Which virus is most commonly associated with disciform keratitis?
Metamorphopsia is seen in?
What is the most common type of congenital cataract?
What is the primary complication associated with Eale's disease?
Which muscle is the earliest to be involved in thyroid ophthalmopathy?
What is the treatment of choice for amblyopia?
Most common orbital tumor has its origin from?
What is the most common cause of intermittent proptosis in adults?
What is the most common protozoan associated with keratitis?
What is the first sign of iridocyclitis?
NEET-PG 2012 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 21: Which virus is most commonly associated with disciform keratitis?
- A. Rubella Virus
- B. Herpes Simplex Virus (HSV) (Correct Answer)
- C. Human Immunodeficiency Virus (HIV)
- D. Hepatitis B Virus (HBV)
Explanation: ***Herpes Simplex Virus (HSV)*** - **HSV** is the most common cause of **infectious disciform keratitis**, often following a primary ocular HSV infection or reactivation. - Disciform keratitis caused by HSV is a form of **immune-mediated stromal keratitis**, characterized by corneal edema, inflammation, and potential vision loss. *Rubella Virus* - While Rubella can cause ocular manifestations, such as **congenital cataracts** and **glaucoma** in infants, it is not typically associated with disciform keratitis in adults or children. - **Congenital rubella syndrome** is the primary context for ophthalmic issues related to this virus. *Human Immunodeficiency Virus (HIV)* - HIV can lead to various ocular complications, such as **CMV retinitis**, **Kaposi's sarcoma** of the conjunctiva, and **HIV retinopathy**. - However, HIV itself is **not directly linked** to disciform keratitis. *Hepatitis B Virus (HBV)* - HBV infection primarily affects the **liver** and is not commonly associated with direct ocular infections like keratitis. - Ocular manifestations are rare and often nonspecific, mainly related to systemic immune responses rather than direct viral replication in the eye.
Question 22: Metamorphopsia is seen in?
- A. Cataract
- B. Glaucoma
- C. Anterior uveitis
- D. Posterior uveitis (Correct Answer)
Explanation: ***Posterior uveitis*** - **Metamorphopsia**, or the perception of distorted images, can occur in **posterior uveitis** due to inflammation affecting the **retina** or **choroid**, leading to retinal edema or detachment. - Inflammatory processes in the posterior segment can cause disruption of photoreceptor alignment and function, altering the perception of straight lines and object shapes. *Anterior uveitis* - Primarily affects the **iris** and **ciliary body**, causing symptoms like **pain**, **photophobia**, **redness**, and reduced vision due to cellular exudates in the anterior chamber. - While vision can be affected, **metamorphopsia** is not a typical hallmark of anterior uveitis, as the retinal architecture is generally preserved. *Cataract* - Involves **clouding of the eye's natural lens**, leading to blurred vision, glare, and dullness of colors. - It does not cause **metamorphopsia** because the retinal structure and its perception of shapes remain intact; the distortion is primarily visual clarity, not shape. *Glaucoma* - Characterized by **progressive optic nerve damage** and visual field loss, often associated with elevated intraocular pressure. - While it causes vision impairment, typically starting with **peripheral vision loss**, it does not cause **metamorphopsia**, as the retina itself is usually not distorted.
Question 23: What is the most common type of congenital cataract?
- A. Blue dot (Correct Answer)
- B. Capsular
- C. Coralliform
- D. Zonular
Explanation: ***Blue dot*** - **Blue dot (punctate) cataracts** are the **most common type of congenital cataract overall**. - They appear as **multiple small, blue-white opacities** scattered throughout the lens cortex. - These cataracts are typically **bilateral, non-progressive, and asymptomatic**, rarely affecting visual acuity. - Often considered **physiological variants**, they usually do not require surgical intervention. *Zonular (Lamellar)* - **Zonular (lamellar) cataracts** are the **most common visually significant** congenital cataract. - They feature **opacities arranged in layers or lamellae** within the lens, classically with alternating clear and opaque zones. - Unlike blue dot cataracts, these **often require surgical intervention** due to visual impairment. *Capsular* - **Capsular cataracts** involve the anterior or posterior lens capsule and are relatively uncommon. - They appear as **small, well-circumscribed opacities** on the lens capsule. - Visual impact depends on size and location relative to the visual axis. *Coralliform* - **Coralliform cataracts** are a rare type characterized by **coral-like branching opacities**. - This distinctive morphology makes them one of the less common congenital cataract types.
Question 24: What is the primary complication associated with Eale's disease?
- A. Retinal hemorrhage
- B. Vitreous hemorrhage (Correct Answer)
- C. Conjunctival hemorrhage
- D. Choroidal hemorrhage
Explanation: ***Vitreous hemorrhage*** - **Vitreous hemorrhage** is a common and often visually debilitating complication of Eale's disease, resulting from the rupture of fragile new vessels. - The proliferative stage of Eale's disease involves the development of **neovascularization** on the retina, which can bleed into the vitreous humor. *Retinal hemorrhage* - While **retinal hemorrhages** can occur in Eale's disease, they are often precursors to or components of vitreous hemorrhage, not the primary, most significant complication. - Retinal hemorrhages alone may cause less severe vision loss compared to the extensive obscuration by vitreous bleeding. *Conjunctival hemorrhage* - **Conjunctival hemorrhage** involves bleeding in the superficial layers of the eye and is not typically associated with the underlying vasculitis of Eale's disease. - This is a benign condition and not a primary complication of a retinal vascular disorder. *Choroidal hemorrhage* - **Choroidal hemorrhage** occurs beneath the retina and is usually associated with trauma, surgery, or degenerative conditions like age-related macular degeneration, not Eale's disease. - Eale's disease primarily affects the **retinal vasculature**, leading to bleeding internally into the vitreous.
Question 25: Which muscle is the earliest to be involved in thyroid ophthalmopathy?
- A. Medial Rectus (MR)
- B. Inferior Rectus (IR) (Correct Answer)
- C. Superior Rectus (SR)
- D. Lateral Rectus (LR)
Explanation: ***Inferior Rectus (IR)*** - The **inferior rectus muscle** is most commonly and earliest affected in **thyroid ophthalmopathy** due to its anatomical location and muscle fiber type, making it highly susceptible to inflammation and edema. - Involvement of the inferior rectus leads to restricted **upward gaze** and **diplopia**, which are characteristic early symptoms of thyroid eye disease. *Medial Rectus (MR)* - While the **medial rectus** is often involved in thyroid ophthalmopathy, it is typically affected *after* the inferior rectus. - Dysfunction of the medial rectus manifests as difficulty with **adduction** (moving the eye inwards). *Superior Rectus (SR)* - The **superior rectus** is less frequently and usually later involved compared to the inferior and medial rectus muscles. - Its involvement typically causes restricted **downward gaze**. *Lateral Rectus (LR)* - The **lateral rectus** muscle is the *least common* ocular muscle to be affected in thyroid ophthalmopathy. - When affected, it primarily causes difficulty with **abduction** (moving the eye outwards).
Question 26: What is the treatment of choice for amblyopia?
- A. Corrective spectacles
- B. Surgical intervention
- C. Occlusion therapy (Correct Answer)
- D. Convergent exercises for vision therapy
Explanation: ***Occlusion therapy*** - **Occlusion therapy** involves patching the stronger eye to force the weaker, amblyopic eye to work harder, thereby strengthening its neural connections. - This treatment is most effective when initiated during the **critical period of visual development** in childhood. *Corrective spectacles* - While essential for addressing **refractive errors** that may contribute to amblyopia, spectacles alone are often insufficient to resolve the amblyopia. - Spectacles primarily optimize the image quality on the retina, but don't directly address the **cortical suppression** of the amblyopic eye. *Surgical intervention* - **Surgical intervention** is typically reserved for correcting structural issues like **strabismus** (misalignment of the eyes) that contribute to amblyopia. - Surgery for strabismus aims to align the eyes, which can then be followed by occlusion therapy or other treatments to address the functional amblyopia. *Convergent exercises for vision therapy* - **Vision therapy exercises**, including convergent exercises, may be used as an adjunct to occlusion therapy or in cases of **convergence insufficiency**. - However, they are not the primary or solitary treatment of choice for amblyopia, which requires direct stimulation of the amblyopic eye.
Question 27: Most common orbital tumor has its origin from?
- A. Blood vessels (Correct Answer)
- B. Nerves
- C. Muscle
- D. Lymph node
Explanation: ***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.
Question 28: What is the most common cause of intermittent proptosis in adults?
- A. Orbital varix (Correct Answer)
- B. Thyroid ophthalmopathy
- C. Neuroblastoma
- D. Retinoblastoma
Explanation: ***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.
Question 29: What is the most common protozoan associated with keratitis?
- A. Plasmodium
- B. Acanthamoeba (Correct Answer)
- C. Toxoplasma
- D. Entamoeba histolytica
Explanation: ***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.
Question 30: What is the first sign of iridocyclitis?
- A. KP
- B. Congestion
- C. Trichiasis
- D. Aqueous flare (Correct Answer)
Explanation: ***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.