completely eliminate hyperopia. They unload the focusing muscle, form a clear picture on the retina and further create a platform for the treatment of possible amblyopia and strabismus.
For patients older than 10 years, the degree of correction is shown if there are complaints of fatigue, discomfort of work near and other subjective sensations.
Can contact lenses be used for children? Yes, but the age limit for all children is different. If we talk about the conscious wearing of lenses as an alternative to glasses, then everything depends on whether the child is able to take care of the lenses, independently install and remove them.
When the refraction of one eye is significantly different from the refraction of the other, then contact correction is already a medical indication. The maximum tolerated difference between the eyes in the glasses is 2-3 diopters, while such a vision cannot be called comfortable.
Laser vision correction - This is a radical method of getting rid of farsightedness. LASIK refractive surgery is performed on the cornea. This method allows you to change its strength, shape and move focus to the retina. The size of the eye remains unchanged. Implantation of an artificial lens also does not change the size of the eye, but only eliminates the refractive error.
Eye charge able to improve the compensatory functions of the ciliary muscle. But this is not a panacea. You should not cling to it if the child has medium or high hyperopia - most often the strengthening of compensatory functions in such cases leads to the appearance of latent or explicit strabismus.
Drug therapy farsightedness is not carried out, since no drops or vitamins can affect the growth of the eye. The same applies to hardware treatment and physiotherapy. Therefore, you should be careful when prescribing any drops from hyperopia and similar types of treatment - often they not only do not bring benefits, but also exacerbate the situation.
During the growth and development of the eye, the lungs and some moderate degrees of hyperopia in children disappear, gradually reducing their strength. Medium and some high degrees of the disease with the right treatment tactics and constant wearing of the correction also have a positive prognosis. Such degrees make themselves felt only at the approaching adulthood.
Prevention of farsightedness does not exist, since the pathology does not depend either on the patient himself or on the lifestyle. The exception is farsightedness due to cataracts, diabetes and other diseases. In these cases, the recommendation is one - to regularly monitor your overall health.
What is farsightedness?
A typical symptom of farsightedness is that a person blurredly sees objects located at close range, while he can recognize what is far away (if he has a low degree of refractive error).
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The fact is that such an important segment of the visual apparatus, as the lens (biconvex natural lens), adapts to various conditions and forcibly increases the optical power of the visual organs due to the elasticity of the eye muscles. For this reason, people with a weak and moderate degree of farsightedness may not notice the presence of the disease.
Over time and age-related changes in the body, the ability to accommodate decreases and characteristic symptoms of pathology appear:
- Poor vision in the distance
- Reduced visibility near
- Eye fatigue when working with small objects, as well as when reading, writing, sewing, etc.,
- Inflammatory processes in the visual system,
- Blurred vision in low light
- Profuse lacrimation, pain in the eyes.
In addition to age-related transformations of the visual system, hyperopia may be associated with a reduced size of the eyeball, which causes malfunctioning of the light-refracting apparatus of the eye. In this regard, the focusing of the image does not occur on the retina, as it should be under normal conditions, but behind it.
The causes of farsightedness
It is important to understand that the human eye is an overly complex system that includes accommodation and light-refracting (refractive) devices, it is they who are responsible for the formation and focusing of the images of the surrounding world on the retina of the eye.
So, the refractive apparatus includes:
- Fluid in the chambers of the eye,
- The lens
- Vitreous body.
It is because of the weak refractive power that the rays of light focus behind the retina. As mentioned above, hyperopia in not all patients is accompanied by a deterioration in visual ability, since the ciliary muscle, which is located in the accommodation apparatus, can respond to changes in the lens curvature.
At the moment when the natural lens becomes more convex, the muscle is stretched and refracts light rays - a person can clearly distinguish even closely located objects, accommodation provides focusing of the image on the retina. As soon as the ciliary muscle relaxes, the lens becomes less elastic, allowing you to clearly see objects in the distance.
Another reason for farsightedness is the small size of the eyeball (its anteroposterior axis). In a healthy person, the length of the axis of the visual organ should be about 23.5 mm, and if its size is less, problems with visual perception arise. This is due to the fact that with a shorter length of the anteroposterior axis, the light beam does not have time to focus on the retina. In childhood, hyperopia is a normal physiological state, since the visual organs still continue to form.
If at 10 years of age the refractive ability has not stabilized in the child, it is necessary to be observed as often as possible by an ophthalmologist in order to adjust visual function.
There is also age-related farsightedness, it is called presbyopia.
Manifestations of the disease are associated with a loss of lens elasticity after 40-45 years, and by the age of 65 a person does not see not only close, but also into the distance due to a loss of accommodation ability. Such a process is absolutely natural.
Hypermetropia according to the degree of manifestation is divided into three types. It happens:
- Weak degrees - up to +3 diopters, while visual acuity in the distance does not suffer, slight difficulties may arise when reading, fatigue of the visual organs appears when working at close range.
- The average degree is from +3.25 to +5 diopters, the patient has serious difficulties in examining closely located objects, and his visual ability remains normal.
- A high degree - from +5.25 and above, the patient does not see the surrounding objects well, not only near, but also far away.
Consider all the degrees of farsightedness in more detail.
Farsightedness of a weak degree
Ophthalmologists notice that visual acuity with farsightedness can be reduced when examining close objects at different distances up to three meters.
With mild hyperopia occurs 40% of children and adolescents over 10 years. A feature of this type of ocular pathology is that a person does not feel discomfort, since it is asymptomatic. In the future, weakening of accommodation occurs, vision begins to fall. If you do not diagnose hypermetropia in time and do not prescribe treatment, it will progress and go to medium and high degrees. That is why children need to visit an ophthalmologist at least twice a year, adults only need once.
At an early age, the presence of hyperopia is in most cases a natural physiological phenomenon, if this refractive anomaly does not disappear, it turns into a pathology that requires correction by contact optics or glasses. With exacerbation of hyperopia, headaches can occur, often along with distortion of the picture, convergent strabismus appears, and the development of eye neurons can also be impaired.
It is important to understand that latent hyperopia (of a weak degree), if it is not detected on time, leads to a depletion of the capacity for accommodation. In order to avoid such consequences, it is worth monitoring the state of eye health and paying attention to the following symptoms:
- It’s hard to focus on small signs, as well as reading, writing and working on a computer,
- Eyes get tired quickly
- The regular or periodic manifestation of latent strabismus,
- Chronic blepharitis
- Chronic conjunctivitis.
Seeking help from a specialist is not only if you find the symptoms described. Routine inspections should be performed.
Farsightedness of medium degree
An average degree of anomaly occurs for various reasons. The task of the doctor in its treatment is to increase the refractive power of the visual organs, only then the light rays will be focused properly, the picture will become clear.
An average degree of farsightedness allows the patient to see objects located at arm's length, however, the closer the subject becomes, the more vague the picture will be. The symptomatology of an average degree (from +3.25 diopters) of farsightedness is the same as with its mild severity. However, vision decreases faster, headache intensifies, performance decreases, conjunctivitis may worsen if treatment is not started in a timely manner.
High degree farsightedness
The most complex form of pathology is hyperopia of a high degree. With its presence, a person does not see objects well, not only near, but also far away. Headaches due to overstrain of the visual system can intensify, many patients have pains and sensations of “sand” in the eyes, which is associated with tiredness of the ciliary muscle, which is regularly in good shape.
Without medical intervention, vision indicators fall, which can lead to complete blindness, the development of strabismus and glaucoma.