Diseases of the Retina — MCQs

A 75-year-old woman with diabetes mellitus and congestive heart failure has a sudden loss of vision in her left eye. Funduscopic examination shows a cherry-red appearance of the foveola, whereas the remaining retina appears pale. No abnormalities of the right eye are noted. Which of the following is the most likely cause for her sudden unilateral visual loss?

Q368Easy

Degree of diabetic retinopathy depends on which of the following?

Q369Easy

Cotton wool spots are commonly seen in which of the following conditions?

Q370Easy

Sea-fan retina is a characteristic feature of which condition?

Diseases of the Retina Indian Medical PG Practice Questions and MCQs

Question 361: A patient presents with flashing lights, sudden floaters, and the perception of a curtain falling in front of the eye. Which of the following is the most likely diagnosis?

A. Rhegmatogenous Retinal Detachment (Correct Answer)
B. Traditional Retinal Detachment
C. Vitreous Hemorrhage
D. Eale's disease

Explanation: ### Explanation **Correct Answer: A. Rhegmatogenous Retinal Detachment** The clinical triad of **photopsia** (flashing lights), **floaters** (sudden onset), and a **visual field defect** (described as a "curtain falling") is the classic presentation of **Rhegmatogenous Retinal Detachment (RRD)**. * **Photopsia** occurs due to vitreoretinal traction stimulating the retina. * **Floaters** (often a "Ring of Weiss") result from a posterior vitreous detachment or pigment release (Shafer’s sign/tobacco dusting). * The **"curtain falling"** sensation represents the progressive separation of the neurosensory retina from the retinal pigment epithelium (RPE) by subretinal fluid entering through a retinal break (*Rhegma*). **Why the other options are incorrect:** * **B. Tractional Retinal Detachment:** Usually seen in proliferative diabetic retinopathy. It is characterized by slow, progressive vision loss and typically lacks photopsia or acute floaters because there is no acute retinal break. * **C. Vitreous Hemorrhage:** While it causes sudden floaters (often described as "black streaks" or "cobwebs"), it does not typically cause photopsia or a localized "curtain" unless associated with an underlying detachment. * **D. Eale’s Disease:** An idiopathic peripheral perivasculitis. While it can lead to vitreous hemorrhage or tractional detachment in late stages, the primary presentation is painless, sudden blurring of vision in young males, not the acute triad of RRD. **NEET-PG High-Yield Pearls:** * **Shafer’s Sign:** Presence of pigment cells in the anterior vitreous; it is pathognomonic for a retinal tear. * **Most common site of RRD:** Superotemporal quadrant. * **Surgery of Choice:** Scleral buckling or Pars Plana Vitrectomy (PPV). Pneumatic retinopexy is used for superior breaks. * **Marcus Gunn Pupil (RAPD):** Often present if the detachment is extensive or involves the macula.

Question 362: A cherry red spot at the macula is typically seen in which condition?

A. Macular infarction
B. Niemann-Pick disease
C. Commotio retinae
D. Central retinal vein occlusion (Correct Answer)

Explanation: **Explanation:** The **Cherry Red Spot** is a classic clinical sign where the fovea appears bright red against a pale, edematous background. This occurs because the fovea is the thinnest part of the retina (lacking the ganglion cell layer); while the surrounding ischemic or storage-laden retina turns opaque/white, the underlying vascular choroid remains visible through the thin fovea. **Analysis of Options:** * **Central Retinal Artery Occlusion (CRAO):** This is the **most common** cause of a cherry red spot. Ischemia causes the nerve fiber and ganglion cell layers to become pale and edematous, making the red choroid at the fovea stand out. (Note: The question lists CRVO as the key, but in standard clinical practice, CRAO is the classic association). * **Niemann-Pick Disease:** This is a lysosomal storage disorder where sphingomyelin accumulates in the retinal ganglion cells, creating the characteristic pale halo around the fovea. * **Commotio Retinae (Berlin’s Edema):** Following blunt trauma, "pseudo-cherry red spot" may appear due to opacification of the outer retinal layers (photoreceptors/RPE) rather than ganglion cell changes. * **Central Retinal Vein Occlusion (CRVO):** This typically presents with a **"Blood and Thunder"** fundus (extensive flame-shaped hemorrhages and macular edema). A cherry red spot is **not** a feature of CRVO; its inclusion as the "correct" answer here suggests a potential typographical error in the source material, as CRAO is the intended classic answer. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for Cherry Red Spot:** "Check My Apple, Night Is Very Dark" (**C**RAO, **M**etabolic [Tay-Sachs/Gaucher], **A**maurotic idiocy, **N**iemann-Pick, **I**nfarction, **V**ertical Macular Hole, **D**amage [Trauma]). * **Tay-Sachs Disease:** The most common metabolic cause. * **Quinine Toxicity:** A rare toxic cause of a cherry red spot. * **Differential:** In **Macular Hole**, the spot is red, but the surrounding retina is usually normal, not pale/edematous.

Question 363: Macular involvement is a common finding in which of the following conditions?

A. Toxoplasma
B. Malaria
C. Cytomegalovirus (CMV) (Correct Answer)
D. Syphilis

Explanation: **Explanation:** **Cytomegalovirus (CMV) Retinitis** is the most common opportunistic ocular infection in patients with AIDS (typically when CD4 counts fall below 50 cells/µL). It is characterized by a necrotizing retinitis that spreads along the retinal vessels. A hallmark of CMV retinitis is its predilection for the posterior pole, frequently involving the **macula** and the optic nerve. This leads to profound, irreversible vision loss if not treated promptly with Ganciclovir or Foscarnet. **Analysis of Options:** * **Toxoplasma (Option A):** While *Toxoplasma gondii* causes retinochoroiditis, it typically presents as a focal "headlight in the fog" lesion. While it can occur at the macula, CMV is statistically more "commonly" associated with extensive posterior pole involvement in the context of systemic immunosuppression. * **Malaria (Option B):** Malarial retinopathy (seen in cerebral malaria) involves retinal whitening, vessel changes, and hemorrhages, but primary macular necrotizing retinitis is not its defining feature. * **Syphilis (Option C):** Known as "The Great Imitator," syphilis can cause various forms of uveitis and placoid chorioretinitis, but it is less common than CMV in modern clinical practice for isolated macular-predominant necrotizing retinitis. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Appearance:** CMV retinitis is often described as **"Pizza-pie"** or **"Cottage cheese and ketchup"** appearance due to the mix of white retinal necrosis and red hemorrhages. * **Brush-fire Border:** The infection typically has a granular, advancing edge. * **Frosted Branch Angiitis:** A severe form of retinal vasculitis that can be seen in CMV. * **Treatment of Choice:** Induction and maintenance with **Intravenous Ganciclovir**; Intravitreal injections are used for immediate sight-threatening (macular) lesions.

Question 364: Pseudoglioma differs from Retinoblastoma in that pseudoglioma is associated with which of the following?

A. Decreased intraocular pressure (Correct Answer)
B. Blurring of vision
C. Enlargement of the optic foramen
D. All of the above

Explanation: **Explanation:** The term **Pseudoglioma** refers to a group of non-malignant conditions that mimic the clinical appearance of Retinoblastoma (RB), typically presenting as a white pupillary reflex (leukocoria). **Why Option A is Correct:** The key differentiating factor lies in the pathophysiology of the conditions. **Retinoblastoma** is a rapidly growing tumor that often causes secondary glaucoma (increased IOP) due to the tumor mass pushing the iris-lens diaphragm forward or tumor cells clogging the trabecular meshwork. In contrast, many causes of pseudoglioma, such as **Endophthalmitis** or **Persistent Fetal Vasculature (PFV)**, are associated with ciliary body traction or atrophy, leading to decreased aqueous production and **decreased intraocular pressure (hypotony)**. This often results in a smaller, shrunken eye (phthisis bulbi), whereas RB usually presents in a normal-sized or enlarged eye. **Why Other Options are Incorrect:** * **B. Blurring of vision:** This is a non-specific symptom found in both Retinoblastoma and Pseudoglioma and cannot be used as a differentiating feature. * **C. Enlargement of the optic foramen:** This is a classic radiological sign of **Retinoblastoma** when the tumor spreads extraocularly along the optic nerve. It is not a feature of pseudoglioma. **NEET-PG High-Yield Pearls:** * **Most common cause of Pseudoglioma:** Persistent Fetal Vasculature (PFV/PHPV). * **Calcification:** Present in 90% of Retinoblastoma cases (seen on CT/USG); rare in pseudogliomas (except in Astrocytic Hamartoma). * **Age of presentation:** RB usually presents before age 3; pseudogliomas like Coats' disease often present slightly later (6–8 years). * **Key Pseudoglioma Differentials:** Coats' disease, Retinopathy of Prematurity (ROP), Toxocariasis, and Endophthalmitis.

Question 365: What is the best treatment for a patient with a retinal condition requiring intervention?

A. Laser photocoagulation
B. Three monthly injections of Ranibizumab (Correct Answer)
C. Photodynamic therapy
D. Observation and follow-up

Explanation: ### Explanation The correct answer is **Three monthly injections of Ranibizumab**. This question addresses the management of **Neovascular (Wet) Age-Related Macular Degeneration (ARMD)** or **Diabetic Macular Edema (DME)**, where Vascular Endothelial Growth Factor (VEGF) plays a central role. **Why Ranibizumab is the Correct Choice:** Anti-VEGF agents, such as **Ranibizumab**, Bevacizumab, and Aflibercept, are currently the **gold standard** and first-line treatment for conditions involving choroidal neovascularization (CNV) or macular edema. The standard induction protocol involves a "loading dose" of **three consecutive monthly intravitreal injections**. This regimen effectively stabilizes vision, reduces subretinal fluid, and causes regression of abnormal neovascular membranes. **Analysis of Incorrect Options:** * **Laser photocoagulation:** While used for Proliferative Diabetic Retinopathy (PDR), it is no longer the first-line treatment for subfoveal CNV because it causes permanent scotomas by destroying healthy retinal tissue. * **Photodynamic therapy (PDT):** This uses verteporfin and a cold laser. It was the previous standard but is now reserved for specific cases like Polypoidal Choroidal Vasculopathy (PCV) or when anti-VEGF therapy fails. * **Observation and follow-up:** Wet ARMD is a rapidly progressive condition. Delaying treatment leads to irreversible scarring (disciform scar) and permanent central vision loss. **Clinical Pearls for NEET-PG:** * **Drug of Choice:** Anti-VEGF is the DOC for Wet ARMD, DME, and Central Retinal Vein Occlusion (CRVO) with edema. * **Mechanism:** Ranibizumab is a monoclonal antibody fragment (Fab) that binds all isoforms of VEGF-A. * **Common Side Effect:** The most feared complication of intravitreal injection is **Endophthalmitis** (presents with pain and decreased vision within 24–72 hours). * **Amsler Grid:** Used by patients for home monitoring to detect early metamorphopsia (distortion).

Question 366: Dot and blot (round) retinal haemorrhages are situated at the level of which layer of the retina?

A. Ganglion cell layer
B. Nerve fibre layer
C. Inner nuclear layer
D. Outer plexiform layer (Correct Answer)

Explanation: **Explanation:** The morphology of a retinal hemorrhage is determined by its anatomical location within the retinal layers. **1. Why the Outer Plexiform Layer (OPL) is correct:** Dot and blot hemorrhages occur due to bleeding from the **deep capillary plexus**. These vessels are located in the inner nuclear layer and extend towards the **Outer Plexiform Layer**. Because the OPL consists of densely packed, vertically oriented neurons (Henle’s fibers in the macula) and supporting structures, the blood is compressed into small, round, or "dot-like" shapes. The structural resistance of the surrounding tissue prevents the blood from spreading horizontally, resulting in the characteristic "blot" appearance. These are hallmark features of **Diabetic Retinopathy**. **2. Analysis of Incorrect Options:** * **Nerve Fibre Layer (NFL):** Hemorrhages here are **Flame-shaped**. Because the axons in the NFL are arranged horizontally and parallel to the retinal surface, blood tracks along these bundles, creating feathered edges. (Common in Hypertension and RVO). * **Ganglion Cell Layer:** This layer is too superficial for dot-blot hemorrhages; bleeding here typically presents as larger, more diffuse patches or contributes to flame-shaped patterns if involving the adjacent NFL. * **Inner Nuclear Layer:** While the deep capillaries originate here, the blood typically pools and manifests its characteristic "blot" shape within the potential spaces of the OPL. **3. High-Yield Clinical Pearls for NEET-PG:** * **Flame-shaped hemorrhages:** Superficial (NFL); associated with Hypertension. * **Dot and blot hemorrhages:** Deep (OPL); associated with Diabetes Mellitus. * **Preretinal (Sub-hyaloid) hemorrhage:** Boat-shaped with a horizontal upper level; located between the NFL and the posterior hyaloid face. * **Roth Spots:** Retinal hemorrhages with a white pale center (composed of fibrin/leukocytes), classically seen in Subacute Bacterial Endocarditis (SABE) and Leukemia.

Question 367: A 75-year-old woman with diabetes mellitus and congestive heart failure has a sudden loss of vision in her left eye. Funduscopic examination shows a cherry-red appearance of the foveola, whereas the remaining retina appears pale. No abnormalities of the right eye are noted. Which of the following is the most likely cause for her sudden unilateral visual loss?

A. Central retinal artery occlusion (Correct Answer)
B. Cytomegalovirus retinitis
C. Primary angle-closure glaucoma
D. Proliferative retinopathy

Explanation: **Explanation:** The clinical presentation of **sudden, painless, unilateral loss of vision** combined with the classic funduscopic finding of a **"cherry-red spot"** at the foveola is pathognomonic for **Central Retinal Artery Occlusion (CRAO)**. **Why CRAO is the correct answer:** In CRAO, the blood supply to the inner layers of the retina is blocked. This leads to intracellular edema and necrosis, making the retina appear **milky-white or pale**. However, the foveola is the thinnest part of the retina and receives its blood supply from the underlying **choriocapillaris** (via the ciliary arteries), which remains patent. Therefore, the reddish color of the vascular choroid shines through the thin foveola, contrasting against the surrounding pale, edematous retina to create the "cherry-red spot." **Why other options are incorrect:** * **Cytomegalovirus (CMV) Retinitis:** Typically presents in immunocompromised patients (e.g., AIDS) with "pizza-pie" or "cheese and ketchup" fundus (hemorrhages and exudates), not sudden vision loss with a cherry-red spot. * **Primary Angle-Closure Glaucoma:** Presents with sudden vision loss but is accompanied by **severe pain**, a red eye, a mid-dilated non-reactive pupil, and a hazy cornea. * **Proliferative Retinopathy:** While common in diabetics, it usually causes gradual vision loss or sudden loss due to vitreous hemorrhage, characterized by neovascularization and "boat-shaped" preretinal hemorrhages. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Most commonly caused by an **embolus** (Hollenhorst plaque) from the carotid artery or heart (relevant to this patient's CHF). * **Management:** CRAO is an ocular emergency. Immediate measures include **digital ocular massage**, anterior chamber paracentesis, and IV acetazolamide to lower IOP and dislodge the embolus. * **Differential for Cherry-Red Spot:** CRAO, Tay-Sachs disease, Niemann-Pick disease, and Gaucher’s disease. * **Cilioretinal Artery:** In 15-20% of the population, this artery (from the ciliary circulation) spares a portion of the macula, preserving central vision despite CRAO.

Question 368: Degree of diabetic retinopathy depends on which of the following?

A. Type of diabetes
B. Duration of diabetes (Correct Answer)
C. Severity of hyperglycemia
D. Retinal involvement

Explanation: **Explanation:** The development and progression of Diabetic Retinopathy (DR) are multifactorial, but the **duration of diabetes** is universally recognized as the **single most important risk factor**. 1. **Why Duration is Correct:** The pathophysiology of DR involves chronic metabolic stress leading to microvascular damage (basement membrane thickening and pericyte loss). This process is cumulative. Statistics show that after 20 years of diabetes, nearly 99% of Type 1 patients and about 60% of Type 2 patients will show some signs of retinopathy. Even with optimal glycemic control, the "metabolic memory" of the retina ensures that time remains the primary determinant of disease prevalence. 2. **Analysis of Incorrect Options:** * **Type of diabetes:** While the prevalence of Proliferative DR (PDR) is higher in Type 1, both types eventually develop retinopathy. The type determines the *onset* of screening, but the *degree* depends on how long the disease has been present. * **Severity of hyperglycemia:** While poor glycemic control (high HbA1c) accelerates the *progression* and severity, it is secondary to duration. A patient with mild hyperglycemia for 20 years is at higher risk for DR than a patient with severe hyperglycemia for only 2 years. * **Retinal involvement:** This is a clinical manifestation/finding of the disease itself, not a factor that the degree of retinopathy *depends* on. **High-Yield Clinical Pearls for NEET-PG:** * **First clinical sign:** Microaneurysms (located in the inner nuclear layer). * **First pathological sign:** Loss of pericytes and basement membrane thickening. * **Screening Guidelines:** * Type 1 DM: Start screening 5 years after diagnosis. * Type 2 DM: Start screening **at the time of diagnosis** (as the actual onset is often unknown). * **Pregnancy:** Can rapidly worsen pre-existing DR; requires close monitoring. * **Hypertension & Nephropathy:** These are the most significant co-morbidities that exacerbate DR.

Question 369: Cotton wool spots are commonly seen in which of the following conditions?

A. HIV
B. Diabetes Mellitus
C. Hypertension (Correct Answer)
D. Cytomegalovirus

Explanation: **Explanation:** **Cotton wool spots (CWS)**, also known as soft exudates, are not true exudates. They represent **focal areas of retinal ischemia** in the nerve fiber layer (NFL). When precapillary arterioles are obstructed, axoplasmic flow within the nerves is interrupted, leading to the accumulation of organelles (mitochondria and debris) that appear as fluffy, white, cloud-like lesions with indistinct margins. **Why Hypertension is the Correct Answer:** In the context of this question, **Hypertension** is a classic and primary cause of CWS. They are a hallmark of **Grade III Hypertensive Retinopathy** (Keith-Wagener-Barker classification). Their presence indicates acute, severe retinal ischemia and is a sign that the systemic blood pressure needs urgent control. **Analysis of Other Options:** * **Diabetes Mellitus:** While CWS are seen in Pre-Proliferative Diabetic Retinopathy (PPDR), they are considered a sign of worsening ischemia but are not as pathognomonic for the acute stage as they are in malignant hypertension. * **HIV:** CWS are the most common finding in **HIV Retinopathy** (non-infectious). However, in a general ophthalmology context, hypertension remains the more classic association for "cotton wool spots" unless the question specifically points toward an immunocompromised state. * **Cytomegalovirus (CMV):** CMV retinitis typically presents with a "pizza-pie" or "cheese and ketchup" appearance (hemorrhage and necrosis). While ischemia occurs, CWS are not the defining feature. **High-Yield Clinical Pearls for NEET-PG:** * **Histology:** On microscopic examination, CWS correspond to **Cytoid bodies** (swollen ends of ruptured axons) in the nerve fiber layer. * **Differential Diagnosis (Mnemonic: SHED):** **S**ystemic Hypertension, **H**IV/Hematological disorders, **E**mboli, **D**iabetes. * **Vanishing Act:** CWS are transient and usually fade within 4–6 weeks as the debris is cleared by macrophages.

Question 370: Sea-fan retina is a characteristic feature of which condition?

A. Central retinal artery occlusion (CRAO)
B. Central retinal vein occlusion (CRVO)
C. Sickle cell retinopathy (Correct Answer)
D. Chloroquine retinopathy

Explanation: **Explanation:** **Sea-fan retinopathy** is a classic hallmark of **Sickle Cell Retinopathy**, specifically the proliferative stage (Stage 3 of Goldberg’s classification). The underlying mechanism involves chronic peripheral retinal ischemia caused by the sickling of red blood cells in small vessels. This ischemia triggers the release of Vascular Endothelial Growth Factor (VEGF), leading to **neovascularization**. These new vessels grow in a distinctive frond-like pattern that resembles the coral *Gorgonia flabellum* (Sea-fan). It is most commonly seen in HbSC and HbS-Thal genotypes rather than HbSS. **Analysis of Incorrect Options:** * **A. CRAO:** Characterized by a "Cherry Red Spot" at the fovea and a pale, edematous retina due to total arterial infarction. * **B. CRVO:** Presents with a "Blood and Thunder" fundus, showing extensive flame-shaped hemorrhages, dilated tortuous veins, and disc edema. * **D. Chloroquine Retinopathy:** Classically presents with "Bull’s Eye Maculopathy" due to RPE atrophy in a concentric ring around the fovea. **NEET-PG High-Yield Pearls:** * **Goldberg’s Stages of Sickle Cell Retinopathy:** 1. Peripheral arteriolar occlusion (Silver wiring) 2. Arteriolar-venular anastomoses (Hairpin loops) 3. **Sea-fan neovascularization** 4. Vitreous hemorrhage 5. Retinal detachment * **Salmon Patch Hemorrhage:** Pre-retinal/Intra-retinal hemorrhage seen in Sickle cell. * **Black Sunburst:** Peripheral RPE hypertrophy following the resolution of a hemorrhage. * **Treatment of choice for Sea-fans:** Scatter laser photocoagulation to the ischemic peripheral retina.

Practice by Chapter

Retinal Anatomy and Physiology

Practice Questions

Age-Related Macular Degeneration

Practice Questions

Diabetic Retinopathy

Practice Questions

Retinal Vascular Diseases

Practice Questions

Retinal Detachment

Practice Questions

Hereditary Retinal Dystrophies

Practice Questions

Inflammatory Retinal Diseases

Practice Questions

Retinal Tumors

Practice Questions

Retinopathy of Prematurity

Practice Questions

Retinal Imaging Techniques

Practice Questions

Intravitreal Pharmacotherapy

Practice Questions

Vitreoretinal Surgery

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free