Ocular Manifestations of Systemic Disorders Practice Questions

Q: What is the most common site of distant metastasis in intraorbital malignant melanoma?

Liver. **Explanation:** **Correct Answer: C. Liver** The liver is the most common site of distant metastasis for uveal (intraocular) melanoma, occurring in approximately **80-90%** of patients with metastatic disease. Unlike most systemic cancers that spread via the lymphatic system, uveal melanoma spreads almost exclusively through the **hematogenous (blood-borne) route**. This is because the uveal tract (iris, ciliary body, and choroid) lacks a formal lymphatic drainage system. Once the tumor cells enter the bloodstream, the liver acts as the primary "filter" and provides a microenvironment highly conducive to the growth of melanoma cells. **Analysis of Incorrect Options:** * **A. Brain:** While melanoma can spread to the CNS, it is a much less frequent site of initial metastasis compared to the liver. * **B. Lung:** The lung is the second most common site of metastasis after the liver, but it rarely occurs in isolation without hepatic involvement. * **D. Lymph Nodes:** Because the intraocular environment lacks lymphatics, regional lymph node involvement is extremely rare. It only occurs if the tumor breaks through the sclera (extraocular extension) and involves the conjunctival lymphatics. **High-Yield Clinical Pearls for NEET-PG:** * **Prognostic Marker:** Monosomy 3 is the most significant genetic predictor of metastatic risk in uveal melanoma. * **Survival:** Once liver metastasis is detected, the prognosis is generally poor, with a median survival of less than 12 months. * **Monitoring:** Patients with uveal melanoma require lifelong systemic surveillance, typically involving periodic Liver Function Tests (LFTs) and abdominal imaging (Ultrasound or MRI). * **Differential:** In contrast to uveal melanoma, **conjunctival melanoma** spreads primarily via the lymphatics to the preauricular and submandibular nodes.

Q: What is the most common cause of visual loss in patients with AIDS?

CMV retinitis. **Explanation:** **CMV Retinitis (Correct Answer):** Cytomegalovirus (CMV) retinitis is the most common opportunistic ocular infection and the leading cause of blindness in patients with AIDS, typically occurring when the **CD4+ T-cell count falls below 50 cells/µL**. It is characterized by a "pizza-pie" or "cheese and ketchup" appearance (confluent areas of yellow-white necrosis with associated retinal hemorrhage). Visual loss occurs due to macular involvement, optic nerve atrophy, or secondary rhegmatogenous retinal detachment. **Incorrect Options:** * **Toxoplasmosis:** While it is the most common cause of posterior uveitis in the general population, in AIDS patients, it is less common than CMV. It typically presents as a "headlight in the fog" appearance due to intense overlying vitritis. * **Herpetic Retinitis:** Includes Acute Retinal Necrosis (ARN) and Progressive Outer Retinal Necrosis (PORN). While highly destructive and rapidly progressive, these are statistically less frequent than CMV retinitis. * **HIV Retinitis:** This is the most common *finding* in the eyes of HIV patients (presenting as cotton wool spots), but it is usually asymptomatic and rarely causes significant visual loss. **High-Yield Clinical Pearls for NEET-PG:** * **Most common ocular finding in AIDS:** HIV Microangiopathy (Cotton wool spots). * **Most common ocular infection/cause of blindness in AIDS:** CMV Retinitis. * **Drug of choice for CMV Retinitis:** Induction with Ganciclovir (IV or intravitreal) or Valganciclovir (oral). * **Immune Recovery Uveitis (IRU):** An inflammatory reaction that occurs in AIDS patients with CMV retinitis after starting HAART, due to a rising CD4 count.

Q: Amaurosis fugax is caused by occlusion of which artery?

Central retinal artery. **Explanation:** **Amaurosis fugax** refers to a sudden, painless, and transient loss of vision in one eye, often described by patients as a "curtain falling" over the field of vision. **Why the Correct Answer is Right:** The underlying mechanism is a temporary reduction in blood flow to the retina. It is most commonly caused by an **embolus** (Hollenhorst plaque) originating from an atherosclerotic carotid artery. This embolus travels through the internal carotid artery and ophthalmic artery to cause transient occlusion of the **Central Retinal Artery (CRA)**. Since the CRA is an end-artery supplying the inner layers of the retina, its occlusion leads to immediate ischemia and vision loss until the embolus dissolves or moves distally. **Why the Incorrect Options are Wrong:** * **A. Facial artery:** A branch of the external carotid artery (ECA) that supplies the muscles and skin of the face; it does not supply the retina. * **B. Occipital artery:** A branch of the ECA supplying the posterior scalp and neck muscles. * **D. Posterior auricular artery:** A branch of the ECA supplying the scalp behind the ear and the auricle. **Clinical Pearls for NEET-PG:** * **Hollenhorst Plaques:** These are bright, refractive cholesterol emboli seen at retinal artery bifurcations during fundoscopy. * **Warning Sign:** Amaurosis fugax is a "TIA of the eye" and is a significant warning sign for an impending **Cerebrovascular Accident (Stroke)**. * **Investigation of Choice:** Carotid Doppler (to check for carotid artery stenosis). * **Differential Diagnosis:** Must be distinguished from Giant Cell Arteritis (GCA) in elderly patients.

Q: Marfan's syndrome has which of the following prominent eye defects?

Ectopia lentis. **Explanation:** **Ectopia lentis** (displacement of the lens) is the most common and characteristic ocular manifestation of Marfan’s syndrome, occurring in approximately 50–80% of patients. The underlying pathology is a mutation in the **FBN1 gene**, which leads to a deficiency in **fibrillin-1**. Since the ciliary zonules (which hold the lens in place) are composed primarily of fibrillin, they become weak and stretched, leading to lens subluxation. In Marfan’s, the displacement is typically **superotemporal** (upward and outward), and the accommodation is usually preserved because the zonules remain intact though stretched. **Analysis of Incorrect Options:** * **Megalocornea (A):** While Marfan’s patients may have a slightly increased corneal diameter or a flat cornea (cornea plana), true megalocornea is more classically associated with X-linked Megalocornea or Congenital Glaucoma. * **Microcornea (B):** This is associated with conditions like Nanophthalmos or Microphthalmos, not Marfan’s. * **Microspherophakia (C):** This refers to a small, spherical lens. While it causes ectopia lentis, it is the hallmark of **Weill-Marchesani syndrome** (the "inverse" of Marfan’s), not Marfan’s syndrome itself. **High-Yield Clinical Pearls for NEET-PG:** * **Direction of Subluxation:** Marfan’s = **Upward** (Superior); Homocystinuria = **Downward** (Inferior). * **Zonular Integrity:** In Marfan’s, zonules are stretched/lax; in Homocystinuria, zonules are completely broken/absent. * **Other Ocular Features:** High myopia, increased axial length, and increased risk of Rhegmatogenous Retinal Detachment. * **Systemic Association:** Always screen for aortic root dilation/dissection and mitral valve prolapse (MVP).

Q: What is Stellwag's sign?

Absence of normal winking.. ### Explanation **Stellwag’s sign** is a classic clinical feature of **Thyroid Eye Disease (TED)**, most commonly associated with Graves' ophthalmopathy. It refers to **infrequent or incomplete blinking**, leading to a characteristic "staring" appearance. #### Why Option A is Correct: In Graves' disease, there is sympathetic overactivity and contraction of the **Müller’s muscle**, along with fibrosis of the Levator Palpebrae Superioris (LPS). This results in lid retraction and a significantly reduced blink rate (normal is 12–15 blinks/minute). This "absence of normal winking" contributes to corneal exposure and dryness. #### Why Other Options are Incorrect: * **Option B (Failure of convergence):** This describes **Moebius sign**. It occurs due to weakness of the medial rectus muscles in thyroid-associated ophthalmopathy. * **Option C (Exophthalmos):** While exophthalmos (proptosis) is a hallmark of Graves' disease, it is a physical finding of eyeball protrusion, not a named "sign" like Stellwag’s. #### High-Yield Clinical Pearls for NEET-PG: To distinguish between the various eponymous signs of Thyroid Eye Disease, remember this "Cheat Sheet": 1. **Dalrymple Sign:** Widening of the palpebral fissure (lid retraction in primary gaze). 2. **Von Graefe’s Sign:** Lid lag (the upper eyelid lags behind the eyeball on downward gaze). 3. **Joffroy’s Sign:** Absence of forehead wrinkling on upward gaze. 4. **Enroth’s Sign:** Fullness/edema of the eyelids. 5. **Gifford’s Sign:** Difficulty in everting the upper eyelid. **Clinical Tip:** Stellwag’s sign is often the earliest sign of thyroid dysfunction and can lead to **exposure keratopathy** if the corneal surface is not adequately lubricated due to the lack of blinking.

Q: All are seen in acute iridocyclitis except:

Mucopurulent discharge. **Explanation:** Acute iridocyclitis (anterior uveitis) is characterized by sterile inflammation of the iris and ciliary body. The correct answer is **Mucopurulent discharge**, as this is a hallmark of **bacterial conjunctivitis**, not intraocular inflammation. **Why Mucopurulent Discharge is the Exception:** In iridocyclitis, the inflammation is internal. While there may be reflex lacrimation (watery discharge) due to pain, there is no bacterial infection of the conjunctival surface to produce pus or mucus. The presence of discharge should immediately point the clinician toward a diagnosis of conjunctivitis rather than uveitis. **Analysis of Other Options:** * **Pain:** This is a cardinal feature of acute iridocyclitis. It is typically a deep, throbbing ache caused by ciliary muscle spasm and irritation of trigeminal nerve endings. * **Ciliary Congestion:** Also known as circumcorneal flush, this is a dusky red injection most intense at the limbus. It occurs due to the engorgement of deep episcleral vessels that supply the iris and ciliary body. * **Small Pupil (Miosis):** The pupil is small and sluggishly reactive due to sphincter pupillae spasm and the presence of inflammatory exudates. This helps differentiate it from acute angle-closure glaucoma, where the pupil is mid-dilated and oval. **High-Yield Clinical Pearls for NEET-PG:** * **The "Triple Sign" of Iridocyclitis:** Ciliary congestion, miosis, and aqueous cells/flare (seen on slit-lamp). * **Keratic Precipitates (KPs):** Inflammatory cells on the corneal endothelium; "Mutton-fat" KPs suggest granulomatous uveitis (e.g., Sarcoidosis, TB). * **Festooned Pupil:** An irregular pupil shape caused by posterior synechiae (adhesions between the iris and lens). * **Treatment Gold Standard:** Topical steroids (to reduce inflammation) and Cycloplegics like Atropine (to relieve pain and prevent synechiae).

Question 1

What is the most common site of distant metastasis in intraorbital malignant melanoma?

Accepted Answer

Liver

Answer

Brain

Answer

Lung

Answer

Lymph nodes

Question 2

What is the most common cause of visual loss in patients with AIDS?

Accepted Answer

CMV retinitis

Answer

Toxoplasmosis

Answer

Herpetic retinitis

Answer

HIV retinitis

Question 3

All of the following are true for Vogt-Koyanagi-Harada syndrome except:

Accepted Answer

More common in Japanese people, who are usually positive for HLA-DR4

Answer

Ocular features include chronic granulomatous anterior uveitis, posterior uveitis, and exudative retinal detachment

Answer

Cutaneous lesions include alopecia, poliosis, and vitiligo

Answer

Neurological lesions include meningism, encephalopathy, tinnitus, vertigo, and deafness

Question 4

Amaurosis fugax is caused by occlusion of which artery?

Accepted Answer

Central retinal artery

Answer

Facial artery

Answer

Occipital artery

Answer

Posterior auricular artery

Question 5

Which of the following statements about dysthyroid eye disease is true?

Accepted Answer

Extreme exophthalmos is usually seen in hypothyroidism.

Answer

Characterized by decreased power of divergence.

Answer

Is the most common cause of unilateral proptosis.

Answer

The lower eyelid does not follow eye movements on looking upwards.

Question 6

A 47-year-old woman develops accelerated hypertension (blood pressure 210/105 mm Hg) but no clinical symptoms except frequent headaches. Which of the following findings are most likely on examination of the fundii?

Accepted Answer

cotton wool spots

Answer

retinitis obliterans

Answer

retinal detachment

Answer

optic atrophy

Question 7

What is the first sign of sympathetic ophthalmitis?

Accepted Answer

Presence of KPs (keratic precipitates)

Answer

Retrolental flare

Answer

Presence of aqueous flare

Answer

Constriction of pupil

Question 8

Marfan's syndrome has which of the following prominent eye defects?

Accepted Answer

Ectopia lentis

Answer

Megalocornea

Answer

Microcornea

Answer

Microspherophakia

Question 9

What is Stellwag's sign?

Accepted Answer

Absence of normal winking.

Answer

Failure of convergence of eyeballs.

Answer

Exophthalmos.

Answer

None of the above.

Question 10

All are seen in acute iridocyclitis except:

Accepted Answer

Mucopurulent discharge

Answer

Pain

Answer

Ciliary congestion

Answer

Small pupil

Ocular Manifestations of Systemic Disorders — MCQs

Ocular Manifestations of Systemic Disorders — MCQs

On this page

Practice by Chapter

Want unlimited practice?