Introduction:
Chronic progressive external ophthalmoplegia is a disorder of the eye wherein the patient gradually loses the ability to move the eyes and the eyebrows. It resembles the feature of mitochondrial disease. Chronic progressive external ophthalmoplegia may coexist with other mitochondrial diseases, such as Kearns-Sayre syndrome. This is a condition wherein there may be a progressive weakness of the eye musculature. It commonly occurs between the ages of 18 to 40 years. The first sign of chronic progressive external ophthalmoplegia is a drooping eyelid. It may be present in one or both eyes. This is caused due to underlying muscular weakness.
What Are the Symptoms of Chronic Progressive External Ophthalmoplegia?
Various symptoms may be associated with chronic progressive external ophthalmoplegia; some may be common, while others may be rare. The various symptoms that may be associated with this condition are:
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Ptosis: Ptosis, or drooping of one or both eyelids, is frequently the initial symptom of increasing external ophthalmoplegia. Ptosis sufferers may try to elevate their eyelids with their forehead muscles as the condition progresses or lift their chin to see.
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Weakness of the Muscles: Weakness or paralysis of the eye muscles is another defining aspect of progressive external ophthalmoplegia. To look in different directions, those affected must swivel their heads, especially as their ophthalmoplegia develops.
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Generalized Muscular Weakness: In addition to muscle weakness (myopathy), those with increasing external ophthalmoplegia may also experience weakness in their neck, arms, or legs.
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Dysphagia: The weakness could be very apparent (exercise intolerance) when exercising. Having trouble swallowing might also result from muscle weakness (dysphagia).
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Other Conditions Associated: Progressive external ophthalmoplegia might include additional symptoms in addition to muscle weakness, which is the main symptom. In these cases, the illness is known as progressive external ophthalmoplegia plus (PEO+).
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Additional signs and symptoms may include depression, ataxia, decreased muscular coordination (neuropathy), sensorineural hearing loss (hearing loss caused by nerve damage in the inner ear), weakness, lack of sensation in the limbs, parkinsonism-like movement abnormalities, and nerve damage.
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What Are the Causes of Chronic Progressive External Ophthalmoplegia?
Chronic progressive external ophthalmoplegia is largely associated with mitochondrial defects. The main cause for the occurrence of external ophthalmoplegia is as explained below:
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Defects in mitochondria, which are parts of cells that use oxygen to transform the energy from meals into form cells can use, are the root cause of progressive external ophthalmoplegia. The term for this procedure is oxidative phosphorylation. The mitochondria also carry a small quantity of their DNA (deoxyribonucleic acid), known as mitochondrial DNA or mtDNA. Still, most DNA is packaged in chromosomes within the nucleus (nuclear DNA). Genes required for oxidative phosphorylation are present in this DNA.
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Several distinct genes can develop mutations that cause progressive external ophthalmoplegia. In some cases, the disorder is brought on by mutations in nuclear DNA. These genes are essential for the synthesis and upkeep of mtDNA. The method may not be evident, but
How To Diagnose External Ophthalmoplegia?
It is vital to separate chronic progressive external ophthalmoplegia from different pathologies that might cause ophthalmoplegia. There are explicit treatments utilized for these pathologies. The various diagnosis that can be used for detecting this condition are:
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Muscle Biopsy: Chronic progressive external ophthalmoplegia is analyzed using muscle biopsy. One can see a collection of augmented mitochondria when assessing muscle filaments stained with Gömöri trichrome stain. This delivers light red staining of the muscle strands that are "worn-out red filaments." While battered red strands are found in typical maturing, sums in overabundance of typical maturing give a finding of mitochondrial myopathy. Polymerase chain response (PCR) from an example of blood or muscle tissue can decide a transformation of the mtDNA.
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Acetylcholine Levels: The raised acetylcholine receptor immune response level, normally found in myasthenia gravis, has been found in specific patients with mitochondrial-related ophthalmoplegia. It is essential to have an enlarged eye test to decide whether there is pigmentary retinopathy that might imply the Kearns-Sayre condition is related to heart abnormalities.
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X-Ray: An X-ray might be useful in the analysis; in one review, volumes of average rectus, sidelong rectus, and second-rate rectus muscles in CPEO were not more modest than ordinary (as opposed to the significant decay commonplace of neurogenic loss of motion). Even though volumes of the unrivaled rectus muscle-levator perplexing and predominant slanted were essentially reduced
What Is the Treatment for External Ophthalmoplegia?
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There is no definitive treatment for chronic progressive external ophthalmoplegia. Mostly the treatment lies in treating the underlying disorder and addressing the specific symptoms.
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Ptosis related to CPEO might be rectified with a medical procedure to raise the lids because of the shortcoming of the orbicularis oculi muscles. Care should be taken to avoid bringing the covers up in overabundance making a failure to close the covers. This outcome is open keratopathy. Hence, the medical procedure must be performed only by a neuro-ophthalmologist acquainted with the infection.
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Diplopia (double vision) can be treated by using a prism lens.
Conclusion :
Chronic progressive external ophthalmoplegia is a progressive condition of the eye that causes progressive muscular weakness. Since this deals with mitochondrial aberrations, its occurrence cannot be prevented. But regular checkups can delay the onset of the symptoms and the disease itself.
