Description And Causes Of Miosis (pupiloconstriction)
Meiosis is the medical term used for pupil constriction. The problem may seem irrelevant, but it reveals a lot about a person’s health. In this article, we will discuss the causes of miosis.
The pupil is the part of the eye that reacts physiologically to light changes, either by contraction or by dilation. In addition, its size changes when a person consumes toxins or when there is damage to the brain.
Meiosis (pupiloconstriction)
As already mentioned, miosis is the contraction of the pupil – the darkest part of the eye located in the center of the iris. The pupil is responsible for controlling the amount of light that reaches the eyeball in the direction of the retina.
The pupil dilates or contracts to adjust the amount of light, depending on the environment. It expands when the environment is dark – the process is called mydriasis. Instead, the pupil becomes smaller when there is a lot of light. This is a normal physiological reflex controlled by the parasympathetic nervous system. These movements occur thanks to the ciliary muscle, the dilator of the iris present in the eyes. The sympathetic nervous system coordinates the action.
Causes of miosis
Opiates alter the functioning of the central nervous system. People use them either as medicines for a certain condition or for recreational purposes. Fentanyl, morphine, heroin and methadone are just a few of them.
Opiates depress the nervous system, and the pupils contract and react poorly to light stimuli. According to an article published by the Universidad Libre Seccional Barranquilla, opioid intoxication is characterized by miosis and respiratory depression and consciousness, among other symptoms.
The symptoms of this condition appear after a nerve injury. Causes miosis and droopy eyelids. In addition, sweating on the affected side of the face decreases.
According to an article published by the Acta Médica del Centro, iatrogenesis is one of the main causes of this syndrome (ie it occurs as a result of medical failure after facial surgery and dental or therapeutic interventions applied for trigeminal neuralgia).
Diagnosis of miosis
To determine the causes of miosis, the simplest thing is to look at the general condition of the patient. Many of the etiologies that cause the symptom, such as opioid intoxication or cerebral hemorrhage, are accompanied by a change in consciousness.
Doctors ask the person if they are under the influence of medication or drugs (if they are aware). The doctor will also monitor how the pupils react to light stimuli. The doctor or even the nurse will test various eye reflexes to check the patient’s neurological condition.
The photomotor reflex is one of the analyzed reflexes. The doctor will notice if the pupil contracts more when exposed to light. Another reflex is the consensual one, which confirms whether the pupil of the other eye (the one that is not illuminated) also contracts. It shows if the lesion is in one of the peripheral nerves or in the upper brain.
A physiological reflex
Miosis or constriction of the pupil is a physiological mechanism that occurs in response to exposure to light. However, the effect may be secondary to neurological damage or intoxication with certain substances.
Thus, this is an essential part of the medical examination and provides a lot of information about the patient’s condition. Physicians should suspect an underlying pathological process when myosis is persistent.
