Munson's sign is a characteristic of advanced cases of?

Chitranjjan National Cancer Institute Kolkata - 2021

Medical & Surgical Nursing

Easy

Appeared in: Chitranjjan National Cancer Institute Kolkata - 2021

Explanation

Munson's sign is a pathognomonic finding in advanced keratoconus.
It is caused by the cone-shaped cornea pushing against and deforming the lower eyelid when the patient looks down, creating a V-shaped appearance as seen in the image.
Keratoconus is a progressive thinning and ectasia (bulging) of the cornea, which alters its normal dome shape into a cone.
This structural change is the underlying reason for the presence of Munson's sign.

Option B: Cataract is an opacification of the crystalline lens inside the eye. It affects vision clarity but does not change the shape of the cornea or cause any external signs on the eyelids.
Option C: Strabismus, or 'squint', is a condition of eye misalignment. It is a neuromuscular disorder affecting the extraocular muscles and does not involve any structural change to the cornea.
Option D: Diabetic Retinopathy is a microvascular complication of diabetes affecting the retina, which is at the back of the eye. It does not affect the anterior segment structures like the cornea or eyelids.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Clinical signs of Keratoconus as background academic context rather than a clinical decision trigger.
Recognizing Munson's sign is crucial for nurses as it indicates advanced disease, requiring prompt referral to an ophthalmologist for management to prevent further vision loss.
Patient education is a key nursing role, including advising patients with keratoconus to avoid vigorous eye rubbing, which can worsen the condition.
What if? If the patient presented with sudden, severe eye pain, photophobia, and a dramatic drop in vision, the nurse should suspect acute hydrops (a complication of keratoconus) and facilitate an emergency ophthalmology consultation.

How to Approach the Question

First, identify the key term in the question: 'Munson's sign'. Recognize this as a specific, named clinical sign.
Access your knowledge base about ophthalmological signs. Recall that Munson's sign is related to a change in the shape of the front of the eye.
Analyze the provided image, which clearly shows a V-shaped deformity of the lower lid on downgaze, confirming the visual characteristics of Munson's sign.
Evaluate the options based on this understanding. Keratoconus is defined by a 'cone-shaped cornea', which provides a direct mechanical explanation for the eyelid bulging.
Eliminate the other options: Cataract (lens issue), Strabismus (muscle alignment issue), and Diabetic Retinopathy (retinal vessel issue) do not involve changes in corneal shape and therefore cannot cause Munson's sign.

Concept Tested & Keywords

Concept Tested: Clinical signs of Keratoconus
Stem keywords: Munson's sign, advanced cases
Lead-in keywords: characteristic of
Clinical cues: Image showing V-shaped indentation of the lower eyelid on downgaze

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