kk Flashcards
What is the definition of ptosis?
Drooping of the upper eyelid to cover more than 2mm (1/6) of the cornea while the patient is looking forward.
What are the different causes of acquired ptosis?
Aponeurotic (most common acquired cause)
Neurogenic (Horner’s syndrome and 3rd nerve palsy)
Myogenic (myasthenia gravis)
Mechanical (large chalazion)
How is the degree of ptosis assessed?
Judged by the lid margin-corneal distance (MRD), which decreases in ptosis. Normal MRD is 4-5mm.
What are the different types of ptosis and their respective causes?
-Congenital (simple): Due to dystrophy of the levator muscle, poor levator contraction, and poor relaxation. Associated with anomalies such as weak superior rectus muscle and Marcus Gunn phenomenon.
-Neurogenic: Associated with 3rd nerve palsy and Horner’s syndrome.
-Myogenic: Associated with myasthenia gravis.
-Trauma can cause aponeurotic, myogenic, or neurogenic ptosis.
What are the suitable surgical procedures for ptosis with good and poor levator action?
- Good levator action: Resection
- Poor levator action: Frontalis sling
What are the complications of unilateral severe ptosis?
Amblyopia and squint
Why can mild bilateral ptosis be managed conservatively until the age of school?
Full development of muscles can lead to spontaneous improvement.
How can trauma cause ptosis?
Trauma can cause aponeurotic, myogenic, or neurogenic ptosis.
What type of ptosis can be mistaken with myogenic (myasthenia gravis) ptosis?
Involutional (senile) ptosis, which worsens at the end of the day due to fatigue of Muller’s muscle.
What is the most important extraocular muscle to be examined during EOMs examination and why?
Superior rectus, because it shares a common embryological origin with the levator, they both share the same common sheath, and have the same nerve supply.
What is squamous blepharitis?
Chronic inflammation of the lid margin characterized by scales
What is ulcerative blepharitis?
Chronic inflammation of the lid margin characterized by ulcers.
Etiology
The cause or set of causes of a disease or condition.
Organism
The specific microorganism responsible for causing a disease.
Predisposing factors
Factors that make an individual more susceptible to a disease or condition.
Symptoms
Subjective evidence of a disease or condition as perceived by the patient
Signs
Objective evidence of a disease or condition as observed by a healthcare professional.
Complications
Additional medical conditions or adverse effects that arise from a primary disease or condition.
Why should we rub antibiotic ointment well into the lid margin?
Because the organism is hidden in the lash root.
Entropion
Rolling in of the lid margin