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Regular Astigmatism

Disease Details

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Description: Regular astigmatism is a common refractive error where the eye's cornea or lens has an irregular shape, causing blurred or distorted vision.
Type: Regular astigmatism is typically considered a refractive error rather than a disease. Its genetic transmission is generally complex and multifactorial, involving multiple genes and environmental factors, rather than following a clear Mendelian inheritance pattern.
Signs And Symptoms: Although astigmatism may be asymptomatic, higher degrees of astigmatism may cause symptoms such as blurred vision, double vision, squinting, eye strain, fatigue, or headaches. Some research has pointed to the link between astigmatism and higher prevalence of migraine headaches.
Prognosis: Regular astigmatism generally has a good prognosis when properly managed. It can often be effectively corrected with glasses, contact lenses, or refractive surgery such as LASIK. Early diagnosis and treatment are essential to prevent complications like amblyopia (lazy eye) in children. Regular follow-ups with an eye care professional are advisable to monitor and adjust the treatment as needed.
Onset: The onset of regular astigmatism is typically present from birth (congenital) or can develop gradually over time. It can occur in childhood or adulthood, and symptoms may become more noticeable as the eye grows.
Prevalence: The prevalence of regular astigmatism varies, but it is quite common. Studies suggest that around 30% to 40% of the population may have some degree of astigmatism. The condition often occurs with other refractive errors like myopia (nearsightedness) or hyperopia (farsightedness). The exact prevalence can vary based on age, ethnicity, and geographic location.
Epidemiology: In 2019, the World Health Organization reported that 123.7 million people worldwide were affected by uncorrected refracting errors, including astigmatism. A compilation of many systematic reviews found that there was an 8-62% prevalence of astigmatism among adults, with an estimated prevalence of 40% worldwide. The country with the highest reported prevalence among the compilation of systematic reviews is China at 62%. The prevalence of astigmatism increases with age due to changes in refractive index gradients. According to an American study, nearly three in ten children (28.4%) between the ages of five and seventeen have astigmatism. A Brazilian study published in 2005 found that 34% of the students in one city were astigmatic.Studies have shown that infants in their first few months have a high prevalence of astigmatism due to a steep cornea. The steepest corneas are found in infants with low birth weights and post-conceptional age. By the age of four, the prevalence of astigmatism has reduced as the cornea flattens. The cornea remains mostly stable during adulthood, and then steepens again in older adulthood (40+ years).Mild astigmatism has a higher prevalence than moderate and significant astigmatisms and increased until the age of 70, while moderate and significant astigmatisms showed an increase in prevalence after the age of 70. Of the levels of astigmatism, mild astigmatism is most prevalent, making up about 82% of the total reported astigmatisms.With-the-rule astigmatism among the total population has a prevalence range of 4 to 98% globally. The prevalence range for against-the-rule astigmatism is from 1 to 58%. For oblique astigmatism, the prevalence range is from 2 to 61%. With-the-rule astigmatism is more prevalent in young adults, and over time, the prevalence shifts to be mostly against-the-rule astigmatism. A Polish study published in 2005 revealed "with-the-rule astigmatism" may lead to the onset of myopia.The main cause of astigmatism is changes in the curvature of the cornea. When left untreated, astigmatism causes people to have a lower vision-related quality of life. Some factors that lead to this are a decrease in vision quality and an increase in glare and haloes. People with astigmatism have more difficulty with night driving and can have a decreased productivity due to errors. However, there are many ways to help correct astigmatisms. The use of glasses, contacts, Toric intraocular lenses, Toric implantable Collamer lenses, corneal refractive surgery have been shown to correct astigmatisms.
Intractability: Regular astigmatism is not considered intractable. It can often be effectively managed with corrective lenses, such as glasses or contact lenses, and in some cases, surgical options like LASIK can provide long-term improvement.
Disease Severity: Regular astigmatism is not classified as a disease but as a common refractive error affecting vision. It occurs when the cornea or lens of the eye has an irregular shape, causing blurred or distorted vision. Severity can vary widely; it can range from mild to severe, impacting visual clarity and quality of life. Treatment options often include corrective lenses (glasses or contact lenses) or refractive surgery, such as LASIK. Regular eye check-ups can help manage and correct vision issues related to astigmatism.
Healthcare Professionals: Disease Ontology ID - DOID:11781
Pathophysiology: Regular astigmatism is an optical condition characterized by an irregular curvature of the cornea or lens. The pathophysiology involves the corneal surface being shaped more like a football rather than a sphere, causing light rays entering the eye to focus on multiple points rather than a single point. This irregular curvature causes blurred or distorted vision. Regular astigmatism is often hereditary and can coexist with myopia or hyperopia, further affecting visual clarity.
Carrier Status: Regular astigmatism is not a genetic condition with a carrier status. It is a common vision problem caused by an imperfection in the curvature of the cornea or lens of the eye.
Mechanism: Regular astigmatism is a common type of astigmatism characterized by a consistent curvature anomaly in the eye, specifically the cornea or lens, where the eye does not focus light evenly onto the retina.

### Mechanism
In regular astigmatism, the cornea or lens has an irregular shape, typically resembling a football rather than a sphere. This irregular curvature causes light rays entering the eye to focus on multiple points rather than a single point on the retina, leading to distorted or blurred vision at all distances.

### Molecular Mechanisms
While the exact molecular mechanisms of astigmatism are not fully understood, potential factors include:
1. **Genetic Influences:** Genetic predisposition is considered one of the potential contributors, as astigmatism often runs in families.
2. **Proteoglycans and Collagen:** The cornea's structure and curvature are influenced by its extracellular matrix, which is rich in proteoglycans and collagen. Abnormalities in the synthesis or arrangement of these molecules can affect corneal shape.
3. **Epithelial and Stromal Interactions:** Proper interaction between the epithelial layer and the underlying stroma in the cornea is essential for maintaining its shape. Disruptions in cellular signaling pathways can lead to irregularities.
4. **TGF-β (Transforming Growth Factor-beta):** This cytokine plays a role in extracellular matrix remodeling and cellular proliferation in the cornea. Dysregulation of TGF-β signaling may contribute to abnormal corneal curvature.

Further research is required to fully elucidate the molecular pathways involved in the development of regular astigmatism.
Treatment: Astigmatism may be corrected with eyeglasses, contact lenses, or refractive surgery. Glasses are the simplest and safest, although contact lenses can provide a wider field of vision. Refractive surgery can eliminate the need to wear corrective lenses altogether by permanently changing the shape of the eye but, like all elective surgery, comes with both greater risk and expense than the non-invasive options. Various considerations involving eye health, refractive status, and lifestyle determine whether one option may be better than another. In those with keratoconus, certain contact lenses often enable patients to achieve better visual acuity than eyeglasses. Once only available in a rigid, gas-permeable form, toric lenses are now also available as soft lenses.
In older people, astigmatism can also be corrected during cataract surgery. This can either be done by inserting a toric intraocular lens or by performing special incisions (limbal relaxing incisions). Toric intraocular lenses probably provide a better outcome with respect to astigmatism in these cases than limbal relaxing incisions.Toric intraocular lenses can additionally be used in patients with complex ophthalmic history, such as previous ophthalmic surgery. In such complex cases, toric intraocular lenses seem to be as effective as in non-complex cases for correction of concurrent corneal astigmatism.
Compassionate Use Treatment: For regular astigmatism, which is an imperfection in the curvature of your eye, standard treatments include corrective lenses (glasses or contact lenses) and refractive surgery (such as LASIK or PRK). However, off-label or experimental treatments might include:

1. **Orthokeratology (Ortho-K)**: Specially designed contact lenses that temporarily reshape the cornea to reduce astigmatism.
2. **Topography-guided laser treatment**: Although primarily used for more complex corneal irregularities, it is being researched for its potential in treating regular astigmatism.
3. **Intrastromal corneal ring segments (ICRS)**: Initially intended for keratoconus, these devices are sometimes explored for regular astigmatism correction.

Compassionate use generally applies to life-threatening conditions, making it less relevant for regular astigmatism.
Lifestyle Recommendations: For regular astigmatism:

1. **Regular Eye Exams**: Schedule routine check-ups to monitor the condition and update prescriptions for glasses or contact lenses as needed.

2. **Proper Eyewear**: Wear prescribed corrective lenses (glasses or contact lenses) as recommended by your eye care professional to ensure clear vision.

3. **Protect Your Eyes**: Use sunglasses with UV protection to protect your eyes from harmful sun rays.

4. **Healthy Diet**: Maintain a balanced diet rich in vegetables, fruits, and omega-3 fatty acids to support overall eye health.

5. **Exercise and Hydration**: Engage in regular physical activity and stay hydrated to promote good circulation and overall health, which can benefit eye conditions.

6. **Screen Time Management**: Limit prolonged use of screens and take regular breaks using the 20-20-20 rule (every 20 minutes, look at something 20 feet away for at least 20 seconds).

7. **Adequate Lighting**: Ensure proper lighting when reading or doing close-up work to avoid straining your eyes.

These lifestyle recommendations can help manage symptoms effectively but consult an eye care specialist for personalized advice and treatment.
Medication: Astigmatism is not typically treated with medication. Instead, it is usually managed with corrective lenses such as glasses or contact lenses, or through surgical procedures like LASIK or PRK designed to reshape the cornea.
Repurposable Drugs: Repurposable drugs for regular astigmatism are not commonly discussed because astigmatism is typically treated with corrective lenses (glasses or contact lenses) or refractive surgery, rather than pharmaceuticals. Astigmatism involves the irregular curvature of the cornea or lens, making it inherently a structural issue better corrected through physical means than medications.

However, some existing drugs might be used to manage any associated symptoms or conditions rather than the astigmatism itself. For example, lubricating eye drops or anti-inflammatory medications could potentially be used to alleviate discomfort or inflammation that may occur alongside or due to the use of corrective lenses.

Always consult a healthcare professional for personalized advice and treatment options.
Metabolites: Regular astigmatism is primarily an optical condition related to the shape of the cornea or lens, causing blurred or distorted vision. It is not typically associated with specific metabolites. Therefore, there are no notable metabolites directly linked with regular astigmatism.
Nutraceuticals: There is no substantial evidence to support the use of nutraceuticals for treating regular astigmatism. Regular astigmatism is typically corrected with prescription eyeglasses, contact lenses, or refractive surgery. Nutraceuticals, which include vitamins, minerals, and other supplements, do not alter the shape of the cornea or lens and therefore are not effective for this condition. It's always best to consult with an eye care professional for appropriate treatment options.
Peptides: For regular astigmatism, peptides are not typically relevant to the condition's diagnosis, treatment, or management. Astigmatism is a common refractive error caused by an irregular curvature of the cornea or lens, leading to blurred vision. Treatment options generally include corrective lenses (glasses or contact lenses) and refractive surgery, such as LASIK. Nanotechnology has potential applications in eye care, including the development of advanced contact lenses and drug delivery systems, but it is not yet a standard treatment modality for astigmatism.