Diseases of the Retina Practice Questions

Q: What is the most common eye pathology in toxoplasma infection?

Retinochoroiditis. **Explanation:** **Toxoplasmosis**, caused by the protozoan *Toxoplasma gondii*, is the most common cause of posterior uveitis worldwide. The parasite has a specific predilection for neural tissue, particularly the **retina**. 1. **Why Retinochoroiditis is correct:** In toxoplasmosis, the primary site of infection is the retina (retinitis). Because the underlying choroid is almost always involved secondarily due to its proximity, the condition is accurately termed **retinochoroiditis**. The classic presentation is a "headlight in the fog" appearance, where an active white fluffy retinal lesion is seen adjacent to an old, pigmented chorioretinal scar. 2. **Why other options are incorrect:** * **Corneal Ulcer:** This is typically caused by bacteria, fungi, or viruses (like HSV) and is not a feature of systemic toxoplasmosis. * **Uveitis:** While toxoplasmosis *causes* uveitis, "Uveitis" is a broad term. Retinochoroiditis is the specific, definitive pathological manifestation. Anterior uveitis seen in these cases is usually a secondary "reactive" phenomenon. * **Cataract:** This is a secondary complication (complicated cataract) resulting from chronic inflammation or steroid use, not the primary pathology. **High-Yield Clinical Pearls for NEET-PG:** * **Congenital Toxoplasmosis Triad:** Chorioretinitis, Hydrocephalus, and Intracranial calcifications. * **Most common site:** Macula (leading to significant vision loss). * **Treatment of choice:** Triple therapy (Pyrimethamine, Sulfadiazine, and Folinic acid) + Steroids (only after 48 hours of antimicrobial cover). * **Key sign:** "Headlight in the fog" (active lesion viewed through vitritis).

Q: A 7-year-old male child presents with normal vision 6/6 in the right eye and hand movement perception close to the face in the left eye. On fundoscopy, his right eye was normal and left eye showed retinal detachment, subretinal yellowish exudates and telangiectatic vessels. What is the most likely diagnosis?

Coats' disease. **Explanation:** The clinical presentation of a young male child with unilateral profound vision loss, **telangiectatic "light-bulb" vessels**, and massive **subretinal yellowish exudates** (due to lipid deposition) is classic for **Coats' disease**. It is an idiopathic non-hereditary condition characterized by abnormal retinal vascular permeability, leading to exudative retinal detachment. **Why the other options are incorrect:** * **Sympathetic Ophthalmitis:** This is a bilateral granulomatous panuveitis that occurs following a penetrating injury or surgery to one eye (the "exciting" eye). There is no history of trauma or bilateral inflammation here. * **Familial Exudative Vitreoretinopathy (FEVR):** While it involves peripheral vascular abnormalities, FEVR is typically **bilateral**, often hereditary (Autosomal Dominant), and characterized by a failure of peripheral retinal vascularization rather than massive lipid exudation. * **Retinopathy of Prematurity (ROP):** ROP is almost always **bilateral** and occurs in infants with a history of prematurity and low birth weight. It is characterized by fibrovascular proliferation at the ridge between vascular and avascular retina, not primary lipid exudation. **High-Yield Clinical Pearls for NEET-PG:** * **Demographics:** Predominantly affects **young males** (85%) and is **unilateral** (90%). * **Key Feature:** "Leopard spot" appearance or "Light bulb" telangiectasia on fluorescein angiography. * **Differential Diagnosis:** It is a major cause of **Leukocoria** (white pupillary reflex) and must be differentiated from Retinoblastoma. Unlike Retinoblastoma, Coats' disease lacks calcification on CT scan. * **Classification:** Staged using the **Staging of Coats' Disease** (Stage 1: Telangiectasia only; Stage 2: Exudation; Stage 3: Exudative RD; Stage 4: Glaucoma; Stage 5: Advanced end-stage).

Q: The type of degeneration most commonly associated with retinal breaks is:

Lattice degeneration. **Explanation:** **Lattice degeneration** is the correct answer because it is the most significant peripheral retinal degeneration predisposing to rhegmatogenous retinal detachment (RRD). It is characterized by thinning of the inner retinal layers, overlying vitreous liquefaction (lacunae), and, most importantly, **strong vitreoretinal adhesions** at the margins of the lesion. These adhesions create tractional forces that lead to "U-shaped" or "horseshoe" tears, which are the primary precursors to retinal breaks. It is found in approximately 8–10% of the general population but is present in about 30% of eyes with RRD. **Analysis of Incorrect Options:** * **Paving stone (Cobblestone) degeneration:** This involves atrophy of the outer retina and choriocapillaris. Since the overlying vitreous is not abnormally adherent, it **does not** lead to retinal breaks or detachment. * **Snowflake degeneration:** These are tiny, white-yellow spots (granular deposits) in the peripheral retina. While they indicate vitreoretinal changes, they are much less frequently associated with clinical breaks compared to lattice. * **Cystoid degeneration:** This is a common age-related change (Blessig-Iwanoff cysts) occurring near the ora serrata. While it can lead to typical degenerative retinoschisis, it rarely causes full-thickness retinal breaks. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Lattice degeneration is most frequently found in the **superior temporal** quadrant. * **Appearance:** Characterized by a "criss-cross" pattern of white lines (sclerosed vessels). * **Myopia Link:** It is significantly more common in myopic eyes. * **Management:** Asymptomatic lattice degeneration usually does not require treatment unless the fellow eye has had a retinal detachment or the patient is undergoing cataract surgery.

Q: Regarding color blindness, which of the following statements are true?

Mainly congenital. **Explanation:** **Color blindness** (Color Vision Deficiency) is a common high-yield topic in NEET-PG. 1. **Why Option A is Correct:** Most cases of color blindness are **congenital**, resulting from X-linked recessive mutations affecting the photopigments in retinal cones. This explains why it is significantly more common in males (8%) than females (0.5%). While acquired causes exist (e.g., optic neuritis, toxic amblyopia), the vast majority of clinical cases are hereditary. 2. **Analysis of Other Options:** * **Option B:** While the **Farnsworth-Munsell 100 Hue Test** is indeed used to assess color vision, the question asks for the "most true" or primary characteristic. In many MCQ formats, if a general characteristic (congenital nature) is pitted against a specific test, the etiology is prioritized. However, note that B and C are technically accurate statements; in a "Multiple True" format, they would be correct. * **Option C:** The **Ishihara Chart** is the most common screening tool specifically designed to detect **Red-Green** color blindness. It cannot detect Blue-Yellow defects (Tritanopia). * **Option D:** This is a distractor. There is no "Jerlin-Merlin cotton wool test" for color vision. Cotton wool spots are clinical findings in diabetic or hypertensive retinopathy, not a color vision test. **High-Yield Clinical Pearls for NEET-PG:** * **Kollner’s Rule:** Outer retinal diseases (e.g., ARMD) usually cause Blue-Yellow defects, while optic nerve diseases (e.g., Glaucoma, Optic Neuritis) cause Red-Green defects. *Exception: Glaucoma and Papilledema often cause Blue-Yellow defects initially.* * **Nagel’s Anomaloscope:** The gold standard for definitive diagnosis and qualitative assessment of color blindness. * **Protanopia:** Red deficiency; **Deuteranopia:** Green deficiency (most common); **Tritanopia:** Blue deficiency.

Q: Salt and pepper fundus occurs in which of the following conditions?

Rubella. **Explanation:** The term **"Salt and Pepper Fundus"** refers to a characteristic clinical appearance of the retina where there are diffuse, mottled areas of pigmentary hypertrophy (black "pepper") and atrophy (white "salt"). 1. **Congenital Rubella (Correct Answer):** This is the most common ocular manifestation of the Rubella virus. It occurs due to damage to the **Retinal Pigment Epithelium (RPE)**. Despite the dramatic appearance of the fundus, the visual acuity is usually preserved, and the condition is non-progressive. It is part of the "Gregg Triad" (Cataract, Heart defects, and Deafness). 2. **Toxoplasma (Incorrect):** Typically presents as a "headlight in the fog" appearance due to active focal necrotizing retinochoroiditis with overlying vitritis. Healed lesions appear as punched-out chorioretinal scars with pigmented borders. 3. **Toxocara (Incorrect):** Usually presents as a unilateral posterior pole granuloma or peripheral tractional bands leading to leukocoria (white pupillary reflex). 4. **Ehlers-Danlos Syndrome (Incorrect):** This connective tissue disorder is classically associated with **Angioid Streaks** (breaks in Bruch’s membrane) and high myopia, not salt and pepper retinopathy. **High-Yield Clinical Pearls for NEET-PG:** * **Differential Diagnosis of Salt and Pepper Fundus:** * Congenital Rubella (Most common) * Congenital Syphilis * Leber’s Congenital Amaurosis (LCA) * Cystinosis * Phenothiazine toxicity (Thioridazine) * **Key Distinction:** Unlike Retinitis Pigmentosa, Salt and Pepper fundus in Rubella does **not** typically show "bony spicule" pigmentation or significant arteriolar narrowing.

Q: Which of the following is NOT a difference between Fluorescein Angiography (FA) and Indocyanine Green (ICG) angiography?

FA is more sensitive for occult CNVM. **Explanation:** The core concept distinguishing these two imaging modalities lies in the **physical properties of the dyes** and their ability to penetrate the Retinal Pigment Epithelium (RPE). **Why Option C is the correct answer (The "NOT" difference):** In reality, **ICG is more sensitive for Occult Choroidal Neovascular Membranes (CNVM)**, while FA is superior for Classic CNVM. Occult CNVM is located beneath the RPE; because ICG uses near-infrared light, it penetrates the RPE and blood better than the visible light used in FA. Therefore, the statement that "FA is more sensitive for occult CNVM" is clinically incorrect, making it the right choice for this "NOT" question. **Analysis of Incorrect Options:** * **A. Dyes used:** This is a valid difference. FA uses **Sodium Fluorescein**, while ICG uses **Indocyanine Green**. * **B. Choroidal capillaries:** This is a valid difference. ICG is 98% protein-bound (to albumin), keeping it within the fenestrated choriocapillaris, whereas Fluorescein leaks out rapidly. Combined with infrared penetration, ICG provides far superior visualization of the choroidal circulation. * **D. Wavelength:** This is a valid difference. FA uses visible light (Excitation: 490nm; Emission: 530nm), whereas ICG uses near-infrared light (Excitation: 805nm; Emission: 835nm). **High-Yield Clinical Pearls for NEET-PG:** * **FA** is the gold standard for **Retinal vascular diseases** (e.g., Diabetic Retinopathy, BRVO). * **ICG** is the gold standard for **Choroidal diseases** (e.g., PCV - Polypoidal Choroidal Vasculopathy, and Occult CNVM). * **Contraindication:** Avoid ICG in patients with **Iodine allergy** (as the dye contains iodine) or liver disease. * **Side Effects:** Nausea is common in FA; anaphylaxis is rare but more common in FA than ICG.

Q: The retinal capillaries are distinguished by having all features except:

Capillary-free zone around the veins. The retinal microvasculature has a unique anatomical arrangement essential for maintaining the blood-retinal barrier and metabolic supply. **Explanation of the Correct Option:** **Option B (Capillary-free zone around the veins)** is the correct answer because it is a false statement. In the retina, a distinct **peri-arterial capillary-free zone** exists (approximately 50–120 μm wide), where capillaries are absent immediately adjacent to the arterioles. This is likely due to the high oxygen tension surrounding the arterioles. There is **no such capillary-free zone around the veins**; capillaries frequently drain directly into or lie in close proximity to the venules. **Analysis of Other Options:** * **Option A (Widening of calibre):** Retinal capillaries are narrowest at the posterior pole (approx. 7 μm) and undergo a **widening of calibre** as they move toward the periphery (up to 50–100 μm), forming a simpler, wider-meshed network near the ora serrata. * **Option C & D (Superficial and Deep networks):** The retinal vasculature is organized into two primary layers: * **Superficial network:** Located in the nerve fiber layer (NFL) or ganglion cell layer. * **Deep network:** A denser, more complex network located in the inner nuclear layer. **High-Yield Clinical Pearls for NEET-PG:** * **Foveal Avascular Zone (FAZ):** A 0.5 mm diameter area at the center of the fovea that is completely devoid of capillaries. Enlargement of the FAZ on Fluorescein Angiography (FFA) is a key sign of **macular ischemia** (e.g., in Diabetic Retinopathy). * **Blood-Retinal Barrier (BRB):** The inner BRB is formed by the **non-fenestrated endothelial cells** of the retinal capillaries (tight junctions/Zonula occludens). * **Pericyte Loss:** The earliest histopathological change in Diabetic Retinopathy is the selective loss of pericytes, leading to microaneurysm formation.

Q: A young male presents with a central scotoma in the left eye. His right eye vision is 6/6. Fundoscopic examination reveals focal foveal detachment in the left eye. What would be the next step in management?

Inquire about the use of steroids. **Explanation:** The clinical presentation of a young male with a sudden central scotoma and focal foveal detachment is classic for **Central Serous Chorioretinopathy (CSCR)**. CSCR is characterized by an idiopathic serous detachment of the neurosensory retina at the macula due to leakage from the choriocapillaris through a defect in the Retinal Pigment Epithelium (RPE). **Why Option B is correct:** The most significant and well-documented risk factor for the development or exacerbation of CSCR is the use of **exogenous steroids** (systemic, inhaled, topical, or even nasal). Steroids increase capillary fragility and alter the permeability of the choriocapillaris. Therefore, the immediate next step in management is to identify and discontinue any steroid use, as most cases of CSCR resolve spontaneously once the trigger is removed. **Why other options are incorrect:** * **Option A:** Retrolental cells (cells in the anterior vitreous) are markers of posterior uveitis. While uveitis can cause macular edema, the focal foveal detachment in a young male is more indicative of CSCR than inflammation. * **Option C:** History of trauma in the *other* eye is relevant for Sympathetic Ophthalmitis, which presents with bilateral granulomatous panuveitis, not isolated focal detachment. * **Option D:** While a slit-lamp exam is necessary for diagnosis, the question asks for the "next step" in the context of identifying the etiology. Inquiring about steroids is a high-yield clinical priority. **High-Yield Pearls for NEET-PG:** * **Demographics:** Typically affects young to middle-aged males with "Type A" personalities. * **FFA Finding:** Classic "Ink-blot" or "Smoke-stack" appearance. * **OCT Finding:** Neurosensory detachment with or without a Pedunculated Pigment Epithelial Detachment (PED). * **Management:** Observation (most resolve in 3–4 months). If persistent, consider Photodynamic Therapy (PDT) or Micropulse Laser.

Q: Which of the following is NOT a risk factor for retinal detachment?

Hypermetropia. **Explanation:** The correct answer is **Hypermetropia**. Retinal detachment (RD) occurs when the neurosensory retina separates from the underlying retinal pigment epithelium (RPE). Understanding the risk factors depends on the type of RD (Rhegmatogenous, Tractional, or Exudative). **Why Hypermetropia is NOT a risk factor:** Hypermetropia (farsightedness) is associated with a **shorter axial length** of the eyeball. This results in a thicker sclera and less stretching of the peripheral retina. In contrast, **Myopia** (Option B) is a major risk factor because the elongated eyeball leads to thinning of the retina and peripheral degenerations (like Lattice degeneration), which predispose to retinal tears and Rhegmatogenous RD. **Analysis of other options:** * **Diabetic Retinalpathy (Option A):** This is a classic cause of **Tractional RD**. Proliferative changes lead to the formation of fibrovascular membranes that contract and pull the retina away from its base. * **Central Retinal Vein Occlusion (Option D):** CRVO can lead to **Exudative (Serous) RD** due to increased vascular permeability and the breakdown of the blood-retinal barrier, or Tractional RD if neovascularization develops. **High-Yield Clinical Pearls for NEET-PG:** * **Most common type of RD:** Rhegmatogenous RD (associated with Myopia, trauma, and aphakia). * **Most common peripheral degeneration leading to RD:** Lattice degeneration. * **Classic Symptoms:** Sudden onset of flashes (photopsia), floaters, and a "curtain-like" loss of vision. * **Shafer’s Sign:** "Tobacco dust" (pigment cells) in the anterior vitreous is pathognomonic for a retinal tear. * **Management:** Rhegmatogenous RD requires surgery (Scleral buckling or Pars Plana Vitrectomy); Tractional RD requires Vitrectomy; Exudative RD is managed by treating the underlying medical cause.

Q: Which of the following is not a prerequisite for performing pneumatic retinopexy?

Inferior retinal detachment. **Explanation:** Pneumatic retinopexy (PR) is a minimally invasive procedure used to treat rhegmatogenous retinal detachment (RRD). It involves injecting an expansile gas bubble (like $SF_6$ or $C_3F_8$) into the vitreous cavity to tamponade the retinal break. **Why Option B is the Correct Answer:** The fundamental principle of PR is **buoyancy**. The gas bubble rises to the highest point in the eye. Therefore, PR is indicated for breaks located in the **superior 8 clock hours** (between 8 o’clock and 4 o’clock). It is **not suitable for inferior retinal breaks** because the gas bubble cannot effectively tamponade a break at the bottom of the eye unless the patient is placed in a physically impossible head-down position. **Analysis of Incorrect Options:** * **A. Fresh retinal detachment:** PR is most successful in acute RRDs where the subretinal fluid is mobile and there is no significant proliferative vitreoretinopathy (PVR Grade C or D). * **C. No air travel:** This is a critical safety prerequisite. Atmospheric pressure changes during flight cause the intraocular gas bubble to expand rapidly, leading to a dangerous spike in intraocular pressure (IOP) and central retinal artery occlusion. * **D. Patient positioning:** Success depends entirely on the patient’s ability to maintain a specific head posture (e.g., "nose-to-shoulder") for several days to ensure the bubble stays against the break. **Clinical Pearls for NEET-PG:** * **Ideal Candidate:** Single break or a group of breaks within 1 clock hour in the superior retina. * **Common Gases:** Sulfur hexafluoride ($SF_6$) and Perfluoropropane ($C_3F_8$). * **The "Steamroller" Maneuver:** A technique used during PR to push subretinal fluid away from the macula. * **Contraindications:** Glaucoma (uncontrolled), cloudy media, and inferior breaks.

Question 1

What is the most common eye pathology in toxoplasma infection?

Accepted Answer

Retinochoroiditis

Answer

Corneal ulcer

Answer

Uveitis

Answer

Cataract

Question 2

A 7-year-old male child presents with normal vision 6/6 in the right eye and hand movement perception close to the face in the left eye. On fundoscopy, his right eye was normal and left eye showed retinal detachment, subretinal yellowish exudates and telangiectatic vessels. What is the most likely diagnosis?

Accepted Answer

Coats' disease

Answer

Sympathetic ophthalmitis

Answer

Familial exudative vitreoretinopathy

Answer

Retinopathy of prematurity

Question 3

The type of degeneration most commonly associated with retinal breaks is:

Accepted Answer

Lattice degeneration

Answer

Paving stone degeneration

Answer

Snow flake degeneration

Answer

Cystoid degeneration

Question 4

Regarding color blindness, which of the following statements are true?

Accepted Answer

Mainly congenital

Answer

Can be tested with the Farnsworth 100 hue test

Answer

Ishihara chart tests red/green color blindness

Answer

Jerlin-Merlin cotton wool tests it

Question 5

Salt and pepper fundus occurs in which of the following conditions?

Accepted Answer

Rubella

Answer

Toxoplasma

Answer

Toxocara

Answer

Ehlers Danlos syndrome

Question 6

Which of the following is NOT a difference between Fluorescein Angiography (FA) and Indocyanine Green (ICG) angiography?

Accepted Answer

FA is more sensitive for occult CNVM

Answer

Dyes used

Answer

Choroidal capillaries are better visualized in ICG

Answer

The wavelength used for viewing is different

Question 7

The retinal capillaries are distinguished by having all features except:

Accepted Answer

Capillary-free zone around the veins

Answer

Widening of the capillary calibre in the periphery

Answer

Superficial network

Answer

Deep denser network

Question 8

A young male presents with a central scotoma in the left eye. His right eye vision is 6/6. Fundoscopic examination reveals focal foveal detachment in the left eye. What would be the next step in management?

Accepted Answer

Inquire about the use of steroids

Answer

Examine for retrolental cells

Answer

Ask for a history of trauma in the other eye

Answer

Perform examination under a slit lamp

Question 9

Which of the following is NOT a risk factor for retinal detachment?

Accepted Answer

Hypermetropia

Answer

Diabetic retinopathy

Answer

Myopia

Answer

Central Retinal Vein Occlusion (CRVO)

Question 10

Which of the following is not a prerequisite for performing pneumatic retinopexy?

Accepted Answer

Inferior retinal detachment

Answer

Fresh retinal detachment

Answer

No air travel

Answer

Patient should be able to maintain position

Diseases of the Retina — MCQs

Diseases of the Retina — MCQs

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