Ophthalmology
8 questionsWhat is the first clinical sign observed in a patient with anterior uveitis?
What is the most common cause of anterior uveitis?
When should surgery be performed for congenital cataracts with visual disturbances?
Which of the following is not a risk factor for angle closure glaucoma?
The 'headlight in fog' appearance is seen in which condition?
What visual disturbance is caused by an optic tract lesion?
How is the angle of squint measured?
Which type of congenital cataract is commonly associated with significant visual defects?
NEET-PG 2012 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 631: What is the first clinical sign observed in a patient with anterior uveitis?
- A. Presence of aqueous flare (Correct Answer)
- B. Presence of hypopyon
- C. Presence of miosis
- D. Presence of keratic precipitates
Explanation: ***Presence of aqueous flare*** - **Aqueous flare** is considered the **earliest clinical sign** of anterior uveitis, representing increased protein content in the anterior chamber due to breakdown of the **blood-aqueous barrier**. - It is detected as a visible "haze" when a **slit lamp beam** passes through the anterior chamber, similar to observing dust particles in a light beam. *Presence of hypopyon* - **Hypopyon** is a more severe sign, indicating a **layer of white blood cells** in the anterior chamber, representing a more advanced inflammatory process. - While it can occur in severe anterior uveitis, it is not typically the **first or earliest** clinical manifestation. *Presence of miosis* - **Miosis** (pupillary constriction) can be present in anterior uveitis due to **iris inflammation** and irritation of the sphincter muscle. - However, it is an indirect sign and typically occurs *after* the initial signs of inflammation in the aqueous humor, such as flare. *Presence of keratic precipitates* - **Keratic precipitates (KPs)** are deposits of inflammatory cells on the **endothelium of the cornea**. - These deposits are a result of sustained inflammation and typically appear *after* the initial inflammatory changes in the aqueous humor, such as flare, have already occurred.
Question 632: What is the most common cause of anterior uveitis?
- A. CMV
- B. Toxoplasma
- C. Idiopathic (Correct Answer)
- D. Ankylosing spondylitis
Explanation: ***Idiopathic*** - In a significant proportion of cases of **anterior uveitis**, a specific cause cannot be identified, leading to a diagnosis of idiopathic uveitis. - This highlights the multifactorial nature of the condition, where various triggers or underlying predispositions may not always be evident. *CMV* - **Cytomegalovirus (CMV)** typically causes a **posterior uveitis** or **retinitis**, especially in immunocompromised individuals. - While CMV can rarely cause anterior uveitis, it is not the most common cause. *Toxoplasma* - **Toxoplasmosis** is a frequent cause of **posterior uveitis** or **chorioretinitis**, characterized by focal necrotic lesions in the retina. - It is not a common cause of isolated anterior uveitis, although anterior chamber inflammation can occur secondary to posterior disease. *Ankylosing spondylitis* - **Ankylosing spondylitis** is a well-known systemic condition associated with **acute anterior uveitis**. - However, while a significant association exists, it is not the single most common cause when considering all cases of anterior uveitis, many of which remain idiopathic.
Question 633: When should surgery be performed for congenital cataracts with visual disturbances?
- A. After 2 months
- B. After 4 months
- C. After 1 year
- D. As soon as possible (within 6-10 weeks) (Correct Answer)
Explanation: ***As soon as possible (within 6-10 weeks)*** - **Early surgical intervention** (within the first few weeks of life) is crucial for congenital cataracts to prevent **irreversible visual deficits**, such as **amblyopia**. - The brain's visual pathways develop rapidly in infancy, and prolonged visual deprivation from cataracts can lead to **permanent impairment**. *After 2 months* - This time frame represents a delay that can increase the risk of **amblyopia** and poorer visual outcomes. - The critical period for visual development is very early in life, making immediate intervention vital. *After 4 months* - A delay of four months significantly increases the likelihood of **dense amblyopia** and **strabismus**, making complete visual rehabilitation much more challenging. - At this age, the potential for achieving good vision post-surgery dramatically decreases due to entrenched abnormal visual processing. *After 1 year* - Performing surgery at one year or later for congenital cataracts is generally considered too late, often resulting in **profound and irreversible amblyopia**. - The visual system will have already established abnormal connections, making significant improvement in visual acuity unlikely.
Question 634: Which of the following is not a risk factor for angle closure glaucoma?
- A. Small eye
- B. Small cornea
- C. Small lens (Correct Answer)
- D. Hypermetropia
Explanation: ***Correct Answer: Small lens*** - A smaller lens would lead to a **deeper anterior chamber**, reducing the likelihood of iridotrabecular contact and angle closure. - In contrast, a **large or thick lens** is a well-established risk factor for angle closure glaucoma as it pushes the iris forward, causing pupillary block. - Small lens size is **NOT a risk factor** for angle closure glaucoma. *Incorrect: Small eye* - A small eye (e.g., in **nanophthalmos**) is associated with a relatively large lens in proportion to the eye size, which can push the iris forward and narrow the angle. - This anatomical configuration makes individuals more prone to **pupillary block** and angle closure. *Incorrect: Hypermetropia* - **Hyperopic eyes** tend to be shorter with reduced axial length, which often results in a shallower anterior chamber and a relatively crowded anterior segment. - This shallow anterior chamber increases the risk of the iris occluding the **trabecular meshwork**, predisposing to angle closure. *Incorrect: Small cornea* - A small corneal diameter can be indicative of a generally smaller anterior segment, often correlating with a **shallow anterior chamber**. - A smaller cornea contributes to a more crowded anterior segment, predisposing to **angle closure glaucoma**.
Question 635: The 'headlight in fog' appearance is seen in which condition?
- A. Syphilis
- B. Toxocara
- C. Herpes
- D. Toxoplasmosis (Correct Answer)
Explanation: ***Toxoplasmosis*** - The "headlight in fog" appearance is a classic description of **chorioretinitis** caused by **congenital toxoplasmosis**. - It refers to an old, healed **retinal scar** (headlight) surrounded by active inflammation and **vitreous haze** (fog). *Syphilis* - Ocular syphilis can cause various presentations, including uveitis, retinitis, and optic neuropathy, but it does **not typically** present with the specific "headlight in fog" appearance. - Ocular lesions are often more diffuse or involve distinct **gummatous lesions**. *Toxocara* - Ocular toxocariasis often presents as a **granuloma** (either peripheral or macular) or as **endophthalmitis**, but not the characteristic "headlight in fog" pattern. - The lesions are usually a result of a direct larval migration and subsequent inflammatory reaction. *Herpes* - Herpes simplex virus (HSV) or varicella-zoster virus (VZV) can cause **acute retinal necrosis** (ARN) or progressive outer retinal necrosis (PORN), presenting with widespread retinal whitening and vascular occlusion. - These conditions have distinct appearances, generally **lacking the central scar** with surrounding active inflammation seen in "headlight in fog."
Question 636: What visual disturbance is caused by an optic tract lesion?
- A. Marcus Gunn pupil
- B. Bilateral blindness
- C. Contralateral homonymous hemianopsia (Correct Answer)
- D. Ipsilateral homonymous hemianopsia
Explanation: ***Contralateral homonymous hemianopsia*** - An **optic tract lesion** interrupts the nerve fibers originating from the contralateral nasal retina and the ipsilateral temporal retina, leading to **vision loss in the contralateral visual field** of both eyes. - This results in a defect where the patient cannot see objects on the **opposite side** of the body from the lesion. *Marcus Gunn pupil* - A **Marcus Gunn pupil**, also known as an **afferent pupillary defect**, indicates asymmetric disease of the **retina** or **optic nerve**, not specifically the optic tract. - It is characterized by paradoxical dilation of the affected pupil when light is swung from the unaffected to the affected eye. *Bilateral blindness* - **Bilateral blindness** typically results from severe damage to both **optic nerves**, the **optic chiasm**, or extensive bilateral lesions in the visual cortex. - An optic tract lesion affects only one side of the visual pathway posterior to the chiasm, thus not causing complete bilateral vision loss. *Ipsilateral homonymous hemianopsia* - **Ipsilateral homonymous hemianopsia** is not a standard neurological visual field defect. Visual field defects are usually described relative to the lesion side as contralateral or ipsilateral based on the specific anatomical location. - An optic tract lesion always produces a **contralateral homonymous hemianopsia** because optic tract fibers cross at the optic chiasm.
Question 637: How is the angle of squint measured?
- A. Gonioscopy
- B. Prism (Correct Answer)
- C. Retinoscopy
- D. Keratometry
Explanation: ***Prism*** - The **angle of squint**, which indicates the deviation of the eyes, is most accurately measured using **prisms** in conjunction with the **prism cover test** or **alternate prism cover test**. - Prisms quantify the degree of ocular deviation in **prism diopters** by neutralizing the misalignment so that the light falls correctly on the fovea. *Gonioscopy* - This technique is used to examine the **anterior chamber angle** of the eye, which is relevant for diagnosing conditions like **glaucoma**. - It does not involve measuring the angle of ocular deviation or misalignment of the eyes. *Retinoscopy* - Retinoscopy is an objective method to determine the **refractive error** of the eye (e.g., myopia, hyperopia, astigmatism). - While it assesses the eye's ability to focus light, it does not directly measure the angle of a squint. *Keratometry* - Keratometry measures the **curvature of the cornea**, primarily used for fitting contact lenses or calculating intraocular lens power for cataract surgery. - It does not assess the alignment of the eyes or the magnitude of a squint.
Question 638: Which type of congenital cataract is commonly associated with significant visual defects?
- A. Punctate Cataract
- B. Blue dot cataract
- C. Fusiform cataract
- D. Nuclear cataract (Correct Answer)
Explanation: ***Nuclear cataract*** - It involves the **nucleus** of the lens, which is the central and most visually critical part. - This type of cataract can cause **significant visual impairment** due to its central location and density, impacting early visual development. *Punctate Cataract* - These are **small, dot-like opacities** that are usually clinically insignificant and do not typically cause significant visual defects. - They are often **peripheral** or very fine, thus not obstructing the central visual axis. *Blue dot cataract* - Also known as **cerulean cataract**, this type consists of small, bluish opacities in the lens cortex. - While congenital, it often has **minimal impact on vision** and is frequently observed incidentally. *Fusiform cataract* - This cataract forms in the shape of a **spindle or needle**, usually along the visual axis. - While it can sometimes cause minor visual compromise, its impact is generally **less severe** compared to a dense nuclear cataract.
Pathology
1 questionsIn which condition is retinal astrocytoma commonly seen?
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 631: In which condition is retinal astrocytoma commonly seen?
- A. Tuberous sclerosis (Correct Answer)
- B. Sturge weber syndrome
- C. Von Hippel-Lindau syndrome
- D. Neurofibromatosis
Explanation: ***Tuberous sclerosis*** - **Retinal astrocytoma**, also known as **retinal astrocytic hamartoma**, is a common ocular manifestation of **tuberous sclerosis complex (TSC)** [1]. - These lesions can appear as **mulberry-like nodules** or flat, whitish patches on the retina. - Found in approximately **40-50% of patients** with tuberous sclerosis. *Sturge weber syndrome* - Characterized by a **port-wine stain (facial nevus flammeus)**, **leptomeningeal angioma**, and **glaucoma**. - Ocular manifestations include **choroidal hemangiomas** and increased episcleral venous pressure. - Does not typically involve **retinal astrocytomas**. *Von Hippel-Lindau syndrome* - Associated with **retinal capillary hemangioblastomas** (vascular tumors) and various tumors in other organs like the kidneys, pancreas, and brain. - This condition involves **vascular tumors** in the retina, not astrocytic tumors. - Important differential as it also presents with retinal lesions. *Neurofibromatosis* - A neurocutaneous syndrome characterized by **café-au-lait spots**, **neurofibromas**, and **Lisch nodules** (iris hamartomas). - Ocular manifestations include **optic nerve gliomas** and iris hamartomas, but **not retinal astrocytomas**. - NF-1 is the most common neurocutaneous syndrome but has different retinal pathology. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1318-1319.
Pharmacology
1 questionsWhat is the best drug for open-angle glaucoma?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 631: What is the best drug for open-angle glaucoma?
- A. Latanoprost (Correct Answer)
- B. Pilocarpine
- C. Physostigmine
- D. Apraclonidine
Explanation: Latanoprost - Latanoprost is a prostaglandin analog and is often considered a first-line treatment for open-angle glaucoma due to its efficacy in reducing intraocular pressure (IOP) and its once-daily dosing. - It works by increasing the outflow of aqueous humor through the uveoscleral pathway, thereby lowering IOP. Pilocarpine - Pilocarpine is a cholinergic agonist that causes miosis and ciliary muscle contraction [3], increasing the outflow of aqueous humor through the trabecular meshwork [4]. - While effective, its side effects (e.g., accommodative spasm, miosis) [1] and more frequent dosing make it generally a second-line or third-line agent for long-term management compared to prostaglandins. Physostigmine - Physostigmine is an acetylcholinesterase inhibitor that indirectly increases acetylcholine, mimicking cholinergic stimulation. - Although it can lower IOP, it is generally not used for open-angle glaucoma due to significant side effects and the availability of safer, more effective alternatives [1]. Apraclonidine - Apraclonidine is an alpha-2 adrenergic agonist [2] used primarily for short-term control of IOP, especially before or after ocular surgery, or as an adjunct therapy. - Its efficacy as a long-term monotherapy for open-angle glaucoma is limited by tachyphylaxis and potential for significant systemic side effects with chronic use.