NEET-PG 2013 — Ophthalmology
70 Previous Year Questions with Answers & Explanations
Cataract is caused by all except:
Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?
Which Goldmann type is considered the standard in perimetry?
During retinoscopy of a 30-year-old male, which cycloplegic is used routinely?
In specular microscopy endothelial density is measured by?
Retinitis pigmentosa is characterized by ?
Arcuate field defect akin to glaucoma is seen in?
Which of the following statements about the c-wave in electroretinogram (ERG) is most accurate?
Binocular single vision is tested by?
Which of the following conditions is NOT diagnosed by fluorescein angiography?
NEET-PG 2013 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 1: Cataract is caused by all except:
- A. Ultraviolet radiation
- B. Infrared radiation
- C. Microwave radiation
- D. MRI (Correct Answer)
Explanation: ***MRI*** - Magnetic Resonance Imaging (MRI) uses powerful **magnetic fields** and radio waves to generate images, which are not known to cause cataracts. - The energy used in MRI is **non-ionizing** and does not directly damage lens proteins. *Ultraviolet radiation* - Prolonged exposure to **UV-B radiation** is a significant risk factor for the development of various types of cataracts, especially cortical and posterior subcapsular cataracts. - UV radiation can cause oxidative damage to lens proteins and lipids, leading to their aggregation and opacification. *Infrared radiation* - Chronic exposure to high levels of **infrared (IR) radiation**, such as that experienced by glassblowers or steelworkers, can lead to "glassblower's cataract" or "heat cataract." - IR radiation causes thermal damage to the lens, particularly the anterior capsule and subcapsular region. *Microwave radiation* - High-intensity **microwave radiation** has been implicated in the formation of cataracts, particularly in occupational exposure scenarios. - It causes thermal effects within the lens due to absorption of energy, leading to protein denaturation and opacification.
Question 2: Large, white keratic precipitates (mutton-fat KPs) are characteristically seen in?
- A. Hemorrhagic uveitis
- B. Old healed uveitis
- C. Granulomatous uveitis (Correct Answer)
- D. Acute anterior uveitis
Explanation: ***Granulomatous uveitis*** - **Mutton-fat keratic precipitates (KPs)** are large, greasy-appearing white deposits on the corneal endothelium, characteristic of **granulomatous inflammation**. - These KPs are composed of macrophages and epithelioid cells, reflecting a **chronic, cell-mediated immune response** seen in granulomatous conditions. *Hemorrhagic uveitis* - This condition involves significant **intraocular bleeding**, which would manifest as hyphema or vitreous hemorrhage, not mutton-fat KPs. - While inflammation may be present, the defining feature is blood, which obscures vision differently than KPs. *Old healed uveitis* - After uveitis heals, KP morphology can change, often appearing smaller, more pigmented, or forming distinct patterns such as **Arlt's triangle**, but not typically actively large, white mutton-fat KPs. - Healed KPs often reflect a less active or resolved inflammatory process, unlike fresh mutton-fat KPs. *Acute anterior uveitis* - This typically presents with smaller, finer, and more numerous **non-granulomatous KPs** (sometimes called "stellate KPs"), in contrast to the large, greasy mutton-fat KPs. - The inflammation is usually acute and less focally organized compared to granulomatous forms.
Question 3: Which Goldmann type is considered the standard in perimetry?
- A. Goldmann type I (small stimulus size)
- B. Goldmann type II (medium-small stimulus size)
- C. Goldmann type IV (large stimulus size)
- D. Goldmann type III (commonly used stimulus size) (Correct Answer)
Explanation: ***Goldmann type III (commonly used stimulus size)*** - This stimulus size is the **international standard** for kinetic perimetry and ensures comparability of visual field charts worldwide. - It provides a balance between **sensitivity** and minimizing the effects of **pupil size** and other ocular factors. *Goldmann type I (small stimulus size)* - While very small, this stimulus type is **not the standard** for general perimetry. - It is sometimes used for detecting **subtle defects** or for patients with very good visual acuity, but its small size can make it harder to detect. *Goldmann type II (medium-small stimulus size)* - This stimulus size is **smaller than the standard** and is not universally adopted for perimetry. - It offers slightly more sensitivity than the standard but can be more affected by **refractive errors** or media opacities. *Goldmann type IV (large stimulus size)* - This stimulus is **much larger than the standard** and is typically used for detecting **gross defects** or in patients with severely impaired vision. - Its large size makes it **less sensitive** to smaller visual field abnormalities.
Question 4: During retinoscopy of a 30-year-old male, which cycloplegic is used routinely?
- A. Homatropine 2% drop
- B. Cyclopentolate 1% drop (Correct Answer)
- C. Atropine 1% ointment
- D. None of the options
Explanation: ***Cyclopentolate 1% drop*** - When cycloplegia is required for retinoscopy, **cyclopentolate 1%** is the preferred agent in adults due to its **rapid onset** (30-60 minutes) and **intermediate duration** (6-24 hours). - It provides adequate **cycloplegia** (paralysis of accommodation) to reveal the full refractive error without the prolonged effects of atropine. - **Clinical note:** In routine practice, most adults aged 30 years undergo retinoscopy **without cycloplegia** as accommodation is usually not a significant factor. Cycloplegia in adults is reserved for specific indications like suspected latent hyperopia, accommodative spasm, or unreliable subjective refraction. *Homatropine 2% drop* - Homatropine has a **slower onset** (1 hour) and **longer duration** (1-3 days) compared to cyclopentolate, making it less practical for routine diagnostic use. - It is typically used for therapeutic purposes such as in **anterior uveitis** to provide cycloplegia and mydriasis. *Atropine 1% ointment* - Atropine is the **strongest** and **longest-acting** cycloplegic with effects lasting **7-14 days**, which is excessively long for diagnostic retinoscopy. - It is primarily used in **young children** (especially under 5 years) for accurate refraction and in therapeutic settings for **cycloplegic refraction in amblyopia** treatment. *None of the options* - While it's true that **routine retinoscopy in a healthy 30-year-old adult** typically does NOT require cycloplegia, this question asks which cycloplegic would be used **when indicated**. - Among the available cycloplegic options, **cyclopentolate** remains the appropriate choice for adults when cycloplegia is deemed necessary.
Question 5: In specular microscopy endothelial density is measured by?
- A. None of the options
- B. Optical doubling
- C. Fixed frame analysis (Correct Answer)
- D. Optical focusing
Explanation: ***Fixed frame analysis*** - This is the **standard method** used in specular microscopy to measure corneal endothelial cell density. - It involves analyzing a specific, fixed area of the **endothelial mosaic** and counting the number of cells within that defined frame. - The cell count from this fixed area is then **extrapolated** to calculate the overall endothelial cell density (cells/mm²). - This technique provides **quantitative assessment** of endothelial health, which is crucial for evaluating corneal function and pre-operative assessment for intraocular surgeries. *Optical doubling* - This is not a standard method for measuring endothelial density in specular microscopy. - Optical doubling relates to **refractive phenomena** or optical measurement techniques used in other contexts, not for endothelial cell counting. *Optical focusing* - While **essential for image acquisition**, optical focusing is merely a preliminary step to obtain a clear, sharp image of the endothelium. - It does not measure or count cells; it only ensures proper visualization before analysis. - The actual measurement requires subsequent **cell counting methods** like fixed frame analysis. *None of the options* - Incorrect because **fixed frame analysis** is indeed the recognized and widely used method for measuring endothelial density in specular microscopy.
Question 6: Retinitis pigmentosa is characterized by ?
- A. Loss of central vision
- B. Visual field constriction
- C. Tubular vision
- D. Loss of peripheral vision (Correct Answer)
Explanation: ***Loss of peripheral vision*** - Retinitis pigmentosa is a group of genetic disorders that cause **progressive degeneration of photoreceptor cells**, primarily rods, which are concentrated in the periphery of the retina. - This degeneration leads to a gradual **loss of peripheral vision**, often beginning with **night blindness** and progressing to tunnel vision. *Loss of central vision* - Loss of central vision is characteristic of conditions affecting the **macula**, such as **age-related macular degeneration** or certain forms of **macular dystrophy**. - While later stages of retinitis pigmentosa can affect central vision, the initial and primary characteristic is loss of peripheral vision. *Tubular vision* - **Tubular vision** is an advanced stage of peripheral vision loss, where the visual field shrinks to a narrow central area, resembling looking through a tube. - While it can be a consequence of retinitis pigmentosa, it is a description of the **extent of visual field constriction** rather than the primary characteristic of the disease itself. *Visual field constriction* - **Visual field constriction** is a general term for any reduction in the extent of the visual field. - While retinitis pigmentosa certainly causes visual field constriction, the term "loss of peripheral vision" is more specific to the initial and dominant pattern of vision loss in this condition.
Question 7: Arcuate field defect akin to glaucoma is seen in?
- A. Optic nerve lesion (Correct Answer)
- B. Pituitary adenoma
- C. Posterior cerebral artery infarct
- D. None of the options
Explanation: ***Optic nerve lesion*** - An **arcuate field defect** is a specific pattern of visual field loss that follows the course of nerve fibers in the retina and is characteristic of **optic nerve damage**, similar to what is seen in glaucoma. - This type of defect is due to damage to the **bundle of retinal nerve fibers** that arch above or below the macula, often causing a scotoma (blind spot) that respects the horizontal meridian. - Common causes include **anterior ischemic optic neuropathy (AION)**, **optic neuritis**, and other optic nerve pathologies that affect the nerve fiber layer. *Pituitary adenoma* - A pituitary adenoma typically causes a **bitemporal hemianopsia** due to compression of the optic chiasm. - This visual field defect involves the lateral halves of both visual fields, which is different from an arcuate defect. *Posterior cerebral artery infarct* - An infarct in the posterior cerebral artery typically leads to a **homonymous hemianopsia** (loss of half of the visual field on the same side in both eyes) or a quadrantanopsia. - This type of defect results from damage to the **visual cortex** or optic radiations, not the optic nerve itself in a glaucoma-like pattern. *None of the options* - This is incorrect because **optic nerve lesion** is a valid and correct answer. - Optic nerve pathologies are well-established causes of arcuate field defects similar to those seen in glaucoma.
Question 8: Which of the following statements about the c-wave in electroretinogram (ERG) is most accurate?
- A. The 'c' wave is a slow positive wave. (Correct Answer)
- B. The 'c' wave is a negative wave.
- C. The 'b' wave arises primarily from photoreceptors.
- D. The 'a' wave is a positive wave.
Explanation: ***The 'c' wave is a slow positive wave.*** - The **c-wave** in an ERG is generated by the **retinal pigment epithelium (RPE)** and is characterized by its **slow, positive deflection**. - It reflects the **hyperpolarization** of the RPE cells in response to light stimulation. *The 'c' wave is a negative wave.* - This statement is incorrect because the **c-wave** is consistently observed as a **positive deflection** in the ERG tracing. - A negative wave like the **a-wave** is generated by photoreceptor hyperpolarization, which is a different component. *The 'b' wave arises primarily from photoreceptors.* - The **b-wave** primarily arises from the **Müller cells** and **bipolar cells**, not directly from photoreceptors. - Photoreceptor activity is primarily reflected in the **a-wave**. *The 'a' wave is a positive wave.* - The **a-wave** is a **negative deflection** in the ERG, representing the **hyperpolarization of photoreceptors** in response to light. - It is the earliest component of the ERG waveform.
Question 9: Binocular single vision is tested by?
- A. Amsler grid
- B. Cardboard test
- C. Synoptophore (Correct Answer)
- D. Maddox rod
Explanation: ***Synoptophore*** - The **synoptophore** is an ophthalmic instrument used to diagnose and treat various binocular vision anomalies, including **strabismus** and suppression. - It allows for the precise measurement and assessment of the eyes' ability to **fuse images** from both eyes into a single perception, which is the essence of **binocular single vision**. *Amsler grid* - The **Amsler grid** is primarily used to detect central visual field defects, such as those caused by **macular degeneration** or other retinal pathologies. - It does not directly assess the brain's ability to fuse images from both eyes into a single vision. *Cardboard test* - The "cardboard test" is not a standard ophthalmic test for binocular single vision. - It may refer to various informal or rudimentary tests, but it lacks the precision and standardization required for accurate assessment of binocular functions. *Maddox rod* - The **Maddox rod** is used to detect and measure **heterophoria** (latent strabismus) or **heterotropia** (manifest strabismus). - It dissociates the images seen by each eye, preventing fusion and revealing the deviation of the eyes, rather than directly testing the ability to achieve binocular single vision.
Question 10: Which of the following conditions is NOT diagnosed by fluorescein angiography?
- A. Diabetes retinopathy
- B. Hypertensive retinopathy (Correct Answer)
- C. Central serous retinopathy
- D. Choroidal neovascularization
Explanation: ***Hypertensive retinopathy*** - This condition is primarily diagnosed by **clinical fundoscopic examination**, not fluorescein angiography - Diagnosis is based on characteristic clinical findings: **arteriovenous nicking, copper/silver wire arterioles, cotton-wool spots, flame-shaped hemorrhages, and papilledema** in severe cases - **Fluorescein angiography** is rarely needed and only used in research settings or to assess severe complications; it is **not a standard diagnostic tool** for hypertensive retinopathy *Diabetic retinopathy* - **Fluorescein angiography** is extensively used for diagnosing and staging diabetic retinopathy - It helps identify **microaneurysms, capillary non-perfusion areas, macular edema, and neovascularization** - Essential for detecting **proliferative diabetic retinopathy** and planning laser photocoagulation *Central serous retinopathy* - **Fluorescein angiography** shows characteristic **"smokestack" or "inkblot" pattern** of leakage at the RPE level - Demonstrates one or more **leakage points** with progressive pooling of dye in the subretinal space - While **OCT** is now preferred for initial diagnosis, FA remains valuable for identifying leakage sites and guiding treatment *Choroidal neovascularization* - **Fluorescein angiography** is the gold standard for diagnosing **choroidal neovascularization (CNV)** - Shows **early hyperfluorescence with progressive leakage** from abnormal vessels - Critical for determining the **type (classic vs occult), location, and extent** of CNV for treatment planning