Iridodonesis: Understanding the Quivering Iris and its Underlying Causes
- Aishwariya V
- May 30, 2023
- 3 min read
INTRODUCTION:
Welcome to our blog post on iridodonesis, a fascinating eye condition characterized by the trembling or shaking movement of the iris. But before we delve into the details, let's start with a lighthearted joke to set the tone:
Now, let's explore iridodonesis and its
underlying causes.
Iridodonesis - The Quivering Iris:
Iridodonesis, derived from the Greek words "iridos" (iris) and "donesis" (movement), refers to the involuntary shaking or trembling of the iris. This condition can be observed during an eye examination and may indicate an underlying systemic or ocular issue.
Understanding Marfan's Syndrome:
One of the known causes of iridodonesis is Marfan's syndrome, a genetic disorder affecting connective tissue throughout the body. The condition is named after Antoine Marfan, a French pediatrician who first described it. Marfan's syndrome is an autosomal dominant disorder, meaning a child can develop the condition if either parent carries the mutant gene.
The Role of Gene Mutation:
Marfan's syndrome is primarily caused by a gene mutation in the fibrillin 1 gene. Specifically, the gene variant Cys576Gly is responsible for encoding the fibrillin protein. Fibrillin is a glycoprotein critical for the durability and pliability of connective tissues, including those in the eye. Alterations in fibrillin-rich microfibrils can lead to various ocular complications associated with Marfan's syndrome and lens dislocation.
Mechanism of Iridodonesis:
Fibrillin polymers structurally support the extensible microfibrils found in ocular elastic tissues, including the ciliary zonule. These microfibrils are organized in parallel bundles to create zonular fibers, and their proper shape and function are essential for ocular health. However, diseases like Marfan's syndrome and ectopia lentis disrupt the structure or function of fibrillin-rich microfibrils, leading to ocular abnormalities. In this blog, we explore the current understanding of fibrillin and fibrillin-rich microfibrils and their role in the eye, including potential pathogenic mechanisms contributing to aging and ocular connective tissue diseases.
Diagnosing and Investigating Iridodonesis:
To diagnose iridodonesis and identify its underlying causes, a comprehensive eye examination (CEE) is crucial. A CEE involves a battery of tests that assess various aspects of eye health, including tonometry, visual acuity tests, slit-lamp examinations, pupil assessments, and assessments of overall eye health. It is recommended that individuals above the age of 40 undergo a CEE annually to detect and diagnose common eye conditions promptly.
In cases of suspected lens dislocation, imaging modalities such as computed tomography (CT) scans or ultrasounds are often used for diagnosis. CT scans are particularly useful in situations where eye compression must be avoided, such as suspected globe rupture. The "floating lens" sign, indicating posterior lens dislocation, can be rapidly identified through a CT scan. Additionally, bedside ultrasonography is often employed in urgent presentations for quick and reliable identification of lens dislocation.
Seeking Professional Guidance:
If you or someone you know experiences iridodonesis or any related ocular symptoms, it is important to consult an ophthalmologist or optometrist for a proper diagnosis and treatment recommendations tailored to the specific circumstances. Professional medical advice and intervention are essential for addressing the underlying causes of iridodonesis and managing any associated.
The zonular in the eye becomes weak and it leads to shaking movement of eyes and releases the gel which is present in the vitreous chamber in the eye.
CCE is not only the way to detect iridodonesis on slit lamp examination is also performed in order to check the displacement of the vitreous fluid.
Eye vibration can be expressed in terms of hertz (Hz- symbol of frequency). A dark background microscope is used to view this using a light source.
About the Author
Aishwariya. V
Biotech Undergraduate
Blog writer
REFERENCE :
Jarrett WH. Dislocation of the Lens: A Study of 166 Hospitalized Cases. Arch Ophthalmol. 1967;78(3):289–296. doi:10.1001/archopht.1967.0098003029100.
Maumenee A.E. Intraocular lenses complications and complicated cases // Rehabilitation of patients with pathology of the organ of vision: Tez. Report Conf. - Odessa, 1986. - S. 195 - 197.
http://www.neurology.org/content/suppl/2015/10/10/WNL.0000000000002025.DC1.html.
IMAGE CREDITS :
Thank you Aishwarya for information.