NEET-PG 2012 - Ophthalmology Practice Questions

Q: Most common orbital tumor has its origin from?

Blood vessels. ***Blood vessels*** - The most common orbital tumor in childhood is a **capillary hemangioma**, which originates from blood vessels. - In adults, the most common primary orbital tumor is an orbital varix, also a **vascular lesion**. *Nerves* - Tumors of neural origin, such as **optic nerve gliomas** or **meningiomas**, are less common than vascular tumors. - While significant, they do not represent the *most* common overall origin for orbital tumors. *Muscle* - Tumors originating from muscle, such as **rhabdomyosarcoma** in children (a malignant tumor), are relatively rare. - **Pseudotumor** (idiopathic orbital inflammation), though common, is an inflammatory condition, not a true neoplasm of muscle origin. *Lymph node* - Tumors of lymphoid origin, such as **lymphomas**, are malignant and can occur in the orbit. - However, they are not the most common primary orbital tumor compared to those of vascular origin.

Q: What is the most common cause of intermittent proptosis in adults?

Orbital varix. ***Orbital varix*** - An **orbital varix** is essentially a varicose vein within the orbit, which can cause intermittent proptosis. - Proptosis in an orbital varix is often exacerbated by activities that increase venous pressure, such as **Valsalva maneuvers**, crying, or bending over. *Thyroid ophthalmopathy* - This condition is characterized by **persistent proptosis**, lid retraction, and ophthalmoplegia, rather than intermittent symptoms. - While it can cause proptosis, it typically presents as **constant and progressive** rather than intermittent proptosis that varies with head position or straining. *Neuroblastoma* - This is a **malignant tumor** that primarily affects infants and young children, not typically adults. - Orbital metastasis from neuroblastoma would cause **progressive, constant proptosis** rather than intermittent proptosis. *Retinoblastoma* - **Retinoblastoma** is a malignant tumor of the retina that primarily affects young children, typically under the age of 5. - While it can cause proptosis in advanced stages, it presents as **constant and progressive proptosis** due to tumor growth, not intermittent proptosis.

Q: What is the most common protozoan associated with keratitis?

Acanthamoeba. ***Acanthamoeba*** - **Acanthamoeba keratitis** is a serious and painful infection of the eye's cornea, most commonly associated with **contact lens wearers** who do not properly disinfect their lenses. - The organism is a **free-living protozoan** found in soil and water. *Plasmodium* - **Plasmodium** species are the causative agents of **malaria**, a disease that primarily affects **red blood cells** and the liver. - While it can manifest with ocular symptoms like **retinopathy**, it does not typically cause **keratitis**. *Toxoplasma* - **Toxoplasma gondii** causes **toxoplasmosis**, an infection that can lead to **chorioretinitis** (inflammation of the retina and choroid), especially in immunocompromised individuals or congenitally infected infants. - It does not directly cause **keratitis** as its primary ocular manifestation. *Entamoeba histolytica* - **Entamoeba histolytica** is the protozoan responsible for **amebiasis**, particularly **amoebic dysentery** and **liver abscesses**. - Ocular involvement with *Entamoeba histolytica* is extremely rare and typically involves **metastatic lesions** to the orbit or eyelids, not directly primary keratitis.

Q: What is the first sign of iridocyclitis?

Aqueous flare. ***Aqueous flare*** - This is the earliest and most subtle sign, representing an increase in **protein content** in the aqueous humor due to breakdown of the **blood-aqueous barrier**. - It is detected by a **slit-lamp examination** as a hazy appearance in the anterior chamber, similar to a car headlight beam in fog. *KP* - **Keratic precipitates (KP)** are deposits of inflammatory cells on the corneal endothelium. - While characteristic of iridocyclitis, they typically appear **after** the initial breakdown of the blood-aqueous barrier that causes aqueous flare. *Congestion* - **Ciliary congestion** (perilimbal redness) is a common symptom of anterior uveitis, but it is a visible sign of inflammation. - The underlying inflammatory process causing the congestion first manifests as **subtle changes in the aqueous humor**, which is aqueous flare. *Trichiasis* - **Trichiasis** is the misdirection of eyelashes to rub against the cornea, causing irritation. - It is an **external ocular condition** and is not a sign of intraocular inflammation like iridocyclitis.

Q: In the context of homocystinuria, which direction does the lens typically subluxate?

Inferonasal. ***Inferonasal*** - In **homocystinuria**, the **ectopia lentis** (lens subluxation) often occurs due to weakening of the **zonular fibers**. - The classic direction for lens subluxation in homocystinuria is **inferior and nasal**. *Inferotemporal* - While lens subluxation can occur in various directions, **inferotemporal** is not the classic or most common presentation in homocystinuria. - This direction is less specific and does not strongly point to homocystinuria as the underlying cause. *Superonasal* - **Superonasal** dislocation of the lens is more characteristic of **Marfan syndrome**, which is important to differentiate from homocystinuria. - This direction helps distinguish different causes of lens ectopia. *Superotemporal* - **Superotemporal** lens subluxation is the hallmark of **Marfan syndrome**, a genetic connective tissue disorder. - This specific finding is crucial for differential diagnosis in patients presenting with lens ectopia.

Q: Which type of cataract is associated with the phenomenon known as 'second sight'?

Nuclear cataract. ***Nuclear cataract*** - A nuclear cataract causes the lens to become more **myopic** or nearsighted due to an increase in its **refractive index**. - This temporary increase in nearsightedness can allow elderly individuals who previously needed reading glasses (due to presbyopia) to read without them, a phenomenon known as "**second sight**." *Cortical cataract* - Cortical cataracts primarily affect the **outer layer or cortex** of the lens, appearing as spokes or wedges radiating from the periphery. - They tend to cause **glare** and **reduced peripheral vision**, but generally do not improve near vision. *Zonular cataract* - A zonular cataract is a **congenital type of cataract**, characterized by opacity in specific layers (lamellae) of the lens, often in the fetal nucleus. - It does not typically lead to the "second sight" phenomenon, as it is present from birth and affects vision differently. *Punctate cataract* - Punctate cataracts are small, **dot-like opacities** scattered throughout the lens, often considered benign. - They are usually **incidental findings** and rarely cause significant visual disturbances or "second sight."

Q: Which of the following statements is false about phacolytic glaucoma?

Primarily caused by iris-lens contact. ***Primarily caused by iris-lens contact*** - This statement is **FALSE** because **phacolytic glaucoma** is caused by the leakage of **lens proteins** from a **hypermature cataract** into the **anterior chamber**, not by iris-lens contact. - **Iris-lens contact** is the mechanism in **pupillary block glaucoma** and **acute angle-closure glaucoma**, not in phacolytic glaucoma. - The pathophysiology involves **macrophages** engulfing leaked lens proteins and obstructing the **trabecular meshwork**. *Open angle glaucoma* - This statement is true because **phacolytic glaucoma** is definitively an **open-angle glaucoma**. - It involves obstruction of the **trabecular meshwork** by **macrophages** laden with **lens proteins**, which is an open-angle mechanism. - The angle remains anatomically open but functionally blocked. *Seen in hypermature stage of cataract* - This statement is true because **phacolytic glaucoma** develops when the **lens capsule** of a **hypermature (Morgagnian) cataract** becomes permeable. - This permeability allows **high-molecular-weight lens proteins** to leak into the **aqueous humor**. *Lens induced glaucoma* - This statement is true as **phacolytic glaucoma** is a specific type of **lens-induced glaucoma**, arising from the toxic effects of **leaked lens material**. - Other forms of **lens-induced glaucoma** include **phacomorphic glaucoma**, **lens-particle glaucoma**, and **phacoanaphylactic glaucoma**.

Q: Broadest neuroretinal rim is seen in -

Inferior pole. ***Inferior pole*** - The **inferior pole** of the optic disc typically has the broadest neuroretinal rim in healthy eyes. - This observation is often remembered by the "ISNT rule," where **I > S > N > T** (Inferior > Superior > Nasal > Temporal) describes the typical thickness of the neuroretinal rim. *Superior pole* - While the superior pole has a relatively thick neuroretinal rim, it is generally **thinner than the inferior rim**. - The superior rim is the second thickest based on the **ISNT rule**. *Nasal pole* - The nasal pole's neuroretinal rim is typically **thinner than both the inferior and superior poles**. - It ranks third in thickness according to the **ISNT rule**. *Temporal pole* - The temporal pole typically has the **thinnest neuroretinal rim**, making it the narrowest part of the disc. - This is due to the larger excavation of the optic cup temporally, accommodating the macular fibers.

Q: What condition is characterized by a salt and pepper fundus appearance in the retina?

Congenital syphilis. ***Congenital syphilis*** - The **"salt and pepper" fundus** appearance is a classic ophthalmologic finding in congenital syphilis, resulting from diffuse pigmentary retinopathy. - This condition is caused by widespread pigmentary changes in the retina, affecting both the retinal pigment epithelium and neurosensory retina. - It represents chronic, bilateral, and symmetric chorioretinitis that is pathognomonic for congenital syphilis. *Congenital toxoplasmosis* - While it can cause chorioretinitis, congenital toxoplasmosis typically presents with **focal, destructive lesions** rather than diffuse "salt and pepper" pigmentary changes. - Classic ocular lesions are often described as a **"headlight in the fog"** or inactive, pigmented chorioretinal scars. *Congenital histoplasmosis* - Ocular histoplasmosis syndrome (OHS) is usually acquired, not congenital, and causes **discrete chorioretinal scars** ("histo spots") often in the macula or peripapillary region. - It does not result in a diffuse **"salt and pepper" fundus** appearance. *Congenital rubella* - Congenital rubella syndrome can cause pigmentary retinopathy, but the pattern is typically **patchy or mottled** rather than the classic "salt and pepper" appearance. - Other ocular findings include cataract, microphthalmos, and glaucoma.

Q: Child with mild squint. Intrauterine, birth history, developmental history till date all normal. Corneal light reflex normal. All other eye parameters normal except exaggerated epicanthal fold. Diagnosis ?

Pseudostrabismus. ***Pseudostrabismus*** * The presence of **exaggerated epicanthal folds** can create the optical illusion of a child having misaligned eyes, even when the eyes are perfectly straight. * The normal **corneal light reflex** (Hirschberg test) confirms that the eyes are properly aligned, and the perceived "squint" is not a true strabismus. *Exophoria (outward drift)* * This condition involves a **tendency for the eyes to drift outwards**, which would be detected by specific cover/uncover tests. * An outward drift would usually result in an abnormal corneal light reflex, and the exaggerated epicanthal folds would not explain this type of misalignment. *Esophoria (inward drift)* * This is a **tendency for the eyes to drift inwards**, which would also be revealed by tests for phorias and often by an abnormal corneal reflex. * The clinical presentation points away from a true inward deviation, as the corneal reflex is normal. *Accommodative esotropia* * This is a **true inward turning of the eye** (strabismus) that is often linked to uncorrected farsightedness (hyperopia). * It would present with an **abnormal corneal light reflex** and would not be explained solely by epicanthal folds, as it involves actual ocular deviation.

Question 1

Most common orbital tumor has its origin from?

Accepted Answer

Blood vessels

Answer

Nerves

Answer

Muscle

Answer

Lymph node

Question 2

What is the most common cause of intermittent proptosis in adults?

Accepted Answer

Orbital varix

Answer

Thyroid ophthalmopathy

Answer

Neuroblastoma

Answer

Retinoblastoma

Question 3

What is the most common protozoan associated with keratitis?

Accepted Answer

Acanthamoeba

Answer

Plasmodium

Answer

Toxoplasma

Answer

Entamoeba histolytica

Question 4

What is the first sign of iridocyclitis?

Accepted Answer

Aqueous flare

Answer

KP

Answer

Congestion

Answer

Trichiasis

Question 5

In the context of homocystinuria, which direction does the lens typically subluxate?

Accepted Answer

Inferonasal

Answer

Inferotemporal

Answer

Superonasal

Answer

Superotemporal

Question 6

Which type of cataract is associated with the phenomenon known as 'second sight'?

Accepted Answer

Nuclear cataract

Answer

Cortical cataract

Answer

Zonular cataract

Answer

Punctate cataract

Question 7

Which of the following statements is false about phacolytic glaucoma?

Accepted Answer

Primarily caused by iris-lens contact

Answer

Open angle glaucoma

Answer

Lens induced glaucoma

Answer

Seen in hypermature stage of cataract

Question 8

Broadest neuroretinal rim is seen in -

Accepted Answer

Inferior pole

Answer

Nasal pole

Answer

Superior pole

Answer

Temporal pole

Question 9

What condition is characterized by a salt and pepper fundus appearance in the retina?

Accepted Answer

Congenital syphilis

Answer

Congenital rubella

Answer

Congenital toxoplasmosis

Answer

Congenital histoplasmosis

Question 10

Child with mild squint. Intrauterine, birth history, developmental history till date all normal. Corneal light reflex normal. All other eye parameters normal except exaggerated epicanthal fold. Diagnosis ?

Accepted Answer

Pseudostrabismus

Answer

Exophoria (outward drift)

Answer

Esophoria (inward drift)

Answer

Accommodative esotropia

NEET-PG 2012 — Ophthalmology